[From the U.S. Government Printing Office, www.gpo.gov]



                                    'ToKe@






                      LAND USE IMPACTS ON NONPOINT SOURCE POLLUTION


                            IN COASTAL NEW HAMPSHIRE WATERSHED@/

                                            FINAL REPORT

        Ln



                            Submitted to the New Hampshire Coastal Program

                                         Office of State Planning
        V-4





                                                  by

                                  Stephen H. Jones and Richard Langan


                                      Jackson Estuarine Laboratory
                             Departments of Natural Resources and Zoology
                  TD                   Center for Marine Biology
                  224                University of New Hampshire
                  N4                Durham, New Hampshire 03824
                 J665




               @This report was funded in part by a grant from the Office of State
                   Planning, New Hampshire Coastal Program, under the auspices of the
                   National Oceanic and Atmospheric Administration (NOAA), Award
'04                Number NA370ZO277-01.
                                                                                            4-6










                                               INTRODUCTION


                   The overall objective of the proposed project was to develop an effective
             system for assessing the potential for NPS pollution problems in coastal New
             Hampshire watersheds. The Oyster River watershed (Figure 1) was chosen for study
             as a model, manageable whole system that has a potentially significant impact on
             coastal water quality, and detailed land-use assessments have been conducted
             recently in the two small watersheds. The approach involved treating tributaries to
             the larger Oyster River watershed as nonpoint sources that could be subject to
             management activities after initial assessment. The results of management of NPS
             problems in the tributaries should be improved water quality in the larger
             watershed as a whole, barring any new or accelerated problems in the main river or
             other, non-target tributaries. Work was concentrated in in the tidal area of the main
             river (Figure 2) and in two small watersheds, the Johnson Creek (Figure 3) and
             Beards Creek (Figure 4) watersheds. Information on land use characteristics and
             natural features of watershed landscapes was integrated with water quality data to
             determine conditions that are conducive for significant NPS pollution. Existing
             literature, NPS models, and related studies were reviewed to insure comprehensive
             consideration of all potential factors. Field assessment activities added to the
             database established in a previous project, but focused in great detail on the Johnson
             Creek sub-watershed, and to a lesser extent, the Beards Creek watershed.
                   The specific objectives were as follows:

                   1. To establish a baseline of water quality data for the Oyster River watershed;
                   2. To conduct an intensive assessment of NPS pollution in a specific sub-
             watershed within the Oyster River watershed;
                   3. To identify the critical elements of watershed characteristics and land use
             information needed to effectively assess the potential for nonpoint source pollution
             and its abatement;
                   4. To evaluate the effectiveness of the critical elements identified in objective
             #3 along with water quality data for predicting NPS loading in other sub-
             watersheds.




             ANALYTICAL AND SAMPLING METHODS


                   Microbiological analysis of water samples included tests for fecal coliforms,
             Escherichia coli , enterococci, and Clostridium perfringens. Fecal coliforms and E.
             coli were measured using standard multiple tube fermentation, MPN analyses, and








            C. perfringens by a standard membrane filtration method. Enterococci were
            measured using methods recommended by the U.S. Environmental Protection
            Agency. Fecal coliforms are the standard indicator for shellfish-growing waters in
            New Hampshire based on recommendations by the National Shellfish Sanitation
            Program. E. coli is the standard for fresh recreational waters of New Hampshire and
            is the actual target organism of fecal coliform tests. Enterococci are the standard
            indicator for the estuarine recreational waters of New Hampshire, and C.
            perfringens is an indicator of long-term fecal contamination that is being used with
            increasing frequency in related studies.
                  Additional water samples taken at the same time as those for microbial
            analysis were analyzed for total suspended solids, % organic content, photosynthetic
            pigments and nutrients. All samples were collected in duplicate and 500 ml of each
            sample were filtered through pre-weighed, pre-dried glass fiber filters (1.2 gm pore
            retention), for suspended solid analysis and % organic content. The remaining 500
            ml of each sample were filtered and analyzed for photosynthetic pigments. Filtrates
            were analyzed for dissolved nutrients (ni trate-ni trite, ammonium, orthophosphate)
            using LACHAT autoanalyzer flow injection, spectrophotometric methods.
                  All water quality data were entered into spreadsheets on Macintosh
            computers for developing a database, statistical analysis and accompanying graphical
            representations of the data. Monthly average rainfall for Durham compared to
            normal rainfall is illustrated in Figure 5. Rainfall amounts for 3 days prior to
            sampling dates are also presented in Table 1.


                                                 RESULTS
            OBJECTIVE 1
                  The geometric average levels of fecal coliforms and enterococci at sites along
            the main tidal portion of the Oyster River are presented in Figure 1-1. Levels are
            relatively low near the mouth of the river (sites 1-3), then increase near site 4, which
            is at the mouth of Bunker Creek. Levels remained high up to site 6, at the mouth of
            Johnson Creek, suggesting that sources of contamination were present throughout
            this area. Levels were lowest at site 8, which is at the end of the effluent pipe from
            the Durham POTW. This was a function of the residual chlorine in the effluent
            that essentially disinfected the river at that point. This effect was also apparent at
            sites just upstream (site 7) and downstream (site 12), which also had low average
            levels. Upstream of this area, the levels increased dramatically once again, with
            highest levels at site 9 at the mouth of Beards Creek. High levels were also observed
            at Town Landing (site 10), and above the dam at site 11. These results suggest that
            Beards Creek and the freshwater portion of the Oyster River are both relatively
            contaminated compared to the well-mixed estuarine waters at the mouth of the


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             Oyster River. At high tide, levels were lower that at high tide at the three sites
             sampled, with levels increasing going upstream.
                   The results for C. perfringens in the tidal Oyster River are presented in
             Figure 1-2. C. perfringens is a spore-forming anaerobic pathogen that can survive
             adverse environmental conditions extremely well. Levels of this indicator
             increased going upstream to sites 12, 8 and 7. These sites are near the POTW outfall
             pipe, and these results show how C. perfringens, which is relatively resistant to the
             chlorination process, is discharged with the effluent. Other related studies have
             shown that C. perfringens is also closely associated with suspended particles in the
             water column, and probably sediments out of the water column with the settling
             particles relatively rapidly. Thus, levels this indicator appears to be related to POTW
             effluent, and probably any resuspension of sediments, in addition to potential direct
             fecal contamination sources. Levels upstream of the POTW were highest at site 9 off
             Beards Creek, and were quite low in the freshwater portion of the river.
                   Analysis of data for specific sampling dates shows that contaminant
             concentrations are quite variable, ranging from relatively low to high levels. In
             addition, comparison of levels to rainfall amounts suggests that the intermittent
             occurrences of elevated contaminant concentrations have not been observed
             necessarily in association with definable events, such as rainfall/runoff events.
             Average levels for samples collected during the four seasons are presented in
             Figures 1-3 to 1-5. It appears that for sites where one season had significantly higher
             levels, the typical season for this occurrence was spring for fecal coliforms and C.
             perfringens, and no season in particular for enterococci. Some of the sampling
             dates during spring followed significant rainfall events, but the dates with the
             highest levels (Table 1-1) followed relatively dry periods (Table 1).
                   Transect stations in the Oyster River were sampled for nutrient
             concentrations in FY 1994, though less frequently than in FY 1993. Stations 1, 6, and
             10 were sampled on 18 occasions while most others were sampled on five occasions.
             Data was collected in the summer, fall and spring only, due to the heavy ice cover
             from late December through March. Nutrient concentrations measured at the
             transect sites are presented in Tables 1-3, 1-4 and 1-5. Annual and seasonal means of
             nutrient concentrations are presented in Figures 1-6 thru 1-11. As was the case for
             FY 1993, Station 8 (Durham POTW) had the highest concentrations of all the
             nutrients measured. It is difficult to compare N03 and NH4 concentrations at the
             outfall site separately for the two years, since the ratio of these two species of
             nitrogen in the effluent fluctuate daily. Combined dissolved nitrogen (N03+NH4),
             however, was slightly higher in FY 1993 than 1994. P04 concentration at the outfall
             site and for most other sites, however, was higher in FY 1994. Concentrations of
             NH4 and N03 at the other stations were similar to FY 1993, and the effect of tidal
             flow direction, with the POTW as a reference point, was evident. Though not

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            illustrated in the charts, samples upstream of the POTW showed elevated levels of
            nutrients at high tide (Tables 1-3 thru 1-5). Besides the POTW site, highest
            ammonium concentrations were detected at stations 12 (Unnamed Creek), 7
            (Horsehide Creek), station 3, station 6 (Johnson Creek), and the Town Landing
            (station 10). The elevated concentrations at stations 7 and 12 are due to their
            proximity to the POTW. High tide concentrations of NH4 at town landing, which
            were higher than at low tide, are likely influenced by the POTW (Table 1-3). Besides
            the POTW` and adjacent stations, N03 concentrations were highest at Johnson Creek
             station 6) and town landing (station 10).
                  Seasonal comparisons were difficult to make for all stations due to the
            unequal number of sample dates for all stations in all seasons. At the stations
            where all seasons were sampled somewhat equally (Stations 1, 6, and 10) highest
            concentrations of NH4 and N03 were obtained in the fall. At stations where only
            summer and spring had a sufficient number of samples, NH4 for the most part was
            higher in the summer, while N03 was higher in the spring. With the exception of
            Station 7, summer P04 levels were higher than the other seasons. The higher
            summer concentrations of nutrients may have been due to the lack of rainfall and
            therefore lower dilution of the nutrients.
                   The effects of rainfall on nutrient concentrations was examined to determine
            if there was a response to rainfall within 24, 48 and 72 hours of sampling. No trends
            were detected, in fact, the day on which all stations had the highest concentrations of
            ammonium and phosphate (9/8/93) was preceded by three days with norecorded
            rainfall.


            Estimated loading of dissolved inorganic nitrogen, phosphate and microbial
            contaminants from point and non-Voint sources in the tidal portion of the Oyster
            River


            Introduction


                  A two part study was conducted in 1993-1994 to determine the contributions
            of dissolved inorganic nitrogen and phosphate from point and nonpoint sources in
            the Oyster River. The initial part of the study focussed on transport and dilution of
            these compounds from the point source origin at the outfall of the Durham Sewage
            Treatment Facility. The effluent plume was tracked along a five station transect in
            the river, and the results indicate that the treatment plant has a significant influence
            on dissolved nutrient concentrations at downstream sites during the ebb tide and at
            upstream sites during the flood tide. Analysis of the nutrient concentrations
            measured over a two year period at 12 sites along a transect in the river, as well as


                                                     4








            site specific studies in the sub-watersheds of the river, indicates that there are other
            more diffuse sources of nutrients to the river as well. In order determine the
            relative contribution of these diffuse sources to the dissolved nutrient concentration
            throughout the river, flows were measured at the mouths of the largest tributaries
            to the river. Mean nutrient concentrations calculated for the two year study period
            were then applied to the flow rates to determine loading.


            Methods


                   Rate of flow was measured during high (March 23, 1994) and low flow
            (September 17,1994) periods in Bunker Creek, Johnson Creek, Unnamed Creek and
            Beards Creek using a Marsh-McBirney model 201D electromagnetic current meter
            attached to a custom stainless steel top setting wading rod. Stream width was
            measured at the location of deployment of the flow meter. Depth was measured
            with the wading rod, and the probe was set at 0.60 the depth of the water (Marsh-
            McBirney, 1988). Water flow was measured at 0.50 meter intervals across the width
            of the stream, and the depth of the probe was adjusted to water depth for each
            measurement. All measurements were made at low slack tide.
                   Stream dimensions and average velocity were used to calculate stream
            discharge for the above mentioned streams. River discharge data for the main stem
            of the Oyster River was obtained from the USGS flow gauge data from the Oyster
            River (Toppin et al. 1994). Average annual stream discharge for the tributaries was
            calculated by averaging the discharge during low flow and high flow conditions.
            Tributary flows for those two dates were then compared to the published discharge
            data for the main stem of the Oyster River. The relationship of the measured flow
            in the Oyster River to the calculated mean daily discharge was used to adjust the
            average stream discharges. Mean concentrations of dissolved inorganic nutrients
            were then used to calculate the # of kilograms per year of nitrogen and phosphate
            entering the river.
                   Nutrient loading from the Durham Sewage Treatment Plant was calculated
            from annual average flow measured at the plant and frorn the mean of values
            obtained for effluent nutrient concentration measured during the
            dispersion /dilution study referenced above.


            Results


                   Results of the determination of total stream discharge from the tributaries
            and the calculated loading of dissolved inorganic N&P from the streams (NPS) and
            the Durham POTW) are presented in Tables 1-6 and 1-7. For dissolved inorganic N
            (NH4+N03), approximately 25,985 kg/yr comes from the POTW, approximately

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            28,541kg/yr from the tributaries for a total of 54,526 kg/yr. The calculated percent
            contribution of dissolved N from nonpoint sources was = 52%, while the POTW
            contributed = 48% (Tables 1-6, 1-7, Fig 1-12) The main stem of the Oyster River
            accounts for >41% of the NPS-N, and =22% of the total N. Of the tributaries,
            Johnson Creek (30% of NPS, 16% of total N), followed by Beards, Bunker and
            Unnamed Creeks, contributes the highest percentage of N to the river.
                  The situation for dissolved inorganic P04 was quite different. Total estimated
            loading was = 10,628 kg/yr, of which 2,421 (=23%) came from nonpoint sources, and
            the remaining 77%, or 8,207 kg from the POTW. Of the nonpoint sources, Johnson
            Creek contributes the largest portion (34% of NPS, 7.7% of total), followed by the
            Oyster River, Beards and Bunker Creeks. Percent contribution of P from Unnamed
            creek is minimal (Tables 1-6,1-78, Fig. 1-13).
                  Calculated annual stream discharge figures were applied to mean
            concentrations of fecal coliforms and enterococci to estimate annual loading of
            microbial contaminants to the river (Table 1-8, Fig. 1-14). These estimates indicate
            that the greatest source of both fecal coliforms and enterococci is the main stem of
            the Oyster River, followed by Johnson, Beards, Bunker and Unknown Creeks. The
            estimated loadings of fecal coliforms from the POTW and enterococci are
            insignificant by comparison.

            Discussion and interpretation

                  Though weights and percentages of nutrient and bacterial loading are
            reported in this study, the reader should be aware that these figures are estimates,
            and that there are many potential sources of error or variation in the data used to
            calculate the figures. To begin with, only the dissolved inorganic portions of both N
            and P were used in the calculations. Though these are the forms of these
            compounds that would be readily available to plants, they by no means represent
            the total picture of nitrogen and phosphorus loading. The flow from each of the
            tributaries was measured on only two occasions, and the river gauge data (Oyster
            River) was used to adjust the average flow. This averaging may also be a source of
            error. Concentrations of nitrogen and phosphorus in the PCITW effluent were
            calculated from relatively few samples, though based on the results of the
            dilution/ dispersion study and the large data set for nutrient concentrations at the
            outfall pipe, these concentrations seem to be a reasonable estimate. Additionally,
            there are other, smaller creeks that empty into the river (Horsehide Creek, Deer
            Meadow Creek, Smith Creek, etc.), so there is likely additional nonpoint source
            input, as well as natural and anthropogenic riparian sources that may have direct
            groundwater or surface flow connection to the river. These sources would be much


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            more difficult to measure, though they may increase the percentage contribution of
            NPS nutrient contamination.
                  It is interesting to note that besides the main freshwater stem of the Oyster
            River (due to the much greater volume of water), Johnson Creek seems to be the
            greatest source of dissolved nutrients and bacterial indicators to the tidal portion of
            the Oyster River. The Johnson Creek watershed was a focus of the land use impact
            assessment study, and the primary land use and possible contaminant sources
            identified were private sewage disposal systems associated with residential
            development.

            Dispersion and dilution of nutrients from the Durham POTW outfall

            Summary

                  In July of 1993, a study was conducted to measure the effect of nutrient
            loading from the POTW effluent on the nutrient concentrations in the Oyster River.
            Five stations were established in a horizontal transect bracketing the outfall pipe
            and sampled hourly for six hours during the ebbing tide on 7/14/93 and hourly
            during the flooding tide on July 21, 1993. Measurements of temperature, salinity,
            dissolved oxygen, and pH were made at the time the samples were taken. Vertical
            profiles of the physical parameter measurements were done each hour at the
            effluent pipe. Water samples were analyzed for concentrations of N03-, NH4+,
            P04-3, total suspended solids, and photosynthetic pigments. Results of the study
            indicate that the POTW effluent has a major impact on the nutrient concentration
            in the River and that the effluent plume travels in the direction of the flow of tidal
            currents, affecting the downstream portions during ebbing tide and the upstream
            portions on the flooding tide. In addition, the nitrogen species in the effluent
            varies, with high N03 and lower NH4 discharged on 7/14 and the reverse on 7/21.


            Introduction


                   From July 1992 thru June 1993, the first year of a study of non-point source
            pollution was conducted on the tidal portion of the Oyster River. Elevated nutrient
            concentrations were detected at 12 stations arranged in a horizontal transect starting
            at the mouth of the river extending to the upper tidal limit at the dam in Durham,
            NH. It was determined that although some of the tributaries contribute to the
            overall nutrient loading in the river., the highest concentrations of nutrients (N03,
            NH4 and P04) were found at the POTW outfall site (station 8, see updated data base
            in another section of this report), and at those stations closest to it, indicating that

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            that the treatment plant was a major source of nutrients (Jones and Langan, 1993).
            A second year of the study was proposed and included in that study was the
            determination of the relative contributions of point and non-point sources to the
            concentration of nutrients in the tidal portions of the river. This report on the
            POTW study represents th& point source portion of the nutrient loading study.




            Materials and Methods


                   Five stations were established along a horizontal transect in the Oyster River,
            with the middle station (station 3) located at the POTW outfall pipe; station 1 in
            mid-channel near the mouth of Beards Creek; station 2 midway between stations 1
            and 3; station 4 in mid-channel near the mouth of unnamed creek; and station 5 in
            mid-channel near the mouth of Johnson Creek. The study was conducted in two
            parts; the ebb tide portion was done on July 14 and the flood tide portion on July 21.
            Replicate one liter water samples were obtained by subsurface grab hourly at each
            station beginning at slack high water on fuly 14 and at slack low water on July 21.
            All sample bottles were previously acid-cleaned, and samples were placed
            immediately on ice and out of direct sunlight. During the third hour of sampling
            on each date, replicate samples were obtained from inside the treatment plant to
            determine the nutrient concentrations of the undiluted effluent samples.
            Measurements of temperature, salinity, dissolved oxygen and pH were made at the
            time the water samples were taken. A vertical profile of temperature, salinity and
            dissolved oxygen at the POTW outfall was established each hour following the last
            sample to determine if stratification was occurring.
                   Samples were filtered within seven hours following the first sample
            collection. 500 ml of each sample was filtered through previously washed, dried and
            weighed glass fiber filters (1.2g nominal pore size) and the filtrate divided into three
            acid cleaned containers. The containers were immediately frozen at - 200C and
            analyzed for nutrient concentration within 14 days. The filter was dried for 24 hours
            at 800C, weighed to obtain the suspended solid weight, then placed in a muffle oven
            at 4500C for 4 hours. The filter was weighed again to determine % organic content
            by combustion. The remaining 500 ml of sample was filtered thru an unweighed
            glass fiber filter of the same pore size. The filter was treated with 1 ml of MgC03,
            frozen at -200C and analyzed for photosynthetic pigments within 14 days.
            Ammonium and nitrate/nitrite concentrations were determined using a LACHAT
            nutrient autoanalyzer (Lachat Instruments, 1991). Orthophosphate concentrations
            were determined using colorometric methods described by Strickland and Parsons
            (1976), and absorbances were read on a Beckman model DU 640 single beam

                                                       8








            spectrophotometer. Chlorophyll a and phaeophytyn concentrations were
            determined using the acetone extraction method (Strickland and Parsons, 1976) and
            absorbances read on a Beckman model DU 640 single beam spectrophotometer.


            Results


                   Vertical profiles of temperature, salinity, and dissolved oxygen obtained
            hourly at the treatment plant outfall station indicate that a certain degree of
            stratification occurs at the slack tides (high and low) with a differential of = 2-3 ppt
            between the surface water and a depth of 0.5 m. Salinity did not change with depth
            below the 0.5 m depth and stratification was reduced or eliminated as the tidal flow
            increased (hours 3-6 ebb tide; hours 9-12 flood tide).
                   Results of the nutrient analyses clearly demonstrated that the POTW effluent
            has a significant effect on nutrient concentrations in the river. The concentrations
            of the nitrogen species were quite different on the two sampling days, illustrating
            the variable degree of nitrification of the treatment plant effluent. On July 14,
            during the ebb tide portion of the study, the undiluted POTW samples had
            ammonium and nitrate concentrations of 132 4M and 1212 gM respectively. On
            July 21, during the flood tide study, the concentrations were 1281 @[M for
            ammonium and 8.23 @M for nitrate; the reverse of the 7/14. For this reason, the
            data is presented as total nitrogen (NH4 + N03) in figures 1-15 thru 1-17, as well as
            for the individual; nitrogen species in figures 1-18 thru 1-20.
                   Dilution from the plant to the outfall sampling site, estimated by comparing
            concentrations of nutrients from replicate samples taken within the plant at mid-
            falling and mid-rising tides (hours 3 and 9) to concentrations at the outfall site, were
            approximately 10:1. As stated, the dominant nitrogen species during the ebb tide
            portion of the study (hours 1-6) was nitrate (Fig. 1-18 thru 1-20). With the exception
            of a high ammonium concentration ( = 8 @LM) at station 2 during hour 4, the nitrate
            and ammonium concentrations (Fig. 1-18) at the two upstream stations (1 and 2)
            were <2@M At stations 4 and 5, downstream of the treatment plant in the direction
            of the tidal flow from the effluent, nitrate and ammonium, and particularly nitrate
            at station 4, increased steadily to and reached a peak ( = 60 @M at station 4) at hour 5
            (Fig. 1-20). The concentrations of nitrogen species at the treatment plant outfall at
            hour 5 were: = 100 gM for nitrate and = 25 @M for ammonium, for a combined total
            nitrogen concentration of 125@LM (Figs.1-16 and 1-19). Peak nitrogen (= 175 gM)
            during the ebb tide portion of the study was detected at hour 6 (slack low water) (Fig.
            1-16). Concentrations had already begun to fall at downstream stations (4 and 5) at
            hour six when the tidal flow was no longer carrying the outfall plume in their
            direction (figs 1-17 and 1-20).


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                   A similar situation was observed during the ebb tide study for phosphate.
             The concentration of phosphate in water taken inside the plant at mid-ebb tide was
             = 102 jiM, and samples at the outfall site at the same time were = 11 @M; showing a
             10:1 dilution, similar to nitrogen (Fig 1-22). Phosphate concentrations at the
             upstream stations (1 and 2), did not change appreciably during the ebb tide and
             ranged between 1.25 and 1.75 @LM (Fig. 1-21). The downstream stations (4 and 5)
             tracked the outfall concentrations with all three stations reaching peak
             concentration at hour 5. The phosphate levels measured at stations 3, 4 and 5 were
             23, 7 and 2.2 gM respectively, indicating a fairly rapid dilution as the distance from
             the outfall increases.
                   Very different nutrient conditions were detected on July 21 during the flood
             tide study. Phosphate concentration of samples taken inside the plant during hour 9
             (mid-flood tide) were = 267 4M, greater than twice concentration during the ebb tide.
             Once again, the dilution at the outfall site was = 10:1, with the concentration of hour
             9 samples measuring = 27 @M As previously mentioned, the concentrations of
             nitrogen species during the flood tide were the reverse of the ebb tide, with
             ammonium being dominant and nitrate levels low. At hour 9, samples taken
             inside the plant had levels of ammonium of = 1281 @M, and nitrate of = 8 @M
             Ammonium concentration of the outfall site samples were = 130 gM at hour 9,
             showing a similar 10:1 dilution (Figs. 1-16 and 1-19). Significant increases in total
             nitrogen were observed at the upstream stations (I and 2) during the flooding tide,
             particularly during the second hour (hour 8) when concentrations peaked at = 21
             @LM at both stations (Figs 1-15, 1-18). The peak concentration of nitrogen at the
             outfall site (725 gM) occurred at hour 8 as well (Figs. 1-16 and 1-19). Concentrations
             at stations 1 and 2 dropped at hour nine, remaining stable at = 7 @tM for hours 10, 11,
             and 12, tracking the outfall concentrations (Figs.1-15 and 1-16). Nitrogen levels at
             downstream stations were for the most part much lower during the flood than the
             ebb tide. Station 4 had an ammonium concentration of = 27 4M at hour 8, and = 12
             gM at hour 12, while both ammonium and nitrate were = 2@tm throughout the
             flood tide at station 5 (Figs.1-17 and 1-20).
                   Similar patterns were observed for phosphate during the flood tide. A peak
             concentration of = 27gM was measured at the outfall site at hour 7, and decreased
             steadily as greater dilution was achieved as the volume of tidal water increased (Fig.
             1-22). The upstream stations (1 and 2) had peak phosphate concentrations at hour 8
             of 5.7 and 5 @tM respectively (Fig 1-21). Concentrations fell during the remainder of
             the flood tide, probably reflecting the greater dilution from incoming tidal water.
             The downstream stations, particularly station 5, showed steadily decreasing (to =
             1@tM) phosphate concentration during the flood tide (Fig 1-23). Phosphate at station
             4 was variable, probably due to its proximity to the outfall pipe, or perhaps an
             additional source.


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            Discussion


                  The results of this study clearly illustrate the effects of point source loading of
            nutrients from the sewage treatment plant on the Oyster River. Stations in the
            direction of the tidal flow exhibited elevated nutrient concentrations during both
            ebb and flood tide, though the flood tide concentrations at upstream stations were
            rapidly diluted by incoming tidal water. Comparison of high and low tide
            concentrations of nutrients at station 10 (Town Landing) in the main river transect
            also support the results of this study (see the updated database section of this report).
            Several samples taken during this study, however, (station 2, NH4 hour 4; station 4
            NH4 hours 8 and 12), as well as data from 1992 (stations 3, 5 6, 9) indicate that there
            are other sources in the river as well. The rapid dispersion/ dilution of phosphate
            and nitrogen observed at station 5 during the ebb tide, also indicates that the POTW
            is not responsible for all of the elevated nutrient levels observed over the past 1.5
            years of the Oyster River NPS study. Using data gathered in this study, along with
            discharge volumes at the POTW and stream flow measurements at the tributaries of
            the river, it will be possible to estimate the relative contributions of nutrients from
            point vs. nonpoint sources to the Oyster River. This estimate will make nutrient
            reduction strategies less difficult to identify if they are deemed necessary.



            OBJECTIVE 2

                  A detailed NPS assessment was focused on Johnson Creek, where a previous
            project indicated temporally fluctuating elevated levels of contaminants. Land uses
            in the Johnson Creek watershed include rural, agricultural, and non-sewered
            residential areas, thus providing the opportunity to determine relative impacts of
            these different land uses. The Strafford Regional Planning Commission provided
            different digitized land use maps. A parcel-based map was provided as an overlay
            for the other maps. A significant amount of the land use data used to generate the
            maps was inaccurate or dated, especially the large areas defined as agricultural lands
            that are simply open fields. Some of the land use data does not reflect recent
            residential development, as might be expected. We are currently working with
            SRPC to correct and update these data, based on our groundtruthing activities. The
            sampling stations have been located using a GPS unit and included on the parcel
            map overlay. The land use information that has been most useful includes the
            following:
                  -a parcel-based overlay map with building and sample site locations;
                  -soil suitability map;








                   -wetlands map;
                   -land 'use map.
            More information on land cover would be useful, and groundtruthing was
            absolutely necessary. In fact, very little active agricultural land use is present in the
            watershed.
                   Sampling was undertaken along longitudinal transects covering the full
            length of Johnson Creek and its tributaries. Sites were chosen to focus on obvious,
            potential NPS pollution problem areas, based on presently available land use
            information. The focus of sampling was to document impacts on water quality
            from different land use areas. Routine sampling along the transect of the creek and
            its tributaries occurred basically on a monthly basis to establish a database for
            contaminant loading to the Oyster River and to allow for detection of any
            contamination that may not be associated with any obvious land use. The results
            are presented in Table 2-1, with calculated geometric means for annual and seasonal
            data presented in Table 2-2. Nutrient concentrations at the sites are presented in
            Tables 2-3 thru 2-5 and annual and seasonal means are presented in Figures 2-5 thru
            2-10.
                     All three indicator bacteria followed similar general trends, with fecal
            coliforms giving the most striking differences between stations (Figure 2-1). Levels
            were relatively low at the mouth of the creek (sites 1&2) compared to levels at
            upstream sites. Along the main branch of the creek (see Figure 3), levels were
            higher at site 3 but increased dramatically at site 4 just downstream of a sewered
            trailer park in Dover. Levels were relatively low in the east branch of the creek at
            site 5, but were again high downstream of the confluence of these two branches at
            site 6. This site is just upstream of a municipal water treatment facility and the land
            upstream to the trailer park is vacant and undeveloped. Thus, levels at site 6
            appeared to be residual from sources near site 4. Levels decreased going
            downstream to site 7, but were still relatively high compared to levels in the west
            branches of the creek. Levels at site 13 were low when sampling was possible, and
            are not presented. Levels at site 12 were the lowest of any of the freshwater sites, but
            then levels were higher at sites downstream and at the mouth of the southwest
            branch at site 10. Levels at the confluence of these two branches at site 9 appeared to
            reflect a combination of the two creek branches, while levels were slightly elevated
            downstream at site 8. Approximately 10 more unsewered houses could potentially
            influence water quality between sites 9 and 8, suggesting that one or some of these
            houses could be contributing contaminants to the watershed. Thus, the trailer park
            and other residences in the watershed appear to be sources of bacterial
            contamination in the Johnson Creek watershed.
                   Summer and autumn appeared to be the seasons with the highest levels of
            fecal coliforms and enterococci at most of the sites (Figures 2-2 & 2-3). High levels in

                                                       12








             summer and autumn at many sites suggest that transport of contaminants is
             favored under those environmental conditions. In addition, high levels in
             summer could reflect low water volumes in the streams, thus concentrating
             contaminants, or regrowth under relatively favorable conditions could also cause
             increased levels. The reason for relatively high levels of C. perfringens during
             winter compared to other seasons at many sites (Figure 2-4) is not known.
                   Elevated N03 concentrations throughout the Johnson Creek watershed
             suggest that there are potentially a number of sources along the branches and main
             stem of the creek, particularly at sites 4 and 12A (Fig. 2-6). Probable cause for the
             elevated N03 at station 4 is a trailer park and other residences in close proximity to
             surface water, while site 12A is influenced by a number of houses with older septic
             systems as well as a farm. Despite the elevated N03 concentrations at most of the
             upstream sites, the tidal sites in Johnson Creek (JC 1&2) are quite low, likely due to a
             combination of dilution, uptake and microbial /biogeochernical activity (Figs. 2-6
             and 2-9). In contrast to the high N03 concentrations, NH4 and P04 were quite low
             throughout, though site 4 was higher relative to the other sites (Figs. 2-5 and 2-7).
             Analysis of the seasonal means indicate that ammonium and phosphate are is
             highest in the summer when the water levels in the streams are the lowest. In
             contrast, nitrate concentrations are highest in the spring and fall when it appears
             that rainfall and high water table conditions mobilize nitrate from soils (or septic
             systems) into the surface waters (Figs 2-8 thru 2-10).
                   Natural processes that may influence contaminant levels are of interest for
             predicting the fate of contaminants to surface waters from land sources. The
             Johnson Creek has an extensive salt marsh at its mouth, and levels of fecal
             coliforms and enterococci were measured at low tide along the length of the marsh
             (between sites 2 and 8) to see what influence mixing of salt and freshwater could
             have on water column bacteria. Results show a relatively rapid decrease in bacterial
             levels between the freshwater head site and next 3 sites with low salinity brackish
             water (Figures 2-11 & 2-12). The dashed lines indicate predicted levels if the waters
             at each end were mixed to give the observed salinities at sites in the middle. At sites
             further downstream levels remained about the same. This suggests that the mixing
             of freshwater with low salinity brackish water could promote flocculation of
             colloidal and particulate material and induce sedimentation of particle-bound
             contaminants, as observed in other similar areas.


             OBJECTIVE 3
                   Determination of nonpoint pollution sources based on detailed digitized
             information and extensive sampling can become extremely expensive, and as the
             geographical area of interest increases, the cost can become prohibitive. For


                                                       13








             assessing large and complex geographical areas, it is important to identify the types
             of data that are most effective for predicting potential NPS loading. The goal for this
             part of the study will be to initiate development of an effective system for predicting
             NPS loading in NH coastal watersheds, based on the most critical combinations of
             land use and watershed characteristics that result in NPS pollution.
                   The most important source of bacterial and nutrient contamination from a
             land use perspective appears to be private residential on-site sewage disposal
             systems. All of the Durham and Madbury areas, and much of the Dover area, of the
             Johnson Creek watershed are not served by municipal sewage systems. The results
             of our water quality analyses give some indications that these residential areas are
             increasing contaminant levels in nearby streams, even though there are houses
             near the heads of all of the streams in the watershed and thus no good pristine,
             upstream sections to use as background references. An in-depth study of a
             residential area in Durham that is unsewered was undertaken to document any
             impacts on the water quality of the nearby south branch of Gerrish Brook (Figure 3-
             1). Gerrish Brook runs at approximately 20 feet lower elevation from the back of the
             development, and two drainage swales, one from within the development, flow
             downslope to Gerrish Brook. All of the soils in the area are designated severely
             limited for septic tank effluent by the Strafford County Soil Survey, either because of
             high seasonal water table/slow permeability, or because of slope restrictions or
             shallowness to bedrock. Most of the houses in the development were built during
             1972-76, and the septic systems were installed according to permit requirements.
             Most of the systems are beds with 3 lines covering areas ranging from 500-700 ft2.
             Based on this information, it was expected that contamination from this
             development could be detected in the brook.
                   Results of sampling the south branch of Gerrish Brook and tributaries near
             the development (Table 3-1; Figure 3-3) indicate elevated levels of bacteria occur
             occasionally in the drainage swales (sites 3-4; Table 3-1) and consistently at site (#8)
             downstream of the main area of focus. N03 concentrations were also high at
             stations 3&4, though only P04 and NH4 was elevated at site 8 (Table 3-3). This site is
             relatively close to a house with a sewage treatment system visible from Gerrish
             Brook and perched approximately 10-15 feet above and approximately only 25 feet
             away from the stream bed. Below this is an oxbow containing ponded, stagnant
             water that is obviously contaminated, based on the high levels of algal growth, color
             of the water, odor, and bacterial (FC = 1060/100 ml; 42,000/100 ml on 6/29/94) and
             nutrient (P04=256.89 @iM; NH4=53.46 @tM on 6/29/94) levels. Phosphate
             concentrations this site were extremely high, with the mean for the four sampling
             dates (138 @tM). Downstream bacterial levels were slightly higher, but not to any
             significant extent on the sample days (Figures 3-4 & 3-5). However, the potential for
             contamination following high-flow events is obvious.

                                                       14








                   Our interpretation of land use from data, maps, and groundtruthing activities
            shows very little active agricultural land use in the watershed. One farm with
            animals exists at the head of the north branch of Gerrish Brook, along with another
            'housing development (Figure 3-4) that may have some impact on water quality.
            The housing development is older than the one previously described, although it is
            located on soils more suitable for septic systems (Figure 3-2). Detailed information
            on se tic systems was difficult to locate, but it is expected that the systems are older
                  lp
            than in the development near the south branch of the brook. Data on bacterial
            contaminants in the north branch of Gerrish Brook near these sites on three sample
            dates is presented in Table 3-2 and Figures 3-6 to 3-8. Nutrient data was collected on
            two dates ate these sites, and is presented in Table 3-4. On the last two sample dates,
            sites downstream near the mouth of the brook (near site 11 of Johnson Creek; see
            Figure 3) were included to determine the influence of -4 unsewered houses in that

            area.
                   The results were quite variable both temporally and spatially. Geometric
            average levels for the different sites suggest that the houses may be sources of
            contamination relative to the other sites (Figure 3-6). The site furthest upstream of
            the housing development was always relatively clean (Figures 3-7 & 3-8). However,
            the next three sites had high levels of both indicators on June 6, following a dry
            period (Table 1). This could reflect some altered farming practices or some other
            influence. Levels near the houses and further downstream were lower on June 6,
            but fecal coliforms (but not enterococci) were high at the site nearest the houses on
            April 5. Neither ammonium nor phosphate concentrations appear o be a problem
            on the north branch of Gerrish Brook, however, N03 concentrations were elevated
            on both sampling dates, and on 6/6 in particular. Based on the location of the
            stations with respect to sources, soil type and topography, it appears that the cow
            pasture ME and 12 D) and the housing development above station 12B and 12B are
            influencing the nitrate concentrations in the brook (Table 3-4).
                   In comparison to the other housing development, there may be some
            potential for the older systems to be sources of bacterial contaminants (April 5 FCs),
            but their location on suitable soils and their setback distance from the brook
            probably enhance removal of contaminants. In addition, the farm may be an
            intermittent source of bacteria. Overall, none of the bacterial levels were very high
            at any sites, unlike the oxbow site in the south branch. The results from both study
            areas suggest that most setback distances, except for the house near the oxbow, from
            the stream surface waters appeared to be adequate for minimizing transport of
            contaminants and contamination of the surface waters. This seemed to be a more
            important factor than age of system of soil suitability, although the amount and
            variability of the data precluded any conclusive determinations of the significance of


                                                       15








             these apparently intermittently important factors. Season and rainfall did not have
             any discernible effects based on the limited sampling frequency of this study. Thus,
             it appears that private, on-site sewage disposal systems in residential areas were the
             most important sources of contamination in the watershed, and setback distance
             was the only obvious critical factor that could be confirmed from the data.
                    The limited area of agricultural land limits our abilities to assess potential
             impacts, but the data thus far suggest that runoff from pastureland can contaminate
             surface waters. Thus, the critical land use factors identified by this study are
             proximity to surface waters and soil and site characteristics as they relate to
             residential on-site sewage disposal systems, and site characteristics and proximity to
             surface waters of agricultural land. As in any NPS pollution assessment, rainfall,
             temperature, storm event incidence and intensity, and accurate land-use data are
             also critical factors. A larger and more intensive study of these areas could probably
             better define the significance of all potential influencing factors.

             Review of Existing Nonpoint Source Pollution Models
                    One objective of this project was to evaluate existing capabilities for predicting
             NPS pollution of coastal NH watersheds. To this end, a number of existing models
             and related literature on pollutant and environmental characteristics and land-use
             interpretation were reviewed to determine the best approaches for assessing NPS
             pollution. The goal was to provide a framework for potential future modification
             and calibration of models to accurately fit physical, chemical, and biological
             processes that affect the fate of target pollutants in the environment. A summary of
             this review is presented below. Existing water quality data have not been used in
             models because of the inaccuracies of existing land-use data and the time required to
             modify and input these data to different individual computer programs for each
             model.
                    The focus of the review was on models that described NPS loading of
             nutrients, fecal-borne bacteria, and sediments to relatively small watersheds. These
             limitations resulted in a small number of models that appeared to be potentially
             useful. To support the mechanistic bases of these models for describing the fate of
             the different pollutants, a review of related literature on the behavior of nutrients,
             bacteria and sediments in watersheds was also conducted. The information can be
             summarized in three parts: estimation of pollutant discharge loading to the
             watershed, pollutant transport through the watershed, and use of supporting land-
             use systems and other data needs. The loading information requires data on load
             generation from a given source relative to eventual discharge load. In addition,
             processes that affect transport of the pollutant from sources to the watershed need to
             be identified, especially relative to stormflow or baseflow conditions.


                                                        16








                   The transport of pollutants through the watershed also requires knowledge of
            the factors that can affect transport, such as pollutant characteristics, environmental
            influences, and land-use characteristics. In terms of pollutant characteristics, again
            we are concerned with fecal-borne bacteria, nutrients, and solids. Because the
            environmental incidence of actual pathogenic bacteria and viruses is relatively rare
            (and if they are present, it would not be appropriate to allow them to persist any
            longer than necessary!), most studies on fecal-borne microbial contaminants focus
            on fecal indicator bacteria. What has been found is that these bacteria have the
            capacity for regrowth under favorable conditions, thus increasing in number and
            potentially indicating more pollution than what is actually occurring. More often
            they are subject to die-off, and this is affected by starvation conditions, inhospitable
            Eh, pH, or oxygen tensions, irradiance in surface waters, and predation (Auer and
            Niehaus, 1993). To complicate their behavior even more, many of the target bacteria
            tend to respond to unfavorable conditions by becoming relatively dormant, and no
            longer can be cultured /enumerated by conventional methods, even though they
            may remain viable, potentially virulent, and subject to predation (Gonzalez et al.,
            1992). Nutrients can also be transformed to other forms that may remain or that are
            lost from the the system. This is especially true of nitrogen, which can be
            transformed to nitrogenous gases and lost from the system, or form particulate to
            dissolved and back to particulate forms that affect the adsorption and settling
            properties of this nutrient. Microbial processes such as nitrification, denitrification
            and nitrogen fixation all are key processes involved in the fate of nitrogen in the
            environment, and the significance of each process is dependent on an integration of
            many environmental conditions and the presence of the bacteria and fungi capable
            of mediating the processes. Solid particulate matter is of direct concern, but also
            affects the transport of bacteria and nutrients. Depending on the size and charge of
            particles and the forms of the other pollutants, bacteria and nutrients can adsorb to
            particles or remain dissolved in aqueous phases of the environment. During
            transport through soils, the soil texture, unsaturated zone moisture, temperature,
            water table and other profile characteristics can also affect subsurface transport of
            pollutants. Surface runoff will also be affected by whether pollutants are associated
            with particulate matter.
                   Environmental characteristics are also important considerations when
            predicting NPS pollution. Meteorological conditions such as precipitation (rain,
            snow), wind, sunshine/ irradiance, and temperature regime can affect pollutant
            behavior. Rainfall affects transport as a function of its duration and intensity.
            Wind can affect evapotranspiration and cause wave action in surface waters.
            Sunshine/ irradiance has a significant affect on plant growth and survival of
            microorganisms in surface waters. Whether temperatures are above or below
            freezing will significantly affect transport, and warmer temperatures will increase

                                                     17








            biological metabolic rates, which affect microbial survival and process rates, plant
            growth, and predator feeding rates. The conditions of soils, land surfaces, and
            aqueous environments in terms of pH, dissolved oxygen/ aeration, irradiance, and
            charged surfaces are important factors for all pollutants, and plant uptake of
            nutrients can be significant (Rogers et al,, 1991). The relative flow rates of water on
            surfaces through runoff and in the subsurface is extremely important, and is a
            function of soil permeability, texture, structure, existence of macropores and
            fractures, other profile characteristics, and water table height. The water flow
            characteristics for the recipient surface streams are critical for determining the fate of
            pollutants and their eventual loading to surface water bodies. Tidal influences can
            also impact pollutant characteristics and vertical mixing.
                   Land use characteristics are the other important aspect of NPS pollution
            prediction. The type of land use or cover is important, such as urban/rural,
            commercial, residential, agricultural (row crop, pastureland, management practices),
            forested, marsh, or idle/ open/ gravel pits/mines. Related data on the distribution of
            specific land types and their area within a watershed are essential, as are
            topographical data on slope and elevation. Most importantly, an understanding of
            the hydrology of the watershed is absolutely essential.
                   Rarely are data available for all of the above factors in a given watershed.
            Even if a significant amount of data is available, meaningful predictions cannot be
            made without integration of pertinent data into forms that are more useful. For
            example, a certain set of conditions at a site may predict denitrification to be a
            significant sink for nitrogen, but seasonal changes in those conditions could result
            in prediction of insignificant denitrification with plant uptake becoming the
            dominant sink. Thus, in New Hampshire, data should be grouped according to the
            seasonality of conditions. One of our other objectives, identification of critical
            factors that are associated with NPS pollution in the target watersheds, is an
            important exercise that should help to narrow data needs to allow for prediction of
            NPS loading from certain land uses under specific conditions (see below). Data gaps
            can be filled using published values from the literature, although caution is
            required. Dierberg (1991) found that measured nitrogen and phosphorus export
            coefficients for an agricultural-suburban watershed in central Florida were more
            similar to published values for Wisconsin, but deviated considerably from those for
            national averages. The next question is, 'What are the predictive needs, and which
            of those require use of models and which can be based on empirical relationships
            developed for specific land use types?'
                   All of the above information can be integrated and used in models to predict
            pollutant loading and fate in the environment. Existing data on pollutant
            concentrations can be used to run sensitivity analyses for different model


                                                       18








             parameters and for curve fitting to modify parameter values. Models can also be
             modified to represent conditions different from present conditions for predicting
             impacts from future development or management practices. These approaches
             were taken by Najarian et al. (1986) for predicting the effects of a proposed land
             development on water quality in a coastal New Jersey watershed. They used a
             modified STORM model that included infiltration of soluble pollutants (nutrients;
             bacteria) to groundwater. Another model that could be useful is the BROOK 6
             model for small watersheds. It would require extensive modification to include the
             impacts of pollutant characteristics and behavior in both surface and subsurface
             transport. Sekine et al. (1991) developed a complicated model for predicting runoff
             loading of nutrients through rivers to lakes and inner sea areas of Japan. Their
             approach used long-term data and curve-fitting to adjust model parameter values
             for simulating pollutant discharge under present conditions and for predicting
             effects of changes in population, industrial production, and land use.
                    Some of the land-use data can be integrated into useful groupings such as
             riparian zones, impervious areas, vegetated buffer strips, soil suitabilities, etc. that
             are useful when going from process modelling for small areas to modeling whole
             watersheds. GIS can be useful for integration and manipulation of land-use data for
             predicting present and future impacts of development, using either models or
             empirical relationships. Basic data required include area and distribution of
             different land uses and cover, length of streams, and area of watersheds. Buffer
             functions in GIS software can also be used to determine areas of critical land uses
             surrounding water bodies that may impact water quality, and to correlate with actual
             pollutant measurements. This empirical approach was taken by Osborne and Wiley
             (1988) to explain measured nitrate and soluble reactive phosphorus levels in an
             Illinois watershed. As a first approximation and an approach that requires less
             technical training, this may be useful in New Hampshire, and can be built off the
             existing data collected for the Oyster River watershed.


             OBJECTIVE 4


                    The critical factors identified from the Johnson Creek portion of the study
             were applied to the Beards Creek watershed, which has a number of features in
             common with Johnson Creek. Digitized land use data was made available for this
             area, though not in the detail that was available for Johnson Creek. Again, there
             was little agricultural activity in the watershed, but it appeared that some high
             density residential areas could give similar results compared to the Johnson Creek
             watershed. In addition, it features portions of the urbanized district of Durham. In
             a few areas, houses were located quite close to the stream surface waters, so setback
             distances were expected to influence water quality.

                                                         19








                    Water quality at 12 sites (Figure 4) located throughout the watershed was
             assessed by measuring bacterial indicator and nutrient concentrations at all sites
             (Tables 4-1 and 4-3). Geometric annual mean fecal coliform and enterococci levels
             followed generally the same trends, while C. perfringens levels were virtually the
             same at all sites (Table 4-2; Figure 4-1). At the northern head of the main stem of
             Beards Creek (sites 6 & 5), levels of fecal coliforms and enterococci were higher than
             in estuarine receiving waters (site 1), but lower than at downstream sites (sites 4 &
             3). Site 4 is just downstream of a high density, sewered residential neighborhood
             where a few unidentified pipes emptying into the stream were also located. Site 3 is
             on the other side of Rt. 4 near a few other houses, Thus, there is an apparent source
             of contamination in this area, based on the observed increased levels compared to
             upstream. On Littlehole Creek, levels were the highest seen in the watershed at site
             12, above a small wetland. However, it appears that the wetland has a favorable
             impact on water quality, as levels were much lower at sites 11 and 10. Even though
             most of the houses in this area are on the municipal sewer system, some houses at
             the ends of streets are known to have on-site septic systems. These results suggest
             that residential areas with on-site septic systems are probably the major sources of
             bacterial contamination in these portions of Beards Creek watershed.
                    The other sampling sites were located in the urban area of Durham along
             Reservoir Brook. Levels of fecal coliforms and enterococci wererelatively high all
             along this brook (sites 9,8,&7), especially near site 8 (Figure 4-1). These results
             suggest that some sources of fecal contamination are present even in a sewered area.
             Site 2 is located at the downstream end of an extensive marsh at the confluence of
             all the branches of the creek. It appears that contaminant levels decrease during the
             residence time for inflowing water into the marsh, as levels at site 2 were lower
             than at sites 3, 7 and 10.    1
                    Analysis of the data with respect to season showed some seasonal differences
             in bacteria levels, but no significant trends (Figures 4-2 to 4-4). Generally, the spatial
             trend observed for annual means (Figure 4-1) were consistent with season. For fecal
             coliforms and enterococci, it appeared that summertime gave the largest differences
             between sites.. with less inter-site differences during autumn and spring.
                    With the exception of a few isolated ammonium samples, NH4 and P04
             concentrations were low at all Beards Creek watershed stations. The highest mean
             NH4 concentrations were measured at stations 4 and 9 (where high fecal coliforms
             were also measured) (Table 4-3, Fig. 4-5). N03 concentrations were relatively high at
             all stations, except for the last two freshwater stations (1&2) in the Beards Pond area
             (Table 4-3, Fig. 4-6). Station 5, which is located near a non-sewered residential area
             in Madbury, had the highest mean N03 concentration, which may be the result of
             the on-site sewage disposal systems associated with the residences. As was the case


                                                         20








            with fecal coliforms, N03 concentrations at stations 7, 8, and 9 were elevated.
            Seasonal analysis of mean nutrient concentrations indicate that for N03, stations
            with the highest annual means were highest in the summer, while those with
            lower concentrations were higher in the wetter spring and fall (Fig. 4-9). This same
            trend was also observed for NH4 (Fig 4-8) while highest P04 concentrations were
            measured in the spring and fall (Fig. 4-10).
                   One potential source of fecal contamination in sewered and urban areas is
            sewer lines for the municipal system. At the mouth of Beards Creek is a mudflat
            area between the dam and the main stem of the Oyster River. A cement-encased
            sewer line crosses the mudflat just downstream of the dam. Sampling around this
            pipe on an outgoing tide near slack low showed a pattern of contamination that
            suggested the pipe may be a source of contamination. Fecal coliforms levels at three
            sites above the pipe were relatively low and similar, with freshwater levels being
            similar to the downstream tidal sites (Figure 4-11). Fecal coliform levels were much
            higher just below the pipe, and the salinity was lower (16.5 vs -23 ppt upstream),
            suggesting that the pipe is a source of fecal coliform-contaminated freshwater. Thus,
            nonpoint sources that are often relatively difficult to identify and observe can
            include sewer system pipes in urban areas.


























                                                      21











                                                REFERENCES


                   Auer, M.T. and S.L. Niehaus. 1993. Modeling fecal coliform bacteria-I. Field
             and laboratory determination of loss kinetics. Wat. Res. 27: 693-701.
                   Dierberg, F.E. 1991. Non-point source loadings of nutrients and dissolved
             organic carbon from an agricultural-suburban watershed in east central Florida.
             Wat. Res. 25: 363-374.
                   Gonzalez, J.M., J.Iriberri, L. Egea, and L Barcina. 1992. Characterization of
             culturability, protistan grazing, and death of enteric bacteria in aquatic ecosystems.
             Appl. Environ. Microbiol. 58: 998-1004.
                   Marsh-McBirney. 1988. Instruction Manual. Model 201D. Portable Water
             Current Meter. Gaithersburg, Maryland.
                   Najarian, T.O., M. ASCE, T.T. Griffin, A.M. ASCE and V.K. Gunawardana.
             1986. Development impacts on water quality: A case study. J. Wat. Res. Planning
             Mngmnt. 112: 20-35.
                   Osborne, L.L. and M.J. Wiley. 1988. Empirical relationships between land
             use/cover and stream water quality in an agricultural watershed. J. Environ.
             Mngmnt. 26: 9-27.
                   Rogers, K.H., P.F. Breen and A.J. Chick. 1991. Nitrogen removal in
             experimental wetland treatment systems: Evidence for the role of aquatic plants. J.
             Wat. Pollut. Control Fed. 63: 934-941.
                   Sekine, M., M. Ukita and H. Nakanishi. 1991. Systematic pollutegraph
             simulation for real scale river basin. Wat. Sci. Tech. 23: 141-150.
                   Toppin, K.W., K.E. McKenna, J.E. Cotton, and S.M. Flanagan. 1994. Water
             resources data New Hampshire and Vermont Water Year 1993. USGS Report NH-
             VT-93-1.
























                                                     22





          Table 1. Rainfall amounts (cumulative) on 3 days preceding sample dates.




                         Precipitation (inches)                               Precipitation (inches)
            Sample Date      1 day    2 days     3 days          Sample Date      1 day    2, days    3 days
                 4/7/93       0.00      0.00       0.06             11/16/93       0.18      0.18      0.24
                4/12193       0.84      1.33       1.33             11/23/94       0.00      0.00      0.18
                5/25/93       0.00      0.00       0.05              12/7/93       0.00      1.55      1.55
                 6/1/93       0.00      0.00       0.00             12/13/93       0.21      1.15      1.15
                6/29/93       0.00      0.00       0.00               1/3/94       0.00      0.00      0.00
                6/30/93       0.13      0.13       0.13              1/26/94       0.00      0.07      0.07
                 7/7/93       0.00      0.00       0.00               2/1/94       0.00      0.00      0.00
                 7/8/93       0.00      0.00       0.00              2/15/94       0.00      0.90      0.90
                7/12/93       0.00      0.00       0.00              2/22/94       0.00      0.00      0.00
                7/13/93       0.00      0.00       0.00               3/1/94       0.00      0.00      0.00
                7/15/93       0.00      0.00       0.00               3/8/94       0.00      0.00      0.00
                7/20/93       0.00      0.00       0.00              3/15/94       0.00      0.00      0.00
                7/21/93       0.21      0.21       0.21              3/23/94       1.91      1.91      1.91
                7/27/93       0.00      0.00       0.00               4/5/94       0.23      0.23      0.23
                7/28/93       0.61      0.61       0.61              4/11/94       0.15      0.15      0.15
                 8/3/93       0.11      0.11       0.16              4/25/94       0.00      0.00      0.00
                8/10/93       0.28      0.28       0.28               5/9/94       1.31      1.37      1.37
                8/11/93       0.00      0.28       0.28              5/1 1/94      0.00      0.00      1.31
                8/12/93       0.00      0.00       0.28              5/18/94       0.25      0.85      0.85
                8/16/93       0.00      0.00       0.00              5/25/94       0.10      0.10      0.10
                8/17/93       0.00      0.00       0.00              5/31/94       0.00      0.00      0.00
                8/18/93       0.00      0.00       0.00               6/1/94       0.00      0.00      0.00
                8/24/93       0.00      0.00       0.00               6/6/94       0.00      0.00      0.00
                 9/8/93       0.00      0.00       0.00               6/7/94       0.00      0.00      0.00
                9/22/93       0.00      0.00       0.00               6/9/94       0.00      0.00      0.00
                9/29193       0.50      1.69       2.66              6/14/94       0.45      0.80      0.80
               10/18/93       0.00      0.00       0.00              6/20/94       0.00      0.00      0.00
                11/2/93       0.60      1.26       1.32              6/28/94       0.00      0.00      0.23
          1     11/9/93       0.00      0.00       0.14        1     6/29/94       0.28      0.28      0.28





                                   FIGURE 1

                         OYSTER RIVER, DRAINAGE  BASIN





                                           D 0 V E R






                 M   A D B     U
















                                      D  U   R  H, A   M


                            CA







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                                                           Ix           (DC


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                                                       tu



                                                       LU

                                        U                   _7DA        M
     Figure 2. Sample sites in the tidal portion of the Oyster River and the major tri



      Johnson CTeek @ra'tershed

         Figure 3. The Johnson' Creek watershed and sampag sites.






                                                      PAW







                                       Ho-ut
                                       Po-Ad              D  ver
                           M a d     r


                                        @O@L71
                                         O@Ln0





                                             paw
                                 Dur      M--'







                                                                          IT



              -BeaTds CTeek Watershed:
                F igur e 4. The Beards Creek watershed and sam@ling sites.


                                    I
                                                     Madbury


                                                  b




                              u




                                 -Du-rha7n
                                   Rese-r-uo


















          -%ir










                                             Figure 5. Average monthly rainfall in Durham, NH: 7/1/93-6/30/94.


                   6                                                                                                                M easured

                                                                                                                          ----O-..Normal


                   5






                   4
























                   0

                     July      Aug       Sept      Oct       Nov       Dec       Jan       Feb       Mar       Apr       May       June




  I
  I
  I
  I                        TABLES AND FIGURES
  I                             OBJECTIVE 1
  1
  1
  1                  1.
  I
  I
  I
  I
  I
  I
  I
  I
. I -
  I
  I                               -








               Table, 1-1. Bacterial indicator concentrations (per 100 ml) at sites in the Oyster River from 7/93 to 6/94.

               Fecal coliforms
               SITE                     OR I OR I OR2 OR3 OR4 OR5                       OR6 OR6 OR7 OR8 OR9 OR10 OR10 OR11 OR11 OR12 OR13
               Tide                     LOW HIGH LOW LOW LOW LOW                        LOW HIGH LOW LOW LOW                LOW     HIGH LOW HIGH LOW LOW
                           7fl/93       7                                               240                                 428
                          7/13/93       1.25                                            5                                   15
                          7/27/93       9.25 6.75                   49.5    66          70  5.5     54      14     78       22.5    93     372.5     11      91      0.5
                           8/3/93       29.8                                            32.5
                          8/10/93       1                           15.5    14          45                  8      52       30      1.5                              16.75
                          8/18/93       33.8 3                                          161 4                               100     29
                          8/24/93       1.25                                            15                                  75
                           9/8/93       4.25        6.5      1      16.5    20          25          23      0.75   32.5     0                8              2.75     1.25
                          9/22/93       5                                               51.5                                61
                         10/18/93       5.5                                             2.5                                 17
                          11/9/93       4.75 13                                         1   4.25                            12      203
                          5/11/94       14         25.5     27.5    50      22          6.3         1.8     0.25   67.5     55              65              0.5      6.5
                          5/18/94       16   15.5                                       63.5 67                             85
                          5/25/94       56                                              170                                 4533
                          5/31/94       9                                               23                                  30
                           6/9/94       29.5 2.5                    235                 195 11.3            0.25 227.5      55      98.8                              1
                          6/28/94       26                                              190                                 85
               Geom. ave.               8.37 6.33  12.87 5.24       43.10 25.25         32.68 9.33  13.08   1.39   72.65    63.87   38.18  57.86 11.00 5.00          2.33
               Std. dev.                3.38 2.29  2.63 10.42       3.02    1.95        5.12 3.24   5.87    6.79   2.05     4.44    6.95   6.84     1.00   14.20     4.27


               Enterococci
               SITE                     OR1  ORI   OR2 OR3          OR4 OR5             OR6 OR6    OR7      OR8    OR9      OR10    OR10   OR11 OR11       OR12      OR13
               Tide                     LOW HIGH LOW LOW            LOW LOW LOW HIGH LOW LOW                       LOW      LOW     HIGH   LOW HIGH LOW              LOW
                           7fl/93       13                                              19                                  10
                          7/13/93       3.75                                            5                                   0.25
                          7/27/93       7.25 2                      28      33.5        31.75 8.5   19.5    0.25   31.5     32      52      20       44     26.5     0.25
                           8/3/93       3.5                                             8.25
                          8/10/93       0.25                        1.5 0.75            3                   2.5    0.5      12.5           32.5                      0.25
                          8/18/93       12.753                                          57.254                              185.5   29









                            8/24/93     0.25   1                                       0.5     1                               12       12
                             9/8/93     1             1.25 0.25 9.75 3.25              2.25           3.5     4.75     16.5    16.75            11               2      0.25
                            9/22/93     8.5   11.5                                     6.5     9                               15.5     26
                          10/18/93      0.25   7                                       0.25    0.5                             146      19
                            11/9/93     0.25   4                                       5.5     0.25                            6        35
                            5/11/94     1.8           2.3     4.5       11     5.5     0.25           0.25 0.25        22.5    20               15              0.25    0.5
                            5/18/94     3     2.3                                      11.5    16                              16       24
                            1/11/04     56                                             39                                      1000
                            5/31/94     1.3                                            1                                       5
                             6/9/94     11.5   2                       22              16.5    0.5            0.25     31      13       0.25                            0.8
                            6/29/94     14.5                                           43                                      12.5
                 Gcom. ave.             2.78  2.56    1.70 1.06 9.98          4.60     5.46    2.33   2.57    0.71     11.26   18.18    10.72 14.89 44.00 2.37          0.36
                 Std. dev.              5.43  1.35    1.54 7.72 3.16          4.80     5.76    6.08   8.98    4.28     5.82    6.41     12.39  1.35    1.00    10.34    1.71


                 C. perfringens
                 SITE                   ORI   ORI OR2 OR3 OR4 OR5                      OR6     OR6    OR7     OR8      OR9     ORIO     ORIO ORII ORII         OR12     OR 13
                 Tide                   LOW HIGH LOW LOW LOW LOW                       LOW HIGH LOW LOW                LOW     LOW HIGH       LOW HIGH LOW              LOW
                            7/13/93     4                                              15                                      2.25
                            7/27/93     1.3   3.25                      5      4       0.5     3.5     8      17.5     8       6        6     0.25      1.5      7      1.25
                             8/3/93     7.5                                            14.5
                            8/10/93     6.25                            11     8       15.5                   82       16      8.5              4                       4.25
                            8/18/93     6.5    3                                       26      4                               7        29
                            8/24/93     3.5   3.5                                      11.5    4.5                             10       9.5
                             9/8/93     5              7       2     7,25 12.25        8.75           105     9.75     14      24.5             3                36     2.25
                            9/22/93     2     1.75                                     5.5     1.25                            9.5      3.5
                          10/19193      12    3.8                                      10,75   4.5                             7        9
                            11/9/93     8.25  5.25                                     7       4.5                             9        27
                            5/11/94     26            19.8     31     30.5     36      63.5           128.5   124      48.8    42.5             30               82     16.5
                            5/18/94     23.5  9.5                                      22.5    17.5                            60       12
                            5/25/94     11.5                                           40                                      38.8
                            5/31/94     12.5                                           33                                      41.3
                             6/9/94     9      3                        11             15      8              75       42.5    12.5     11                               2
                            6128/94     45                                             10                                      6
                 Geom. ave.             6.77  4.29 11-77 7.87 10.60 10.90 12.80 6.15 47.61 41.96 20.61                         12.12    15.08 2.82     1.50 27.44 3.31
                 Std. dev.              2.23  1.65 2.09 6.95          1.97 2.51        2.95    1.94 4.70 3.01          2.16    2.59     2.13  10.96 1.00        3.50    2.72








              Table 1-2. Annual and seasonal geometric means (per 100 ml) for bacterial indicators in the Oyster River: 7/93-6/94.


              Fecal coliforms
              SITE              OR1    ORI OR2 OR3          OR4 OR5 OR6 OR6 OR7 OR8 OR9 ORIO ORIO ORII ORII OR12 OR13
              Tide              LOW HIGH LOW LOW            LOW LOW LOW HIGH LOW LOW LOW                          LOW HIGH      LOW HIGH LOW LOW
                 GEO AVE           8      36     13     5     43     25      33      9       13       1     73      64     38       58     11   5      2
                 STD DEV           3      2      3      10    3      2       5       3       6        7     2       4      7        7      1    14     4
                   Summer          5      5      7      1     23     26      41      5       35       4     51      56     16       55     11   16     2
                   Autumn          5      13                                 5       4                              23     203
                   Spring          21     6      26     28    108    22      62      28      2        0     124     120    99       65          1      2


              Enterococci
              SITE              ORI    ORI    OR2     OR3   OR4     OR5     OR6     OR6     OR7 OR8        OR9    ORIO ORIO ORII ORII OR12 OR13
              Tide              LOW   HIGH LOW       LOW    LOW     LOW    LOW     HIGH LOW LOW            LOW    LOW   HIGH LOW HIGH LOW LOW
                 GEO AVE           3      3      2      1     10     5       5       2       3        1     11      18     11       15     44   2      0
                 STD DEV           5      1      2      8     3      5       6       6       9        4     6       6      12       1      1    10     2
                   Summer          2      2      1      0     7      4       7       6       8        1     6       11     39       15     44   7      0
                   Autumn          1      4                                  2       0                              24     35
                   Spring          6      2      2      5     16     6       7       3       0        0     26      25     0        15          0      1

              Clostridium perfringens
              SITE              ORI ORI OR2 OR3 OR4                 OR5 OR6 OR6 OR7 OR8                    OR9    ORIO ORIO ORII ORII OR12 OR13
              Tide              LOW HIGH LOW LOW LOW                LOW LOW HIGH LOW LOW                   LOW    LOW HIGH LOW HIGH LOW LOW
                 GEO AVE           7      4      12     8     11     11      13      6       48       42    21      12     15       3      2    27     3
                 STD DEV           2      2      2      7     2      3       3       2       5        3     2       3      2        11     1    3      3
                   Summer          4      3      7      2     7      7       9       4       29       24    12      6      13       1      2    16     2
                   Autumn          6      5                                  7       5                              8      27
                   Spring          12     5      20     31    18     36      26      12      129      96    46      26     11       30          82     6







          TABLE 1-3. NH4 CONCENTRATIONS FOR THE OYSTER RIVER TRANSECT STATIONS 7/93-6/94



               NH4              OR1 H OR1 L          OR2 L OR3 L OR4 L OR5 L OR6 H OR6 L                         OR7 L OR8 L OR9 L OR1 0 H OR1 0 L                 OR11L OR12L OR13L
                      7/7/93                  6.17                                                        4.58                                               3.37
                     7/13/93                  1.54                                                        0.35                                               0.16
                     7/21/93                  4.58                                                        7.55                                               3.09
                     7/27/93       1.52       8.93                        13.35     10.91       4.38     23.25     18.61     25.85      6.25     14.36     14.43       0.85      36.50     0.54
                      8/3/93                  1.44                                                       19.06
                     8/10/93                12.36       0.321     0.59       0.53     0.141               0.92      4.32       0.46     0.28                 0.02      3.92       0.51     4.15
                     8/18/93                  1.03                                                       19.97                                               8.94
                     8/24/93       7.00       0.63                                              1.041     3.07                                   10.06     18.37
                      9/8/93                37.68      11.77     58.83    30.24     23.48                29.09     61.39   998.36       39.72              15.06       2.77    112.04      11.24
                     9/22/93       3.54     23.45                                              16.00     28.56                                   39.90     29.68
                    10/18/93       9.03       7.45                                              2.98     34.65                                   27.14     11.19
                     11/9/93       2.56     13.73                                               7.44     10.44                                     4.41    13.54
                     5/11/94                  6.28      5.22      5.84      6.67      6.95                8.74     40.74   106.63       5.71                 3.59      7.62      12.34     9.30
                     5/18/94       4.43       7.50                                              8.25      5.15                                      5.13   12.80
                     5/25/94                14.60                                                         7.84                                             11.43
                     5/31/94                12.04                                                         9.53                                               5.83
                      6/9/94       6.86       9.60                        13.80                 3.71     14.77             186.39       6.67     15.77       9.34                          2.28,
                     6/28/94                  6.52                                                        7.28                                               9.32
                                                                                 1                             1
               1 MEAN              4.99       9.75       5.77    21.75    12.921    10.371      6.26     13.041    31.261  263.54       11.731   16.681    10.01       3.79      40.35     5.50





                TABLE 1-4. N03 CONCENTRATIONS FOR THE OYSTER RIVER TRANSECT STATIONS 7/93-6/94


                         N03
                             DATE       OR1 H OR1 L         OR2 L OR3 L OR4 L ORS L OR6 H OR6 L                     OR7 L OR8 L OR9 L ORI 0 L             OR11 L OR12L OR13L
                               7/7/93                1.40                                                    8.67                                   2.08
                             7/13/93                 0.17                                                    1.06                                   0.06
                             7/21/93                 1.75                                                    1.42                                   0.58,
                             7/27/93       0.00      0.64                        1.77               0.771    2.14                1.25     2.91      1.371                       1.19
                               8/3/93                2.35                                                    3.44
                             8/10/93                 0.97     0.70     0.60      6.79     3.81               9.24    11.20 304.67         0.00      0.71     2.16     25.23     0.00
                             8/18/93                 1.61                                                    6.23                                   1.46
                             8/24/93       1.21      1.91                                           1.19     3.65                                   2.92
                               9/8/93                1.28     1.06     0.03      1.75     0.53               1.13      2.70      0.92     2.87      1.36     3.80       1.26    0.95
                             9/22/93       1.32      2.05                                           1.911    3.11                                   5.331
                             10/18/93      3.51      6.79                                           6.16     10.71                                  6.761
                             11/9/93       6.78      4.66                                           4.70     5.90                                   7.97
                             5/11/94                 2.02     2.89     1.63      2.40     2.34--             5.59      9.29     71.58     9.05      7.95     8.04      8.74     1.84
                             5/18/94       2.30      4.68                                           8.91     6.75                                   7.48
                             5/25/94                 4.41                                                    2.89                                  14.16
                             5/31/94                 8.79                                                    9.96                                  11.55
                               6/9/94      3.36      0.16                        5.08-              1.51     4.89               82.25     3.23      7.321                       4.25
                             6/28/94                 0.28                                                    3.31                                   3.65
                                                         1                                                                   -
                         MEAN              2.641     2.551    1.551    0.76      3.56     2.23      3.59     5.00      7.73     92.14     3-61      4.86     4.661 11.741       1.651







           TABLE 1-5. P04 CONCENTRATIONS AT THE OYSTER RIVER TRANSECT STATIONS 7/93-6/94



              DATE
             P04               OR1 H OR1 L          OR2 L OR3 L OR4 L OR5 L OR6 H OR6 L                           OWL OR8L OR9L OR10H OR10L                          OR11H OR11L OR12L OR13L
                    7/7/93                  1.06                                                          1.70                                                 1.22
                   7/13/93                  1.12                                                          1.55                                                 1.40
                   7/21/93                  1.21                                                          3.40                                                 1.32
                   7/27/93        0.82      1.76                           2.89       2.96      1.47      4.161      4.65       3.35     1.73       2.95       2.43     0.33       0.43       6.34      1.12
                    8/3/93                  1.751                                                         2.361                     1                               1
                   8/10/93                  1.321      1.63      1.571     1.94       1.79                1.92       2.75    17.15       1.93                  1.82                0.30       3.21      1.03
                   8/18/93                  1.821                                                         2.75                                                 1.95
                   8/24/93        1.06      1.801                                                         2.93                                      3.26       2.94
                    9/8/93                  2.361      2.87      1.88      4.71       4.64                5.14       7.25    79.24       5.36                  3.57                0.26     10.36       1.41
                   9/22/93        1.26      1.80                                                1.61      2.51                                      3.15       3.15
                  10/18/93        1.11      1.28                                                1.03      1.911                                     2.57       1.901
                   11/9/93        0.92      1.91                                                1.32      1.631                                     0.96       1.64
                   5/11/94                  0.57       0.67      0.76      0.951      1.08                1.601     10.13    37.601      1.13                  0.58                0.52       2.951     0.23
                   5/18/94        0.58      1.00                                                1.29      0.79                                      0.50       0.53
                   5/25/94                  0.801                                                         1.32                                                 0.84
                   5/31/94                  0.84                                                          1.86                                                 0.60
                    6/9/94        0.85      1.15                           1.38                 0.68      0.97               24.16       1.34       1.23       1.10                                       .8
                   6/28/94                  1.27                                                          0.60                                                 2.04

                                                                                                                     6.191   32.301      2.301      2.09       1         0.331     0 q R
              MEAN           1    0.94      1.38       1.721     1 401     2.371      2.621     1.281     2.171                                                  .71                     1    5.71      0.92





                 Table 1-6. Calculated loading of dissolved inorganic N and P from the Tributaries to the Oyster River and the Durham POTW


           Beards Greek                                                                                                                                                                                      I
                                    low Flow m3lyr high flow m3/yr average m3/yr Adj Average m3/yr avg liters/yr             Mean mq1L N             kg N/yr    POTW- T N kg/yr Mean P04 mg/L kg P/yr        POTW Total kg/yr P
                                             1261.44     4257360.00 21293107.20            18921055.06      18921055057.92                     0.31     5865.53                               0.036   681.16


           Unnamed Creek
                                              630.72      256703.04      1286668.80          1143333.90      1143333895.68                     0.74      846.07                            0.0194       22.18


           Johnson Creek
                                          200884.32         7221744      37113141.6        32988387.04         32988387043                     0.26     8576.98                            0.0248     818.11


           Bunker Creek
                                           38158.56      1302436.80      6702976.80          5956265.18      5956265184.48                     0.23     1369.94                            0.0355     211_45

           Oyster River (main stem)
                                                                                              49511520      49511520000.00                     0.24    11882.76                            0.0139     688.21             8207.27



                                                                                                                             Total N from tributaries  28541.28           25985 Total kg/yr P NPS    2421.11

                                                                                     TI kglyr N-NPS      TI kg/yr N-POTW     TI kg/yr Wall sources

                                                                                              28541.28             25985.00                54526.28


                                                                                     % N-NPS             % N-POTW


                                                                                                   52.34               47.66


                                                                                     TI kglyr P-NPS      TI kglyr P-POTW     Total kglyr P-all sources


                                                                                                2421.11             8207.27                10628.38


                                                                                     % P-NPS             % P-POTW

                                                                                                   22.781              77.22
                                                                                                                                                                                                             IPOTW Total k I r P





          Table 1-7. Estimated amount and % contribution of dissolved inorganic N and P to the Oyster River





                                                    kg N/yr % N of NPS % N of Total*            kg P/yr % P of NPS % P of Total



                  Beards Creek                       5865.53       20.55%          10-76%        681.16         28-13%         6.41%



                  Unnamed Creek                       846.07         2.96%           1.55%         22.18         0.92%         0.21%



                  Johnson Creek                      8576.98       30.05%          15-73%        818-11         33.79%         7.70%



                  Bunker Creek                       1369.94       11.53%            2.51%       211.45          8.73%         1.99%



                  Oyster River (main stem)          11882.76       41.63%          21.79%        688.21         28.43%         6.48%


                  Total kg/yr NPS                   28541.28                       52-34%        2421.11                      22.78%

                  kg/yr POTW                           25985                       47-66%        8207.27                      77.22%

                  Total kgN/yr                      54526.28                                    10628-38






           TABLE 1-8. ESTIMATED ANNUAL LOADING OF FECAL COLIFORMS AND ENTEROCOCCI FROM THE
           OYSTER RIVER TRIBUTARIES AND THE DURHAM POTW



                                          FC x one billion/yr ENT x one billion /yr % OF TOTAL FC % OF TOTAL ENT



                      Beards Creek                 4,940                    1,306                 9.56%               4.30%



                      Unnamed Creek                  72                     348                   0.14%               1.15%



                      Johnson Creek                11,600                  10,556                 22.44%              34.78%



                      Bunker Creek                 2,690                    774                   5.20%               2.55%



                      Oyster River                32,300                   17,329                 62-49%              57.09%


                      POTW                          86                       41                   0.17%               0.14%










                     Figure 1-1. Geometric average fecal coliform and enterococci concentrations along a transect in the
                              Oyster River from 7/93 to 6/94. High tide samples are site #s followed by H.


             80

                                  -M- Fecal coliforms
             70                          Enterococci

             60




             50




             40

           CL

           U 30


             20,


             1.0


               0

                                en              I'D  Cq   00              CD
                     0     0    0    0     0    0         0     0
                0                                    0                    0          0
                                                                                                0










                               Figure 1-2. Geometric average C. perfringens concentrations along a transect in the Oyster River
                                                 from 7/93 to 6/94. High tide samples are site #s followed by H.


                   50


                   45



                   40



                   35



                   30



                   25

                CL

                U  20


                   15



                   10



                     5



                     0

                                                                                  00
                                                                                  C4                                                   CD
                              0       0                                           0       0      0










                   Figure 1-3. Seasonal geometric average fecal coliform concentrations along a transect in the Oyster
                             River from 7/93 to 6/94. High tide samples are site #s followed by H.


              250-1






               200-
                                 El Annual


                                   summer


                150-               Autumn

                                   Spring



            U 100-






                50-






                0
                   OR13 ORI OR2  OR3 OR4  OR5 OR6  OR12 OR8 OR7 OR9   ORIO OR11 ORIH OR6H ORIOH










                           Figure 1-4. Seasonal geometric average enterococci concentrations along a transect in the Oyster
                                        River from 7/93 to 6/94. High tide samples are site #s followed by H.


                     4 0-




                     35-
                                           El Annual

                     30-                     Summer


                                             Autumn
                     25-
                                             Spring


                     20-



                 U
                     15-




                     10-




                       5-



                      0 -                                                              If
                         OR13 ORI     OR2 OR3      OR4   OR5   OR6   OR12 OR8 OR7 OR9         OR10 OR11   ORM OR611 OR10H











                          Figure 1-5. Seasonal geometric average C. perfringens concentrations along a transect in the
                                 Oyster River from 7/93 to 6/94. High tide samples are site #s followed by H.


                  140-1




                   120-

                                      El Annual

                   100-               12N, Summer


                                         Autumn

                   80-                   Spring


                   60-




                   40-




                   20-
                                                    61
                                                 ;:z::                                                   @i@.
                     0-                                T
                       OR13 ORI OR2 OR3 OR4 OR5 OR6           OR12  OR8   OR7  OR9 ORIO   ORII ORM OR6H OR10H



























                      FIGURE 1-6. MEAN NI-14 CONCENTRATIONS FOR THE OYSTER
                                 RIVER TRANSECT STATIONS 7/93-6/94


                        300.00'

                     2
                     ::L 250.00-
                     z
                     0  200.00-
                  Z  <
                  z     150.00-

                  L
                     z
                   u
                  2  oul 100.00-
                     z
                     C)   50.00-

                          0. o o

                                         c\j  co  "It  Lo  (D       co           c>
                                         Ir   Ir  cr   cr  cr       CC  CC   cr
                                 Ir
                                 0   0   0    0   0    0   0        0   0    0   cr
                                                               0                 0    0

























                      FIGURE 1-7. MEAN N03 CONCENTRATIONS FOR THE OYSTER
                                 RIVER TRANSECT STATIONS 7/93-6/94


                        100.00-/
                          90.00-
                      =L  80.00-
                      z
                  cn  0   70.00-
                  0
                  Z       60.00-
                  Z       50.00-
                  Lu  Z   40.00-
                      Lu
                      ()  30-00-
                      z
                      0)  20.00-
                          10.00-
                             o o

                                                   11'  LO  (.0       QO  I-   M

                                      0   C)   0   0    0   0        0    0    0
                                 0                               0                 0    0























                   FIGURE 1-8. Mean P04 Concentrations at the Oyster Riv
                                Transect Stations 7/93- 6/94


                      35.00-/

                      30.00-

                      25.00-

                 0    20.00-
                 C.)2
                 IRT =L 15.00-
                 0
                      10.00-

                       5.00-

                        0.00-
                                                              -j   --j    j
                                    CQ  M "t LO (D     N   M  r'- M   0
                                CC  cl: x m m M        -   M  = M     -
                            0   0   0  0 0 0 0         m   0  0 0     m
                                                       0              0   0

























                        FIGURE 1-9. SEASONAL MEAN NI-14 CONCENTRATIONS FOR
                                 THE OYSTER RIVER TRANSECT STATIONS



                          350-00-1

                          300.00-
                       =L                     El summer
                       z  250.00-
                                                 Fall
                          200.00-
                    z =
                    <     150.00-                Spring
                    LU z
                       LU
                       0  100.00-
                       z
                       0
                            50.00-

                             0.00-
                                   co       cli  co       Lo   (D                0)
                                   0    0   0    0    0   0    0        0    0   0
                                                                   0                  0   0
























                      FIGURE 1-10. SEASONAL MEAN N03 CONCENTRATIONS FOR
                          TYHE OYSTER RIVER TRANSECT STATIONS 7/93-6/94



                         120.00-1
                  z
                  0
                         100.00-

                  cc
                                                  summer
                  z       80.00-
                  w                            17
                  0                            M... Fall
                  62      60.00-
                  0
                  0
                  M       40.00-                  Spring
                  0
                  z
                  z
                  <       20.00
                  LU
                            0.001
                                 co       C\j M 'It      Lo (o
                                      Ir       M M       M  M
                                      0        0 0       0  0        0   0 o
                                 0                              0                 0    0





















                      FIGURE 1-11. Seasonal Mean Po4 Concentrations for Oysl
                                    River Transect Stations 7/93-6/94



                        35.00-1
                     =L
                        30.00-
                     .2                        Summer
                        25.00-
                                               Spring
                        20.00-

                     0
                     () 15.00-                 Fall
                     00 10.00-

                         5.00
                         0.00                                  ;=7
                                                           -i   -i  -j
                                CY)      C\1  M            (0   C\1 CO   N    (n  C)
                                    cc   Cc   C:  Ir  Ir   C:       M    M   X    -
                                    0    0    0   0   0    0        0    0   0    Cc   M
                                0                               0                 0    0

















                      FIGURE 1-12. ESTIMATED ANNUAL CONTRIBUTION OF
                          DISSOLVED INORGANIC N IN THE OYSTER RIVER



                  30000'



                  25000-


              z
              a   20000-
              Lu
              0
              U)
              Ln  15000-



                  10000-



                   5000-





                            ui
                            co




















                      FIGURE 1-13. ESTIMATED ANNUAL CONTRIBUTION OF
                         DISSOLVED INORGANIC PIN THE OYSTER RIVER



                 9000--l'


                 8000-


                 7000-


                 6000-
              Lu
              >
              -j
              0  5000-
              (n
              cn
              5  4000-
              cc

                 3000-


                 2000-


                 1000-


                    0

                           w
                           co                             cn














                                FIGURE 1-14. ESTIMATED ANNUAL LOADING OF FECAL COLIFORMS AN[
                                                   ENTEROCOCCI IN THE OYSTER RIVER



                               35,000-/


                               30,000-
                                                             FC x one billion/yr
                            .2 25,000-r
                                                             ENT x one billion /yr
                               20,000-
                            0

                            cn 15,000-

                            Lu
                               10,000-


                                 5,000-
                                                                                   Z771
                                                                       .iX
                                                                                  Lk
                                    0



                                                                                   0              cc        a_
                                        cn                           c
                                                       0)            0              a)             a)
                                        al             E             (n
                                        0)             cz            c:
                                        co
                                                                                                  0










                                                                                              30 '0
                                                                                              28.0                                                                            Stations 1 and 2
                                                                                              26.0.                                                                          Upstream from Treatment Plant
                                                                                              24,0                                N03.NH4-1
                                                                                              22-0                                N03.NW-2
                                                                                              20.0
                                                                                   u          18.0
                                                                                              16.0
                                                                                              14.0-
                                                                                              12.0-.
                                                                                              10.0-
                                                                                              8.0
                                                                                              6.0
                                                                                              4.0
                                                                                              2.0
                                                                                              Ox
                                                                                                       1        2            3         4          5          6         7          8       .9          10         1 1        12
                                                                                                                        F.11i.g                                                           Rising
                                                                                                                                                        HOUR

                                                                                   Figure 1.11 Total nitrogen content (ammoniiam and nitrate concentrations (uM)) at Stations I and 2. upstrean% fimm the
                                                                                   Sewage Treatment Plant.






                                                                                              750.0
                                                                                              700.0-
                                                                                              650.0-                                                                                  Sewage Treatment Plant
                                                                                              600.0-,                             N03.NH4-3
                                                                                              550.0
                                                                                              500.0
                                                                                              450.0-
                                                                                              400.0
                                                                                              350.0-
                                                                                              300.0-
                                                                                  Z           250.0-,
                                                                                              200.0-.
                                                                                              150 '0
                                                                                              100.0
                                                                                              so.
                                                                                              0.0
                                                                                                       1        2            3         4          5          6         7          8        9          10         1 1        12

                                                                                                                                                                                          Rising
                                                                                                                                                        HOUR

                                                                                              Figure 1-16. Total nitrogen content (ammonium and nitrate concentrations NMI) at Station 3,
                                                                                              the Sewage Treatment Plant.







                                                                                              75.0-
                                                                                              70.0-
                                                                                              65.,-'                      N03.NIIA4                                     Stations 4 and 5
                                                                                              60.0-'                      N03.NH4-5                                     Downstream from Treatment Plant
                                                                                              55.0-
                                                                                              50.0-
                                                                                              45.0-
                                                                                              40.0-.
                                                                                              35.0-
                                                                                              30.0-
                                                                                              25.0-
                                                                                              20.0..
                                                                                              15.0
                                                                                              i0.0 -
                                                                                              1.0
                                                                                              0.0      1        2            3                    5@         6         7          8        9          10         1 1        12
                                                                                                                        Falling                                                           Rising
                                                                                                                                                        IlOl!R

                                                                                              Figure 1-17. Total nitrogen content (ammuni@ and nitrate concentrations (uM)) at Stations 4                               and 5@
                                                                                              downstream from the S-ge Treatment Plartt.
                                                                                                                                  ,W
                                                                                                                                                                                                                 tment@
                                                                                                       @NZN                                                             &o,@nstrejm from Tr@eal







                                                                                              2&0 -
                                                                                              24.0-.               -0- N114-1                                             Stations 1 and 2
                                                                                              210.,                                M14.2                                  Upstream from Treatment Plant
                                                                                              20.0.
                                                                                                                                   N03-1

                                                                                                                                   N03 2
                                                                                              16.0.

                                                                                              14.0

                                                                                              120-
                                                                                      z       10.0-
                                                                                              &.0-
                                                                                              &0   ,.

                                                                                              4.0-
                                                                                              2.0
                                                                                              U                                              ....
                                                                                                        1          2         3            4        5                      7          8        9         10         1 1        12
                                                                                                                          Falling                                                            Riti.g
                                                                                                                                                           HOUR


                                                                                              Figurel-M Ammonium and nitrate concentrations (u.M) at Stationsland Zup6tMMcdLhe Sewage Treatment PlartL






                                                                                              750.0-
                                                                                              700.0-                                                                                 Sewage Treatment Plant
                                                                                              650.0-                               N114-3
                                                                                              600.0                                N03-3
                                                                                              550.0
                                                                                              500,0-
                                                                                              MO
                                                                                              400.0
                                                                                              35(XO-.
                                                                                 z            30(10,
                                                                                 1            25010'
                                                                                              20(10 -
                                                                                              150.0.
                                                                                              100.0.,
                                                                                              510.0 --
                                                                                              0.0  1
                                                                                                       1                     3                               6            7          8       9         10          11         12
                                                                                                                         F.lli.g                                                            Rising
                                                                                                                                                          HOUR


                                                                                              Figum 1.19. Amumoniuxii and nitrate concentrations (uM) at Station 3, the Sewage Tmatcrumt PlanL










                                                                                              70.0-
                                                                                              65.0-                       N'114 4                                     Stations 4 and 5
                                                                                              60.0.:                                                                 Downstream from Treatment Plant
                                                                                              55.0-              jC,       N114-5
                                                                                                                           1,1034
                                                                                              50.0-
                                                                                              45.0-                        N03-5
                                                                                              40.0-
                                                                                              35.0-
                                                                                              30.0-

                                                                                              25.0-
                                                                                              20.0-
                                                                                              15.0*
                                                                                              10.0-
                                                                                              5.0,
                                                                                              0.0.
                                                                                                      1          2          3             4       5          6            7          8        9         10         1 1        12
                                                                                                                         Falling                          HOUR                               Rising

                                                                                              Figure I-ZM Ammonium and nitrate concentrations ONO at Station. 4 and 5@ downstream from the Sewage T-troterd
                                                                                              Plant.
                                                                                                                                                                                                                      ----    A-






                                                                                      7.0-                                                   Stations 1 and 2
                                                                                      &3 -.                                                  Upstream from Treatment Plant
                                                                                      &0,
                                                                            i                                                                                                      P04-1
                                                                                      5.01                                                                                         P04-2
                                                                                      4.5-

                                                                                      4.0-
                                                                            C,        3.5
                                                                                      3.0-
                                                                                      2.5.
                                                                            c         10"
                                                                                      5'


                                                                                      0.5
                                                                                      0.01
                                                                                         1        2         3        4        5        6        7          8       9       10        1 1      1
                                                                                                        F&IIing                                                  Rising
                                                                                                                                      HOUR


                                                                            Figure 1-2L Phosphate concentrations, (uM) for Stations I and 2, upstream from the Sewage Treatment Plant.







                                                                                      3110-






                                                                                      20LO -
                                                                                                                                                    Sewage Treatment Plant
                                                                                      15.0

                                                                                                                                                                         P04-3
                                                                         u

                                                                         I
                                                                         0

                                                                                      5.0


                                                                                      ao                                                                                             L
                                                                                        1        2         3        4        5        6         7          8      9        10       1 1      12

                                                                                                                                                                [email protected]
                                                                                                                                     HOUR


                                                                                      Figure 1-22. Phosphate Concentrations (04) at Station 3, the Sewage Treatment Plant.










                                                                                      9.0-
                                                                                      7.0-              P044                                 Stations 4 and 5
                                                                                             ---A- P04-5                                     Downstream from Treatment Plant
                                                                                      6.0-


                                                                                      5.0.


                                                                                      4.0-


                                                                                      3.0-


                                                                                      2.0


                                                                                      1.0


                                                                                      0.0
                                                                                        1       2         3        4        5        6         7         8       9        10       1 1      12
                                                                                                      Falling                                                  Rising
                                                                                                                                    HOUR


                                                                            Ftgwe 1.23. Phosphate concentrations (uM) at Stations 4 and 5, downstream of the Sewage Treatment Plant.
                                                                                                                                                    S
                                                                                                                                                           .9
                                                                                                                                                         W




 I
 I
 I
 I                        TABLES AND FIGURES
 I                             OBJECTIVE 2
 1
 1
 1                                       ..
 I
 1. ,
 I
 I
 I
 I
 I
 I
 I
 I
 I







               Table 2-1. Indicator concentrations and geometric means (per 100 ml) in Johnson Creek: 7/93-6/94.


              Fecal coliforms
                    DATE             1       2       3       4        5        6        7         8       9       10       11       12      12A     13
                    7/7/93                   85      745     1250              495     400      550       590
                    7/12/93          13      28      2420    1400              450     475      205       815     795      550
                    7/20/93          23      14      780     7890              4640    2405     385       460     230
                    7/28/93                  60                                                 445
                    8/12/93                  190     850     300               600     390      60        110     215      105
                    8/16/93          5       25      100     700               600     570      60        175     85       113
                    9/29/93                          412     210    4000       400     245      236       328     234      733      420
                    11/2/93          85      264     70      160     80        111     120      365       35      43       45       60      120
                    1/26/94                          3,0
                    2/1/94                           5.0
                    2/22/94                          22.8                                                 26.0                              27.5
                    3/1/94                           30.5                              42.5                                                 105.0
                    3/8/94                           126.3                             75.0               53.5                              85.0
                    3/15/94                          22.5    14.0    5.0       20.0    115.0    26.0      45.0             59.0     0.5     117.5
                    4/11/94        35.5      9.0     93.8    1.0     3.5       13.8    6.0      9.5       10.0    4.0      54.0             35.0    0
                    6/1/94         28.0 105.0        50.0    1500.0 53.0 318.0         55.0     61.0      68.0    31.5     85.0     23.5    1.3     0
                  GEO AVE         22.25 51.04        95.20   269.83 49.49 260.70       163.3 )6 122.14  106.30    89.82  124.58 23.33       39.55  0.00
                  STD DEV          2.62 3.19 6.96 13.44             16.77      5.57    4.71     3.76      3.98    5.11     2.88 16.93       5.13


              Enterococci

                    DATE             1       2       3       4        5        6        7         8       9       10       11       12      12A     13
                    7/7/93                   15      240     585               845     330      160       155
                    7/12/93          28      59      890     1220              1170    1530     235       508     400      293
                    '7/20/93         35      70      1330    12700             8050    132      400       460     175
                    7128/93                  16                                                 300
                    8/12/93          23      26      150                       1       230      85        90      70       48
                    8/16/93          57      7       60      1000              100     720      50        65      35       55
                    9/29/93                          265     135     336       84      108      160       36      64       78       55









                    11/2/93        23      144    110      150      80     138      165      200      40       8      50       179    59
                    1/26/94                       0.5                               3.8
                    2/1/94                        8.8
                    2/22/94                       55.0                                                6.5                             9.0
                    3/1/94                        7.3                                                                                 95.5
                    318194                        109.0                             83.0              37.5                            42.5
                    3/15/94                       20.0     1.5      45.0   3 .8     2.5      18.5     14.5            22.01    1.0    47.5
                    4/11/94        3.5     6.5    3.8      1.0      1.3    2.5      0.5      4.5      5.5      2.0    13.0     0.5    7.0
                    6/1/94         3.8     61.5   80.0     35.5     29.0   65.8     25.8     25.5     19.5     27.7   7.0      3.0    7.0   173.0
                  GEO AVE          16.8    27.9   53.6     128.8    33.8   70.1     59.5     83.1     47.0     38.2   39.5     6.8    24.3  173.0
                  STD DEV          3.0     3.0    8.3      22.6     7.9    20.2     11.3     4.0      4.3      5.4    3.2      12.9   3.1


              Clostridium pe 'ngens
                    DATE            1       2      3       4        5       6        7        8       9        to     11       12     12A     13
                    7/12/93        6.00    18.00  1.25     7.50            3.50     4.50     5.50     12.50    10.50  8.50
                    7/20/93        7.50    8.00 0.75       2.00            5.50     45.00    6.50     7.50     8.00
                    8/12/93        5.50    2.00   52.50    9.50            2.50     0.50     8.00     5.50     5.00   4.00
                    8/16/93        1.50    2.00   4.00     7.00            3.75     0.50     1.50     2.00     0.50   2.00
                    11/2/93        10.50   10.50  12.00    1.00     16.00  7.00     10.50    17.50    21.00    25.00  5.50     4.00
                    1/26/94                       16.0                                                                                        2.0
                    2/1/94                        14.0
                    2/22/94                       29.5                                                38.0                            36.8
                    3/1/94                        46.7                              21.0                                              20.0
                    3/8/94                        102.5                             60.0              0.5                             0.5
                    3/15/94                       36.3     7.0      46.3   42.5     27.5     13.0     8.8             20.5     3.0    21.3
                    4/11/94        9.5, 11.5      8.0      7.5      12.5   15.0     2.5      1.3      5.0      1.5    18.5     2.5    2.0     14.0
                    6/1/94         0.5     7.5     5       11.5     5.0    15.0     5.5      4.5      8.0      1.5    16.0     0.5    14.0    1.0
                  GEO AVE          4.1     6.6    12.0     5.3      14.7   7.7      6.9      5.2      6.5      3.8    8.1      2.0    7.8     3.0
                  STD DEV          3.1     2.4    4.3      2.3      2.5    2.6      5.6      2.6      3.3      3.9    2.4      2.5    5.3     3.9








             Table 2-2. Annual and seasonal geometric means (per 100 ml) for bacterial indicators in Johnson Creek: 7/93-6/94.


             Fecal coliforms
                                  1     2      3       4      5      6       7       8       9      10      11        12
                 GEO AVE          22    51     95      270    49     261     163     122     106    90      125       23
                 STD DEV          3     3      7       13     17     6       5       4       4      5       3         17
                  Summer          11    46     654     1237          821     633     203     336    240     187
                  Autumn          85    264    170     183    566    211     171     293     107    100     182       159
                  Winter                       18      14     5      20      72      26      40             59        1
                  Spring          32    31     68      39     14     66      18      24      26     11      68        24


             Enterococci
                                  1     2      3       4      5      6       7       8       9      10      11        12
                 GEO AVE          17    28     54      129    34     70      60      83      47     38      40        7
                 STD DEV          3     3      8       23     8      20      11      4       4      5       3         13
                  Summer          34    24     303     1735          209     406     164     184    114     91
                  Autumn          23    144    171     142    164    108     133     179     38     22      62        99
                  Winter                       13      2      45     4       9       19      15             22        1
                  Spring          4     20     17      6      6      13      4       11      10     7       10        1

             Clostridium perfringens
                                  1     2      3       4      5      6       7       8       9      10      11        12
                 GEO AVE          4     7      12      5      15     8       7       5       7      4       8         2
                 STD DEV          3     2      4       2      2      3       6       3       3      4       2         3
                  Summer          4     5      4       6             4       3       5       6      4       4
                  Autumn          I I   11     12      1      16     7       11      18      21     25      6         4
                  Winter                       32      7      46     43      33      13      5              21        3
                  Spring          2     9      6       9      8      15      4       2       6      2       17        1





           TABLE 2-3. AMMONIUM CONCENTRATIONS AT THE JOHNSON CREEK STATIONS 4/93-6/94


                          DATE          1      2       3        4       5      6      7      8      9      10     1 1     12     12A    13
                            4/7/93 5.12        8.61    5.95                   3.95                 3.13                   3.80
                           4/12/93     4.44    4.06    7.15                   7.53                 2.99                   2.35
                           5/25/93     6.50  12.35     10.29    6.27   3.22   5.82          4.26   3.11
                            6/1/93     14.30 16.11     1.79            2.31   4.94   2.49   4.05   2.67    5.95  10.12
                           6/29/93     1.98,   2.73    5.29     6.56  36.52   3.98   5.76   4.84   6.561   5.03   3.92   15.14
                            7/7/93             4.35    4.96    28.54          4.401  5.87   5.11   5.82
                           7/20/93     1.00    2.38    1.91     6.93          4.021  7.70   5.72   2.78   '1.19
                           9/29/93                     2.70     5.30   3.58   2.74   6.49          6.79    9.05   5.13           2.84
                           11/2/93     15.70   5.69    0.49     2.27   0.46   0.90   0.51   2.37   0.65    0.66   0.601   0.46
                           12/13/93                                                              1 2.18           1.991
                           3/15/94                     3.67     2.43   3.06   2.54   4.80   8.79   7.99           1.10    4.61   0.65
                            4/5/94                                                                         1.97   2.18    1.53   0.41
                           4/11/94     2.93    5.38    3.11,    2.08   0.53   3.61   6.76   2.68   4.48    0.78   1.11    2.54   0.81   1.03
                           4/25/94                                                                 1.50    1.17   1.20
                            6/1/94     5.42  11.67    4.236    7.649   1.90   5.49   2.16   4.63   2.78    1.91   2.73    2.06   2.49   3.13
                           6/29/94                                                                         3.25   4.31

                    MEAN            1 6.38   7.33  1 4.29 1   7.56 1  6.45  1 4.16   4.721  -4.721  3.821  3.101 3.12  1 4.06    1.44  2.08
                                    Ll @98
                                       1.00



  mmmm mmm = m mmmm =
          TABLE 2-4. NITRATE CONCENTRATIONS AT THE JOHNSON CREEK STATIONS 4/93-6/94


                DATE                  1      2          3         4         5       6        7         8        9       10       1 1      12 12A           13
                     4/7/93      9.93 11.64       15.76                       15.07                       15.58                         3.44
                    4/12/93      9.97   10.03     10.41                       10.81                       11.92                         0.69
                    5/25/93      4.56    -6.99     9.28      79.71    0.84    24.67              26.49    29.39
                     6/1/93      5.31    5.25      3.48               1.90      7.80      9.79   11.85    12.65     20.16    12.20
                    6/29/93      4.09    1.95     13.58      33.97    4.96    35.28    49.79     34.821   35.63     32.62    30.65,     1.08
                     7/7/93              4.84     29.99      53.60            53.18    37.80     13.91    39.01
                    7/20/93      1.70    0.74      7.32      15.60            45.04    37.88     12.33    18.91       2.85
                    @9/29/93                       5.96      54.52    37.401  24.94       8.51            25.09       1.18   29.87              79.72
                    11/2/93      3.32   -12.18     3.80        8.57   0.691   10.47    11.35     14.12    13.85    114.54    15.15      3.59
                    12/13/93                                                1                             22.74              16.62
                    3/15/94                       21.23      52.42    16.331  20.84    16.61     19.921   17.63              17.91    33.101    27.37
                     4/5/94                                                                                         15.24    15.41      0.00    28.72
                    4/11/94     21.80    9.06     21.12      86.59    2.16    17.16    20.88     50.38    17.3'1    13.46    40.11      0.00    50.12    4.58
                    4/25/94                                                                               14.15       4.65   26.68
                     6/1/94      2.58    9.58     21.415    96.786    0.21    30.66    21.06     17.77    24.25     18.04    30.64     67.56    57.60    0.03
                    6/29/94                                                                                         18.47    20.80
               Imean          1  7.03 1 7.23 1 13.61     1 53.53 1 8.06      24.66 1   23.74  1 22.40 1 21 .29     24.12   1 23.28  1 13.681   48.701   2.31 1
                                                                   @
                                                                      0  6  9


                                                                         33


                                                                      26





           TABLE 2-5. PHOSPHATE CONCENTRATIONS AT THE JOHNSON CREEK STATIONS 4/93-6/94


                     DATE              1       2      31     4     5      6      7      8      9     10   1 1       12 12A              13
                          4/7/93    0.24   0.29   0.201               0.25                 0.30                   0.25
                         4/12/93    0.38   0.32   0.251               0.44                 0.46                   0.29
                         5/25/93    0.58   0.66   0.161  0.10  0.35   0.30          0.42   0.43
                          6/1/93    0.84   0.87   0.23,1       0.36   0.22   0.20   0.39,  0.36   0.23  0.41
                         6/29/93    0.46   0.18   0.451  0.38  2.10   0.52   0.30   0.63   0.57   0.50  0.50      0.39
                          7/7/93           1.46   0.381  0.50         0.42   0.27   0.69   0.69
                         7/20/93    1.57   1.55   0.141  4.64         0.44   0.24   0.62   0.51   0.63
                         9/29/93                  0.58   0.37  1.46   0.34   0.27          0.82   0.46  0.57                0.48
                         11/2/93    1.13   0.49   0.30   0.38  0.41   0.30   0.31   0.55   0.44   0.35  0.64      0.49
                         12/13/93                                                          0.62   0.61
                         3/15/94                  0.24   0.26  0.22   0.39   0.31   0.39   0.46         0.37      0.46      0.46
                          4/5/94                                                                  0 .38 0.31      0.31      0.37
                         4/11/94    0.16   0.22   0.17   0.15  0.23   0.22   0.25   0.29   0.37   0.45  0.41      0.33               0.10
                         4/25/94                                                           0.36   0.38  0.29
                          6/1/94    0.26   0.40   0.23   0.22  0.44   0.49   0.25   0.27   0.45   0.69  0.34      0.35      0.44     0.60
                         6/29/94                                                                  1.60  0.70


                     MEAN         1 0.621  0.641 0.281   0.781 0.701  0.361  0.271  0.47   0.491  0.571 0.451     0.361     0.441    0.351










                                 Figure 2-1. Geometric average bacterial indicator concentrations in the Johnson Creek watershed
                                                                          from 7/93 to 6/94.



                   300

                                                                                                                    Fecal coliforms


                                                                                                                    Enterococci
                   250
                                                                                                                    C. perfringens



                   200




                                                                                            N

                   150





                   100





                     50





                      0

                        0         1         2        3         4         5         6        7         8         9        10        11        12
                                                                                Site










                                 Figure 2-2. Seasonal geometric average fecal coliform concentrations in the Johnson Creek
                                                                  watershed from 7/93 to 6/94.



                          1400-/




                           1200-


                                                                                                                         Summer
                           1000-                                                                                         Autumn

                                                                                                                         Winter
                           800-
                                                                                                                         Spring


                           600-
                      U



                           400-




                           200-


                                                                                                                    M@

                             0
                                            2         3        4        5        6        7        8        9        10       11       12
                                                                                   Site










                              Figure 2-3. Seasonal geometric average enterococci concentrations in the Johnson Creek watershed
                                                                         from 7/93 to 6/94.



                           1800-/



                           1600-


                           1400-                                                                                       El summer


                                                                                                                           Autumn
                           1200-

                                                                                                                           Winter

                           1000-
                                                                                                                           Spring


                            800-



                            600-



                            400-



                            200-



                              0
                                                                              F
                                             2         3        4        5        6        7        8         9       10        11       12
                                                                                    Site









                                  Figure 2-4. Seasonal geometric average C. perfringens concentrations in the Johnson Creek
                                                                  watershed from 7/93 to 6/94.



                             50-11



                             45-


                             40-                                                                                     Summer

                             35-                                                                                  M".1 Autumn

                             30-                                                                                     Winter

                                                                                                                     Spring
                             25-



                             20-



                             15-



                             10-



                              5-



                             0
                                    1       2        3       4        5       6        7        8       9        10      11       12
                                                                                Site


























                     FIGURE 2-5. MEAN NH4 CONCENTRATION FOR THE JOHNSON
                                      CREEK STATIONS 4/93-6/94


                     8.00-Z

                     7.00"

               cc    6.00-

               z
               Lu    5.00-1,

               0
               z     4.00-/
                     3.00-"
               z     2.00-/
               z
               Lu    1.00-/
               2                                       -                  I         I v     /7
                     0. 0 0                                               1-14
                            1   2    3    4    5    6   7    8    9   10 11     12 12A   13


























                FIGURE 2-6. MEAN N03 CONCENTRATION FOR THE JOHNSON
                               CREEK STATIONS 4/93-6/94



                60. 0 0
           z
           0
                bu.00--/

           z    40.00-/

           C.)
           z M  30.00"
           ou,
           Q
           CV)
           0    20.00-/
           z
           z
           <    10.00-
           uj


                 0.00-
                      1   2   3   4   5   6  7   8   9   10 11  12 12A 13


























                 FIGURE 2-7. MEAN P04 CONCENTRATION FOR THE JOHNSON
                              CREEK STATIONS 4/93-6/94


               0.80-/

                  0-/
             z 0.7

               0.60-
             cc
             1" 0.50-/
             z
             Lu
             0 0.40-/
             z
             0    0-11
             Q 0.3
             RT
             0
             IL 0.20-/
             z
               0.10
             U, O.OOD      .-l 14-1                   e@@] !4]           lf@?
                     1   2   3   4   5  6   7   8   9   10 11  12 12A  13














                             FIGURE 2-8. SEASONAL MEAN NI-14 CONCENTRATION FOR JOHNSON CREEH
                                                         STATIONS 4/93-6/94



                   40.00-11



                   35.00-/


               z   30.00-/                                                  El Spring

                                                                               Summer
                   25.00-

               LU                                                              Fall
               C)  20.00-'
               z


                   15.00-/
               z
               z
               <   10.00-/-
               LU


                     5.00-'

                                                                                           OWN @-
                     0.00-A                                                 lmml@, MMIK,  nmll@,
                             1     2      3      4      5     6      7      8      9      10.   11     12     12A    13















                         FIGURE 2-9. SEASONAL MEAN N03 CONCENTRATION FOR JOHNSON CREEH
                                                      STATIONS 4/93-6/94


                80.00                                                       El SPRING

                70.00f                                                         SUMMER


            0
            z   60.00'                                                         FALL

            cr- 50.00f



                40.00



            c,) 30.00


                20.00-



                10.00-



                 0.00-
                         1      2      3      4      5      6      7      8      9     10     1 1    12    12A     13
                                                                                              - @,KK















                                   FIGURE 2-10. SEASONAL MEAN P04 CONCENTRATION FOR JOHNSON CREEH
                                                                 STATIONS 4/93-6/94



                           2.50-"


                                                                                         Spring
                        =L 2.00-@
                        z                                       M1                       summer
                        0                               4-m-,

                                                                                         Fall
                        cc
                           1.50-/
                        z
                        LU

                        z
                        0
                           1.00-/
                                                                "-j

                        z
                                                          'U.
                        uj 0.50-



                                                                                                    W

                           0.00
                                   1      2      3      4      5      6      7       8      9     10      11     12    12A     13










           Figure 2-11.      Fecal coliform concentrations compared to salinity levels at sites along a freshwater-
                                                        tidal transect on Johnson Creek.



                 300 -





                 250





                 200





                 150





                 100





                   50





                    0

                      0             2              4              6             8             10             12             14
                                                                   Salinity (ppt)









             Figure 2-12.     Enterococci concentrations compared to salinity levels at sites along a freshwater-
                                                       tidal transect on Johnson Creek.


                  120




                  100




                  80





                  OU





                  40





                  20





                     0

                      0             2             4             6             8             10            12            14
                                                                  Salinity (ppt)




 I
 I
 I
 I                        TABLES AND FIGURES
 I                             OBJECTIVE 3
 1
 1
 1
 I .
 I
 I
 I                         -
 I
 I
 I
 I  I
 I
                I
 I
 I



              M M M M = MM= M                                                                         :     = = = M MI M = M =-


                 Table 3-1. Bacteria (per 100 ml) at sites in Gerrish Brook (south branch) near a housing development.

                                                        CANNEY           LANE        (South branch Gerrish Brook)
                 Fecal coliforms
                                  Far           Near    Upstream Downstream Swale #2 Downstream Upstream Oxbow Near                                   At     GB north       Below
                             upstream      upstream      swale #1       swale #1                     of swales     oroxbow                mouth mouth         branch      connuence
                   SITE           CR            CF2          CF3           CF4            CF5           CF6             CF7        CF8     CF9      CHO        JC11           JC9-
                   DATE
                   11/23/93       5.0           6.0          5.0           30             38            13              43         1000     3 6       52         70           80
                   12/13/93       13            7.0          230           114            8.0           4.0             18         360      16        16         34           30
                   4/25/94        32            32           3             16             11            32              31         28                 99         20           8.0
                   6/7/94         74            46           975           1800           7.5           33              15         3200               18                      95
                   6/29/94        450           498          105           155            9.0           465             143      42000                270        103          710
                 GEO AVE          37.0          31.4         50            109            12            30.1            35         1063     24        52         47           66
                 STD DEV 1        5.6           6.0          12            6.2            1.9           5.8             2.4        14.9     1.8       3.3        2.2          5.1


                 Enterococci
                   11/23/93       7.0           9.0          2.0           10             32            13              9,         200      10        25         23           10
                   12/13/93       16            10           153           60             36            16              16         90       14        30         14           12
                   4/25/94        24            21           3.5           58             17            31              54         43                 40         16           9.5
                   6/7194         48            38           544           1680           23            19              63         118                36                      9.0
                   6/29/94        606           534          190           990            122           560             430        328                602        135          80
                 GEO AVE          38            33           41            142            35            37              44         125      12        58         22           18
                 STD DEV          5.5           5.3          13            8.6            2. 1          4.8             4.7        2.2      1.3       3.8        3.4          2.4




    MM MMMMM




                Table 3-2. Bacterial concentrations (per 100 ml) at sites in Gerrish Brook (north branch) near a housing development and farm.



                Fecal coliforms
                       Site         Stream Upstream          Wetland          Between farm        Near   Downstream Downstream above Below houses Below At mouth At mouth of
                    description     source of farm           near farm         and houses       houses    of houses       Rt. 108 farms        on Rt. 108       barn   of stream other branch
                       Site #          12        12E            12D                 12C           12A         12B                lic               IIB          IIA        11             10
                       1/3/94          4.0       2.5            13.0                12.0          13.0        8.0
                       4/5/94          26.5      25             17.5                22.5          276         7.5                4.3               5.5          2.8        5             0.5
                       6/6/94          0.5       600            161                 110           65          69                 73.3              113.5        104        94.5          17.5
                    GEO AVE            3.8       33.5           33.2                31.0          61.6        16.1               17.8              25.0         17.1       21.7          3.0
                    STD DEV            7.3       15.7           4.0                 3.1           4.6         3.5                7.4               8.5          12.9       8.0           12.4


                   Enterococci
                       Site #          12        12E            12D                 12C           12A         12B                11C               IIB          IIA        I 1            10
                       1/3/94          2.5       0.5            3.0                 3.0           2.0         2.5
                       4/5/94          0.5       0.5            1.25                0.5           3.8           5                5                 6.5          4          2.5           1
                       6/6/94          5.3       108            27.5                67.5          13            6                9.5               8.5          11         9            35.5
                    GEO AVE            1.9       3.0            4.7                 4.7           4.6         4.2                6.9               7.4          6.6        4.7           6.0
                    STD DEV            3.3       22.3           4.9                 12.0          2.6         1.6                1.6               1.2          2.0        2.5           12.5






             TABLE 3-3. NUTRIENT CONCENTRATIONS AT SITES IN GERRISH BROOK (SOUTH BRANCH) NEAR A HOUSING DEVELOPMENT


                       CANNEYLANE

                         gm N03                         1         2         3     4       5         6.      7         8         9    ic 11       ic 9
                                          12/13/93     10.68                                               23.89    51.78      14.73      16.62      22.74
                                          4/25/94       6.40      0.58  88.071   80.10 22.65        9.94   10.05    14.66                 26.68 - 14.15
                                             6/7/94     6.53      8.20  48.05    45,87 23.77       16.49   16.74      0.00                30.64      24.25
                                          6/29/94       8.40      9.62  50.18    45.56   35.40     16.72   20.12      6.31                  2 0.8


                                     MEAN               8.00      6.13  62.10    57.18   27.27     14.38   17.70   -18.19      14.73      23.69      20.38




                      @LM NH4                           1         2         3     4-      5         6       7         8         9    ic 11       ic 9
                                          12/13/93      0.66                                                1.00      9.45      2.75        1.99      2.18
                                          4/25/94       3.11      1.64      1.211 2.98    1.71      0.83    1.77      1.02                    1.2        1.5
                                             6/7/94     2.67      2.06      7.591 1.55    3.24      2.12   21.23      1.12                  2.73      2.78
                                          6/29/94       4.71      2.73      4.501 2.40    2.84      2.'51   3.36    53.46                   4.31

                                     MEAN               2.79      2.14      4.43 --2.31   2.60      1.82    6.84    16.26       2.75        2.56      2.15



                      @LM P04                                1        2       3       4       5         6   -7            8        9 ic 11       -ic 9
                                          12/13/94      0.72                                                0.84    77.98       1.10                  0.62
                                          4/25/94       0.37      0.38      0.39  0.31    0.20      0.36    0.40      0.37                  0.29      0.36
                                             6/7/94     0,.-65    0.62      0.56  0.60    0.22      0.52    0.63   220.24                   0.34      0.45
                                          6/29/94       1.17      1.09      0.73  0.83    0.48      1.18    1.16   25-6.89                    0.7   _

                                     MEAN               0.73,     0.70,-    0.56  0.58,   0.30      0.69,   0.76   138.87,      1.10,       0.441     0.48
                                                                      @
                                                                            7'59
                                                                            4-50


                                                                              3
                                                                            44






             TABLE 3-4. NUTRIENT CONCENTRATIONS AT SITES IN GERRISH BROOK (NORTH BRANCH) NEAR A HOUSING
             DEVELOPMENT.



                          NH4


                                             12        12e      12d        12c       12a 12b llc llb                     lla        11        10
                                 4/5/94 1.53 1.65               27.43        1.26 0.41 0.21 0.88 1.88                    31.92 1.11           1.17
                                 6/6/94      12.38       0.87   -1.31        1.74     1.78    4.70      3.66      2.52    3.02       2.57     4.02





                          N03
                                             12        12e      12d        12c       12a      12b      llc      llb      lla        11        10
                               4/25/94                 29.13,   31.73      30.17              27.07,   13.15 14.34       18.31,     26.68     4.65
                                6/6/94        2.18 108.04       132.15     114.80   69.15     71.54    32.20    31.96    30.91      28.86     19.14



                          P04


                                             12        12e      12d        12c       12a      12b      lic      11 b     11 a       1 1       10
                                4/25/94                  0.31      0.35      0.33              0.38     0.32      0.29    0.34       0.29     0.38
                                6/6/94 1      0.321      0.44     0.431      0.491    0.521    0.421    0.441    0.401    0.361      0.36     0.60



  FI=3-1-off&hB=holloTist@okgo@ango@LanoiWslilglMvelqMiit)imsall@
  @ites (CF 1-10; JC9-11) and soil mapping units.


                                                                            OL"

                                             rk
                                                                                                  9A


  rexture -WaT) ivmbQl       Limit( ti n   r     i  tank sewa,&
    sil           BzB             severe:  slow penneability
    fsl           GsD             severe:  slope
    gls           I-IdB&C         severe:  shallow bedrock
    fsl           LrA             severe:  high water table
                                                                          -neability                 'CF-g,,
    sil           ScA             severe:  high water table and slow pen
    sil           SfC             severe:  slow pen-neability
    Ifs           WfC             severe:  moderately slow permeability








                                                                                                           cF-tj




                                        4:i
















                           Jo       I      h. I
                                                                                                     q vjy@

           4,
                                                                                                     AMY
                                                                         9af

                   ,x'I.





         Figure 3-;I.North Branch of Gerrish Brook, farm/cowfield and Madbury housing development with
         sample sites (12, 12 A-E) and soil mapping units.




                                                                                    -17




                                                                   9                                           y"Y'








                                                                                            7 -






       r



                                                                                 I;-
                                                                   .2


















                                                                                           7




                    N



                                                                                                            -F-L 0




               Texture                  Limitation for septic tank sewaze effluent dispo5al
                 sl           EaT           severe: seasonal high water table
                 glS          HdB           -severe: shallow bedrock
                 sl           GsE           severe: slope
                 Is           HaB           slight: possible hazard of pollution
                 Is           WdB           slight: possible hazard of pollution










                              Figure 3-3. Geometric mean fecal coliform and enterococci concentrations in Gerrish Brook (south
                                                                  branch): 11/93-6/94.


                    10000                                                                                                Fecal colifonns

                                                                                                                         Enterococci


                     1000





                      100





                       10






                                                                     0                   >1
                                                   CI3        M                 0
                                                   (D 'D      -@:    E          .0                0        0                0  Q)
                                                              Cn     C's C4     x                                              :3
                         Ln       (4       W          Cd                a)      0                                           _6 @"
                                  ID4                                   Cd              0
                                           03                                   >
                                                                        C.0     0
                                                                                                 z
                                                                     0
                                           Ln
                                           @D
                                                                         SITE









                                   Figure 3-4. Fecal coliform concentrations in Gerrish Brook (south branch): 1/94-6/94.

                                        11/23/93          12/13/93         4/25/94          6/7/94  -A- 6/29/94



                  100000

                                                                                      A


                   10000




                    1000
                         T


                     100




                      10





                         E        E
                                                            Cd
                         Cd       Cd              C@j                        0        0
                         U        0               0 'D             E         -0       -0                        Cd
                         ti       b               !Z -      &n     Cd                 X
                                                    Cd
                                                                             0        0
                                                                      Cd                               <
                                  @D      03               CI4               >                 0                          0
                                                  0                          0                z                 0
                                                                   0
                                                                   1:21

                                                                       SITE










                                     Figure 3-5. Enterococci concentrations in Gerrish Brook (south branch): 1/94-6/94.


                                          11/23/93          12/13/93         4/25/94           6/7/94            6/29/94



                   10000




                    1000





                     100





                       10






                                                                     t4"
                         as       03               01        03                                   ::3      5
                                  U                                  E                            0        0        Ca
                                  b                                             X        X                                  0  :3
                         CA       C4       Cn      C4 Cd                        0       0
                                                                        Cd
                                  @D       m
                                                                                                 z



                                                                         SITE










                           Figure 3-6. Geometric mean fecal coliform and enterococci concentrations in Gerrish Brook (north
                                                                branch): 1/94-6/94.


                  70                                                                                          -0- Fecal coliforms

                  60                                                                                                    Enterococci


                  50



                  40



                  30



                  20



                  10



                    0

                                                     Cn       CA        4.                   C6
                                                     0)       0          0                   0
                      Cd                             C4       CA                             U)
                                                                         E          C4                                     0
                                                     0        0           CA        C)       0
                                0                                                   C4                            E
                      Cd                 Cd
                                                                                    0
                                E                                                                                 2
                                                                                  > .
                                Cd
                     Cn         0                             z                                                            0
                                tj                                       0                                       C110
                                C4

                                D
                                                                       SITE










                                        Figure 3-7. Fecal coliform concentrations in Gerrish Brook (north branch): 1/94-6/94.


                                                                       1/3/94            4/5/94             6/6/94



                     1000






                      100







                        10












                                                                                    (41        00


                                                                                     j CA
                                                                                       C4         (A                                          C+1 Cd


                                                                         z                                              pq
                         0 up
                            L



















                                                                                    SITE










                                                                       Figure 3-8. Enterococci concentrations in Gerrish Brook (north branch): 1/94-6/94.


                                                                                                             0- 1/3/94                                   4/5/94                         6/6/94



                                      120



                                      100



                                       80
                                F::


                                       60



                                       40



                                       20



                                          0

                                                                                                                                                                    00
                                                                                                                                                                    CD                                                              :3
                                                                                                                              CA
                                                                                                                                                                                                                                    0
                                                                Cd                                          0                 0                      C4                                                                                              0
                                                                                                                                                     0                   Cn                                                                         14-   m
                                                                                                                                                     C4                                                                                              0
                                                                                                           6@8                                  C4   =S
                                                                C4
                                                                                                                                                     0                                                                              Cd
                                                                                                                                                                     >                     0
                                                                                                                                                                     0
                                                               @D                                                            z
                                                                                                                                                                                                                                   C/)

                                                                                                                                               SITE




 I
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 I                        TABLES AND FIGURES
 I                            OBJECTIVE 4
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            Table 4-1. Indicator concentrations and geometric means (per 100 ml)
             in Beards Creek: 7/93-6/94.




            Fecal coliforms
                  DATE          1    2     3     4      5    6     7      8     9     10   11    12
                  7/8/93             83    595                                             50    37750
                  7/13/93       24   23    525   225    11   49    2480 1770    0          35    6000
                  7/15/93            70    2315                                 17         258   10500
                  8/11/93       26   23    135   126    6    43    720    235   30         150   200
                  8/17/93       25   14    360   1360 1800   24    670    680   1245             630
                  8/24/93       20   14                 550        290
                  11/16/93      73   76    95    23     4    5     10     415   58    1    1     3
                  7-Dec         300  250   185   143    280  63    25     16    300   240  54    83
                  2/1/94                                                  155   88
                  2/15/94                                                       93
                  2/22/94            150                                  308   355
                  3/1/94                                                  110   100
                  3/8/94             368                                  230   240
                  3/15/94                                                 5b
                  3/23/94       13   25    63    40     115  6     2      190   140   15   56    30
                  5/9/94        365  221   438   295    240  123   10     235   275   25   405   113
                  6/14/94                  100   400         300   185    2700  6600             1000
                  6/20/94       200  5     145   100    15   590   240    1400  100   16   50    7100
               GEO AVE          57   51    251   157    67   50    97     281 171     16   54    162
                STD DEV         4    4     3     3      9    5     10     4     5     8    6     18





            Enterococei
                  DATE          1    2     3     4      5    6     7      8     9     10   It    12
                  7/8/93             3     450                                             28    5760
                  7/13/93       18   228   280   690    5    23    600    190   0     15   8     26000
                  7/15/93            27    1230                                 0          239   44000
                  8/11/93       2    6     125   445    155  38    230    210   0          74
                  8/17/93       20   1     40    0      15   12    40     515   0          142   220
                  8/24/93       6    0                  6          95
                  11/16/93      6    2     50    30     10   18    5      255   68    3    0     5
                  7-Dec         400 400    418   500    1110 114   22     26    68    78   400   500
                  2/1/94                                                  335   81
                  2/15/94                                                       23
                  2/22/94            35                                   25    38
                  3/1/94                                                  28    31
                  3/8/94             195                                  164   87









                 3/15/94                                                 28
                 3/23/94        86 98     30     23    60    16    5     43     53    43   35    6
                 5/9/94         300  210  211    301   813   121   17    189    40    13  228    98
                 6/14/94        255  5    130    600   300   110   85    300    288   26 40      235
                 6/20/94        18 73     173    410   25    180   72    220    0     120  10    855
               GEO AVE          32 19     164    229   56    46    44    115    36    24 61      462
               STD DEV          6    11   3      4     7     3     5     3      6     4    4     22




            Clostridium perftingens
                 DATE           1    2    3      4     5     6     7     8      9     10   It    12-
                 7/13/93        9    6    81     6     1     0     16    59     8     1    5
                 7/15/93             4    68                                    3          49    43
                 8/11/93        1    2    9      13    6     6     6     8      8          51    150
                 8/17/93        6    2    22     56    6     9     11    26     6          6     495
                 8/24/93        3    1                 11          8
                 11/16/93       12   35   1      9     10    4     6     83     47    5    5     60
                 7-Dec          61   68   22     41    36    22    5     20     13    17   48    39
                 2/1/94                                                  7      8
                 2/15/94                                                        7
                 2/22/94             40                                  26     31
                 3/1/94                                                  11     16
                 3/8/94              180                                 114    74
                 3/15/94                                                 24
                 3/23/94        39   93   34     21    44    11    5     19     19    13   29    25
                 5/9/94         75   70   39                       3     15     6     5    71    29
                 6/14/94
                 6/20/94        4    16   19     10    9     36    5     23     16    8
               GEO AVE          10   15   20     17    9     11    6     24     12    6    21    66
               STD DEV          4    6    4      2     3     2     2     2      2     3    3     3







               Table 4-2. Annual and seasonal geometric means (per 100 ml) for bacteria] indicators in Beards Creek: 7/93-6/94.


                Fecal coliforms
                                   t     2      3       4      5      6       7       8       9        10    11     12
                  GEO AVE          57    51     251     157    67     50      97      281     171      16    54     562
                  STD DEV          4     4      3       3      9      5       10      4       5        8     6      18
                    Summer         24    29     512     338    90     37      767     656     85             91     3128
                    Autumn         148   138    13 3@   57     31     17      16      81      132      13    7      16
                    Winter               235                                          143     147
                    Spring         97    30     141     147    75     108     31      641     399      18    104    393


                 Enterococci
                                   1     2      3       4      5      6       7       8       9        10    11     12
                  GEO AVE          32    19     164     229    56     46      44      115     36       24    61     462
                  STD DEV          6     11     3       4      7      3       5       3       6        4     4      22
                    Summer         8     5      239     554    16     22      151     274     0        15    56     6170
                    Autumn         49    24     145     122    107    45      10      81      68       14    400    50
                    Winter               83                                           64      45
                    Spring         104   52     109     202    138    79      27      152.    85       36    42     105


               Clostridium perfringens
                                   1     2      3       4      5      6       7       8       9        10    11     12
                  GEO AVE          10    15     20      17     9      11      6       24      12       6     21     66
                  STD DEV          4     6      4       2      3      2       2       2       2        3     3      3
                    Summer         3     2      32      16     4      7       10      23      6        1     17     147
                    Autumn         26    48     5       19     18     9       5       41      25       9     15     48
                    Winter               85                                           22      18
                    Spring         22    47     29      15     20     20      4       19      12       8     45     27










             TABLE 4-3. NI-14, N03 AND P04 CONCENTRATIONS AT THE BEARDS CREEK STATIONS
             NH4
                 DATE          1       2          3         4       5         6         7       8         9       9A        10       1 1       12
                 6/30/93               0.58       4.61      4.27   14.09      3.96    21.05     9.86      59.26             21.88     7.24      8.57
                 7/13/93       0.89    4.70       5.62    15.25    10.57    42.54     22.23     5.09      0.36              18.63    17.04
                 8117193       4*21    2,38       2*53    51,116    7,94    11,22     13*31     3*82      6*89      9,76              5,33      5, 31
                11/16/93       2.70    0.59       1.30      2.89    5.78      6.22      7.66    3.32      4.55               0.95     1.87      1.95
                 12/7/93       1.73    1.21       1.99      1.11    2.61      2.78      1.81    3.21      3.70               2.98     3.68      0.97
                 3/15/94                                                                        1.01
                 3/23/94       4.97    3.78       2.36      3.02    1.85      3.43      0.91    6.74      7.32               5.26     3.88      0.96
                  5/9/94       3.93    2.32       1.42      2.73    4.73      2.60      1.84    2.12      16.62              7.61     2.55      1.70
                 6/14/94       9.86    2.05     10.10       4.84   11.79      5.38      2.83    9.61      10.12              4.83     7.31      9.14
                 6/20/94       2,83   10,00       8,99      4,51    6,41    11,14       5,96    6,94      10,92              3,04    20*76


             MEAN NH4          3.89    3.07       4.32    10.06     7.31      9.92      8.62    5.17      13.31     9.76     8.15     7.74      4.67




             N03
             DATE                  1        2         3        4         5        6         7       8         99A               10       11        12
                 6/30193               0*70     13,16     20*811   79*72    21,86     56,12    46*93      32*81              1*4 9    1 *07    24,36
                 7/13/93       0.21    0.33     13.10     22.40    56.93    10.03     49.04    63.04      61.52              0.99     3.89
                 8/17/93       2.98    0.55       2.33      4.42   79.83      7.07    29.54    47.75      57.42   50.18              18.31     14.60
                11/16/93       6.01   10.30     10.52     14.56    32.22    23.37     24.97    32.49      30.96              0.53     0.45     10.62
                 12/7/93      27.08   32.04     24.48     28.51    58.15    15.67     20.58    12.38      29.36             25.11    30.23     28.72
                 3/15/94                                                                        4.93
                 3/23/94      20.63   21.25     37.41     16.95    47.67    14.38     13.28    22.79      26.73             10.13    20.15     19.81
                  519/94      10.87    9.75       9.95    10.59    26.33      2.75      7.12    9.71      7.68               0.19     9.26     18.29
                 6/14/94       6.69    0.10       6.84    11.67    24.82      3.02    15.53    43.17      30.63              1.17     2.55     19.08
                 6/20/94       0.57    0.26     11.87     20.45    15.36      4.77      8.40   52.56      42.39              2.66     2.68     31.83


             MEAN N03          9*311   8,36     14,41     16,72    46,711   11,118    24*96    33*57      3  50   10*111              9,84     20,91



             P04
             DATE                  1        2         3        4         5        6         7        8        9       9A        10        11       12
                 6/30/93               0.16       0.52      0.34    0.34      0.18      0.53    0.35      0.10               0.18     0.32      0.70
                 7/13/93       1.02    0.25       0.52      0.46    0.26      0.53      0.45    0.71      1.32               0.93     0.51
                 8/17/93       1,74    0,02       0,04      0,75    1*06      0,34      0*28    0,34      0,18      0*37              0,14      0*6
                11/16/93       0.49    0.38       0.17      0.27    0.40      0.33      0.28    1.85      0.25               0.12     0.17      0.42
                 12/7193       0.55    0.49       0.59      0.64    1.07      0.52      0.29    0.23      0.31               0.33     0.49      0.39
                 3/15/94                                                                        0.39
                 3/23/94       0.52    0.65       0.48      0.36    0.65      0.25      0.20    0.48      0.48               0.44     0.46      0.40
                  5/9/94       0.44    0.46       0.39      0.51    0.84      0.31      0.20    0.37      0.21               0.18     0.52      0.38
                 6114/94       0.15    0.26       0.31      0.18    0.50      0.30      0.20    0.48      0.28               0.22     0.20      0.50
                 6/20/94       0,28    1,33       0*62      0*34    0*14      0*36      0,30    0,45      1*30               0*41     0*67      0*58


             MEAN P04          0.65    0.44       0.40      0.43    0.47      0.35      0.30    0.57      0.38      0.37     0.35     0.39      0.50









                                           Figure 4-1. Geometric mean bacterial indicator concentrations in Beards Creek: 7/93-6/94.


                                                                    Fecal coliforms               Enterococci                   C. perfringens



                        600




                        500




                        400




                        300



                    Cj
                        200




                        100



                           0  +                                                +-+
                                          2            3           4           5            6           7            8           9           10           11          12

                                                                                                SITE










                                        Figure 4-2. Seasonal fecal coliform concentrations in Beards Creek: 7/93-6/94.


                                          -0- summer                 Autumn            Winter            Spring


                    10000






                     1000






                      100






                       10






                        1

                         1        2         3        4        5        6        7         8        9        10       11        12

                                                                          SITE










                                        Figure 4-3. Seasonal enterococci concentrations in Beards Creek: 7/93-6/94.


                                         -0- Summer                 Autumn           Winter      0     Spring



                   10000





                    1000





                     100





                      10






                                  2        3        4        5        6        7        8                 10       11       12
                                                                                                \9

                       0


                                                                         SITE










                                 Figure 4-4. Seasonal C. perfringens concentrations in Beards Creek: 7/93-6/94.


                                            summer         Autumn -*-Winter               Spring



               1000









                100









                 10









                     1      2        3       4       5       6       7       8       9       10      11      12

                                                               SITE






























                            FIGURE 4-5. MEAN NI-14 CONCENTRATION AT THE BEARDS CREEK
                                                   STATIONS 6/93-6/94


                 z       14.00-"'
                 0
                         12.00---@

                         10.001",
                 z
                 w
                 0       8.00-z
                 z 2
                 0
                 C.)     6.00--@

                 z       4.00-
                 z
                         2.00'
                         0.00--@  1     2     3     4     5     6     7     8     9    9A 10       11    12 e7





























                   FIGURE 4-6. MEAN N03 CONCENTRATIONS AT THE BEARDS CREEK
                                    STATIONS 6/93-6/94


           cn   60.00"
           z
                50.00-/

                40.00-/
           z
           w
           oz   30.00-/
           0
           0
           (n   20.00--/
           0
           z
           z
           <    10.00-
           w
                 0.00-JITIT
                       1   2   3   4    5   6   7   8   9   9A  10   11  12































                    FIGURE 4-7. MEAN P04 CONCENTRATIONS AT THE BEARDS CREEK
                                     STATIONS 6/93-6/94


             z    0.70.
             0
                  0.60-

                  0.50-/
             z
                  0.40'
             z 2
             0 =i.
                  0.30-/

             0
             IL   0.20-/
             z
                  0., OD
                  0.00  1   2   3    4   5   6    7   8   9   9A   10  11  12


























                         FIGURE 4-8. SEASONAL MEAN NI-14 CONCENTRATIONS A7
                                        THE BEARDS CREEK STATIONS



                     25.00-1


                 z                                                                            Summer
                 0   20.00f
                 <                                                                            Fall
                 a:
                 z   15.00-1
                 LU                                                                           Spring
                 z
                 0   10.00-,
                 0


                 z                        AN
                 z     5.00-@

                 LU
                      0 .00-
                              1    2     3    4     5     6    7     8    9    9A    10   11    12
                                                         I L.AK
                                                    !g
                                                                                             Alm


























                        FIGURE 4-9. SEASONAL MEAN N03 CONCENTRATIONS Al
                                       THE BEARDS CREEK STATIONS


                 2  80.00-1                                                       El Summer
                 =L
                 z  70.00-1
                 0                                                                   Fall
                 P: 60.00-
                                                                                     Spring
                    50.00-1
                 z
                 w
                 0  40.00f
                 z
                 0
                 U  30-00-1
                 cl
                 0
                 z  20.00-
                 z
                    10.00-


                     0.00-
                             1    2    3     4    5     6    7    8     9    9A 10      11   12


























                    FIGURE 4-10. SEASONAL MEAN P04 CONCENTRATIONS Al
                                   THE BEARDS CREEK STATIONS



                  1.40-

               ZL
               (0 1.20-,                                             Summer
               z
               0
               .P: 1.00-1                                            Fall
               M
               z  0.80-                                              Spring
               w
               oz 0.60-
               C.)
               0  0.40-,
               (L
               z
               <  0.20-
               LU
                  0.00@-
                         1   2    3    4    5   6    7    8    9    9A  10   11   12










                       Figure 4-11, Fecal coliform levels near a sewage pipe at the mouth of Beards Creek: 9/23/93. Salinities
                                          were 0, 25,22.5, and 16.5 ppt from above dam to below pipe.


              300




              250




              200




              150




              100

              50 t

                0
              Above dam                          Below dam                         Above pipe                          Below pipe
                                                                     SITE











































































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