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ASSESSMENT OF NONPOINT SOURCE POLLUTION IN TRIBUTARIES TO THE GREAT BAY ESTUARY FINAL REPORT Submitted to the New Hampshire Coastal Program, Office of State Planning as part of a cooperative, interagency monitoring effort for the 6217 program by Stephen H. Jones and Richard Langan Jackson Estuarine Laboratory University of New Hampshire TD 224 .G72 J66 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 Number NA370ZO277-01. FINAL REPORT FOR NONPOINT SOURCE POLLUTION TRIBUTARY SAMPLING INTRODUCTION In August of 1993, a project was initiated to monitor water quality conditions in both freshwater and tidal portions of the tributaries of the Great Bay Estuary. The purpose of the project was to gather broad scope information on spatial and temporal aspects of NPS pollution in the watershed, and to determine the effects of storm events on the levels of surface water contamination. The project was a cooperative effort between the NH Dept. of Environmental Services, NH Div. of Public Health Services, NH Fish and Game Dept., Jackson Estuarine Laboratory (UNH) and the NH Office of State Planning. METHODS Thirteen sites in the Great Bay watershed in addition to a site at the Hampton Harbor Inlet, area were sampled and analyzed following eight rain events by JEL personnel, and eight times under a random (meteorological) sampling protocol @958P)-by DES@, OSP and DPHS personnel (Figure 1). The sites consisted of one freghi@ater and one tidal site each in the Cocheco, Bellamy, Salmon Falls, Lamprey, Exeter-Squarnscott and Oyster Rivers, with additional tidal sites in the lower Piscataqua River and the Hampton Harbor Inlet. Each month, a sample from a freshwater site and a tidal site sample were split for comparative nutrient and microbial analyses by the JEL and State laboratories. The criterion used for defining a storm sampling date was > 0.25 " of rain prior to sampling on the sample date and during the previous day. Measurements of temperature, salinity, dissolved oxygen, pH and observations of weather conditions were recorded at the sampling times. Separate containers were used for collection of water samples for microbial and suspended solids/nutrient analyses. Storm sample collection and processing methods were conducted according to JEL SOP's 1.05 and 1.06. Nutrient analyses for JEL samples were done using Lachat Method 11-107-06-1-C for ammonium, method 30-107-04-1- A for nitrite/nitrate and the wet chemistry method of Parsons et al (1981) for orthophosphate. Microbial analysis of JEL samples involved standard membrane filtration methods using mTEC agar for detection of fecal coliforms and Escherichia coli and mE agar for detection of enterococci. RESULTS Nutrients and physical parameters Since nutrient analyses were performed by different laboratories for the storm samples and randomly collected samples, sample splits were used to compare results generated by the DES and JEL analytical laboratories. Results of the split sample analyses are presented in Tables 1 through 3. Regressions of the results from the two laboratories as well as scatter plots of JEL data vs. DES data are included in these tables. The best R2 value was obtained for N03 (.91) (Table 2), followed by NH4 (.78) (Table 1) and P04 (.58) (Table 3). The primary differences in results for the nitrogen species were associated with the lower concentrations, probably due to the high detection limits (6.3 @tM NH, 1.4 @tM N03) in the LACHAT methods used by DES. There was poor agreement in results for the P04 methods, at both the high and low end. Though split samples were not run for suspended solids, the DES data, particularly the estuarine sites, were consistently higher than the JEL data. Nevertheless, the data were analyzed as (1) a combined data set; (2) random sampling compared to storm sampling; (3) random samples that were collected within 24 hours of substantial rainfall (11/2/93, 5/17/94 and 6/14) were combined with s-torm sampling and compared as "wet" samples to the remaining random or ryT -$am les --Storm's amp les which were found to violate the criteria for "wet"' condifibris (5/3/94 and 6/22/94) were included in the "dry" data. Combined nutrient and suspended solids data from the random sampling and storm sampling are presented in Table 4. Figures 1A-4 illustrate the site means for all samples for the ten month period. For ammonium, the highest concentrations were observed in the freshwater and estuarine site in the Cocheco and Salmon Falls rivers, the estuarine site in the Squarnscott River, and the freshwater site in the Oyster River (Fig. IA). The highest nitrate concentrations were measured in the freshwater sites in the Cocheco and Salmon Falls rivers, with the estuarine sites in the same two rivers also showing high concentrations. The tidal site in the Squarnscott River and the freshwater site in the Oyster River also had elevated N03 by comparison to other sites (Fig. 2). With the exception of the Salmon Falls and Cocheco rivers, P04 levels were generally low at the freshwater sites, and elevated in the estuarine sites in the Cocheco, Lamprey, Squarnscott and Oyster rivers (Fig. 3). Total suspended solids were consistently lower in the freshwater sites of each river. Highest concentrations were measured in the Squamscott tidal site, followed by the Lamprey River, Oyster River and Hampton Harbor (Fig 4). Storm sampling data (Table 5) were analyzed independently from the random 2 samples, and station means are presented in Figures 5 through 11. The highest ammonium concentrations were measured in the freshwater site in the Salmon Falls River. Both Cocheco River sites, the tidal sites in the Salmon Falls, Squarnscott and Oyster rivers, and the freshwater site in the Oyster River also showed elevated ammonium concentrations (Fig. 5). The freshwater sites in the Salmon Falls and Cocheco also had the highest concentrations of nitrate, followed by their tidal counterparts and the tidal Squamscott and freshwater Oyster river sites (Fig. 6). As was the case with the combined data analysis, P04 concentrations were generally lower in the freshwater sites with the exception of the Salmon Falls and Cocheco rivers. The highest P04 concentrations were found in the tidal portions of the Squarnscott, Oyster and Lamprey rivers (Fig. 7). Suspended solids following storms were all quite low in the freshwater sites, and with the exception of the Squarnscott and Lamprey river tidal sites, quite low at the tidal sites as well (Fig. 8). Percent organic content was high (45-67%) at the freshwater sites with low suspended solids concentrations, and from 17-32 % at the tidal sites with higher solids concentrations (Fig. 9). Mean salinities following rain storms for the tidal sites are shown in Fig. 10. The highest salinities were measured in the lower Piscataqua, Bellamy and Oyster River mouths, and the inlet to Hampton Harbor. Similar salinities were measured in the Salmon Falls, Cocheco, Squarnscott and Lamprey Rivers (Fig. 10). Mean pH for the freshwater sites (7.1-7.3), and tidal sites @@77;9-) were similar (Fig 11). :Nutrient and suspended solid data from the random sampling are presented in Table 6, and comparisons of the sample site means for storm samples and random samples are shown in Figures 12 through 15. For most sites, the same pattern of ammonium concentrations (in terms of which stations had the greatest mean concentration of ammonium) was observed for random and storm samples, with storm samples generally higher. The exceptions to this pattern were for sites with storm sample means lower than the DES detection limit (Fig. 12). The station means for nitrate concentrations were very similar for the sites with higher concentrations, and higher in the randorn samples at sites with lower concentrations (Fig 13). Storm sample concentrations of P04 were higher than the random samples for all the freshwater sites and the tidal sites in the Cocheco, Salmon Falls, Oyster and Piscataqua Rivers. Mean storm P04 concentrations were lower than the random sample means in the Bellamy, Lamprey, and Squamscott rivers and Hampton Harbor tidal sites (Fig. 14). Mean TSS concentrations in both storm and random samples were similarly low for all the freshwater sites, and with the exception of the tidal Squarnscott River site, much higher in the random samples than the storm samples (Fig. 15). In examining actual rainfall amounts for the sampling dates (Table 6A), three of the random sample dates fit the rainfall criteria for storm sampling (11/2/93, 3 5/17/93 and 6/14/93), while two of "storm sample" dates did not meet the criteria (5/3/94 and 6/22/94). In order to obtain a more accurate picture of potential differences in contaminant conditions between sampling dates that followed rain events and those conducted during a dry period, the "wet" samples from the random data set were added to the storm sample data set, and the "'dry" storm samples were added to the random data set, thus creating a more accurate assessment of wet and dry conditions. Sample site means were calculated for the nutrients and suspended solids for the two conditions. Comparisons are presented in Figures 16 through 19. Rearranging the ammonium data in this way did not change the relationship that was observed for the storm-random data (Figs 12 and 16). The changes observed for mean N03 concentration , however, were that N03 was higher in the "dry" samples at the freshwater sites in the Cocheco and Salmon Falls rivers., and higher in the "wet"' samples at the tidal Squamscott River site. Otherwise, the site comparisons did not change with the data transformation (Figs. 13 and 17). Site means for P04 concentration and TSS concentration in the "'dry"- ffwet" comparisons were no different than the storm-random comparisons (Figs. 14 and 18, Figs. 15 and 19). Individual sampling dates for all the nutrient and suspended solids data combined were plotted to see if there were any obvious temporal trends. This type of analysis would not be definitive because of the sampling gap between December I For each plot (Figures 20-31) a single parameter (ie. NH4) at freshwater and corresponding tidal sites for two tributaries were plotted vs time. The two tidal only sites (GB 13 and FIH 1A) were plotted together. For ammonium at the Cocheco and Salmon Falls river sites, the highest concentrations were measured in the fall, though the concentrations in the freshwater portion of the Salmon Falls River appear to be independent of season (Fig. 20). No temporal trend was observed for ammonium concentration in the Bellamy and Lamprey Rivers, though the November-December concentrations seemed lower that expected (Fig 21). In the Exeter-Squarnscott and Oyster Rivers, a single very high ammonium concentration was observed in the freshwater portion of the Oyster River in December. Otherwise, the only observable temporal trend was that concentrations were lowest in April- May (Fig. 22), probably coincident with the spring phytoplankton bloom. No ammonium concentration trend was obvious from the Piscataqua River and Hampton Harbor data, other than that the two sites appeared to have similar variation, and lowest concentrations were observed in the late fall and early spring (Fig. 23). Nitrate levels throughout the year were consistently higher in the freshwater sites in the Cocheco and Salmon Falls Rivers, and concentrations at all sites, both tidal and fresh, were lowest in early spring, and highest in freshwater sites in the early fall (Fig. 24). Nitrate concentration in the Bellamy and Lamprey Rivers 4 was highest in the late fall and winter, and highest at that time in the freshwater portions of those rivers. Lowest concentrations were observed at all sites in the spring (Fig. 25). A similar temporal trend was observed in the Exeter-Squarnscott and Oyster rivers, though the highest nitrate concentrations were measured in the tidal Squamscott River and freshwater Oyster River sites in the fall (Fig. 26). At the Hampton and Piscataqua River sites, the highest nitrate concentrations were measured in fall and winter, and the lowest in spring (Fig. 27). A single high phosphate concentration measured in the tidal Cocheco River sample in early September was the exception to the high late fall-low spring trend in the Cocheco and Salmon Falls Rivers. The freshwater Cocheco River site was higher for most sample dates than the others (Fig. 28). P04 concentrations in the freshwater sites in the Bellamy and the Lamprey rivers were lowest in the summer and early fall, increased in the winter months, and decreased again in the early spring. This trend was not as clear cut for the tidal sites in the Bellamy and the Lamprey rivers, and concentrations were also quite a bit higher in the fall and winter (Fig. 29). The Exeter-Squamscott River and Oyster River P04 concentrations were very similar, both for temporal trends and freshwater- tidal differences, to the Bellamy and Lamprey Rivers (Figs. 29 and 30). In the Hampton and Piscataqua River samples, the only noticeable temporal trend was that the early spring samples had the lowest P04 concentrations. Bacteiidl- Indicators The same approach for data analysis given the nutrient data was applied to the bacteriological data. The data for fecal coliforms, E. coli and enterococci concentrations from split samples are presented in Table 7. Geometric means for analyses from the two labs showed relatively good agreement. Generally, higher fecal coliform and E. coli levels were detected in the freshwater sites and lower levels in tidal sites at both labs. For enterococci, the State numbers were higher for freshwater compared to tidal sites, while little difference was observed for JEL analyses. Thus, the overall mean for State enterococci levels is higher than that for JEL data. Because E. coli is one of numerous bacterial species that constitute fecal coliforms, their levels should be lower than fecal coliform levels. This was the case for JEL analyses, but the fecal coliform levels for the State analysis were consistently lower than E. coli levels. This was a function of DES using mFC medium for detecting fecal coliforms and mTEC medium for E. coli, while JEL used mTEC for both. The mTEC method could be expected to give higher detectable colonies because it involves a 2-step temperature incubation designed to better detect injured 5 bacteria, and it also uses a smaller pore size (0.45 gM) filter compared to the mFC method (0.7 gm). Thus, the mTEC method could be expected to detect more injured and smaller cells compared to the mFC method. In many instances in the following presentation of bacterial results, the State fecal coliform concentrations are presented as 'modified' data. For this modification, fecal coliform levels that were less than reported E. coli levels were considered to be equal to E. coli levels. The split sample results are analyzed separately for each indicator in Tables 8- 10. Comparison of JEL fecal coliform data to raw State data gave an r2 value of 0.45, indicative of a poor direct relationship between results of analyses from the same sample (Table 8). After modifying the State data as previously described, an excellent relationship was indicated between labs, with an r2 value of 0.97 for all data. Inspection of specific pairs of numbers shows a consistent trend for each pair, with high or low JEL numbers corresponding to the same for State data. A strong direct relationship for analyses from the two labs is expected, and modification of the State data for better intepretation of results appears to be justifiable from this regression analysis. A similar strong direct relationship between State and JEL E. coli analyses is presented in Table 9. The results for the two indicators are expected to be similar because of the similarity in methods. The enterococci splits did not agree as well. Generally, high or low JEL data were also high or low for corresponding State data, although the State numbers were often higher than cpcre - ding JEL numbers (Table 10). However, there were a few instances where spon , pair6cl-11ata- were- -different by a large degree. Of particular concern are two pairs where one lab reported its highest level and the other lab reported a much smaller level. As shown in the graph, these opposing, highly variable results can ruin the overall relationship between the two sets of data, as reflected in the r2 value (0.36). These differences could be a function of variability within a split sample if the splitting or initial sampling procedure is faulty. More likely, differences in analytical methods or sample handling procedures between labs could cause observed differences. Data for the JEL storm sampling are presented in Table 11, and data for the State random sampling are presented in Table 12. Geometric averages of the three indicators for data combined are summarized in Table 13, and the geometric means for the combined data from the different sites are illustrated in Figures 32-34. Results with raw and modified State data are presented in Figures 32 and 32A, respectively, with the only difference being higher overall levels in Figure 32A compared to Figure 32. The data show high overall levels at the freshwater sites in the Oyster River, Exeter River, and especially the Cocheco River. These areas are the most urbanized of the freshwater sites. Other freshwater and tidal sites had relatively low levels, except for the tidal site in the Lamprey River, which is much more influenced by urban Newmarket compared to the freshwater site. High fecal 6 coliform levels at this site have been observed consistently for a number of years, and independent efforts are being made to identify sources. As expected, the same trend was observed for E. coli results (Fi-ure 33). Overall enterococci levels were not as high as for fecal coliforms and E. coli, so differences between sites were not as pronounced. The four sites with the highest levels were the same four as with fecal coliforms, but the highest levels were observed at the Oyster River freshwater site, with the freshwater Cocheco River site next highest. On two dates, the State also sampled upstream from the freshwater sites in the Cocheco, Oyster and Exeter rivers to potentially bracket sources of contamination. Inspection of specific data for all three indicators at the different sites shows upstream sites in the Cocheco and Exeter rivers were more contaminated than the routine sites on 5/17, but not on 6/14. Levels of E. coli were slightly higher at the Oyster River upstream site on 6/14. In the Cocheco River, the furthest upstream site (22-CCH) had somewhat lower levels of indicators compared to the middle site (11-CCH), and more comparable to the routine site. A major focus of this study was to see if contaminant levels are relatively higher following rainfall events at the different sites. The JEL sampling was designed to follow rainfall events, and the geometric means for these samples are summarized in Table 13 and illustrated in Figures 35-37. Storm sample means for fecal coliforms a7nd E. coli are all higher than the means for the combined data, Pt -or the tidal. sites at the mouths of the Bellamy and Oyster rivers (Table 13). This: sUg.'ges"ts that rainfall increases contamination of the sites. The highest fecal coliform and E. coli levels were observed in the freshwater sites of the Oyster, Exeter, and Cocheco rivers, and the tidal site in the Lamprey River (Figures 35-36). In addition, levels in the tidal site of the Cocheco River were also relatively high, with E. coli levels higher than in the freshwater site. The same relationships between levels at freshwater compared to corresponding tidal sites as observed for the combined data are observed for the storm data, except for the tidal site storm data being higher than the freshwater sites in the Salmon Falls and Cocheco rivers for E. coli and for the fecal coliform data at the Salmon Falls River sites. Other sites with relatively high levels are the tidal site in the Salmon Falls River and the freshwater site in the Bellamy River. Enterococci levels from JEL data were not as high compared to the combined data as with the other two indicators (Table 13), reflecting the relatively higher levels reported by the State. Again, the highest sites were the same as with the combined data, with the two highest sites being the freshwater Oyster River site and the tidal Lamprey River site (Figure 36). The same relationships between levels at freshwater compared to corresponding tidal sites as observed for the combined data are observed for the storm data. The geometric means from the random samples analyzed by the State are also 7 presented in Table 13. These samples represent for the most part dry samples, and the geometric means are compared to JEL storm sample results in Figures 38-40. The two sets of data do not give similar spatial trends for different fecal coliform. and E. coli levels, except that the freshwater site in the Cocheco River again had the highest levels (Figures 38-39). The sites with the next two highest levels were the tidal sites at the mouths of the Oyster and Bellamy rivers, sites that had the lowest levels for storm samples. For enterococci, the levels were again all relatively low, so differences among sites were minimal (Figure 40). The sites with the three highest means are the freshwater sites in the Cocheco and Oyster rivers, similar to storm samples, and the tidal site in the Oyster River. For all three indicators, levels at the tidal sites on the Salmon Falls, Cocheco and Lamprey rivers were all relatively low, whereas these sites had high levels of indicators following storm events. This suggest that these sites may be most affected by runoff- associ a ted contamination. A more accurate way of determining the effects of rainfall events is to compare results for samples collected according to the criteria upon which storm sampling was based. For this, rainfall data from the Durham station were used to determine if rainfall on the day of sampling and the previous day combined was >0.25 inches, in which case the sample date could be considered a storm, or 'wet' sampling date, and all other dates (<0.25 inches) are considered 'dry' dates. Storm and random data were reorganized to meet these criteria, and the geometric means f;@i---the--differ-er@t---'sites are summarized in Table 13. Comparisons of dry vs. wet concefttra'tions for the three indicators are illustrated in Figures 41-43. For all three indicators at all sites, levels for all geometric means for wet samples were greater than the means for dry samples, although to varying extents. This analysis did not show higher dry-date levels for the two tidal sites in the Oyster and Bellamy rivers, as did the storm vs. random data analysis. The sites with the four highest means for wet samples are the freshwater sites in the Cocheco, Exeter, and Oyster rivers and the tidal site in the Lamprey River for all three indicators (Figures 41-43). The difference between wet and dry levels at these four sites was most striking for all three indicators, illustrating the apparent large influence of runoff on contaminant levels. Again, these sites are all directly influenced by densely populated urban areas, while the other tributaries, including the Bellamy, Salmon Falls, and (freshwater) Lamprey rivers are impacted by less densely-populated upstream areas. Concentrations of the three bacterial indicators on individual dates were plotted chronologically to see if there were any apparent seasonal or other temporal trends. The data set is not extensive, with no sampling in July or January through March. For each graph (Figures 44-55), data for a single indicator at freshwater and tidal sites for two tributaries are plotted together. As expected, the highest levels were apparent during wet sampling dates for fecal coliforms (Figures 44-47). The 8 highest levels (>1000 FC/100 ml) were observed on wet dates during autumn (9/7, 9 / 27, 11 / 18) and late spring (6 / 13) for the freshwater sites in the Cocheco, Exeter and Oyster rivers (Figures 44 and 46) and the tidal sites in the Salmon Falls (Figure 44), Bellamy (Figure 45) and Piscataqua (Figure 47) rivers. These four dates had four of the five rainiest periods prior to sampling of the nine wet dates, suggesting that amount of rainfall may have some direct relationship to level of contamination. Using modified data, fecal coliforms >1000/100 ml were also observed at the freshwater Cocheco River site on 8/24/93, a dry date. E. coli levels followed similar trends as observed for fecal coliforms (Figures 48-51). Generally, levels were highest on wet dates, with highest levels observed on three of the autumn dates and 6/13/94 at the same sites as for fecal coliforms. The trends for enterococci were not as distinctly related to wet/dry conditions (Figures 52-55). The highest levels (>250/100 ml) were observed at a number of sites on 9/27, 11/18 and 12/6, the top three rainiest dates, and 11 /2, another wet sample date. The levels were consistently low for all sites on 12/20, 4/19 and 5/3, all dry dates sampled by the State (Figures 52-55). DISCUSSION AND INTERPRETATION Nu-trien-ts The data gathered for this project provide a broad scope assessment of the spatial distribution of potential sources of nutrients in the Great Bay watershed. Both the random and storm sampling data indicate that certain tributaries are contributing greater amounts of dissolved inorganic nitrogen and phosphorus than others. The problem areas for ammonium are the fresh and tidal portions of the Cocheco and Salmon Falls rivers (particularly the freshwater Salmon Falls site), the tidal portion of the Squamscott River, and both fresh and tidal portions of the Oyster River. The freshwater portions of the Cocheco and Salmon Falls rivers by far had the highest nitrate concentrations, with the tidal portions of these rivers and the freshwater Oyster and tidal Squamscott rivers also showing elevated levels. Elevated phosphate levels were observed in the freshwater and tidal Cocheco samples, and the tidal Lamprey, Oyster and Squamscott samples. Suspended solids were the highest in the tidal Squamscott River samples, and very low in the freshwater samples. The other tidal sites were all higher than their freshwater counterparts, indicating either that there are sources of suspended sediments to the tidal areas or that resuspension is occurring. Comparison of storm sampling data with random data and the "wet" vs "dry" data, indicates that some sites had elevated ammonium concentrations following 9 storm events. The sites with lower concentrations, however, did not appear to increase following rain events. Very little difference in mean nitrate concentration was observed between storm and non-storm samples and differences in P04 levels were inconsistent. The observed inconsistencies in the storm/non-storm. nutrient comparisons may be the result of the different analytical methods used by the two laboratories, particularly in the case of ammonium. This problem with detection limits may be solved in the next phase of the project as one laboratory will be conducting all the nutrient analyses. Salinity and pH measurements taken during the storm sampling indicate that the greatest freshwater influence in the estuarine system is from the Cocheco, Salmon Falls, Lamprey and Squamscott rivers, which are the same rivers in which high nutrient concentrations were measured. This suggests that nutrients may be entering the estuary from freshwater sources, although not necessarily in association with rainfall events. Bacterial Indicators The results of this study allow for an assessment of relative bacterial contamination entering the waters of the Great Bay Estuary from its major tributaries based on synoptic sampling during wet and dry periods. The tributary sites with the highest levels of contaminants were in the freshwater of the Cocheco, Oyster and Exeter rivers and the tidal portion of the Lam p" re' y' lUer. All of these sites are surrounded by and are dominated upstream by densely populated urban areas, in contrast to the less-densely populated areas surrounding the other tributaries (Bellamy, Salmon Falls, upstream Lamprey rivers). This suggests that either runoff, direct sources, or high densities of either on-site private sewage disposal sites or leaky municipal system pipes are contaminating these tributaries and eventually the estuary. The tidal site in the Lamprey River has been under investigation to locate contamination sources. Results from another study consistently show that the contaminants have a major impact on the water quality of Great Bay at the mouth of the river. The effect of rainfall and associated runoff appears to intensify the nonpoint source contamination problem. In fact, except for the tidal portion of the Cocheco River, levels of bacterial indicators were relatively low at tidal sites for the other tributaries during dry periods compared to wet periods. The strong response to rainfall events, especially at the more urban areas, suggests that the downstream quality of estuarine water is most susceptible to degradation by these events. This was especially true during autumn when the heaviest rainfall events were sampled. Rainstorms recorded at the 10 Durham station are typically heaviest and most frequent during the autumn season (data not shown). A better understanding of sources and the influence of rainfall/runoff events is needed, and should become more clearly defined with a continuation of this study. One of the most critical issues that is affected by nonpoint source microbial contamination is the harvesting of shellfish. There are abundant oyster resources throughout the Great Bay Estuary, although only some areas in Great and Little bays are currently classified as approved in New Hampshire. However, the Maine side of the Piscataqua River is classified as restricted, and it is an active site for commercial shellfishing; the harvested oysters are purified before marketing, as required by law from restricted areas. The continued contamination of these areas by nonpoint source pollution is an issue that needs attention, as increased economic pressures bring greater attention to New Hampshire's untapped shellfish resources. Based on the results of this study, it appears that storm events and urban areas have a large influence on contamination in the tributaries, with only the tidal site in the Squarnscott River and the mouth of Hampton Harbor meeting NSSP criteria (geometric mean = <14 FC/100 ml) for dry periods, with no sites meeting these criteria for wet periods (Table 13; modified data). The splitting of a tidal and freshwater sample each month for analysis by I.-C-_:both involved labs proved to be a useful and necessary exercise to undertake -for- this- study. It is especially important for deciding how to interpret the results. For fecal coliforms, it appeared that the different analytical methods used by the State compared to E. coli analysis caused reported levels to be lower than expected. The exercise of modifying the data to increase some fecal coliform data to becoming equal to E. coli data was based on the fact that E. coli can only constitute a portion or potentially equal concentration relative to fecal coliforms. Because both labs used mTEC medium forE. coli analysis, use of mTEC E. coli data for fecal coliform data allowed for a consistency within data sets including data from both labs, giving a more accurate interpretation of results. The lack of consistent agreement between enterococci data from the two labs is not well understood at this time. Overall Study A number of points pertain to the overall study independent of either category of contaminants studied. First, the splitting of analysis between two labs presented problems in interpreting data for all parameters. This is probably the result of different analytical methods being conducted by the two 11 labs, although efforts may still be needed to standardize common methods. This would include sample processing and holding procedures, as it is obvious that more time before analysis is necessary for the State labs because of the distance between sampling sites and the State labs. The method of splitting samples should also ensure that no inter-sample variability is introduced at that time. Another issue is storm sampling. By taking a single sample on the day following a storm event, it is always possible that sampling could miss the major contamination pulse. However, the consistent trend of higher bacterial levels after wet compared to dry periods suggest that at least part of a contaminant pulse was caught by the sampling that occurred. Other factors that can affect the contamination response following a rainfall event include seasonal influences (temperature, presence of snow, evapotranspiration, etc.), intensity and duration of storms, and conditions prior to events (dry vs. wet). It appeared that for bacterial contaminants, the heavier rainfall events caused relatively greater amounts of contamination to occur at some sites. In addition, the present approach to rainstorm sampling could be improved if more immediate knowledge of the amount of rainfall that has occurred could be made available. At present, JEL personnel prepare for sampling upon hearing of predicted events, then confirm that the sampled event met the -preset criteria only at the beginning of the next month when data for the 15ixr-h-am station are.published. This worked quite well, despite several false starts, although two of eight 'events' did not meet the criteria. Despite these concerns, it appears that some useful trends were apparent from this first year of study on the tributaries to Great Bay Estuary. 12 Table 1. Regression of NH4 concentration for split samples. DES @trn NH4 JEL Wn NH4 6.30 1.84 Regression Statistics 6.30 1.14 6.30 4.82 Multiple R 0.881701893 16.80 18.72 R Square 0.777398228 6.30 10.82 Adjusted R Square 0.758848081 14.00 15.90 Standard Error 1.970582441 7.00 11.97 Observations 14 6.30 5.94 6.30 3.53 14.00 16.23 6.30 0.38 14.70 21-30 6.30 6.25 7.00 .5-60 DES vs. JEL @Lm NH4 25 20 15 LU 1 0 5 0 0 5 10 15 2 0 DES Table 2. Regression of N03 concentration for split samples. DES gm N03 JEL gm N03 8.4 5.13 Regression Statistics 1.26 3.63 13.3 6.27 Multiple R 0.954599147 25.2 35.12 R Square 0.911259531 4.2 8.02 Adjusted R Square 0.903864492 4.2 5.99 Standard Error 6.108090128 9.8 4.42 Observations 14 60.9 65.51 39.9 39.27 54.6 43.61 11.9 6.38 9.1 5.82 11.2 13 39.2 50.31 DES vs. JEL @tm N03 80 60 40 20 .Jam 0 0 20 40 60 80 DES Table I Regression of P04 concentration for split samples. DES lim P04 JEL pm P04 1.271 1.6 Regression Statistics 1.736 2.22 2.046 2.14 Multiple R 0.75891422 1.054 1.41 R Square 0.575950794 2.139 1.29 Adjusted R Square 0.54061336 0.217 0.43 Standard Error 0.468213726 0.93 0.94 Observations 14 0.558 0.78 0.031 0.45 1.395 2.24 1.891 1.06 0.372 0.52 0.558 0.92 1.209 1.43 DES vs. JEL @tm P04 2.5 2 1.5 LU 1 0.5 0 0 0.5 1 1.5 2 2.5 DES TABLE 4. ALL DATA COMBINED -6/14/94 7.00 7.00 9.80 25.90 21.70 7.00 9.80 39.20 32.20 4.20 7.00 5.60 9. 10 -6/22/94 0.06 1.11 2.36 15.91 9.70 0.70, 1 3.54 4.60 39.54 53.92 3.57 4.91 3.20 14.22 MEAN 5.07 5.24 6.18 14.31 11.40 5.66 4,35 32.68 39.79 6.10 5.10 5.33 11.34 P04 CONCENTRATION @tM DATE GB 2 um GB 13 urn GB 15 urn GB 21 urn GB 22 urn GB 50 urn GQ80urn HH IA urn 7 CCH urn 5SFRum 5 BLM urn 5LMPum 9 EXT urn 5 OYS urn -8/24/93 1.18 0.68 1.83 1.27 1.40 1.71 T.27 0.84 0.56 0.22 0.16 0.12 0.12 0.25 9/7/93 1.02 0.71 2.11 0.93 1.05 1.52 1.74 0.96 0.03 0.53 0.03 0.03 0.03 0.03 9/9/93 1.39 1.04 2.92 2.97 1.42 2.58 2.03 0.96 0.38 0.97 0.33 0.17 0.24, 0.29 -9/27/93 1.09 0.94 0.89 0.79 0.90 1.70 1.54 1.11 1.30 0.75 0.37 0.21 0.31 0.20 -10/5/93 0.65 0.90 2.33 0.74 0.68 1.36 2.05 0.65 1.40 0.96 0.12 0.06 0.03 0.06 11/2/93 0.71 0.81 0.62 0.68 0.71 0.99 1.05 1.12 1.02 0.59 0.06 0.28 0.22 0.09 11/18/93 0.72 0.94 0.92 0.97 1.04 1.47 1.51 0.83 1.80 1.42 0.62 0.20 0.35 0.46 -12/6/93 0.53 0.86 0.70 1.39 0.55 1.01 1.00 0.68 1.22 0.42 0.77 0.66- 0.59 0.60 12/20/93 2.51 1.27 0.78 1.12 1.12 1.61 2.14 1.89 0.81 1.30 0.78 0.99 1.05 -4/19/94 0.06 0.56 0.12 0.25 0.31 0.22 0.90 0.37 0.03 0.19 0.03 0.06 5/3/94 0.23 0.31 0.22 0.50 0.39 0.47 0.90 0.54 0.72 0.23 0.24 0.17 0.32 0.28 -5/17/94 0.34 0.37 0.22 0.43 0.40 0.68 0.56 0.22 0.03 0.03 0.12 0.03 5/26/94 0.55 0.59 0.62 0.63 0.62 0.83 1.30 0.58 1.02 0.58 0.39 0.38 0.45 0.45 -6/13/94 0.66 0.79 1.14 1.04 0.95 1.07 0.97 0.59 1.47 1.18 0.32 0.37 0.41 0.27 -6/14/94 0.71 0.65 0.84 0.62 0.81 0.99 0.93 1.21 0.74 0.31 0.28 0.12 0.19 -6/22/94 0.78 0.77 1.04 0.93 0.96 1.22 1.07 0.72 1.38 1.11 0.72 0.48 0.63 0.54 Mean 0.82 0.76 1.08 0.95 0.83 1.21 1.39 0.80 1.05 0.69 0.36 0.28 0.31 0.30 TSS mg/liter DATE GB2 GB 13 GB 15 -dB -21 GB 22 GB 50 GB 80 H H.-I A 7 CCH 5 SFR 5 BLM 5 LMP 9 EXT 5 OYS -8/24/93 8.00 6.00 24.50 20.50 19.00 - 4 0.00 - 41.50 11.00 7.00 9.00 1.50 0,09 1.50 2.50 9/7/93 25.00 5.00 6.00 11.00 13.50 8.00 8.50 11.00 7.00 1.00 5.50 3.00 4.00 1.00 9/9/93 3.80 0.40 3.20 12.80 1.60 2.20 7.80 2.80 7.20 0.60 3.40 0.20 0.80 1.20 -9/27/93 1.60 1.40 18.60 1.60 2.40 3.40 30.60 3.00 5.00 3.00 2.60 1.20 3.40 2.40 -10/5/93 51.00 55.00 37.00 30.00 36.00 52.00 57.00 57.00 3.00 3.00 5.00 5.00 3.00 6.00 11/2/93 14.00 3.00 43.00 19.00 87.00 70.00 36.00 56.00 1.00 3.00 1.00 0.90 2.00 0.09 11/18/93 6.00 3.20 10.00 5.80 4.00 5.40 31.00 9.80 4.60 0.80 7.80 1.00 3.00 9.00 -12/6/93 3.40 13.20 24.60 8.40 4.80 5.00 28.20 6.80 7.60 1.20 4.00 7.80 5.00 9.20 TABLE 4. ALL DATA COMBINED -4119/94 3.00 1.00 12.00 3.00 1.00 4 00 2.00 0.90 1.00 0.90 1.00 1.00 5/3/94 6.20 12.20 2.00 7.40 6.20 10.80 37.00 13.60 4.40 3.20 2.00 0.60 1.80 5.40 -5/17/94 5.50 2.50 12.50 6.00 7.00 5.90 4.00 4.00 2.00 1.00 2.00 4.50 -5/26/94 6.80 4.80 18.40 6.80 7.80 6.60 11.40 2.20 2.00 2.00 0.80 1.00 3.40 -6/13/94 5.40 3.80 9.60, 7.00 7.60 5.80- 40.00 2.60 3.00 4.40 2.20 3.40 2.00 8.80 -6/14/94 5.50 2.00--7.00 5.50 3.50 4.50 35.00 2.00 3.00 2.00 3.001 2.00 9.00 -6/22/94 6.20 6.40 32.20 5.80 5.80 6.40 19.80 3.601 3.20 3.60 2.80 1.20 1.20 4.20 12/20/94 5.00 6.50 19.00 5.00 6.00 5.00 1 17.00 4.80 4.40 3.20 4.00 4.50 4.00 Mean 9.781 7.901 17.48, 9.73, 13.33, 14.66, '35.43 15.72 4.25, 2.94, 3.00 2.13 2.39@ 4.48 TABLE 5. STORM SAMPLING DATA NH 4 CONCENTRATION [tm DATE GB2 GB 13 GB 15 GB 21 GB22 GB50f! GB 80 HH IA 7 CCH 5 SFR 5BLM 5LMP 9 EXT 5 OYS 9/9/93 8.25 2.20 17.23 0.63 2.09 fl ;'8 6' 12.69 4.60 7.12 23.49 1.60 3.02 3.11 2.59 9/27/93 4.02 3.03 3.59 4.07 4.27 '.6.53 12.41 5.45 5.84 12.69 5.26 2.52 3.14 3.68 11/18/93 1.79 1.49 4.07 33.04 26.97 12.10 3.96 1.23 16.33 29.41 0.91 0.34 1.34 0.58 12/6/93 0.06 3.49, 3.17 23.36 9.90, 8.116 7.66 1.20 19.67, 11.72 2.42 2.06, 1.20 73.55 5/3/94 12.85 1.98 2.12 8.09 7.10 1'a5 6.20 1.81 13.58 13.30 2.47 2.04 1.79 2.39 5/26/94 5.11 3.08 4.41 8.69 7.91 5.99 11.09 2.79 14.20 36.86 4.81 4.89 5.13 10.66 6/13/94 4.52 6.78 11.78 9.26 20.02 4.95 11.18 4.51 7.56 30.37 3.44 6.30 2.34 5.10 6/22/94 2.69 19.04 3.35 7.822 8.405 15.81 9.26 3.71 8.45 32.35 5.39 4.96 4.62 10.68 MEAN 4.91 5.14 6.21 11.87 10.83 8.34 9.31 3.16 11.59 23.77 3.29 3.27 2.83 13.65 Splits NH4 8/24/93 5,94 1.84 9/7/93 3.53 1.14 10/5/93 16.23 4.82 11/2/93 0.38 12/20/93 21.30 18.72 4/20/94 10.82 5/18/94 6.25 15.90 6/15/94, 11.97 N03 CONCENTRATION gm DATE GB2 GB13 GB15 GB 21 GB 22 GB50 GB 80 HHlA 7CCH 5SFR 5 BLM 5LMP 9 EXT 5 OYS 9/9/93 1.45 0.38 4.09 0.81 2.19 1.64 8.05 1.22 32.38 76.69 0.37 1.74 7.08 3.94 9/27/93 2.07 1.31 6.32 6.99 5.27 2.37 3.91 1.46 73.07 91.31 0.66 0.97 6.10 4 n4 11/18/93 4.97 9.10 10.17 21.91 12.16 7.06 27.96 7.53 27.41 21.62 9.72 4.79 10.30 25.37 12/6/93 10.05 0.88 15.96 15.42 21.23 8.16 11.67 5.53 16.47 22.71 14.67 7.12 4.92 7.03 5/3/94 5.76 6.81 2.16 3.32 8.62 8.41 10.30 5.31 13.29 11.80 1.39 3.94 1.73 13.95 5/26/94 4.08 1.88 5.43 9.62 5.61 3.85 8.00 0.65 23.38 15.26 5.38 3.43 7.03 16.53 6/13/94 3.91 1.02 4.19 42.43 13.39 3.45 6.07 1.58 44.60 35.30 4.36 4.56 4.54 12.69 6/22/94 0.06 1.11 2.36 15.91 9.70 0.70 3.54 4.60 39.54 53.92 3.57 4.91 3.20 14.22 ,MEAN 4.04, 2.81, 6.33 14.55, 9.77, 4.46, 9.94 3.48, 33.77, 41.08, 5.02, 3.93, 5.61, 12.22, TABLE 5. STORM SAMPLING DATA splits N03 8/24/93 5.13 65.51 63 9/7/93 3. 39.27 10/5/93 6.27 43.61 11/2/93 35.12 12/20/93 8.02 6.38 4120/94 5.82 5/18/94 5.99 13.00 6/15/94 4.42 50.03 P04 CONCENTRATION @tm DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 HHlA 7CCH 5 SFR 5 BLM 5 LMP 9 EXT 5 OYS 9/9/93 1.39 1.04 2.92 2.97 1.42 2.58 2.03 0.96 0.38 0.97 0.33 0.17 0.24 0.29 9/27/93 1.09 0.94, 0.89 0.79 0.90, 1.70 1.54 1.11 1.30 0.75 0.37, 0.21 0.31 0.20 11/18/93 0.72 0.94 0.92 0.97 1.04 1.47 1.51 0.83 1.80 1.42 0.62 0.20 0.35 0.46 12/6/93 0.53 0.86 0.70 1.39 0.55 1.01 1.00 0.68 1.22 0.42 0.77 0.66 0.59 0.60 5/3/94 0.23 0.31 0.22 0.50 0.39 0.47 0.90 0.54 0.72 0.23 0.24 0.17 0.32 0.28 5/26/94 0.55 0.59 0.62 0.63 0.62 0.83 1.30 0.58 1.02 0.58 0.39 0.38 0.45 0.45 6/13/94 0.66 0.79 1.14 1.04 0.95 1.07 0.97 0.59- 1.47 1.18 0.32 0.37 0.41 0.27 6/22/94 0.78 0.77 1.04 0.93 0.96 1.22 1.07 0.72 1.38 1.11 0.72 0.48 0.63 0.54 MEAN 0.74 0.78 1.06 1.15 0.815 1.29 1.29 0.75 1.16 0.83 0.47 0.33 0.41 0.39 splits P04 8/24/93 1.60 0.78 9/7/93 2.22 0.45 10/5/93 2.14 2.24 11/2/93 1.41 12/20/93 1.29 1.06 V 04 55 9 0-@ 0. 3 0. 62 4/20/94 0.52 5/18/94 0.43 0.92 6/1 5-/9-4r 0.94 1.431 TABLE 5. STORM SAMPLING DATA TSS Mg/l DATE GB2 GB 13 GB 15 GB 21 GB 22 GB$0 -'i,GB80 HHlA 7CCH 5SFR 5 BLM 5 LMP 9 EXT 5 OYS 9/9/93 3.80 0.40 3.20 12.80 1.60 2.20 7.80 2.80 7.20 0.60 3.40 0.20 0.80 1.20 9/27/93 1.60 1.40 18.60 1.60 2.40 3.40 30.60 3.00 5.00 3.00 2.60 1.20 3.40 2.40 11/18/93 6.00 3.20 10.00 -- 5.80 4.00 5-4.0 3 1. 0 0 9.80. 4.60 -0.80 7.80 1.00---- 3.00- 9.00 12/6/93 3.40 13.20 24.60 8.40 4.80 5.00 28.20 6.80 7.60 1.20 4.00 7.80 5.00 9.20 5/3/94 6.20 12.20 2.00 7.40 6.20 10.80 37.00 13.60 4.40 3.20 2.00 0.60 1.80 5.40 5/26/94 6.80 4.80 18.40 6.80 7.80 6.60 106.67 11.40 2.20 2.00 2.00 0.80 1.00 3.40 6/13/94 5.40 3.80 9.60 7.00 7.60 5.80 40.00 2.60 3.00 4.40 2.20 3.40 2.00 8.80 6/22/94 6.20 6.40 32.20 5.80 5.80 6.40 19.80 3.60 3.20 3.60 2.80 1.20 1.20 4.20 MEAN 4.93 5.68 -14.83 6.95 5.03 5.70 37.63 6.70 4.65 2.35 3.35 2.03 2.28 5.45 % ORGANIC DATE GB2 GB 13- GB 15 GB 21 GB 22 GB 50 GB 80 HH 1 A 7 CCH 5 SFR - 5 BLM 5 LMP 9 EXT 5 OYS I - 9/9/93 21.05 50.001 37.50 41.25 52.50 18.18 30.77 21.43 52.78 55.00 58.82 57.00 57.00 62.00 9/27/93 51.00 24.301 9.68 33.33 50.00 23.53 16.99 40.00 64.00 66.67 92.31 66.67 62.35 63.33 11/18/93 26.67 37.501 22.00 34.48 45.00 25.93 16.13 24.49 47.83 50.00 30.77 80.00 60.00 31.11 12/6/93 41.18 21.211 16.26 30.95 37.50 24.00 17.02 32.35 26.32 83.33 60.00 28.21 40.00 26.09 5/3/94 12.90 13.111 50.00 24.32 19.35 20.37 14.41 19.12 36.36 43.75 30.00 66.67 55.56 33.33 5/26/94 26.47 25.00 15.22 29.41 25.64 12.12 15.00 15.79 63.64 60.00 50.00 100.00 80.00 47.06 6/13/94 22.22 15.79 22.92 28.57 23.68 17.24 12.00 38.46 40.00 72.73 63.64 23.53 80.00 45.45 6/22/94 25.81 25.00 13.04 31.03 34.48 18.75 14.14 44.44 56.25 77.78 64.29 83.33 100.00 52.38 MEAN 28.41 26.49 23.33 31.67 36.02 20.02 17.06 29.51 48.40 63.66 56.23 63.18 66.86 45.09 ---I I TABLE 5. STORM SAMPLING DATA SALINITY ppt DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 HHlA 7CCH 5SFR 5 BLM 5 LMP 9 EXT 5 OYS - . 1 9/9/93 32.00 31.00 24.00 24.00 23.00 3 0.'0 0 22.90 31.00 0.00 0.00 0.00 0.00 0.00 0.00 9/27/93 29.50 31.00 22.00 23.50 22.50 29.50 24.00 31.00 0.00 0.00 0.00 0.00 0.00 0.00 11/18/93 26.00 29.50 6.00 7.80 13.00 25.20 9.00 25.00 0.00 0.00 0.00 0.00 0.00 0.00 12/6/93 24.00 25.00 3.00 0.00 0.00 23.@O 2.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5/3/94 19.00 24.00 0.00 5.00 4.50 20.00 0.00 25.00 0.00 5/26/94 17.50 23.00 5.50 5.50 5.20 16.50 2.00 24.00 0.00 0.00 0.00 0.00 0.00 0.00 6/13/94 22.00 26.00 16.00 5.00 6.00 21.00 14.00 28.00 6/22/94 24.00 -19.00 15.80 15.50 23.50 17.00 1 - MEAN 24.25 27.07 11.94 10.83 11. 1 23.65 11.43 23.43 0.00 0.00 0.00 0.00 0.00 0.00 TEMPE@ATUA DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 HHlA 7CCH 5 SFR 5 BLM 5 LMP 9 EXT 15 OYS 9/9/93 20.00 16.00 21.10 21.00 21.00 19.60 22.20 16.50 9/27/93 14.50 13.00 15.50 15.00 15.00 14.50 15.50 13.00 11/18/93 7.20 7.00 4.80 6.00 7.20 7.20 4.90 8.00 6.00 5.90 7.00 7.00 7.50 6.50 12/6/93 5.50 5.50 4.80 3.00 4.00 5.20 4.00 6.00 4.50 4.00 3.50 3.50 6.80 4.00 5/3/94 12.00 10.00 13.00 13.00 13.00 11.80 13.00 10.00 11.40 11.20 11.00 13.00 12.50 11.50 5/26/94 14.00 16.80 16.00 15.80 14.50 17.20 17.20 16.50 15.50 17.50 17.50 16.50 6/13/94 18.50 19.80 22.00 20.90 18.80 21.00 22.30 23.70 22.10 6/22/94 21.50 22.20 23.00 23.00 22.00 23.50 28.30 24.10 28.80 25.90 27.10 28.20 MEAN 14.15 10.30 14.75 14.88 14.99 14.20' 15.16 10.70 13.48 14.00 14.92 13.38 14.28 14.80 TABLE 5. STORM SAMPLING DATA PH DATE GB2 GB 13 GB 15 GB 21 GB 22 GB,5.0 GB 80 HH 1A 7CCH 5 SFR 5 BLM 5 LMP 9 EXT 5 OYS - 9/9/93 7.90 7.97 7.77 8.01 8.05 7.66 8.05 7.45 7.16 7.12 7.23 7.15 7.45 9/27/93 7.98 8.11 7.45 8.03 8.01 .7.99 7.96 7.94 7.55 7.46 7.43 7.30 7.21 7.24 11/18/93 7.90 8.04 7.73 7.52 7.57 7.95 7.57 7.85 7.12 6.86 6.90 6.89 6.77- 7.27 12/6/93 7.69 7.77, 7.22 7.23 6.92 744, 6.90 7.61 6.99 7.45, 6.86 7.28 7.54 6.93 5/3/94 5/26/94 6/13/94 6/22/94 MEAN 7.87 7.97 7.54 7.70 7.64 7.81 7.52 7.86 7.28 7.23 7.08 7.18 7.17 7.22 D.O. mg/l DATE GB 2 GB 13 GB 15 GB 21 GB22 GB50 GB80 HHIA 7CCH 5SFR 5 BLM 5 LMP 9 EXT 5 OYS 9/9/93 7.40 8.20 7.30 6.20 6.20 7.60 5.90 7.60 9/27/93 8.20 8.40 7.00 6.00 6.20 8.20 7.20 8.00 11/18/93 9.60 11.40 9.80 9.50 12.20 10.60 11.40 12.20 12.20 12.40 12/6/93 10.20 14.50 10.50 12.70 5/3/94 10.50 10.40 9.90 10.45 5/26/94 7.70 9.00 8.00 7.70 7.80 6.80 6/13/94 7.20 7.10 7.60 5.90 6/22/94 6.00 5.00 7.10 7.20 6.20 5.90 MEAN 8.35, 8.30, 8.32, 8.18, 7.83, 8.48, 7.40, 7.80 12.20 10.60 11.40, 12.20 12.20, 12.40, TABLE 6. DATA FROM RANDOM SAMPLING BY STATE PERSONNEL NH 4 CONCENTRATION @Lm DATE GB2um GB13um GB15um GB21um GB22um GB50 ur@ qWPO um HHlA um XCH um 5 SFR um 5 BLM um 5 LMP urr 9 EXT um 50ysum -8/24/94 6.30 6.30 6.301 6.30 6.30 6.3b 6.30 6.30 6.30 6.30 6.30 6.301 6.30 6.30 - 9/7/94 6.30 6.30 6.30 6.30. 6.30 6.30. 6.30 6.30 6.30 6.30 6.30 6.301 6.30 6.30 -10/5/94 6.30 6.30 6.30 6.30 7.00 6.30 14.00 6.30 6.30 28.00 6.30 6.301 6.30 6.30 11/2/94 6.30 6.30 6.30 7.00 7.70 7.00 6.30 6.30 7.70 9.10 6.30 6.30 6.30 6.30 -12/20/94 6.30 6.30 6.30 13.30 9.10 6.30 14.70 6.30 16.80 7.70 6.30 6.30 6.30 6.30 -4/19/94 6.30 6.30 6.30 6.30 6.30 6.30 6.30 6.30 6.30 6.30 6.30 6.30 5/17/94 6.30 7.00 6.30 7.00 6.30 6.30 14.00 14.00 6.30 6.30 6.30 6.30 -6/14/94 6.30 6.30 6.30 6.30 14.00 6.30 7.00 7.00 21.00 6.30 6.30 6.30 6,30 6.30 6.39 6.30 7.50 7.88 6.39 9.10 6.30 8.84 12.34 6.30 6.30 6.30 6.30 SM DEV 0.00. 0.25. 0.00 2.58 2.67 0.25 4.08 0.00 4.15 8.15 0.00 0.00 0.00 0.00 N03 CONCENTRATION @Lm I - - - DATE GB2 um GB 13 urr GB1 5 um GB 21 um GB22 um GB50 um GB80um HH 1A um 7 CCH um 5 SFR um 5BLM um 5LMPum 9 EXT um 5 OYS um -8/24/94 1.26 1.26 3.50 8.40 4.20 2.80 8.40 1.26 60.90 44.10 1.26 1.26 5.46 1.26 9/7/94 1.26 1.26 1.26 1.26 1.26 1.40 1.26 7.70 39.90 84.00 1.26 1.26 1.261 1.26 10/5/94 4.20 6.30 9.10 28.00 29.40 4.90 13.30 6.30 54.60 94.50 25.20 18.20 2.10 12.60 11/2/94 5.60 11.20 7.00 18.20 18.20 4.90 25.20 9.10 25.20 21.70 8.40 4.90 4.20 23.10 -12/20/94 14.70 21.70 7.70 11.20 11.20 16.80 4.20 11.90 11.90 8.40 7.00 12.60 16.10 4/19/94 9.80 8.40 5.60 10.50 9.80 8.40 9.80 9.10 3.15 6.30 5.60 11.20 - 5/17/94 4.90 4.20 4.20 9.10 8.40 9.10 11.20 10.50 5.60 4.20 3.50- 9.10 - 6/14/94 7,00 7.00 9.80 25.90 .21.70 7.00 9.80- 39.20 32.20 4.20 7.00 5.60 9.10 MEAN 6.09 7.67 6.02 14.07 13.02 6.91 10.36 6.09 31.59 38.50 7.18 6.27 5.04 10.47 STD DEV 4.48 6.62 2.93 9.20 9.42 4.78 8.41 3.42 20.12 33.63 7.80 5.34 3.46 7.27 P04 CONCENTRATION @tm P 6 ---7- 6 6 6 IDATE___LGB 2 um IGB_13 um JGB 15 um GB 21 um]GB 22 um JGB 50 um GB 80 um HH 1A umJ7 CCH um 15 SFR um 5 BLM um 5 LMP um 19 EXT um 5 OYS um TABLE 6. DATA FROM RANDOM SAMPLING BY STATE PERSONNEL 8/24/94 1.18 0.68 1.83 1.27 1.40 1.71 7 0.84 0.56 0.22 0.16 0.12 0.12 0.25 9/7/94 1.02 0.71 2.11 0.93 1.05 1.5Z 1.74 0.96 0.03 0.53 0.03 0.03 0.03 0.03 10/5/94 0.65 0.90 2.33 0.74 0.68 1.3& Z.U 0.65 1.40 0.96 0.12 0.06 0.03 0.06 11/2/94 0.71 0.81 0.62 0.68 0.71 -0.99 1.05 1.12, 1.02 0.59 0.06 0.28 0.22 0.09 -12/20/94 2.51 1.27 0.78 1.121 1.12 1. 6 1' 2.14 1.89 0.81 1.30 0.78 0.99 1.05 -4/19/94 0.06 0.56 0.12 0.25 0.31 0.22 0.90 0.37 0.03 0.19 0.03 0.06 5/17/94 0.34 0.37 0.22 0.43 0.40 0.68 0.56 0.22 0.03 0.03 0.12 0.03 6/14/94 0.71 0.65 0.84 0.62 0.81 0.99 0.93 1.21 0.74 0.31 0.28 0.12 0.19 1 MEAN 0.90 0.74 1.10 0.76 0.81 1.14 1.53 0.89 0.95 0.55 0.25 0.22 0.21 0.22 STD DEV 361.37 0.27 0.86 0.34 0.37 0.51 0.52 0.20 0.57 0.27 0.43 0.25 0.32 0.35 TSS mg/liter DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 HH 1A 7 CCH 5 SFR 5 BLM 5 LMP 9 EXT -5 OYS 8/24/94 8.00 6.00 24.50 20.50 19.00 40.00 41.50 11.00 7.00 9.00 1.50 0.09 1.50 2.50 9/7/94 25.00 5.00 6.00 11.00 13.50 8.00 8.50 11.00 7.00 1.00 5.50 3.00 4.00 1.00 10/5/94 51.00 55.00 37.00 30.00 36.00 52.00 57.00 57.00 3.00 3.00 5.00 5.00 3.00 6.00 11/2/94 -14.00 3.00 43.00 19.00 87.00 70.00 36.00 56.00 1.00 3.00 1.00 0.90 2.00 0.09 -12/20/94 5.00 6.50 19.00 5.00 6.00 5.00 17.00 4.80 4.40 3.20 4.00 4.50 4.00 4/19/94 3.00 1.00 12.00 3.00 1.00 4.00 2.00 0.90 1.00 0.90 1.00 1.00 5/17/94 5.50 2.50 12.50 6.00 7.00 5.50 4.00 4.00 2.00 1.00 2.00 4.50 6/14/94 5.50 2.00 7.00 5.50 3.50 4.50 35.00 2.00 3.00 2.00 3.00 2.00 9.00 MEAN 14.63 10.13 20.13 12.50 21.63 23.63 32.50 33.75 3.85 3.54 2.65 2.24 2.50- 3.51 STD DEV 16.34 18.24 13.75 9.65 28.70 26.44 17.41 26.27 2.28 2.54 1.75 1.76 1.22 3.00 % ORGANIC DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 HH 1 7 CCH 5 SFR 5 BLM 5 LMP 9 EXT 5 OYS 8/24/93 31.25 16.67 24.49 36.59 34.21 30.00 27.71 27.27 TABLE 6. DATA FROM RANDOM SAMPLING BY STATE PERSONNEL 8/24/94 1.18 0.68 1.83 1.27 1.40 -1.,71- 1., 1.27 0.84 0.56 0.22 0.16 0.12 0.12 0.25 9/7/94 1.02 0.71 2.11 0.93 1.05 1.5a 1.74 0.96 0.03 0.53 0.03 0.03 0.03 0.03 10/5/94 0.65 0.90 2.33 0.74 0.6B i !@@i,'1'2.05 0.65 1.40 0.96 0.12 0.06 0.03 0.06 11/2/94 0.71 0.81 0.62 0.68 0.71 1.05 1.12 1.02 0.59 0.06 0.28 0.22 0.09 12/20/94 2.51 1.27 0.78 1.12 1.12 1.151 2.14 1.89 O.Bl 1.30 0.78. 0.99 1.05 4/19/94 0.06 0.56 0.12 0.25 0.31 0.22 0.90 0.37 0.03 0.191 0.03 0.06 5/17/94 0.34 0.37 0.22 0.43 0.40 0.68, 0.56 0.22 0.03 0.031 0.12 -0.03 6/14/94 0.71 0.65 0.84 0.62 0.81 -0.99 0.93 1.21 0.74 0.31 0.281 0.12 0.19 MEAN 0.90 0.74 1.10 0.76 0.81 1.14 1.53 O.B9 0.95 0.55 0.25 0.22 0.21 0.22 STD DEV 361.37 0.27 0.86 0.34 0.37 0.51 0.52 0.20 0.57 0.27 0.43 0.25 0.32, 0.35 TSS mg/liter DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 HH 1A 7 CCH 5 SFR 5 BLM 5 LMP 9 EXT 5 OYS 8/24/94 8.00 6.00 24.50 20.50 19.00 40.00 41.50 -11.00 7.00 9.00 1.50 0.09 1.50- 2.50 9/7/94 25.00 5.00 6.00 11.00 13.50 8.00 8.50 11.00 7.00 1.00 5.50 3.00 4.00 1.00 10/5/94 51.00 55.00 37.00 30.00 36.00 52.00 57.00 57.00 3.00 3.00 5.00 5.00 3.00 6.00 1 1/2/94 14.00 3.00 43.00 19,00 87.00 70.00 36.00 56.00 1.00 3.00 1.00 0.90 2.00 0.09 -12/20/94 5.00 6.50 19.00 5.00- 6.00 -5. 0 0 - 17. 0 0 4.80 4.40 3.20 4.00 4.50 4.00 - 4/19/94 3.00 1.00 12.00 3.00 1.09 4.00--- 2.00 0.90 1.00 0.90. 1.00 1.00 - 5/17/94 5.50 2.50 12.50 6.00 7.00 5.50- 4.00 4.00 2.00 1.00 2.00 4.50 6/14/94 5.50 2.00 7.00 5.50- 3.50 4.50 35.00 2.00 3.00 2,00 3.00 2.00 9.00 MEAN 14.63 10.13 20.13 12.50 21.63 23.63 32.50 33.75 3.85 3.54 2.65 2.24 2.50 3.51 STD DEV 16.34 18.24 13.75 9.65 28.70 26.44 17.41 26.27 2.28 2.54 1.75 1.76 1.22 3.00 % ORGANIC DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 HH 1A 7 CCH 5 SFR 5 BLM 5 LMP 9 EXT 5 OYS 1 10*1 3 178124 8/24/93 31.251 16.67 24.49 36.59 34.21 30.00 27.71 27.27 TABLE 6. DATA FROM RANDOM SAMPLING BY STATE PERSONNEL 9/7/93 32.00 20.00 33.33 54.55 51.85 2 5 0 0 0 4. 17.65 10/5/93 23.53 1.82 35.14 26.67 16.67 17.31 21.05 21.05 11/2/93 7.14 18.60 21.05 18.39 25.71 16.67 19.64 12/20/93 20.00 15.38 13.16 25.00 ; 117.65 4/19/94 33.00 100.00 8.33 33.00 100.00 25.00 5/17194 6/14/94 MEM 24.49 30.77 22.18 34.37, 41.02 24.60 20.15 22.65, #DIV/O! #DIV/O! #DIV/O! #DIV/O! #DIV/01 #DIV/01 STD DEV 9.97 39.31 10.80 12.75 31.64 4.58 4.54 4.06 #DIV/O! #DIV/O! #DIV/01 #DIV/01 #DIV/01 #DIV/O! SALINITY DATE GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB 80 t -HH 1A 7 CCH 5 SFR 5 BLM 5 LMP 9 EXT 5 OYS 8/24/93 26.00 26.00 23.50 21.00 23.50 27.00 22.00 0.00 0.00 0.00 0.00 26.00 0.00 9/7/93 30.00 30.50 27.00 20.00 21.00 30.00 28.00 0.00 0.00 0.00 0.001 30.50 0.00 10/5/93 26.00 29.00 14.00 10.001 12.00 26.00 18.00 29.00 0.00 0.00 0.00 0.00 29.00 0.00 11/2/93 22.00 26.00 8.00 2.00 3.00 22.00 8.00 28.00 0.00 0.00 0.00 0.00 26.00 0.00 12/20/93 14.00 24.00 0.00 0.00 0.00 13.00 0.00 29.00 0.00 0.00 0.00 0.00 24.00 0.00 4/19/94 10.00 25.00 0.00 2.00 6.00 12.00 0.00 0.00 0.00 0.00 25.00 0.00 5/17/94 14.00 23.00 2.00 1.00 12.00 0.00 -0.00 0.00 0.00 0.00 6/14/94 0.00 0.00 0.00 0.00 0.00 MEAN 20.29 26.21 12.08 8.14 9.50 20.29 15.20 28.67 0.00 0.00 0.00 0.00- 26.75 0.00 STD DEV 7.61, 2.67, 11.53 9.03 9.59 7.80 11.19 0.58 0.00 0.00 0.00 0.00 2.48 0.00 Table 6A. Rainfall conditions relative to sampling dates and classification based on the following criteria: Wet=>0.25" prior to sampling on sample date and previous day; Dry=<0.25". Inches of rain Sampling on sample date Condition DATE Agency & previous day classification 24-Aug-93 DES 0/0 Dry 7-Sep DES 0/0 Dry 9-Sep JEL 0.5/0.66 Wet 27-Sep JEL 1.19/2.16 Wet 5-Oct DES 0.0510.05 Dry 2-Nov DES trace/0.6 Wet 18-Nov JEL 0.83/1.15 Wet 6-Dec JEL 0/1.55 Wet 20-Dec DES trace/0.05 Dry 19-Apr-94 DES 0.05/0.05 Dry 3-May JEL 0/0.06 Dry 17-May DES 0.25/0.6 Wet 26-May JEL trace/0.42 Wet 13-Jun JEL 0.45/0.8 Wet 14-Jun DES 0.03/0.48 Wet 22-Jun JEL 0/0.19 Dry Table 7. Split sample analysis of bacterial indicators by State and JEL labs. Fecal coliforms JEL STATE JEL STATE DATE Freshwater Sites Tidal Sites 24-Aug 1260 220 9.5 7 7-Sep 293 133 9 5 5-Oct TNTC 166 25 6 2-Nov ND 48 76 67 20-Dec 84 22 83 46 19-Apr 48 29 36 20 17-May 150 112 82 55 Overall data 14-Jun 5 200 5 23 JEL State Geometric mean 101.9 86.5 25.8 18.9 46.5 36.3 Standard deviatioi 6.4 2.7 3.1 2.8 4.9 3.5 E. cot! JEL STATE JEL STATE DATE Freshwater Sites Tidal Sites 24-Aug 1250 1390 9.5 6 7-Sep 193 240 9 6 5-Oct TNTC 330 12.5 13 2-.Nov -ND 80 38 90 20-Dec -76 25 76 51 19-Apr 26 21 27 34 17-May 138 90 78 61 Overall data 14-Junj 4 189 0.8 16 JEL State Geometric mean 80.1 120.0 16.4 22.7 32.3 46.4 Standard deviatioi 7.0 4.8 4.4 2.8 6.2 4.5 Enterococci JEL STATE JEL STATE DATE Freshwater Sites Tidal Sites 24-Aug 48 70 1.5 9 7-Sep 25 50 3 9 5-Oct 72 80 6 10 2-Nov ND 60 111 60 20-Dec 12 20 51 40 19-Apr 0 9 6 6 17-May 20 20 7 7 Overall data 14-Jun, 29 130 10 10 JEL State Geometric mean 14.8 31.7 10.8 17.9 12.4 22.9 Standard deviatioi 5.9 2.4 4.4 3.2 4.7 2.8 Table 8. Regression analysis of fecal coliform concentrations for paired split samples. Fecal coliform NTN per 100 ml JEL DES: raw DES: modified Regression Statistics: raw data 1260 220 1390 R Square 0.45 293 133 240 Standard Error 55.14 84 22 25 Observations 14 48 29 29 150 112 112 Regression Statistics: modified data 5 200 200 R Square 0.97 9.5 7 7 Standard Error 61.20 9 5 6 Observations 14 25 6 13 76 67 90 83 46 51 36 20 34 82 55 61 5 23 23 1 JEL fecal coliform levels compared to paired DES (modified) levels. 1500 1000 500 0 0 500 1000 1500 DES Table 9. Regression analysis of E. coli concentrations for paired split samples. E. COU NTN per 100 ml JEL DES Regression Statistics: 1250 1390 R Square 0.97 193 240 Standard Error 61.86 76 25 Observations 14 26 21 138 90 4 189 9.5 6 9 6 12.5 13 38 90 76 51 27 34 78 61 0.8 16 JEL E. coli levels compared to paired DES levels. 1400 1200 1000 04 800 600- 400 t 2007 _ 0 a- ---------------4 0 200 400 600 800 1000 1200 1400 DES Table 10. Regression analysis of enterococci concentrations for paired split samples. Enterococci NTN per 100 ml JEL DES Regression Statistics: 48 70 R Square 0.36 25 50 Standard Error 30.27 72 80 Observations 15 12 20 0.5 9 20 20 29 130 1.5 9 3 9 6 10 ill 60 51 40 6 6 7 7 10 10 JEL enterococci levels compared to paired DES levels. 140 120 100 80 60 40 20 t N 0 0 0 20 40 60 80 100 120 DES Ij Table 11. Bacterial indicator concentrations at all study sites sampled by JEL following rain storms. FECAL COLIFORMS DATE 5-SFR 7-CCH 5-BLM 5-OYS 5-LMP 9-EXT GB22 GB21 GB2 GB50 GB15 GB80 GB13 HH1A 9-Sep 10 3110 103 660 40 1240 258 1180 10.5 4.5 160 17.5 35 464 27-Sep 14 2800 36 1160 30 820 100 140 19.5 2.5 3040 280 190 40 18-Nov 132 3600 180 1520 50 460 405 645 210 54.5 200 160 165 84 6-Dec 120 360 90 420 328 260 110 540 75 58 360 15 3-May 73 59 53 100 19 77 27 86 14 2.25 27 86 56 49 26-May 143 102 85 210 16 115 111 295 47 55 165 60 6.25 61.25 13-Jun 40 325 130 3200 70 210 5700 5500 35 52.5 355 22.5 5 40 22-Jun 217.5 72.5 220 75 15 32.5 55 100 6.25 11.25 100 70 5.5 2.75 Geom. ave. 61 447 97 472 40 228 180 410 29 15 220 67 25 47 E. COLI DATE 5-SFR 7-CCH 5-BLM 5-OYS 5-LMP 9-EXT GB22 GB21 GB2 GB50 GB15 GB80 GB13 HHIA 9-Sep 4 1300 53 310 25 480 186 820 9 4.5 110 12 23 420 27-Sep 7 2200 18 880 20 640 100 120 19.5 2.5 2990 270 134 40 18-Nov 53 3200 172 1300 44 440 320 625 198 41 200 150 130 84 6-Dec 108 240 90 420 323 240 90 350 60 53 340 10 --3-May 47 -47 43 59 18 67 15 70 3.25 1.25 27 64 56 47 98 9 83 130 15 112.5 43 200 16.5 54 142 20 6.25 55 13-Jun 35 305 115 3000 60 195 500 4200 33.75 52.5 425 17.5 3 40 22-Jun 127.5 37.5 220 75 14 27.5 45 100 6.25 8.75 100 62.5 5 1.25 Geom. ave. 37 239 78 356 34 184 97 326 20 13 209 49 20 41 ENTEROCOCCI DATE 5-SFR 7-CCH 5-BLM 5-OYS 5-LMP 9-EXT GB22 GB21 GB2 GB50 GB15 GB80 GB13 HHIA 9-Sep 8.5 85 10 28 80 100 68.5 52.5 74 72 60 92 15 73 27-Sep 8 268 10 262 17.5 80 24 14 98 0.8 4180 30 118 60 18-Nov 13.5 120 700 1930 84 233 190 265 240 70 200 400 70 98 6-Dec 52 210 240 1020 403 505 265 345 260 196 350 75 3-May 3 5 12 50 9 4 14 6 0.5 10 10 14 8 14 26-May 30.5 37 43.5 102 3 16 16 124 17 59 112.5 135 10 55 13-Jun 46 90 22 75 155 7.5 60 257.5 19 10 60 5 3 32 22-Jun 3 39 14 50 11.5 20 3 0.8 9 3 10 0.8 1 3 Geom. ave. 13 66 36 151 35 42 37 42 30 19 102 26 15 32 Table 12. Bacterial indicator concentrations at all study sites sampled NH DES under random meteorological conditions. FECAL COLIFORMS DATE 5-SFR 7-CCH 11-CCH 22-CCH 5-BLM 5-OYS 8-OYS 5-U@V,@,9@P-XT 14-EXT GB2 GB13 GB15 GB21 GB22 GB50 GB80 HHIA 24-Aug 4 220 3 6 4 6 5 0.8 60 54 11 1 7 10 7-Sep 2 133 7 5 5 51 1 1 15 74 8 4 5 5 5-Oct 4 166 6 13 2 1 8 8 1 50 91 41 0.8 6 26 2-Nov 220 48 168 122 16 '105' 60 5 43 183 220 14 67 8 20-Dec 23 22 2 9 6 5 12 49 177 47 4 46 19-Apr 29 12 7 8 4 26 2 20 20 29 30 0.8 17-May 98 112 125 75 71 183 145 46 220 220 20 11 55 146 36 31 14-Jun 200 200 112 92 133 158 200 24 57 18 28 2 70 330 106 22 23 -Geom. ave. 23 78 118 83 15 24 170 8 33 63 8 3 41 106 38 4 16 10 E. COLI DATE 5-SFR 7-CCH 11-CCH 22-CCH 5-BLM 5-OYS 8-OYS 5-LMP 9-EXT 14-EXT GB2 GB 13 GB 15 GB21 GB22 GB50 GB90 HHIA 24-Aug 6 1390 4 21 3 12 4 0.8 115 63 6 4 6 11 7-Sep 1 240 10 20 4 98 2 3 18 137 27 7 6 9 5-Oct 6 330 3 41 3 10 15 3 131 108 88 2 13 25 2-Nov 280 80 280 140 40 190 90 10 50 230 200 30 90 8 20-Dec 46 25 6 23 15 19 4 11 61 140 44 11 51 19-Apr 21 21 8 10 8 16 4 23 34 22 8 3 17-May 130 90 140 160 79 360 160 52 240 800 28 7 64 190 47 32 14-Jun 280 189 169 95 110 133 192 30 62 -21 4 5 105 220 97 14 16 Geom. ave. 28 129 154 123 19 48 175 11 42 130 8 5 61 114 38 8 18 12 ENTEROCOCCI DATE 5-SFR 7-CCH 11-CCH 22-CCH 5-BLM 5-OYS 8-OYS 5-LMP 9-EXT 14-EXT GB2 GB13 GB15 GB21 GB22 GB50 GB80 HH1A 24-Aug 10 70 10 9 10 9 9 9 9 10 9 9 9 40 7-Sep 10 50 60 10 20 20 10 9 9 9 9 9 9 9 5-Oct 9 80 9 20 9 9 10 9 50 40 20 9 10 30 2-Nov 110 60 270 390 70 250 40 20 60 100 90 20 60 20 20-Dec 10 20 9 io 50 9 10 10 40 50 30 9 40 19-Apr 9 9 10 9 20 10 9 9 9 10 10 9 17-May 20 20 300 30 70 170 30 9 80 170 30 10 60 90 20 20 14-Jun 70 130 30 20 20 110 70 9 60 10 20 9 50 240 40 9 10 Geom. ave. 18 41 95 24 26 32 46 18 25 41 14 10 27 37 21 11 16 22 Table 13. Geometric average concentrations for bacteria] indicatprs at all sites common to JEL and DES. 15-SFR 7-CCH 5-BLM 5-OYS 5-LMP 9-EXT GB22 GB21 GB2 GB50 GB15 GB80 GB13 HHIA FECAL COLIFORMS JEL 61.4 447.2 96.8 472.0 39.8 228.2 179.5 410.3 28.7 15.0 220.3 67.5 25.1 47.1 DES 23.5 78.1 15.2 23.7 8.0 32.8 7.8 .3.5 40.5 106.4 37.9 4.2 15.7 10.1 DES (modified) 31.5 133.9 20.7 48.7 12.1 44.9 11.0 5.7 60.9 127.3 50.2 8.9 19.7 12.0 Combined 38.0 186.8 38.3 105.7 17.9 86.5 37.4 37.7 34.1 40.0 91.4 15.4 20.5 26.9 Combined (modified) 44.0 244.7 44.8 151.6 21.9 101.2 44.4 48.3 41.8 43.7 105.2 22.9 22.6 28.6 Wet 72.4 419.5 100.6 471.8 41.8 250.4 142.6 129.5 45.8 45.9 228.9 42.2 30.7 55.9 Wet (modified) 79.7 444.0 107.7 516.5 48.1 272.6 154.9 154.9 49.5 48.5 235.7 46.6 31.9 55.9 Dry 16.5 66.1 11.1 15.5 6.0 22.1 6.7 7.7 23.4 33.5 28.1 4.8 12.0 11.2 Dry (modified) 20.5 113.8 14.5 31.3 8.0 28.3 17.2 15.3 33.7 38.3 37.2 10.2 14.3 12.8 E. COLI JEL 36.7 238.9 77.7 355.8 33.6 184.0 96.9 325.7 19.8 12.9 209.0 49.0 19.5 40.6 DES 27.8 129.4 18.5 47.6 11.3 42.2 8.1 5.3 60.9 113.5 38.2 8.4 18.0 11.9 Combined 31.9 175.8 38.0 130.2 19.5 88.1 28.1 41.6 34.7 38.2 89.4 19.1 18.9 26.0 Wet 56.2 272.2 88.8 418.0 41.9 232.8 78.7 122.8 41.8 44.4 220.5 35.1 23.9 54.0 Dry 15.4 100.3 12.7 29.1 7.3 25.3 7.5 10.4 27.3 31.6 28.0 9.6 13.7 10.8 ENTEROCOCCI JEL 12.5 66.3 35.8 151.4 35.1 41.6 36.8 42.3 30.0 18.5 102.1 26.1 14.7 31.6 DES 18.3 40.9 25.6 32.3 17.8 25.4 14.5 10.2 26.8 37.5 20.8 11.0 16.4 21.6 Combined 15.1 52.1 30.3 69.9 25.0 32.5 23.1 20.8 28.3 26.4 46.1 16.5 15.4 27.5 Wet 27.9 87.4 56.7 210.3 36.8 80.1 49.9 53.9 66.8 46.5 126.9 35.8 25.3 49.7 Dry 6.9 26.8 13.5 17.0 15.2 10.2 8.6 6.1 9.4 12.7 12.5 6.8 8.0 13.5 Table 14. Concentrations and geometric mean levels (per 100 ml) of bacterial indicators at routine freshwater sampling sites and sites upstream of routine sites. FECAL COLIFORMS DATE 7-CCH 11-CCH 22-CCH 5-OYS 8-OYS 9-EXT 14-EXT 24-Aug 220 6 6 7-Sep 133 5 51 5-Oct 166 13 8 2-Nov 48 122 105 20-Dec 22 9 16 19-Apr 12 8 26 17-May 112 125 75 183 145 220 220 14-Jun 200 112 92 158 200 57 18 Geometric average 78 118 83 24 170 33 63 E. COLI DATE 7-CCH 11-CCH 22-CCH 5-OYS 8-OYS 9-EXT 14-EXT 24-Aug 1390 21 12 7-Sep 240 20 98 5-Oct 330 41 10 2-Nov 80 140 190 20-Dec 25- 23 19 'I-O-Apr 2-1. 10 16 O:iby 90 140 160 360 160 240 800 14-Jun 189 169 95 133 192 62 21 Geom. ave. 1 129 154 123 48 175 42 130 ENTEROCOM DATE 7-CCH 11-CCH 22-CCH 5-OYS 8-OYS 9-EXT 14-EXT 24-Aug 70 9 9 7-Sep 50 10 20 5-Oct 80 20 9 2-Nov 60 390 250 20-Dec 20 10 9 19-Apr 9 9 10 17-May 20 300 30 170 30 80 170 14-Jun 130 30 20 110 70 60 10 Geom. ave. 41 95 24 32 46 25 41 DURHAM MAINE 43 0 5'- 66k5 GREAT BAY PORTSMOUTH NEW HAMPSHIRE q-Ex.r ATLANTIC OCEAN 4255- 10 km 7055 70 45' Figure 1. Sampling sites for the tributary NPS study: 1993-94. FIGURE 1 A. MEAN NI-14 CONCENTRATION FOR ALL SAMPLE%c COMBINED 18.00-/' 16.00" 14.00" 12.00- 10.00- Z-@ -- Z. --8.00-'/ uj 6.00-" 4.00-/ 2.00' 0.00-r/ ------ r- I I I i I I C) x c\j cc: N N EL Lo ce) u- co :E T- co co m w m m U) co m 0 _3 0 ca Lo Lo to to FIGURE 2. MEAN N03 CONCENTRATION FOR ALL SAMPLES COMBINEE 40-" 35--@ 3 0 25' cn 0 ,@z 20-/ -Lu 5 f V- 0 1`1 @l 1 cc Cj 0- Lo F- C) co C) co N LL c\j 2 X co L0 co U) m co -j co LL) co co co Lo 0 Lr) 0 QD a) c) Lo c) FIGURE 3. MEAN P04 CONCENTRATION FOR ALL SAMPLES COMBINEE 1.4" 0.8" ui 0.4' 0.2-11 0 &@p lep ep c\j C\j a- c@ c:> c.) < LL cq Lo 00 Lo U) 2 m Lo m -i ui co 0 fn co U.) u') U.) FIGURE 4. MEAN TOTAL SUSPENDED SOLIDS FOR ALL SAMPLE%c COMBINED 40-," 35--/ 3 0 -/ cn 25--/ in tn 0-/ Z_ 2 10- 5- 0- Z: CA c\j c) co 0 co < u- C\j co >- U-) m U) co m m w co 0 co fn Lo Lo V) V) -r FIGURE 5. MEAN NH4 CONCENTRATION (@t!Vl) FOR STORM SAMPLES 25-/ 2 0-` 15- 10-1 Lu 5 0 cr N c%J a- u') 0 C) cf) < C) clj u- N m :E @ co LO w co _3 0 m Lo m m FIGURE 6. MEAN N03 CONCENTRATION (@t]Vl) FOR STORM SAMPLES 4.5-/ 40-/ 35- 30-. cl o 25-- .25 Z 20- 15- Lu 10 5-/ fa@:@ I 0 CC C\l C\l 0- LO C) CD m < LL " m :E @ CO >- Ln @ , rn co (5 -1 co co 0 m m r- to FIGURE 7. MEAN P04 CONCENTRATION (@tM) FOR STORM SAMPLES ..z0.6' Lu 0.4' 0.2L /L 0 2: CC N D- LO 0 CD co N LL :E co LO ED U) (13 _3 co w m 0 ca CC -r Lo 0 Lo Lo 0 Lo (D (D FIGURE 8. MEAN TSS (mg/1) FOR STORM SAMPLES 40-/ 35-` 30-/ E 25-/ cn ---cn 20-/ -15 Lu 10-/ 5 - 0 m N a- m o U) C=, co N Lj- C\J fn 2 co >- Lo - co V) m co _3 co Lu co 0 m M U-) Lo Lo 0 m 0 Ln FIGURE 9. MEAN % ORGANIC CONTENT FOR STORM SAMPLES 7 0 6 0' z 50-11 Z cc uj 40f' o 3 0 -Z uj 20-" 0 Ld Ld 4 Ld 1,@i N 0- Lo a co C) cl cl, u- cq 00 LO w m m 0 L0 Lo m m FIGURE-10. MEAN STORM SAMPLING SALINITY AT TIDAL STATIONS 30.00- 25.00- CL 20.00- CL 10.00- 5.00-/ Z-1 0.000 Z7 GB2 GB 13 GB 15 GB 21 GB 22 GB 50 GB80 HHlA FIGURE 11. MEAN pH FOR STORM SAMPLES 7.8-" 7.6-" 7.4-" 7.2 - - - - - - - - - - - - - - - - - - - - - - - 6.6 L@l N CL m C) CD co Cq LL co u') 0 m 0 U-) Lo LC) Lo FIGURE 12. COMPARISON OF MEAN NI-14 CONCENTRATIONS FOR STORM SAMPLES AND RANDOM SAMPLES 25.00 =L Mean NH4 RANDOM a 0 = 20.00 ca El Mean NH4 Storm 1 5X 0 z 5.00 2 0.00 Z: 01 cm LO 0 C) co < u- c\j c\j ca co LO co M U) ca -j w 0 ca ED LO W) LO 0') u') (5 0 0 0 FIGURE 13. COMPARISON OF MEAN N03 CONCENTRATIONS FOR STORM SAMPLES AND RANDOM SAMPLES 45 Z 40 Mean N03 RANDOM 0 35 cc 30 mean N03 storm z 1,5 0 z 10 z < 5 w 2 0 t c/) N N LO C) C) CO < u- @7< >- c\j c\l CO LO U) 0 co M UD u') U'> u') (9 0 t@L FIGURE 14. COMPARISON OF MEAN P04 CONCENTRATION FOR STORM SAMPLES AND RANDOM SAMPLES 2 z 0 1.8 1.6 Mean P04 RANDOM a: 1.4 I-- El Mean P04 Storm 0 0.6 0 a. 0.4 Z 0.2 Lu 0 a- c\j c\j LO 0 0 co u- 2 @-< :@ C-\j co co LO _j ui 0 Lo LO u') 0 0 FIGURE 15. COMPARISON OF MEAN TSS (mg/1) FOR STORM SAMPLES AND RANDOM SAMPLES E 40 z 35 Mean TSS Random 30 cc Mean TSS Storm 1-- 25.,-- z -6-2,0- Z 0 15 0 cl) 10 @2 5 z NFI,Nr-@. 0 a: M 2 c\j N LO 0 0 co 0 LL -j c\j c\j cn - CO u') - ca co co co U) ca I Lu 0 M M I- LO LO u') FIGURE 16. COMPARISON OF MEAN NI-14 CONCENTRATION IN DRY AND WET SAMPLES 25 20 MEAN NH4 DRY 15 EIMEAN NH4 WET z < - J.0- Lu 5 0 X: Cc 0- Ln cn C) cy) C-) N LL co 1-- 00 2 x m U) ino 0 -1 cn w co 0 Lr) Lr) Lr) 0) Lo 0 Q) UIL FIGURE 17. MEAN N03 CONCENTRATION FOR DRY AND WET SAMPLES 45 40 35 30 mean no3 dry 0 El mean No3 wet Z-2 0 w 15 10 5 0 cli Lo cv) < c\l u- CIA co Lo co U) co x M (5 Lo 0 0 co co Lo u') u') 0 (D FIGURE 18. MEAN P04 CONCENTRATION FOR DRY AND WET SAMPLES 1.6 Mean P04 Dry 1.4 2 1.2 Mean P04 Wet =L -0. 6-:- Lu 0.4-- 0.2 0 cc CL Lo C) c/) c) co cq LL c\j co x co >- u') co U) m m w m 0 m co 0 u') Lo u') uj FIGURE 19. COMPARISON OF MEAN TSS; CONCENTRATION FOR DRY AND WET SAMPLES 40 35 MEAN TSS DRY 30 E 25 MEAN TSS WET cn lo-- 5 0 C\l (\I Lo C) C) cl) C) CIA LL C\l 00 to co co x C) w 0 m co u') Lo Lo a) Lo 0 0 FIGURE 19. COMPARISON OF MEAN TSS CONCENTRATION FOR DRY AND WET SAMPLES E 40 z 35 Mean TSS Dry 30 cc Mean TSS Wet 25 0 15 0 co 10 cf) 5 z < 0 Lu a- N N Lo C) C) co Q u- @7< @clj c\j co 00 Lo m w 0 m m w co m Lo Lo Lo Lo Figure 20. NI-14 concentrations at FW and estuarine sites on the Cocheco and Salmon Falls Rivers 40.00 - 35.00 7CCH 30.00 GB21 25.00 5 SFR 2 0. &Q. - GB22 E - I - =L 15.00 10.00 5.00 -- 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 N Figure 21. NH4 concentration at FW and estuarine sites on the Bellamy and Lamprey Rivers 18.00 5 BLM 16-00 G B2 14.00 - - 12.00 - - 5 LMP :r-:A -0 00 G B 15 E- '8-00- =L 6.00 4.00 2.00 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 22. NH4 concentrations at FW and estuarine sites on the Exeter and Oyster Rivers 80.00 70.00 60.00 9 EXT 5 0. 0 0- - GB 80 4 0. GG 5 OYS E - - ; -- " =L 30.00 GB50 20.00 10.00 El a 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 23. NH4 concentrations at the Piscataqua River and Hampton Harbor sites 7.00 6.00 5.00 4--i 0 0 -E- GB13 7Z@ M E -3.66 H H 1 A 2.00 - - M 1.00 - - 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 C Figure 24. N03 concentrations at FW and estuarine sites on the Cocheco and Salmon Falls Rivers 100.00 90.00 XCH 80.00 GB21 70.00 Cn 60-00 5 SFR 0 5 0---GO GB22 E =L 40.00 30-00 20.00 10.00 0.00 8/6/93 9/30/93 11/24/93 1/18/94 3/14/94 5/8/94 7/2/94 Figure 25. N03 concentrations at FW and estuarine sites on the Bellamy and Lamprey Rivers 30.00 5 BILM 25.00 G132 CI 20.00 - 5 LMP 0 GB15 1.5.-OD E =L 10.00 5.00 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 26. N03 concentrations at FW and estuarine sites on the Exeter and Oyster Rivers 30.00 9 EXT 25.00 GB 80 20.00 5 OYS .0 z-* - , - 0 GB50 E 10.00 5.00 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 27. N03 concentrations at the Piscataqua River and Hampton Harbor sites 25.00 GB13 20.00 H H 1 A 15..Q-O - - E R, 10.00 5.00 EN % 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/11 9/94 5/8/94 6/27/94 Figure 28. P04 concentrations at FW and estuarine sites on the Cocheco and Salmon Falls Rivers 3.00 7CCH 2.50 GB21 5 SFR 2.00 - G822 -@5 0:- - E 1.00 0.50 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 29. P04 concentrations at FW and estuarine sites on the Bellamy and Lamprey Rivers 3.00 2.50 5 BLM G B2 2.00 5 LMP Q-.. T.-@ -5 a-. E G815 =L 1.00 0.50 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 30. P04 concentrations at FW and estuarine sites on the Exeter and Oyster Rivers 3.00 2.50 9 EXT GB 80 2.00 5 OYS E 0 GB50 1.00 0.50 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 31. P04 concentrations at the Piscataqua River and Hampton Harbor sites 1.40 1.20 GB13 1.00 H H 1 A 0.80--- E 0.6-0 - - 0.40 - 0.20 - 0.00 7/12/93 8/31/93 10/20/93 12/9/93 1/28/94 3/19/94 5/8/94 6/27/94 Figure 32. Geometric average fecal coliform concentrations for all data. Consecutive pAirs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 200 180- 160- 140- 120- 100- U 80- 60- 40- 20- 12: L4 0 1 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LNIP. @GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA Figure 32A. Geometric average fecal coliform concentrations (modified State data) for all data. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 250 200- 150- U 100- 50- Z@ L4 14-1 L4 -1 14- 1/ 0 1 1 1 1 1 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LW GB15 9-EXT GB80 5-OYS GB50 GB13 HH1A ,,Srr, E Figure 33. Geometric average E. coli concentrations for all data. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 180 160- 140- 120- 100- 80- 60- 40- 20- L4 za 0 1 1 1 7-CCH GB21 5-SFR GB22 5-BLM GB2. 5-LNW @GB15 9-EXT GB80 5-OYS GB50 GB13 HH1A ;,SITE Figure 34. Geometric average enterococci concentrations for all data. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 70 60- 50- 40- 30- P Q *J 20- 10- 0- F- 11 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LNM GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA IT" E Figure 35. Geometric average fecal coliform concentrations for JEL storm samples. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 500 450- 400- 350- 300- 250- 200- 150- 100- 50 0 IX- 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LM? @GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA ,qT E Figure 36. Geometric average E. coli concentrations for JEL storm samples. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 400 350- 300- 250- 200- W 150- 100- 50- 0- -z7 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LW `.GB15 9-EXT GB80 5-OYS GB50 GB13 HH1A SITE Figure 37. Geometric average enterococci concentrations for JEL storm samples. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 160 140- 120- 100- 80- Q P (V 60- 40- 20- L4 0- 1 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LNP 'GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA SITE Figure 38. Geometric average fecal coliform concentrations for JEL storm compared to DES random samples. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 500- 450- 400- JEL 350- DES 300- 250- 06 U 200- 150- 100- 50- EMW I WOW III 0 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LMP 'GB15 9-EXT GB80 5-OYS GB50 GB13 HH1A IT,@@ E 4= Figure 38A. Geometric average fecal coliform concentrations for JEL storm compared to DES (modified data) random samples. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 500-/' 450- 400- JEL 350- DES 300- 250- U 200- 150- 100- 50 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LMP.@,GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA Sff.,E Figure 39. Geometric average E. coli concentrations for JEL storm compared to DES random samples. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 400-@ 350- 300- El jEL DES 250- 200- 150- 100- 50- O-e 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LUP .,GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA i,SITE Figure 40. Geometric average enterococci concentrations for JEL storm compared to DES random samples. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 160-/ 140- 120- JEL DES 100- 80- 60- 40- 20- 0 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LNP. @GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA ,;SrIrE Figure 41. Geometric average fecal coliform concentrations following rainstorms or dry weather. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 500--@ 450- 400- El wet 350- Dry 300- cz T--4 250- C6 U 200- 150- 100- 50- WL 0 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LNW GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA SrYk Figure 41A. Geometric average fecal coliform concentrations (modified State data) following rainstorms or dry weather. Consecutive pairs of sites are freshwater followed by tidal sites name=fresh; GB#=tidal). 600--/ 500- Wet 400- Dry 300- CL U 200- 100- 0 ------- 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LNP. bB15 9-EXT GB80 5-OYS GB50 GB13 HHIA Figure 42. Geometric average E. coli concentrations following rainstorms or dry weather. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 450-,/ 400- 350- Wct 300- Dry 250- Lw 200- 150- 100- 50- 0 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LMP GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA j SITE Figure 43. Geometric average enterococci concentrations following rainstorms or dry weather. Consecutive pairs of sites are freshwater followed by tidal sites (#-name=fresh; GB#=tidal). 250-" 200- Wet Dry 150- 100- 50- 0 7-CCH GB21 5-SFR GB22 5-BLM GB2 5-LMP GB15 9-EXT GB80 5-OYS GB50 GB13 HHIA $ITE Figure 44. Fecal coliform concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Cocheco (7-CCH & GB21) and Salmon Falls (5-SFR & GB22) rivers. 10000 7-CCH GB21 5-SFR 1000 GB22 100 U 10 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov Dec Dec Apr May May May Jun Jun Jun Figure 45. Fecal coliform concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Bellamy (7-BLM & GB2) and Lamprey (5-LMP & GB15) rivers. 5-BLM 10000 D- GB2 5-LMP GB15 1000 100 10 L@j 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov Dec Dec Apr May May May Jun Jun Jun Figure 46. Fecal coliform concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Exeter/Squamscott (7-EXT & GB80) and Oyster (5-OYS & GB50) rivers. 9-EXT 10000 GB80 5-OYS 1000 GB50 100 W U 1064 10 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aig Sep Sep Sep Oct Nov Nov Dec'I Dec Apr May May May Jun Jun Jun 0.1 1 DATE Figure 47. Fecal coliform concentrations at sites in the Piscataqua River (GB13) and Hampton Harbor (HHIA). 10000 GB13 HH I A 1000 100 C6 U ;X4 10 El 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov Dec Dec Apr May May May Jun Jun Jun 0.1 DAA Figure 48. E. coli concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Cocheco (7-CCH & GB21) and Salmon Falls (5-SFR & GB22) rivers. 10000 7-CCH GB21 5-SFR 1000 GB22 100 10 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov Dec Dec Apr May May May Jun Jun Jun 6A@ TIE Figure 49. E. coli concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Bellamy (7-BLM & GB2) and Lamprey (5-LMP & GB15) rivers. 5-BLM 1000 GB2 5-LMP GB15 100 10 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov Dec @.@Dec Apr May May May Jun Jun Jun 1)4kT@ Figure 50. E. coli concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Exeter/Squamscott (7-EXT & GB80) and Oyster (5-OYS & GB50) rivers. 10000 GB80 5-OYS 0 GB50 1000 100 10 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov Dec Dec Apr May May May Jun Jun Jun I% - '; V DATE Figure 51. E. coli concentrations at sites in the Piscataqua River (GB13) and Hampton Harbor (HHIA). 10000 GB13 HH I A 1000 100 10 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov D e c Dec Apr May May May Jun Jun Jun 0.1 DATE Figure 52. Enterococci concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Cocheco (7-CCH & GB21) and Salmon Falls (5-SFR & GB22) rivers. 7-CCH 10000 GB21 5-SFR 1000 GB22 100 10 Q 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aug Sep Sep Sep Oct Nov Nov bec, Dec Apr May May May Jun Jun Jun 0.1 i)A:I'E Figure 53. Enterococci concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Bellamy (7-BLM & GB2) and Lamprey (5-LMP & qB15) rivers. 5-BLM 1000 GB2 5-LMP 0 GB15 100 10 24- 7- 9- 27- 5- 2- 18- 6- 20- 19- 17- 26- 13- 14L 22- Aig Sep Sep Sep Oct Nov Nov Dec' Dec Apr May May May Jun Jun Jun 0.1 ]jAT!k Figure 54. Enterococci concentrations at freshwater (closed symbols) and tidal (open symbols) water sites in the Exeter/Squamscott (7-EXT & GB80) and Oyster (5-OYS & GB50) rivers. 9-EXT 10000 GB80 5-OYS 1000 GB50 100 W 10 0 24- 7- 9- 27- 5- 2- 18- 6-' 20- 19- 3- 17- 26- 13- 14- 22- A ig Sep Sep Sep Oct Nov Nov Dec', Dec Apr May May May Jun Jun Jun 0.1 D.ATE 00 eq Figure 55. Enterococci concentrations at sites in the Piscataqua River (GB13) and Hampton Harbor (HHlA). 00 (0 CD CD 1000 GB 13 HHIA 100 10 P El 2, t- 7- 9- 27- 5- 2- 18- 6- 20- 19- 3- 17- 26- 13- 14- 22- Aig Sep Sep Sep Oct Nov Nov Dec Dec Apr May May May Jun Jun Jun 0.1 DATE