[From the U.S. Government Printing Office, www.gpo.gov]
Sediment and Nutrient Contributions
of Selected Eroding Banks
of the Chesapeake Bay
Estuarine System










by Nancy A. Ibison, Chris W. Frye, Jack E. Frye,
Carlton Lee Hill and Ned H. Burger




January 1990












Department of Conservation and Recreation
Division of Soil and Water Conservation
Shoreline Programs Bureau
Gloucester Point, VA

Sediment and Nutrient Contributions of
Selected Eroding Banks of the Chesapeake Bay
Estuarine System



by


Nancy A. Ibison, Chris W. Frye, Jack E. Frye,
Carlton Lee Hill and Ned H. Burger
Department of Conservation and Recreation
Division of Soil and Water Conservation
Shoreline Programs Bureau
Gloucester Point, Virginia





Technical Report to Council on the Environment
for Coastal Zone Management Grant: #NA88AA-D-CZ09'1
This report was produ'ced, in part, through
financial support from the Council on the
Environment pursuant to Coastal Resources
Program Grant No. NA88AA-D-CZ091 from the
National Oceanic and Atmospheric
Administration.
January 1990





Virginia Department of Conservation and Recreation, Division of Soil and Water Conservation
programs, activities, and employment opportunities are available to all people regardless of race,
color, religion, sex, age, national origin, or political affiliation. An equal opportunity/affirmative action
employer.

EXECUTIVE
SUMMNARY
In the 1987 Chesapeake Bay Agreement, the participants targeted
-nitrogen and phosphorus contributions to the mainstem of the Chesapeake Bay
for a 4-0% reduction by the year 2000.  To meet this goal, all possible
sources of poi-nt and nonpoint source nutrient inputs need to be examined.
Although research has been or is being conducted on agricultural,
atmospheric and groundwater contributions of nonpoint source pollution, the
role of sediment and nutrients from tidal shoreline erosion has not been
addressed.


To examine the role of sediment and nutrients from tidal shoreline
erosion, 14 eroding banks were selected on the Chesapeake Bay and the
Potomac, Rappahannock, York and James Rivers. Site selection was based on
historical erosion rates of greater than 2.0 feet per year and erosion
volumes of greater than 1.0 cubic yard per foot per year. Most sites were
also located within 1400 feet of living marine resources. Soil samples were
collected and analyzed for grain size, total nitrogen, total phosphorus and
inorganic phosphorus.

Results of grain size analysis indicated a large difference between
shore sediments and fastland sediments, attributed to transport of fine
grained fractions away from the foreshore. Fastland nitrogen and phosphorus
concentrations were not found to differ significantly among the sites.
Nitrogen concentrations at the sites showed a more consistent relationship
with grain size and bank height than phosphorus concentrations.  Nutrient
loading rates differed among the sites due to the influence of bank height
and erosion rate on the calculated volume rates.


A quantitative compariso-n of upland erosion with shoreline erosion
indicates that the large volumes of material lost by shoreline erosion
processes result in large nutrient inputs directly into receiving waters.
An estimated 1.37 million pounds per year of nitrogen is entering the Bay
ii

ecosystem through shoreline erosion. This quantity of nitrogen is
equivalent to 5.2% of the controllable nonpoint source nitrogen load.
Additionally, an estimated 0.94 million pounds per year of phosphorus,
equivalent to 23.6% of the controllable nonpoint source phosphorus load, is
entering the Bay ecosystem. Further research is needed to better determine
the total magnitude of nutrient inputs from shoreline erosion and to
determine the influence of the shoreline erosion contribution on the 40%
nutrient reduction goal.
iii

ACKNOWLEDGEMMiT
S
The authors wish to thank the following individuals for their contribu-
tions to this project. Special thanks to C. Scott Hardaway of the College
of William and Mary, Virginia Institute of Marine Science (VIMS) for help
with project design and field work. Thanks to Cindy Fischler, Betty Salley,
Charlie Adams, Grace Battisto and Arvilla Mastromarino of VIMS who conducted
the sediment and nutrient analyses. Special thanks to Susan Townsend of the
Department of Conservation and Recreation, Division of Soil and Water Con-
servation for assistance with layout of the report. J. Michael Flagg of the
same agency aided in various aspects of the project. Thanks to John Poland,
formerly with the Division, for initial coordination of the project.  Dr.
Saied Mostaghimi, Dr. Ray Reneau and Dr. Thomas W. Simpson of Virginia
Polytechnic Institute and State University (VPI&SU) advised us on nutrient
analysis questions. Dr. Robert Byrne, Dr. William Macl-ntyre, Dr. Ken Webb
and Dr. Bruce Neilson of VIMS provided information about previous research.
Bob Hodges and Pam Thomas of VPI&SU soil survey personnel provided
unpublished soils information for Surry County. Rodney Lewis of the Soil
Conservation Service provided unpublished soils information for Northampton
County.
iv

TABLE OF CONTENTS
I. INTRODUCTION ..............
Background Literature ..........
Nutrient Studies and Budgets ....
Sediment Studies and Budgets ....

II.  SITE DESCRIPTION AND SAMPLING PROCEDURES
Site Selection .............
Sampling Procedures ...........
Site Description ............
Site  1:  Nomini Cliffs (NC) ....
Site 2: Great Point (GP) .....
Site	3:	Chesapeake Beach (CB). . .
Site	4:	Fleets Island (FI) ....
Site 5: Wellford (WE) .......
Site  6:  Canoe House Landing (CL) .
Site 7: Rosegill (RO) .......
Site	8:	Bushy Park Creek (BP). . .
Site	9:	Sycamore Landing (SL)...
Site 10:	Pipsico Camp (PC) .....
Site 11:	Chippokes State Park (CH).
Site 12:	Mogarts Beach (MB) ....
Site 13:	Silver Beach (SB) .....
Site 14:	Tankards Beach (TB) ....
ï¿½	.	.	.	.	.	.	.
	.	. I 1
ï¿½	.	.	.	.	.	.	.
	.	. .	3
ï¿½	.	.	.	.	.	.	.
	.	.	.	3
ï¿½	.	.	.	.	.	.	.
	. .	.	4

ï¿½	.	.	.	.	.	.	.
	.	.	.	8
ï¿½	.	.	.	.	.	.	.
	.	.	.	8
ï¿½ .	.	.	.	.	.	.	.
	.	.	8
...........12
...........13
...........14
...........15
...........16
...........17
...........18
...........19
...........20
...........21
...........22
...........23
....... ....24
...........25
...........26
III. METHODOLOGY .....................
Laboratory Analyses .................
Nutrient Analyses ................
Grain Size Analysis ...............
Nutrient Differences among the Sites ........
Nutrient Loading Rates ...............
Nutrient Concentration, Grain Size and Bank Height

VI. RESULTS .......................
Grain Size of Fastland versus Shore Sediments ....
Nutrient Concentrations and Loading Rates ......
Nutrient Concentration, Grain Size and Bank Height

V. DISCUSSION .....................
Comparison of Shoreline Erosion and Upland Erosion
Estimated Magnitude of NPS Nutrient Inputs from
Shoreline Erosion .................
.....  27
..... 27
.....  27
..... 27
.....	28
.....	28
.....	29

.....	30
.....	30
.....	30
.....	32

.....41
.....41

.....  46
VI.  RECOMMENDATIONS FOR FURTHER RESEARCH .......
49
VII. BIBLIOGRAPHY ....................
.....  50
..............  52
VIII. APPENDICES
Appendix A: Bank Face Samples - Physical and Chemical
Characteristics ....................
Appendix B: Shore and Nearshore Samples - Physical and
Chemical Characteristics ...............
Appendix C: Nutrient Loading Rates ...........
Appendix D: Regression Analyses ............
ï¿½   .  .
52

ï¿½ . . 54
ï¿½ . . 56
ï¿½ . . 70
V

LIST OF TABLES
Table	Pa2e

1	Site Information.
	....................10
2	Soil Classification Criteria.
	..............12
3	Sediment Loss and Nitrogen Loading Rates.
	........45
4	Sediment Loss and Phosphorus Loading Rates.
	.......45
vi

LIST OF FIGURES
Fl
Lgure

1 Site Locations ..................

2 Site Definitions .................

3      Site  1:  Stratigraphic cross section and sample
locations - Nomini Cliffs .............

4      Site  2:  Stratigraphic cross section and sample
locations - Great Point ..............

5      Site  3:  Stratigraphic cross section and sample
locations - Chesapeake Beach ...........

6      Site  4:  Stratigraphic cross section and sample
locations - Fleets Island .............

7      Site  5:  Stratigraphic cross section and sample
locations - Wellford ...............

8      Site  6:  Stratigraphic cross section and sample
locations - Canoe House Landing ..........

9      Site  7:  Stratigraphic cross section and sample
locations - Rosegill ...............

10      Site  8:  Stratigraphic cross section and sample
locations - Bushy Park Creek ...........

11      Site  9:  Stratigraphic cross section and sample
locations - Sycamore Landing ...........

12      Site 10:  Stratigraphic cross section and sample
locations - Pipsico Camp .............

13      Site 11:  Stratigraphic cross section and sample
locations - Chippokes State Park .........

14      Site 12:  Stratigraphic cross section and sample
locations - Mogarts Beach .............
15      Site 13:  Stratigraphic cross section and sample
locations - Silver Beach .............

16      Site 14:  Stratigraphic cross section and sample
locations - Tankards Beach ............

17      Nitrogen and phosphorus loading rates .......
Page
ï¿½ . . .  9

. . . . 11


. . . . 13


. . . . 14


. . . . 15


. . . . 16


. . . . 17


.. . . s18


. . . . 19


. . . . 20


. . . . 21


. . . . 22


 . . .23


. . . . 24


. . . . 25


. . . . 26

. . . . 31
vii

18      Grain size, total phosphorus and total nitrogen
concentration: a) Nomini Cliffs and b) Great Point ï¿½ . .

19      Grain size, total phosphorus and total nitrogen concen-
ï¿½ 33


ï¿½ 34


ï¿½ 35


ï¿½ 36


ï¿½ 37


.38


ï¿½ 39

.42


ï¿½ 48
tration: a)

20      Grain size,
tration: a)

21      Grain size,
tration: a)

22      Grain size,
tration: a)

23      Grain size,
tration: a)

24      Grain size,
tration: a)
Chesapeake Beach and b) Fleets Island. ...

total phosphorus and total nitrogen concen-
Wellford and b) Canoe House Landing .....

total phosphorus and total nitrogen concen-
Rosegill and b) Bushy Park Creek ......

total phosphorus and total nitrogen concen-
Sycamore Landing and b) Pipsico Camp . ...

total phosphorus and total nitrogen concen-
Chippokes State Park and b) Mogarts Beach.

total phosphorus and total nitrogen concen-
Silver Beach and b) Tankards Beach .....
25	Illustration of upland erosion versus shoreline erosion.

26	Loading rates for Virginia's portion of the Chesapeake
Bay: a) nitrogen and b) phosphorus ...........
viii

I. INTRODUCTION
Although the Chesapeake Bay estuary has been threatened and ex-
ploited by man's activities, extensive efforts are underway to reverse
the trend toward decline. Virginia, Maryland, Pennsylvania and the
District of Columbia have made a joint commitment to improve conditions
in the Bay. Water quality was one of the key priorities targeted in the
1987 Chesapeake Bay Agreement. According to the Agreement, the improve-
ment and maintenance of water quality are the most critical issues for
the restoration of the Chesapeake Bay.  To address the water quality
issues, a joint commitment was made to reduce the nitrogen and phos-
phorus entering the mainstem of the Chesapeake Bay by 40% by the year
2000. The reduction is to be achieved by control of both point and non-
point source pollution. Point source pollution results from the dis-
charge of sewage treatment plants, industries or other operations where
effluent is discharged at a specific location. Nonpoint source pollu-
tion is diffuse and may result from human activities or natural causes.
N1onpoint source pollution includes surface water runoff from rural and
urban land, groundwater and atmospheric inputs and the contribution from
shoreline erosion. It is the latter source which we will address in
this report.


In the Commonwealth of Virginia, the Division of Soil and Water
Conservation of the Department of Conservation and Recreation is the
lead agency for nonpoint source pollution control.   The Division
addresses the 40% nutrient reduction goal through several programs. The
Division administers the Chesapeake Bay Agricultural BMP Cost-Share pro-
gram which seeks to reduce the agricultural nonpoint source inputs
through the use of best management practices (BMPs) on the land.  The
N~utrient Management program also provides advice to farmers on fertil-
izer application, crop planning and livestock manure control.   Urban
nonpoint source pollution is addressed through the Erosion and Sediment
Control program and the new Stormwater Management program. In order to
achieve the 40% nutrient reduction goal, all possible sources of non-
point source nitrogen and phosphorus need to be examined. However, the
contribution of sediment and nutrients from tidal shoreline erosion is
not known. Therefore, the present study was undertaken by the Shoreline
I







Programs Bureau of the Division to identify and quantify the importanceI
of this source.


Tidal shoreline erosion contributes to the nonpoint source pollu-
tion of the Chesapeake Bay through the introduction of sediment and
nutrients into the system.  Shoreline erosion provides a maj'or source ofI
sa-nd for the estuarine beach and bar system. However, the deposition of
sediment on sessile aquatic organisms, such as oysters, clams or sub-
merged aquatic vegetation, may also occur. The finer sediment fractions
become incorporated into the suspended sediment load, increasing the
turbidity of the estuary. Moreover, nutrients adsorbed to clay parti-
cles increase the eutrophication problems of the Bay.

In an ecosystem, the health of the whole community depends on the
health of the primary producers. Excessive nutrient enrichment a-nd in-
creased turbidity from suspended solids are thought to be major factors
in the decline of submerged aquatic vegetation in the Chesapeake Bay.
The increased nutrient levels also cause algal blooms and subsequent
declines in dissolved oxygen levels.


Sediment budgets, shore erosion rates and eroded sediment volumesI
for selected portions of the Bay and the entire system have been calcu-
lated in previous studies.  This information is useful in evaluating theI
role of shoreline erosion in nonpoi-nt source pollution. Only limited
work has been done on the grain size of fastland soils as a sediment
source to the Bay.  (The term fastland refers to the high ground along
the shore, not the marshland.) Similarly, considerable nonpoint source
nutrient work has focused on soluble nitrogen and phosphorus concentra-I
tions in runoff. Studies of atmospheric nutrient inputs have been con-
ducted and studies of nutrient inputs from groundwater have also been
initiated. However, the contribution of nitrogen and phosphorus from
the introduction of sediment into the Bay via shoreline erosion has -not

been examined.

Because of the importance of nonpoint source pollution to the 40%
nutrient reduction commitment, this study provides a preliminary esti-
mate of the contributions associated with shoreline erosion. Specifi-

cally, we will examine the following objectives:

2I

1. To select study sites from shoreline areas, in Virginia's por-
tion of the Chesapeake Bay estuary with the highest erosion
rates and volumes that are located within 1400 feet of living
marine resources.


2. To calculate nutrient loading rates for the selected sites
based on measured nutrient concentrations, erosion rates and
erosion volumes.


3. To determine if significant differences exist in the nitrogen
and phosphorus concentrations among the sites sampled.


4. To investigate the differences in nutrient concentration and
grain size distribution between fastland and shore sediments.


The findings of this study will help clarify the role of shoreline ero-
sion to nonpoint source nutrient pollution.



Background Literature

Nutrient Studies and Budgets


Because of the need to quantify the role of agricultural runoff to
nonpoint source pollution, a number of studies have examined agricultual
runoff or studied the effectiveness of Best Management Practices (BMPs)
in controlling surface water concentrations of nitrogen, phosphorus and
sediment.  The studies that examined runoff have little relevance to
this project because residual nutrient conce-ntrations in the soils were
not measured.  Mostaghimi et al. (1989) measured the nitrate nitrogen
remaining in the soil profile above the water table at Nomini Creek
watershed in Westmoreland County, Virginia. Soil extractable nitrate
nitrogen was measured in mg/l and converted to kg/ha using the bulk den-
sity of the soil.


The U.S. Environmental Protection Agency report ChesaDeake Bav
Proaram Technical Studies:  A Synthesis (1982) presented an estimated
nitrogen and phosphorus "budget" for the Bay that partitioned the nutri-
ent load to the Bay among the following sources: atmospheric inputs,
3







riverine inputs, point source contributions, bottom sources and oceanI
sources.  The report excluded nonpoint source pollution inputs from
below the fall line due to the lack of data. Nutrient loads due to the
sediment contributions from shoreline erosion, the ocean and planktonic
slkeletal material were not estimated. The accuracy of the proposed bud-
get is limited by lack of data from these nutrient components.


Correll (1987) also partitioned the nitrogen and phosphorus inputs
to the Bay. lie attributed 65% of the nitrogen and 22% of the phosphorus
to "land discharge" (nonpoint source pollution) .  Point sources were
estimated to contribute 25% of the nitrogen load and 73% of the phos-
phorus load. Atmospheric contributions of nitrogen and phosphorus were
10% and 5%, respectively.  Correll concluded that the largest land dis-I
charge nitrogen component is nitrate nitrogen, which is mainly released

to groundwater. The remaining nitrogen would primarily be organic
nitrogen, which is released in runoff. The phosphorus in the land dis-
charge component would primarily be adsorbed to soil particles and re-

leased in rutnoff.

Sediment Studies and Budgets3

Annual shoreline erosion rates and volumes were calculated for the
Virginia portion of the Chesapeake Bay and its tributaries by Byrne and
Anderson (1977), the U.S. Army Corps of Engineers (1986) and the VIMS
Shoreline Inventory Computer Database (unpublished). The information3
provides an insight into the quantity of sediment historically lost to
erosion in a given area. The current project used the U.S. Army Corps
of Engineers (1986) report and the VIMS Shoreline Inventory ComputerI
Database to identify reaches with critically eroding shorelines adjacent
to living marine resources and to select sampling sites in reaches where3
shoreline erosion might adversely impact these resources.


Biggs (1970) developed a suspended sediment (silt and clay) budgetI
for the Chesapeake Bay north of the Potomac River. He examined the sus-
pended sediment contributions from shoreline erosion, biological sources3
and fluvial inputs.  He sampled fastland banks in 40 locations for an
area he termed the "middle bay" which extended from the Chester River
south to just above the Potomac River. Thickness of the strata as well
as the amount of silt and clay was measured. A weighted average percent
4~~~~~~~~

of silt and clay for a given bank was obtained from the previous infor-
mation and bank height. The volume of sediment lost was determined
using lengths of shoreline reaches. Biggs determined the mass of sedi-
ment eroded in the middle bay to be 1.3 x 106 metric tons, of which 21%
(2.75 x 10 5 metric tons) was silt and clay. For the middle bay, 52% of
the suspended sedime-nt budget was attributed to shoreline erosion.  He
also constructed a suspended sediment budget for the "upper bay" from
the Susquehanna River south to the Chester River. For the upper bay,
13% of the suspended sediment budget was attributed to shoreline ero-
sion. The total mass of sediment on which the upper bay budget was
based was 7.58 x l0~ metric tons.


Schubel and Carter (1976) constructed a suspended sediment model
for the Chesapeake Bay.  Several inorganic origins for silt and clay
were identified as follows: fluvial inputs from the Susquehanna River,
shoreline erosion inputs and oceanic inputs. The silt and clay contri-
bution from shoreline erosion was a rough estimate based on data from
previous research for the Bay north of the Potomac River plus a-n esti-
mated contribution for the remainder of the Bay. They attributed 1.07 x
106 metric tons (57%) of suspended sediment to the Susquehanna River,
approximately 6.0 x 105 metric tons (32%) to shoreline erosion and ap-
proximately 2.2 x 10 5 metric tons (12%) to oceanic inputs. Their model
used salt flux equations to determine suspended sediment fluxes.  The
model identified the Bay as a source of suspended sediment to the tribu-
taries while the tributaries were sinks for suspended sediment.


Byrne et al. (1982) developed an inorganic sediment budget for the
Virginia portio-n of the Bay. Their study examined the total sediment
budget, not just the suspended sediment portion. The sediment compon-
ents represented in their budget include contributions from the Maryland
sectio-n of the Bay, Virginia's major tributaries, oceanic sources,
shoreline erosion, shell material, planktonic skeletal material, and the
material on the Bay floor. The findings of Biggs (1970) and Schubel and
Carter (1976) were used as estimates for some of the components, while
values for the other components were measured. The quantity of material
eroded was obtained from Byrne and Anderson (1977). The percentages of
sand, silt and clay were calculated by extrapolating measured values
collected from fastland and beach samples. The samples were taken ap.-
5







proximately every mile along the main Bay. They determined that ohore-
line erosion in Virginia accounted for 2.5 x  04maetric tons of silt and
clay per year, an estimate an order of magnitude less than Schubel andI
Carter's estimate (2.0 x 105 metric tons per year) for Virginia's silt
and clay shore erosion contribution. Byrne et al. (1982) reported shore
erosion in Virginia accounted for 6% of the 4.0 x l0 5 metric tons of
suspended sediment in the budget. The Byrne et al. (1982) study also
gav,e a measured value for the sand component from Virginia's shoreU
erosion as 4.0 x 105 metric tons per year.


Lukin (1983) constructed a sediment budget for the Rappahannock
River. lie identified 4 sediment sources: shoreline erosion, suspended
sediment from the Chesapeake Bay, suspended sediment from the coastalI
plain and suspended sediment from the Blue Ridge-Piedmont Sub-basi-n
(west of the fall line). Using the work of Byrne and Anderson (1977)
and two different estimates of the bulk density of shoreline sediments,
he estimated the sediment contribution from shoreline erosion to vary
from 52% to 75% of the total budget.  However, his work did not estimateI
the proportion of silt and clay since no fastland grain size measure-
ments were obtained. He also concluded that there was a net deposition3
of sediment in the Rappahanniock Ri-ver.

Miller (1983) constructed a sediment budget for the Potomac RiverU
from the Chesapeake Bay to the fall line. He examined the mass of sedi-
ment contributed from shoreline erosion and de-veloped an historical, a3
modern and an adjusted modern estimate of the soil lost to shoreline
erosion.  The adjusted modern estimate incorporated the reduaction in
erosion due to shoreline erosion control structures.  Miller obtained
soil samples from fastland banks and determined the percent of silt and
clay to be roughly 40% of the total mass eroded.  Miller developed a3
suspended sediment budget for the e-ntire Potomac River and identified
the following influx components: the Potomac River above Chain Bridge,
tributary creeks and rivers, shoreline erosion and the Chesapeake Bay.
The silt and clay contribution from shoreline erosion to the entire sus-
pe-nded sediment budget varied from approximately 6% to 9%.  South of theI
Route 301 bridge, the contribution from shoreline erosion was greater,
resulting in a silt and clay contribution of approximately 11% to 18%.3
Miller also noted the variation in bulk density values used in other


6I

sediment budget studies and the impact such values had on the reported
mass of material eroded.
7








1I. SITE DESCRIPTION AND SAMPLING PROCEDURES



Site Selection


Fourteen sites were selected for the project using the data in
Byrne and Anderson (1977), the U.S. Army Corps of Engineers (1986) and
the VIMS Shoreli-ne Inventory Computer Database (unpublished) to identifyI
shoreline "reaches" with historical erosion rates of greater than 2.0
feet per year and erosion volumies of greater than 1.0 cubic yard per
foot per year. The VIMS Shoreline Inventory Computer Database also pro-
'vided information on the prese-nce of living mari-ne resources (clams,
oysters or submerged aquatic vegetation) in the reaches.  The reachesI
identified by the database were then examined for potential sampling
sites.  One sampling site was chosen per reach based on the accessibil-3
ity and suitability for sampling.  Sites with little or no vegetation on
the bank slope were selected.  Of the 4 Chesapeake Bay sites, 2 were
located on the Eastern Shore of Virginia.  Four of the remaining sitesI
were located on the Rappahannock River, 3 on the James River, 2 on the
Potomac River and 1 on the York River. Site locations are depicted in
Figure 1. Site names were primarily selected using landmarks ide-ntified
on the U.S. Geological Survey topographic quadrangles. The site number,
name, county, body of water, reach length (statute miles), erosion rate,I
volume eroded and presence of living marine resources data are presented
in Table 1.3


Sampling ProceduresI


Field sampling involved collection of soil samples from various
horizons on the bank face.  Samples were taken directly from the bank3
face where undisturbed sediments were present. It was necessary to dig
down to undisturbed soils where sloughing had occurred. Samples were
taken from each horizon for nutrient and grain size analyses.   Samples
were placed in sterile whirlpaks and the texture and color of sediment
noted.3


The sample positions and horizon endpoints were surveyed where3
slope conditions allowed. Horizons on steeper slopes were measured with
a tape measure or surveyor's rod. Shore sample locations were surveved


Figure 1. Site Locations.


9

Table 1. Site Information
Reach
Length
(miles)
5.1
0.8
3.3
4.1
3.9
2.9
1.0
0.7
3.0
3.8
2.3
7.0
1.8
1.3
Erosion
Rate
(ft/vr)
3.5
10.6
6.1
7.9
2.4
6.5
2.3
3.1
1.6
1.8
1.1
3.8
5.7
7.0
Volume
Eroded
(cv/ft/vr)
7.9
2.1
2.3
2.0
1.1
1.3
1.6
3.1
1.2
2.5
2.0
2.8
1.9
2.1
Living
Marine
Resources
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Site
No.

1
2
3
4
5
0     6
7
8
9
10
11
12
13
14
Site Name
County
Body of Water
Potomac River
Potomac River
Chesapeake Bay
Chesapeake Bay
Rappahannock River
Rappahannock River
Rappahannock River
Rappahannock River
York River
James River
James River
James River
Chesapeake Bay
Chesapeake Bay
Nomini Cliffs (NC)
Great Point (GP)
Chesapeake Beach (CB)
Fleets Island (FI)
Wellford (WE)
Canoe House Landing (CL)
Rosegill (RO)
Bushy Park Creek (BP)
Sycamore Landing (SL)
Pipsico Camp (PC)
Chippokes State Park (CH)
Mogarts Beach (MB)
Silver Beach (SB)
Tankards Beach (rB)
Westmoreland
Northumberland
Northumberland
Lancaster
Richmond
Middlesex
Middlesex
Middlesex
James City
Surry
Surry
Isle of Wight
Northampton
Northampton
IIImmmmIII/mII//~m/

or measured with a tape measure. Shore samples were obtained at loca-
tions on the backshore, foreshore and nearshore. The backshore is
defined as the area between the base of the bank and mean high water.
The foreshore is the intertidal zone or area between mean high and mean
low water. The nearshore extends channelward of mean low water and was
generally sampled adjacent to mean low water. See Figure 2 for an il-
lustration of the site definitions.
15 -





10 -





5-
/ top of
bank



C
o
_+_



c)
L
,- bankface


_,,, base of bank
backshore                    foreshore
-------MW
0-
i    nearshore
shore
I	I	I I I	I I I	I	II
0    10	20	30   40    50	60   70    80	90
	100
Distance (ft)


Figure 2. Site Definitions.
11

!1
I
Site Description

The 14 sites are described and stratigraphic cross sections and
sample locations presented graphically in the following section. The
sites are described according to the numerical order presented in Figure
1. Reach characteristics and individual sampling site characteristics
are discussed. The horizons shown on the cross sections are based on
the grain size analysis of the soil samples as defined in Table 2.


Table 2. Soil Classification Criteria
I
I
I
I
I
Composition
greater than 60% sand
with 20% or greater gravel

greater than 80% sand
less than 20% silt and clay

50% to 80% sand
20% to 50% silt/clay
Symbol

Li
i
Description

gravel and sand


sand


silty/clayey sand
I
I
I
I
m
i
50% to 80% silt/clay
20% to 50% sand
sandy silt/clay
I
greater than 80% silt/clay
less than 20% sand
silt/clay
I
I
I
I
I
I
U
12
I

Site 1: Nomini Cliffs (NC)


The Nomini Cliffs reach is located on the Potomac River in West-
moreland County. The reach extends for 26,700 feet or approximately 5.1
miles. The sampling site is located on a vacant lot in a subdivision
just upriver from Westmoreland State Park. The bank has an elevation of
30 feet above mean low water and a nearly vertical slope.  The Nomini
Cliffs reach includes bluffs reaching 150 feet. The publication Soil
Survey of Westmoreland County. Virginia (1981) classifies the upper soil
horizons as Rumford and Tetotum. These soils are typically sandy and
vary in color from dark brown to yellow with depth. Six bank face sam-
ples were taken. According to grain size analysis and the soil classi-
fication criteria in Table 2, the bank has 3 distinct horizons:
silty/clayey sand, sand and sandy silt/clay. In addition, 3 shore sam-
ples were obtained. The backshore width is negligible.
30
4---

0



II
I
20




10

MLW
0
30
0         10          20
Distance (ft)

Figure 3. Stratigraphic cross section and sample locations - Nomini
Cliffs.
13

II
I
Site 2: Great Point (GP)

Great Point is located on the Potomac River downriver from the
Coan River in Northumberland County. The reach extends for 4,000 feet
or approximately 0.8 mile. The sampling site is wooded. The bank has
an elevation of 4.5 feet above mean low water with a slope of approxi-
mately 1.5:1 (horizontal/vertical).  The publication Soil Survey of
Northumberland and Lancaster Counties. VirEinia (1963) classifies the
upper soil horizons as Mattapex silt loam. Mattapex soil is described
as brown in color and varying with depth from a silt loam to a silty/-
clay loam or sandy/clay loam to sand. Three bank face samples were ob-
tained.  According to grain size analysis and the soil classification
criteria in Table 2, the bank consists of a sandy silt/clay.  In addi-
tion, 3 shore samples were obtained. The backshore width is approxi-
mately 6.5 feet.
I
I
I
I
I
I
I
5 -

4-
GP1R
GP2


 GP3
I
I
I
I
3 -

2-


1 -


0 -


c-
o

>
L1J
II
GP4 -
....--. M..W
GP4
I
-1
GP4
I	I	I
20	30
	40
50
50
0
0
I
Distance (ft)
ve= 6
I
Figure 4. Stratigraphic cross section and sample locations - Great
Point.


14
I
I
I

Site 3: Chesapeake Beach (CB)

The Chesapeake Beach site is located on the Chesapeake Bay south
of Gaskin Pond in Northumberland County. The reach extends for 17,200
feet or approximately 3.3 miles. The sampling site is a residential
property with a small cottage.  The bank has an elevation of 10 feet
above mean low water and an approximate upper slope of 1:1 (horizontal/-
vertical) with a flatter portion at the base. Although a groin system
and riprap sill are present on the property, the bank continues to
erode. The publication Soil Survey of Northumberland and Lancaster
Counties. Virginia (1963) classifies the upper soil horizons as "sloping
sandy land." The soil is described as primarily sandy, but is quite
variable in composition. Four bank face samples were obtained. Accord-
ing to grain size analysis and the soil classification criteria in Table
2, the bank has 3 distinct horizons:  silt/clay, sandy silt/clay and
sand.  Four shore samples were also obtained.  The riprap sill is lo-
cated between the points CB4 and CB5 in Figure 5 below. The backshore
width is influenced by the presence of the sill and is approximately 26
feet wide.  The most seaward shore sample was obtained with a bucket
auger and contained clay.


10-	-0 81
10 ~	-6




C   5-       :
0
)     --


0--c






I	I	I	I	I	I	I   I
0	10	26	36	40	50	66     166
v.= 3Distance (ft)

Figure 5.  Stratigraphic cross section and sample locations -Chesapeake
Beach.
15

!


Site 4:  Fleets Island (FI)

The Fleets Island site is located on the Chesapeake Bay in Lancas-
ter County. The reach extends for 21,500 feet or approximately 4.1
miles. The site is wooded. The bank has an elevation of 4.5 feet above
I
mean low water. The bank face is irregularly shaped due to differential
erosion of the clay base versus the overlying sandy soil and has an ap-
proximate slope of 5:1 (horizontal/vertical).  The publication Soil Sur-
vev of Northumberland and Lancaster Counties. Virginia (1963) classifies
the upper soil horizons as Othello silt loam.  The soil is described as
poorly drained and composed of silt loam grading to clay loams grading
to sand.  Three bank samples were obtained.  According to grain size
analysis and the soil classification criteria in Table 2, the bank has 2
horizons:   sand and sandy silt/clay.  Four shore samples were also ob-
tained.  The backshore width is 7 feet.



5-                                                                                1

R1


O~~~~~~~H



RS-
(0   -I
wo-~~~~~~~~~~~~~~


-1-
R7f
I	I	I	~    ~ ~        ~ ~       ~ ~~~~~I	I	I	I
0	10	20	30	40	50	60
ve-6	Distance (ft)


Figure 6.  Stratigraphic cross section and sample locations - Fleets                      3
Island.

16                                                     U

Site 5: Wellford (WE)

The Weliford site is located on the Rappahannock River in Richmond
County. The reach extends for 20,400 feet or approximately 3.9 miles.
The sampling site is located on a wooded bluff adjacent to agricultural
fields and a small stream. The bank height is nearly 20 feet above mean
low water and the slope is approximately vertical. The publication Soil
Survey of Richmond County. Virminia (1982) classifies the upper soil
horizons as Suffolk sandy loam. The soil is described as well drained
and varies from a sandy loam to loam or loamy sand with depth. Five
bank face samples were obtained. According to grain size analysis and
the soil classification criteria in Table 2, the bank has 3 distinct
horizons: sand, gravel and sand, and silty/clayey sand. In addition, 3
shore samples were obtained. The backshore width is negligible.

20 -

-WEI


: ..15-...         WE2
c-
C~~                ~   ~ . ï¿½  -
0
_10-           .:o  ~ .. ï¿½   0*   -WE3









I__WE4




0e -                --                         - '-ï¿½
WE4
~~~~~&W5

WVE7	/ -8~


I	I	I	I	I	I
0	10	20	30	40	50
ve = 2          Distance (ft)

Figure 7. Stratigraphic cross section and sample locations - Wellford.





17







Site 6:  Canoe House Tanding (CL)

The Canoe House Landing site is located east of Bayport on the
Rappahannock River in Middlesex County. The reach extends for 15,500
feet or approximately 2.9 miles of shoreline.  The sampling site is lo-
cated on a wooded property with a summer cottage and is downriver from
the Canoe House Landing public beach.  The bank has an elevation of 40
feet above mean low water and a slope slightly steeper than 1:1 (hori-
zontal/vertical). The publication Soil Survey of Middlesex County. Vir-
ginia (1985) classifies the upper soil horizons as Kempsville sandy
loam.  The upper horizons are described as well drained, with brown
sandy loam grading to sandy clay loam with depth.  Ten bank face samples
were obtained.  According to grain size analysis and the soil classifi-
cation criteria in Table 2, the bank has 6 distinct horizons: silty/-
clayey sand, sand, silty/clayey sand, silt/clay, sandy silt/clay and
sand.  Three shore samples were also obtained.  The backshore width is
15 feet.




40-	CLI                                                             I


0 30-	- CL2
30-                  CI



0

L'                      -.-    CL4
20 -



--1 0 _'  -ï¿½CL4
OL3



G L10      L
------------- CW

0~~~                                             CL_ CL1  3ew
:~	~CL13	6






0      10      20     30      40	50      60	70                 1
Distance (ft)


Figure 8. Stratigraphic cross section and sample locations - Canoe I
House Landing.
18 ,
I

Site 7: Rosegill (RO)

The Rosegill site is located east of Urbanna Creek on the Rappa-
hannock River in Middlesex County. The reach extends for 5,400 feet or
approximately 1 mile. The site is adjacent to an agricultural field.
The.bank has an elevation of approximately 24 feet above mean low water
and an irregular slope of approximately 1:1 (horizontal/vertical). The
publication Soil Survey of Middlesex County. Virzinia (1985) defines the
upper soil horizons as Suffolk-Remlik complex. The upper horizons are
primarily sandy loam grading to a loamy sand with depth. Nine samples
were obtained from the bank face because of the variation in soil color
in the lower part of the bank. According to grain size analysis and the
soil classification criteria in Table 2, the bank has 3 distinct hori-
zons: sand, gravel and sand, and sand. Three shore samples were also
obtained. The backshore width is approximately 5 feet.


25 -
-ROi
R02

20 -




15 -
C             -P~~~~~~~04
o0 ï¿½    ''.,..:",' -R05

(D
--   "   . ''.'  ~~~~~R07

-   R08



RIll-        - - --

P12

0      10     20     30      40     50     80
2              Distance (ft)

Figure 9. Stratigraphic cross section and sample locations - Rosegill.





19

!


Site 8: Bushy Park Greek (BP)

The Bushy Park Creek site is located on a residential property                  I
east of Bushy Park Creek on the Rappahannock River in Middlesex County.
The reach extends for 3,600 linear feet or approximately 0.7 mile of
shoreline.  Although a groin system had been installed on the property,
active bank sloughing is still occurring. The bank has an elevation of
40 feet above mean low water and the slope is approximately 1:1 (hori-
zontal/vertical). The publication Soil Survey of Middlesex County. Vir-
ginia (1985) classifies the upper soil horizons as Suffolk fine sandy
loam.  The soil is described as a well drained, yellowish to brown sandy
loam grading to a loamy sand with depth. Eight bank face samples were
taken.  According to grain size analysis and the soil classification                  1
criteria in Table 2, the bank has 3 distinct horizons:	sand, sandy
silt/clay and sand.  Three shore samples were taken.	The backshore                   3
width is approximately 25 feet.  The groin system affects the beach
width.  Figure 10 provides a cross section of the site and sample loca-
tions.

40-   ~,BPI
BP2


30-   BP
I.     8P5~~~~~~~
I
C: 20-                      -ORe
(U                                                            ~~~~~~I
-BP7
LLJ  10                             -
BPS


0-	BP9 -----	w

0    1    20   30   40   50	8    70   80  90'	100
ve 1.7            Distance (ft)
Figure 10.  Stratigraphic cross section and sample locations - BushyI
Park Creek. 2
~  ~     2  ,
I

Site 9: Sycamore Landing (SL)

The Sycamore Landing site is located upriver from York River State
Park on the York River in James City County.  The reach extends for
15,700 feet or approximately 3 miles. The sampling site is located in a
wooded area adjacent to a subdivision.  The bank has an elevation of
approximately 54 feet above mean low water. The lower slope is approxi-
mately 1:1 (horizontal/vertical) below the vertical top portion.  The
publication Soil Survev of James City and York Counties and the City of
Williamsbura. Virginia (1985) classifies the upper soil horizons as
Emporia complex.  The soils are described as steep, well drained and
having fossil rich layers underneath. Eight samples were obtained from
the bank face. According to grain size analysis and the soil classifi-
cation criteria in Table 2, the bank has 3 horizons: silty/clayey sand,
sandy silt/clay and sand. Three shore samples were also obtained. The
backshore width is approximately 6 feet.



80 -


.  SL
50-  .  -2

-93

40-





c

:C   '  ) '-'.; ;'- ' -  ' . : .  '  6
 30-
ï¿½ 0-  "::.:. '.. : ....  ..
20 -









0-                                        0 *  .        - .>W
S11-

I	I	I	I	I I	,	I
0	10	20	30	40     50	60	70    180
Distance (ft)

Figure 11. Stratigraphic cross section and sample locations - Sycamore
Landing.


21

I
I
Site 10: Pipsico Camp (PC)

Pipsico Boy Scout Camp is located on the James River in Surry
County. The reach extends for 20,200 feet or approximately 3.8 miles.
The sampling site is adjacent to the rifle range at the Scout camp. The
bank has an elevation of approximately 65 feet above mean low water.
The lower slope is approximately 1:1 (horizontal/vertical) below the
steeper top section. Recent unpublished soil survey data for Surry
County classifies the upper soil horizons of the bank face as Nevarc-
Remlik gravelly complex.   Inland from the bank face, the upper soil
horizons are classified as Uchee loamy sand. Seven bank face samples
were obtained. According to grain size analysis and the soil classifi-
cation criteria in Table 2, the bank has 4 distinct horizons: silty/-
clayey sand, silt/clay, silty/clayey sand and sand. Four shore samples
were also obtained. The backshore width is approximately 15 feet.
I
I
I
I
I
I
I
I
I
I
I




-- -- P'








~~P0C ~ ~~2
PC3
-P04
-P05













P= B -
_.~~~~~~~~~~~~P1 \01
.~~ ~ ~~~~~~ .       I
60-



50 -




O

>
a)
20-
10 -



0-
I
I
0    10    20    30   40    50    60    70    80   90    100
Distance (ft)
Figure 12. Stratigraphic cross section and sample locations - Pipsico
Camp.



22
I
I
I
I

Site 11:  Chippokes State Park (CH)

Chippokes Plantation State Park is located on the James River in
Surry County. The reach extends for 12,000 feet or approximately 2.3
miles.  The sampling site is adjacent to a large pasture on the model
farm and downriver of a gapped breakwater system. The bank has an ele-
vation of approximately 47 feet above mean low water with a nearly ver-
tical slope. Recent unpublished soil survey data for Surry County clas-
sifies the upper soil horizons of the bank face as Nevarc-Remlik com-
plex. Inland from the bank face, the upper soil horizons are classified
as Newflat silt loam. Six bank face samples were obtained. According
to grain size analysis and the soil classification criteria in Table 2,
the bank has 4 distinct horizons: sandy silt/clay, silty/clayey sand,
sandy silt/clay and silty/clayey sand.  Four shore samples were also
obtained. The backshore width is approximately 16 feet.


-C0-
_H1

CH2
40-
=CH3




-i-CH4


 20-_                           -





10 -

-  CH7



CH0 I
t i	I	I	i   ~	l_	I
0      10	20	30	40	60	70
Distance (ft)

Figure 13. Stratigraphic cross section and sample locations - Chippokes
State Park.
23

I
i
Site 12: Hogarts Beach (NB)


Mogarts Beach is located on the James River upriver from the Pagan
River in Isle of Wight County. The reach extends for 36,800 feet or
approximately 7 miles. The sampling site is a vacant lot adjacent to a
residence. The bank has an elevation of 26 feet above mean low water
and a nearly vertical slope.  The publication Soil Survey of Isle of
Wight County. Virginia (1986) classifies the upper soil horizons as Pea-
wick silt loam. Peawick silt loam varies from a silt loam to a clay
loam with depth. Four bank face samples were obtained. According to
grain size analysis and the soil classification criteria in Table 2, the
bank has 2 distinct horizons: sandy silt/clay and silty/clayey sand.
The lower section of the bank is a dense marine clay that proved to have
a fairly high sand content. In addition, 3 shore samples were obtained.
The backshore width is 7 feet.
I
I
I
I
I
I
- MB1
25 -




20 -
I
I
I
I
I
I
I

c-
0

Q)
LL
J
15 -
MB4
5 -




0-
-    ----   -----M.LW.
MB5/
MO6 -/
I
0

ve = 2
I	I	I I
10            20	30	40            60
Distance (ft)
I
Figure 14. Stratigraphic cross section and sample locations - Mogarts
Beach.




24
I
I
I

Site 13: Silver Beach (SB)
The Silver Beach reach is a section of agricultural land and sum-
mer cottages on the Chesapeake Bay in Northampton County.  The reach
extends for 9,700 feet or approximately 1.8 miles. The sampling site is
located at the agricultural field immediately south of Silver Beach.
The property was recently subdivided and sold for residential develop-
ment.  The bank has an elevation of 15 feet above mean low water and a
nearly vertical slope. Recent unpublished soil survey data classifies
the upper horizons as Bojac loamy sand.  Four bank face samples were
taken.  According to grain size analysis and the soil classification
criteria in Table 2, the bank has 3 distinct horizons:   silty/clayey
sand, sandy silt/clay and sand. Three shore samples were also obtained.
The backshore width is approximately 9 feet.
15
-






10 -


C
H_
c
-
0

>
a1)
O
- SB4
5 -




QQI                    - -
SB5 -
0 -
Z-U -
--
SB7
80
0
I	I
10
	2
0
30
40
40
Distance (ft)
ve= 3
Figure 15.
Stratigraphic cross section and sample locations - Silver
Beach.
25

I
I
Site 14: Tankards Beach (TB)

The Tankards Beach site is located on the Chesapeake Bay in North-
ampton County.  The reach extends for 7,000 feet or approximately 1.3
miles. The sampling site is an agricultural field. The bank has an
elevation of 12 feet above mean low water and a nearly vertical slope.
Recent unpublished soil survey data classifies the upper soil horizons
as Bojac loamy sand. Four bank face samples were taken. According to
grain size analysis and the soil classification criteria in Table 2, the
bank has 3 distinct horizons:  sandy silt/clay, silty/clayey sand and
sand. Four shore samples were also obtained. The backshore width is 32
feet.
I
I
I
I
I
I
15-





10 -





5-
I
I
I
-TB1
TB2

TB3





>
C)
4_,
(D
0
O
TB5
I
'--- -- -- -- -  - -------- -HW
TB6 '
TB7 /
0-
- MLW
I
TB8
A-
I     I I I I I I I I I v I
0 10 20    30 40    50    60 70 80    90   130
I
Distance (ft)
ve= 4
I
Figure 16. Stratigraphic cross section and sample locations - Tankards
Beach.






26
I
I
I
I

III.- METHODOLOGY
Laboratory Analyses

Laboratory analyses were conducted by the Virginia Institute of
Marine Science sediment and water quality labs. The water quality lab
uses EPA approved procedures.


Nutrient Analyses


The total nitrogen (TN) determination included nitrate nitrogen
and total Kjeldahl nitrogen (TKN; includes ammonia and organic forms of
nitrogen) . TN analysis procedures can be found in the Carlo Erba Stru-
mentazione Carbon Nitrogen Analyzer 1500 Instruction Manual (1986) .  TN
analysis was conducted using 10 to 20 mg samples of air-dried, ground
soil. Each soil sample was analyzed for TN using a Carlo Erba NA1500
C/N Analyzer. The mean detection limit for TN was 0.18 mg/g.


Phosphorus determinations included total phosphorus (TP) and inor-
ganic phosphorus (IP; orthophosphate). Phosphorus procedures were taken
from the following reference manuals:   "Laboratory Procedure for the
Soil Testing and Plant Analysis Laboratory" (1988) and Methods for Chem-
ical Analvsis of Water and Wastes (1974). TP and IP were measured by
extraction and ignition of approximately I g samples of air-dried,
homogenized, ground soil.  The samples were combusted at 475 0 C for 5
hours. TP was extracted from the ashed sample using HCI, while IP was
extracted with HCI and H2so4' Sample extracts were filtered through
Whatman C/F glass fiber filters and then analyzed using a continuous
flow analyzer. The mean detection limit for TP was 0.01 mg/g and 0.001
mg/g for IP.


Grain Size Analysis

The sediment samples were split, wet sieved and separated into the
gravel, sand, silt and clay fractions. To determine a weight percent,
the gravel fraction (material coarser than 2.0 mm) was dried and
weighed. The sand fraction (0.0625 to 2.0 mm) was analyzed using a
rapid sediment analyzer (RSA) to determine the grain size distribution
27







and weight percent.  The weight percentages of the silt and clay frac-I
tions (material finer than 0.0625 mm) were measured according to sta-n-
dard pipette methods.

Nutrient Differe-nces among the Sites3


Because the scope of this project covered a large geographic area
and many different soil types, analysis of variance (ANOVA) was used to
determine if any of the banks were "richer" in nutrients than the
others. Specifically, the analysis of variance tested whether or not
significant differences exist in the nutrient concentration levels
among the banks sampled. Because of the variability in bank height and
number of samples per site, the analysis of variance was conducted usingI
3 samples from each bank. A top of bank (topsoil), a midbank and a base
of bank sample were selected for each site.


Nutrient Loading Rates3

Nutrient loading rates were calculated for each site using the
following information:  nutrient concentration, estimated average bulk3
density, bank height, horizon thickness and annual erosion rate. All of
the above variables were known except bulk density. The limited scope
of the study did not allow field measurements of the bulk densities ofI
the soils sampled. Therefore, we used an estimated average bulk density
of 1.5 g/cm .  The bulk density value used was based on conversationsI
with soil scientists and researchers from VPI&SU. Moreover, the value
used was similar to the bulk densities reported in the soil surveys for
some of the soils studied.  Finally, the sediment budget literatureI
reports great variability in the bulk densities used for sediment budget
calculations.  Miller (1983) used 1.67 g/cm , the average dry bulk den-
sity from Pleistocene sediment test borings. Miller noted bulk density
values used by other researchers which varied from 1.4 to 2.65 g/cm 3

(Schubel, 1968; Biggs, 1970; Byrne et al., 1982 and Lukin, 1983).









28I

To calculate a nutrient loading rate for each site, the bank ero-
sion volume was first calculated using the following equation:


V - B E W                             (1)

where:  V - Unit bank erosion volume (ft3/ft-yr)
B - Bank height (ft)
E - Unit erosion rate (ft/ft-yr)
W - Unit width (1 ft)

Nutrient loading rates were then derived using the following equation:


R  -         V N D c)                        (2)


where: R - Nutrient loading rate (lbs/ft-yr)
B - Bank height (ft)
D - Bulk density (1.5 g/cm3)
H - Horizon thickness (ft)
N - Nutrient concentration (mg/g)
V - Unit bank erosion volume (ft3/ft-yr)
C - Conversion factor to English units (0.062)

Nutrient Concentration, Grain Size and Bank Height

Nutrient concentration, grain size and elevation were graphically
compared to determine if any relationships were apparent.  Linear re-
gression analysis was performed to test for possible significant rela-
tionships between nutrient concentration and grain size.
29







IV.  RESULTSI



Grai-n Size of Eastland versus Shore Sediments


Fastland sediments had higher percentages of silt and clay thanI
shore sediments, as would be expected. Approximately 70% of the bank
samples had more than 10% silt and clay in contrast to 7% of the shore
samples with the same silt and clay content. The lower silt and clay
content of shore samples results from winnowing by waves and dispersal
of finer grained fractions offshore.  Moreover, littoral drift trans-I
ports shore sediments, making the origin of the sediments difficult to
identify. Appendices A and B list the grain size data for the fastland
and shore samples.


Nut-rient Concentrations and Loading RatesI


Total nitrogen concentrations ranged from 0.01 to 3.34 mg/g for3
the fastland bank samples.  Total phosphorus varied from 0.01 to 1.28
mg/g. No significant differences were found among the 14 sites in
eit'her nitrogen or phosphorus concentrations according to the analysisI
of variance test results.  Thus no site was significantly "richer" in
nutrients than the others.  Nutrient concentrations are presented in
Appendix A.


Although the range of nutrient concentrations among the 14 sitesI
was small, large differences were found in nutrient loading rates due to
the influence of physical conditions such as bank height and erosion3
rate on the calculated volume rates (Figure 17). Total nitrogen loading
rates varied from 0.14 to 6.44 pounds per foot per year and total phos-3
phorus loading rates varied from 0.04 to 4.42 pounds per foot per year.
Moreover, sites with high loading rates of one nutrient did not always
contribute equivalent amounts of the other nutrient.  (Loading rate cal-I
culations for the sites are provided in Appendix C.)


The highest nitrogen loading rates were observed at Canoe House
Landing (Site 6) and Nomini Cliffs (Site 1). The high nitrogen loading
rate of 6.44 pounds per foot per year at Canoe House Landing can be at-I
tributed to the high nitrogen concentration found in the rich, organic

303

- - m -  _ -  m - -- -- -  m - m m -
L'oading Rate (Lbs/Ft/Yr)
7

6 -

5 -

4 -

3 -




I
X
.....
.....
........
.....
....
.....
......
....
I ...
I....
.....
 
I.
...
...
"
. .... M.:.: I ... . .... . ....... . ....... . . ......-.. .
..... . ............... --- ...........-.... ........... ....
....
: . .. ...... . .... . .......-....-........................................................................................................



....
......
I...
....
...
....
...
w-
.... --
....
...I...
I...
....
....
....
....
........
....
2

1

0
............... ......... ...... .I... ---, ........ --
- ......... . ..... ...... --1--- ... ---- ...... .
...... . ...................... . ...........
I.................... ..... .
.............................. .-1
...... .... .. . .... .. ..... .
....... ---
...
...
...
...
...
.I
...
...
...
...
...
...
 
...
...
...
...
...
...
..
...
...
...
...
..
I.
...
...
...
...
...
...
...
 























































































































i_J
I_1
. .... :::: .............. . ... . .
...........




....... ..... ...
......... .......
.. .. ....... ...
FM
7       -                              1
I ,
I    -   -     I      -        I
1    2    3    4    5    6    7    8    9    10   11   12   13   14

Site Number

MI Total Nitrogen
MTotal Phosphorus
Figure 17. Nitrogen and phosphorus loading rates.






sandy silt/clay horizon and the relatively high erosion rate.  NominiI
Cliffs had a nitrogen loading rate of 5.30 pounds per foot per year.
The high rate was due to high nitrogen concentrations in the topsoil and
in the deeper sandy silt/clay horizon.

Phosphorus loading rates were highest for Mogarts Beach (site 12),I
Nomini Cliffs (Site 1) and Pipsico Camp (Site 10). The phosphorus load-
ing rates at the three sites were 4.42, 4.16 and 2.59 pounds per foot
per year. Mogarts Beach had high phosphorus concentrations throughout
the lower profile. At Nomini Cliffs, the phosphorus values were low in
the upper horizons but increased markedly with depth in the sandy silt/-I
clay layer. At Pipsico Camp, phosphorus concentrations were high in the
silt/clay horizon and the silty/clayey sand directly beneath.


Nutrient Concentr-ation, Grain Size and Bank Height

Grain size and total nitrogen and total phosphorus concentrations
are plotted against bank height for each site in Figures 18 through 24.
Grain size analysis revealed that the clay base at Great Point (Site 2),
Fleets Island (Site 4) and the "tmarine clay" base at Nomini Cliffs (Site
1), Wellford (Site 5), Rosegill (Site 7), Sycamore Landing (Site 9) and
Mogarts Beach (Site 12) have a higher sand concentration than expected.
According to grain size a-nalysis, Nomini Cliffs, Great Point and Fleets
Island have a sandy silt/clay base. The marine clay base at Wellford
and Mogarts Beach is a silty/clayey sand, while the marine clay layer at
Rosegill and Sycamore Landing is classified as sand.

Nitrogen concentrations at each site showed a more consistent re-
lationship with grain size and bank height than the phosphorus concen-
trations (Figures 18 through 24). Profiles typically showed peak nitro-
gen concentrations in upper soil layers and lower, more constant values
throughout the remaining profile. Exceptions to the pattern occurred at
Nomini Cliffs (Site 1), Wellford (Site 5), Canoe House Landing (Site 6),I
Sycamore Landing (Site 9) and Pipsico Camp (Site 10) where finer grained
layers were found in the profile. In these cases, finer grained sedi-
ments had higher nitrogen concentrations than the other horizons.
Fleets Island had a lower nutrient concentration in the "topsoil" (actu-

ally an overwash sand layer).

32I

a
Perucde Size
Welahtt at

___ dGaM --m- W-cm



as 8
Total Fhos"w,

I~ I I IU
Total Nlfrogen
MW~GE
so0-















-   I_ 7- -i'- NZ4



 NOS - - -
II
I
k
I
I
IK
I
II
I
II
II
1_
t
I
I
I
I
le
I
I
WI



c-
)
O
20 -




10 -












_'..
r
IJ
0 -
b
ParWIe Sim


Sod arld 018	---*	O.12%
Sp a-d ow	-.--	".O%

a	so	io
Total nmtuwai
w3aa
on BUS   0.1
Total Nit-ogen
M31G
soel        m          lim
6

4

=
10
I
II
II
II
II
I
iI
I
I
I
Ik
f
II
II
II
II
II
II
II
I
I
3 -


2 -


I1-

c
C)
co
)
w
D
0 -O4 - - - MF
I - C'% - - - Ntw
-1
Figure 18. Grain size, total phosphorus and total nitrogen


concentration: a) Nomini Cliffs and b) Great Point.
33

I
I
a
Pwftie Size


S&dar a"1e	-~--W	a UW
0	an	1Ko -0
	n-e
I
TotW PhoeO-"
WO
eim Om 0% eon 0.10
I II 1   3

11

II
oI
11
II
II
I
I
i
I
I
I


II
II
II
II
Total l'tfrgen

an 0.11 i20 elm GAO 02
I
I



io4-


c 5 -
Ci)
Ei
Z1:__Z1_:
1v
..... .-
...... __

=-Z-7-

... _ '... .4


4
ol
I
I
I

II
I
iI
II
I
tI
II
t























TOW "ftgM
male
OM 053 IN iS 2M
1    1    1 I -1
It
II
II
t
I
I
i
I
I
I
I
.4
I
I
I


- - - mw

4k- CD7
I
b
I
Patzici Sizs
Waloh Pmant
S" 'd &"'a -- 0 - M
0S4IRd   U  -0 w -  10%-
a lm
I

Total Ptc~~rwx
eea  0.1G  em0  em   0.41
I
5.-
P-FI


S.


II

II


;1
I
I
I

I.1
I



i
I
II
II


Ip
4
I
3


2





0


'-1-

01
L
LJ
PI

I


AI
I
i
I
I
 -   1`1

I-FIB
- -- ktw
-1
- Fr7
I
Figure 19.
I
Grain size, total phosphorus and total nitrogen concen-
tration: a) Chesapeake Beach and b) Fleets Island,
I
34
 
I

a
PardeSze
WeiQht P4cel


swar    aa -4-  a -S%
Total Fhztslalug
M3MG

I  IM I  -
Total Nifogen

on Sim " Ws  2
a 50          8


I

m	68a~

I




II
k









aï¿½ï¿½
i -  VVE1


' - VVE2


I -	WE3













i -	E6- ---1W

10-	WES -    PLW
I
I
I

III
II
I
Ii
II
II
II
i
II
1,I
15

c


cii
W
1
0




5

I







--.---------I


-I
*5
b
Palclo Size
Welaht P=Wt

S,Id asS	4 ---M-'	-10
sn " clay	-4--	Im.0%


S	IE	I I I
1e	4	a
Total Phosphaus

eM WO B28 O25 00,1
I    I    I    I ---
Totl Nfrogen
M3/G
to IM  220 see 4
40-
II
I
r
I-I-02








i
I I





I          I


0
o

(L
)
Lu
20-
- -CL4
ii - CLS
;-  C17


i- CL7i


'- CL13
- mA
 IAW
0-
Figure 20.
Grain size, total phosphorus and total nitrogen
concentration: a) Wellford and b) Canoe House Landing.



35

I
Pa-uab stzo
Webint Poromi
B"amsGe   -ni.  8-W

Smics I I-II I I I
im      68     a












II




II
a
I
TotEd Phomhww
mcva
000 0.10 020 OM OAO OFA
7


I
I
11
I
II
II
II
tI
II
II
II
I
Toted Nbomw


I     I     I     I     III
I
25 -




20 -
0-   RC)

p- R02



- RO8



- R04
o- R0
I-ROB

i- R07

- R08
1-mRe
--RIO   - - - f*W
-Rl- - -44tW
-- R12
I
H-P



a1
)
w
L
IS
I
I
I
5
I
I
Partlcb8Sze
Wdpatt PFfrtt

Swd ad umm --n.- e- mm
GM wd OW	-C-- -  -01%
0	68 a
i II IIrnIrtI
b
Towa Phfroprn
WIYG
on0889 0.94 0r.1 ea
Towa  Ofrogm

020 91150- 920 GA 020
I
40-





1%0
-
I
_7_-7-73
=-=-r
. . .

 
I
i

I


.	.
11

.	. I
I
I
1-
I


I .4
f
t
11
i
I
i i
I
1.
1.
I
14, ,
I
I
I ,
I
I II

i                    1.
I
I
I
I
,I
I
I - BP3
0 - EN
I
I
I
I

c-
4-
T
a)
wi
20-





10 -
0- GP?

- - 44W
I
Figure 21.
Grain Size, total phosphorus and total nitrogen
concentration: a) Rosegill and b) Bushy Park Greek.
I
I
36
I

par" 825



mncwom	-.*-	S-GIG

,6	ES	a
a
Totd Rmmmjs
mm
OOD 005 0.10 OJS 020 025


11

II
II

'I_

II
II
II
II
II
II
II
II
II
II
II
II
II


II
IJ'_
Totd WCOM
MaG
000 005 0.10 0.15 020 026 030
1  1   1   1   1

11
1



I








II
I
II
II
I
II

II
II
II
L,






o- GL4
o- aB

c-

Co

(1)
wi
20 -
- SU
- SLB
 u- - 5*55
 LO- - I&W
- SLil
0 -
Parfici SIZ
Welehi PSoffrt

sit al OWl	-m--	IN - %
ekdM	so-	15-5
5	I 5 I	iII
iog	FA    '
b
Tot iosphoromn
em0 gm 540 see eme
Total "mmn

ORB sie0 e1m gm 0ese
I
II
I
II


K

II
II
II
II
II
41




II




II
II
II
II

pI




1-
I
I
I
I
I
I
I
I
p
I
I
I
I
I
I
I
-- - - -- - - - -
I

o- P04
- __



I
I
I
I
I



II






II
II
II

I
N-
c-
Co

a)
wL
20 -
 - P07
IS -



0-


I :- PGIO
-Poll
- -5*6

- - 1kw
Figure 22. Grain size, total phosphorus and total nitrogen concen-

tration: a). Sycamore Landi-ng and b) Pipsico Camp.
37

I
Petdcle Size
Wainht Panen

Bwds 'dGs	---	6-10%
GtM Od Cby	-.*-	IM-O


5	55	ee
9	60 JJ mi
a
Totai PhoMIcXnU


I      I      AI     I    --
Total N"Ogei
s	*a2
eim	103	200	SOO
I	I	I
I
60-
I
I
I
I


--
-'-
''
--
'-
'-









,-
._
_I







--
.-
--
-







_
_
_.
_.
,





i
r
 






i
;
ï¿½






:
-
ï¿½

i
-ï¿½
4 - CHI
I

i

II
i
II
II
II
II
II
II
c-

-f-
C


(O
0)
Ll
i
30-



20-



I


t
I
I
I
I
I
41
i- CH4
I11

II
I-MB




-	CH7
-I	-6 --- -I
-Q-F  ---lAW
- CHOe





I 1'
10-





0-
I
I
I
I
Palcieb Si
Wehht Percent
b
anss,,ce~ -u- '5-5%
S"a	_	- as	55
si a cw	.*	"O
0	w	imlrIl
i l i l l	l l i l
Tot Phosphous
CT seG
000 020 OAO 08a 080
Tow	1bcren
5	W.es
	W	se   e














----'





































--






















-L
25-
I
It
II
II
II
II

I
II
I
I
II
II
II
II
II
II
I
I
I
II
p
L ------
I 0 - NIB2
I
I
I

c-
C


a
LU
15-
I
II
II
II
I
II
- - - --k
IIi





5
I

?v67
-MMJ8

- - - MM
---M-W
I
Figure 23. Grain size, total phosphorus and total nitrogen concen-
tration: a) Chippokes State Park and b) Mogarts Beach.


38
I
I
I

a
Ptttdd Sze
Weloht Pmtai

Swid d G'ofo -i      0-603%
SR md Clay -a-*- loo-O%

0       60      iN
hlllym1
TotEd R-Q_
MS/0
OM 005 0.10 0.15 020 025
1   11 1 I 7


1,




I1.







II
II
II
II
II
II
II
II
II

pI
II
Total Nltrogm
N"o
eim OJO 020 Om OA_ 0-10
I III I -1



I-
I
.-I
I
I
I
I

I
II
II

4
II
II
II

II
II
I
t
II
tI
II
II
6







16
-









5 -







I- S82



I- S85



P- SB4



0      5- - - +w
I.

c-
o

II- SB7
b
PertIco Size
Wsiaht Parognt

Sand anid et"o	- b	0 - %
SRi anid CIsy	.*--	MN- 01
0	60	609
Total PhioSO-
sns


00 0.1 02 OS 04 00 90
Total IbtVA,t


90 9.1 02 03 OA 90 00 e.7
is -






'P    10 -
'4-



>   5 -
(D
w



Ci-
o- TBi





0-TB3








- TB4




o-TB5

0- TBe
p






















4
f,



II
II
II
I
II
I
II
41

II
II
II
II
II
i
II
II
II
- -- M-W
I0- TBB
total phosphorus a.nd total nitrogen concen-

Silver Beach and b) Tankards Beach.
Figure 24. Grain size,

tration: a)
39






Phosphorus concentrations were more erratic than the nitrogen con-
centrations. There was no consistent evidence of a relationship between
phosphorus concentration, grain size and bank height.3


Because of the evidence of a trend in nitrogen concentrations,
linear regression analysis was used to determine whether or not a sig-
nificant relationship exists between grain size and the concentration of
nitrogen or phosphorus. When all bank samples were included in the
analysis, the regression of nitrogen with grain size had an r 2 of 0.26.I
No relatio-nship between phosphorus concentration and grain size was
shown. However, when the nutrient rich upper horizons (approximately 5-
7 feet or the top two samples) were excluded from the analysis, the
regression of nitrogen with grain size had an r2	of073Uh
regression of phosphorus with grain size had a low  r	2of 0.18.  (The
regression equations are provided in Appendix D.)


The work of Mostaghimi et al. (1989) with deep soil cores showed
similar trends in nitrate nitrogen with depth.  M4ostaghimi et al. at                -
tributed increases ("spikes") in the nitrate nitrogen concentration at
depth to decreased permeability of fine grained layers.  Simpson
(personal communication) noted that nitrate nitrogen is stored in soilI
micropores. Simpson theorized that nitrogen spikes associated with fine
grained layers may also be influenced by increased micropore volume of
fine textured soils.





40~~~~~~~~

V. DISCUSSION
Comparisou of Shoreline Erosion and 'Upland Erosiou


To address the role of tidal shoreline erosion as a contributor to
nonpoint source pollution, the nutrient concentrations and loading rates
calculated in this study should be compared with other nonpoint source
data. Given the emphasis on agriculture as a major nonpoint source con-
tributor (U.S. Environmental Protection Agency, 1983), one can compare
the relative "importance" of nonpoint source pollution from shoreline
erosion with agricultural nonpoint source pollution. As the first step
in making a comparison, the nature of the processes of upland erosion
and shoreline erosion must be understood.


In the upland erosion process, sediment particles and soluble
nutrients from the topsoil layer are initially carried off by rainfall.
The resulting runoff from agricultural fields transports the nutrients
and sediments through the natural drainage system to the rivers and Bay.
In the case of shoreline erosion, the entire soil profile of the exposed
banks is eroded directly into the estuary. The interaction of several
forces results in the loss of large volumes of soil. Wave attack is the
primary agent in shoreline erosion and undermines the base of the bank.
The combined forces of gravity, raindrop impact, surface water runoff
a-nd wind also act to rapidly erode steep, unstable banks. Once soil has
been transported from the bank to the shore, the sediment particles are
.sorted and dispersed by waves and tidal currents.


To compare the relative magnitude of soil lost by upland erosion
to that lost by shoreline erosion, loading rates were determined for
equivalent surface areas of one acre. Documented erosion rates for the
Northern Neck of Virginia were used in the following example.  An acre
of land may have any combination of length and width dimensions that
equals 43,560 ft.  In Westmoreland and Richmond Counties, the average
erosion rate per acre for 3 highly erodible agricultural subwatersheds
is 14 tons per year (Brown and Price, 1988).


To obtain an equivalent surface area (acre) for the shoreline
case, the width dimension used equals the average shoreline erosion
41

I
I
rate.  The length, therefore, was calculated by dividing the surface
area of the acre of shoreline by the width.  For example, the average
shoreline erosion rate at Nomini Cliffs (Site 1) in Westmoreland County
is equal to 3.5 feet per year (Byrne and Anderson, 1977). A representa-
tive acre (43,560 ft2) of shoreline therefore has a width of 3.5 feet
and length of 12,446 feet or 2.4 miles (see equation and figure below).
I
I
I
Surface area (ft 2)
Width (ft)
43.560 ft2
3.5 ft
Length (ft)
12,446 ft
(3)
I
I
I
I
I
I
I
I
I
I
I
Figure 25. Illustration of upland erosion versus shoreline erosion.






42
I
I
I

The total volume of soil lost by shoreline erosion varies with the
bank height at the shore. The bank height at Nomini Cliffs is 29 feet
from the base to the top.   The entire bank face is subjected to
shoreline erosion through the undermining and sloughing process and
retreats inland at the average erosion rate. The total volume of soil
lost from erosion of an acre of shoreline at Nomini Cliffs in one year
was found by multiplying the width (annual erosion rate) times the
length of shoreline times the height of the bank.


Volume (ft3)  Width (ft) x Length (ft) x Height (ft)    (4)


=3.5 ft x 12,446 ft x 29 ft


=1,263,269 ft3

Using a soil bulk density of 1.5 g/cm 3(93.6 lb/ft 3), the volume
of eroded soil can be converted to mass (tons). Thus, erosion of one
representative acre of shoreline at Nomini Cliffs annually contributes
59,121 tons of soil directly to the adjacent Potomac River waters. In
contrast, erosion of a representative acre of cropland results in the
loss of 14 tons of soil per year. In this example, the volume of soil
lost to the estuary by shoreline erosion exceeds that lost by erosion of
cropland by 3 orders of magnitude (4,223 times greater). Given the mag-
nitude of the difference in soil loss between the two cases, the next
step is to determine the nutrient inputs from each source.

Nutrient concentrations measured in this study, however, cannot be
directly compared with those measured in agricultural runoff from other
Chesapeake Bay area studies.  Past studies of agricultural nonpoint
source pollution measured soluble nutrient concentrations in runoff
leaving the field. Research underway by various investigators also
seeks to measure the soluble nutrient concentrations in groundwater. In
the present study, residual total nitrogen and total phosphorus in the
soils were measured.  Mostaghimi et al. (1989) measured the remaining
nitrate nitrogen in deep soil cores. As nitrogen was not measured in
the same form, no comparison between their nitrate nitrogen and our to-
tal nitrogen data was made.
43







However, nutrient loading factors from existing studies can beI
compared for upland and shoreline erosion and used to calculate nutrient
loading rates. Nutrient loading factors are used in the Chesapeake Bay
Agricultural BMPB Cost-Share program to determine the effectiveness of
best management practices (BMPs). The projected nitrogen loading factor
used in the Cost-Share program is 5.44 pounds per ton of soil lostI
(Chesapeake Executive Council, 1988). In comparison, nitrogen loading
factors calculated in this study range from 0.06 to 1.77 pounds per ton
of soil lost (Table 3). The Cost-Share program used phosphorus loading
factors calculated for each county. For the counties studied in this
report, the Cost-Share phosphoruis loading factors range from 1.04 to
1.54 pounds per ton (Flagg, personal communication). Statewide, phos-
phorus loading factors range from 0.64 to 1.88 pounds per ton. In this
shoreline erosion study, phosphorus loading factors range from 0.04 to
1.02 pounds per ton (Table 4).


The fundamental difference between the nutrient load from upland
erosion versus shoreline erosion lies in the large mass of material lost
through shoreline erosion and the influence of mass on calculated load-
ing rates. Nutrient loading rates are derived by multiplying the nutri-
ent loading factors by the mass of soil lost. Using the Cost-Share
loading factors discussed above to demonstrate the contrast, approxi-
mately 76 pounds of nitrogen and 26 pounds of phosphorus would be con-
tributed for each acre of cropland which loses 14 tons of soil per year.
In contrast, the erosion of an equivalent acre of shoreline yields a3
nitrogen loading rate ranging from 2,153 to 66,214 pounds per acre per
year with a mean rate of 19,636 pounds per acre per year. For phosphor-
us, the loading rate contributed by shoreline erosion ranges from 196 toI
63,613 pounds per acre per year with a mean rate of 20,940 pounds per
acre per year.

Another notable difference between shoreline erosion and upland
erosion involves the proximity of the nutrient input to the water body.
In the Cost-Share program, delivery ratios are used to pro-rate the de-
creasing nutrient influx from cropland erosion to the water body with
increasing distance from the water body. If the land being treated with
the BMP is directly adjacent to the water body, the delivery ratio is 1.3




44I

TABLE 3. Sediment Loss and Nitrogen Loading Rates
Sediment Loss              Nitrogen
Site           (tons/ft/yr)	(lbs/ton) (lbs/ft/yr) (lbs/ac/yr)*

Nomini Cliffs	4.75	1.12	5.30	66,214
Great Point	1.19	0.44	0.52	2,153
Chesapeake Beach	1.64	0.49	0.79	5,794
Fleets Island	0.85	1.77	1.49	8,299
Wellford	1.97	0.25	0.49	8,918
Canoe House Ldg	10.96	0.59	6.44	43,300
Rosegill	2.45	0.06	0.14	2,789
Bushy Park Creek	5.26	0.13	0.68	9,620
Sycamore Landing	3.37	0.19	0.64	17,430
Pipsico Camp	4.53	0.25	1.14	27,419
Chippokes State Pk	2.14	0.53	1.13	44,839
Mogarts Beach	4.42	0.41	1.78	20,478
Silver Beach	3.10	0.40	1.23	9,459
Tankards Beach	2.39	0.55	1.30	8,185

Average	3.50	0.51	1.64	19,636



TABLE 4. Sediment Loss and Phosphorus Loading Rates


Sediment Loss              Phosphorus
Site           (tons/ft/yr)	(lbs/ton) (lbs/ft/yr) (lbs/ac/yr)*

Nomini Cliffs	4.75	0.88	4.16         52,025
Great Point	1.19	0.04	0.04	196
Chesapeake Beach	1.64	0.13	0.22	1,537
Fleets Island	0.85	0.30	0.25	1,407
Wellford	1.97	0.12	0.22	4,281
Canoe House Ldg	10.96	0.11	1.16	8,073
Rosegill	2.45	0.23	0.55	10,691
Bushy Park Creek	5.26	0.16	0.86	11,840
Sycamore Landing	3.37	0.25	0.84	22,934
Pipsico Camp	4.53	0.58	2.59	63,613
Chippokes State Pk	2.14	0.69	1.45	58,376
Mogarts Beach	4.42	1.02	4.42	50,945
Silver Beach	3.10	0.13	0.40	3,074
Tankards Beach	2.39	0.28	0.66	4,167
20,940
Average
3.50
0.35
1.27
* Pages 42 and 43 illustrate method used to
lost/shoreline acre. Tons/shoreline acre
(column 2 above) = lbs/ac/yr.
calculate
x lbs/ton
tons of soil
of nutrient
45







As the distance between the treated land and water body increases toI
1400 feet, the nutrient load to the water body is logarithmically de-
creased. Thus a large nutrient load originating 1400 feet inland may be
greatly reduced before reaching the adjacent water body, in contrast to
an initially smaller load closer to the water body that is not reduced
at all before entering the water.  In all shoreline erosion cases,I
nutrient loads are input directly into the water body.                              I


A final, major difference in the nature of shoreline erosion ver-
sus upland erosion is that the former results in the complete loss of
land and subsequent unrecoverable loss in real estate tax base. In con-
trast, upland erosion primarily damages the topsoil's ability to support
agriculture. Shoreline land loss may also damage or destroy ahore ad-
jacent BMPs that were installed to minimize upland nonpoint source pol-
lution.

Estimated Magnitude of NPS Nutrient Inputs from Shoreline Erosion


All sources of nonpoint source nitrogen and phosphorus inputs to
the Chesapeake Bay ecosystem need to be examined to achieve the 40%
nutrient reduction goal by the year 2000. The previous discussion shows
that large amounts of nitrogen and phosphorus are directly released into
the Bay and its major tributaries from shoreline sources (Tables 3 andI
4). The next step is to estimate the relative magnitude of the nitrogen
and phosphorus contribution to the Chesapeake Bay ecosystem attributable
to shoreline erosion as compared with other nonpoint source inputs.


Nutrient loading estimates for Virginia's tidal waters wereI
reported as 59.64 million pounds per year of nitrogen and 8.46 million
pounds per year of phosphorus (Chesapeake Executive Council, 1988).
The 1987 Chesapeake Bay Agreement targeted a 40% reduction in point
source and nonpoint source nitrogen and phosphorus. Year 2000 target
loads for nitrogen and phosphorus have been developed to meet this goal.I
Virginia's year 2000 target load for nitrogen is 35.78 million pounds
per year and 5.07 million pounds per year for phosphorus (Chesapeake
Executive Council, 1988). The total nutrient loads and year 2000 target
loads represent the sum of the point source and "controllable" nonpoint
source fractions.  Although the controllable nonpoint source fractionI
was not specifically defined, atmospheric nutrient inputs were excluded

46I

from the controlIlable fraction (Chesapeake Executive Council, 1988).
Controllable nonpoint source nitrogen was reported to be 25.99 million
pounds per year and controllable nonpoint source phosphorus as 3.98 mil-
lion pounds per year (Chesapeake Executive Council, 1988).

An estimate of the total quantity of nitrogen and phosphorus
entering Virginia's tidal waters from shoreline erosion can be made by
multiplying the average of the nitrogen and phosphorus loading factors
for the 14 sites studied (Tables 3 and 4; lbs/ton) by the annual net
soil loss attributed to shoreline erosion, 2.68  x 10 6 tons/year.  The
annual net soil loss was derived by multiplying the soil bulk density by
the eroded volume of soil (2.12 x 10 6 cubic yards/year) for approxi-
mately 1,600 miles of tidal shoreline (Byrne and Anderson, 1977).
Although nutrient inputs from shoreline erosion were apparently not con-
sidered as part of controllable nonpoint source inputs, inputs attribut-
able to shoreline erosion can be compared with controllable nonpoint
source estimates to assess the relative importance of the shoreline ero-
sion contribution. Figure 26a indicates that an estimated 1.37 millio-n
pounds per year of nitrogen is entering the Bay ecosystem through shore-
line erosion. This quantity of nitrogen is equivalent to 5.2% of the
controllable nonpoint source nitrogen load. Additionally, Figure 26b
shows that an estimated 0.94 million pounds per year of phosphorus,
equivalent to 23.6% of the controllable nonpoint source phosphorus load,
is entering the Bay ecosystem.

In order to provide an equivalent reduction of 5.2% and 23.6% to
the amount of controllable nitrogen and phosphorus entering Virginia' s
portion of the Bay through shoreline erosion, it would appear that 1,600
miles of shoreline would have to be stabilized with erosion control
measures. If this were the case, funding such an effort would be expen-
sive because of the length of shoreline involved. However, in reality,
because shoreline erosion rates and the accompanying bank heights are
known, the areas with the largest shoreline nutrient and sediment con-
tributions can be identified. Since these critically eroding areas can
be delineated, they represent a potentially controllable source of
nitrogen, phosphorus and sediment that could be effectively eliminated
from the already overloaded nutrient bludget.
47

I
a
I
Nitrogen Loading Rates for
Virginia's Portion of the Chesapeake Bay
I
Million Pounds/Year
70

60

50

40

30

20

10

0
0 Total PS & Controllable NPS
EN Loading Target for the Year 2000
I: Controllable NPS
[ Shoreline Erosion

Shoreline erosion contributes a quantity
of nitrogen equivalent to 6.2 % of the
controllable NPS.
59.64
I
I
35.78
101001
I

 11111-. ..
..iii.iiii
ii.ii.i. l




............
I
I
I
b
Phosphorus Loading Rates for
Virginia's Portion of the Chesapeake Bay
I
Million Pounds/Year
10
9-
8-

7-
1
I
I
I
I
I
* Total PS & Controllable NPS
[ Loading Target for the Year 2000
i] Controllable NPS
O   Shoreline Erosion

Shoreline erosion contributes a quantity
of phosphorus equivalent to 23.8 % of
6             -
...........
....
...........
 
..  ............ ...... .... . ..... .................. ......... ..................... ........... ... .. ......... ni  .M7   . . ............ ............ ....... ..............
the controllable NPS.
5.07

3.98
......................    s   s s   s  .' .' '   .....
;;;;........
. .-
............
..........
............
............
..... .....
...... .
............
.........
............
..
...
..................
.......,.'..''''-


'...........         0.94
5   -
...........
...........
..
4   --
...........
...........
......
3
..----------
2 -------- -
1-
0 -
Figure 26.
Loading rates for Virginia's portion of the
Chesapeake Bay: a) nitrogen and b) phosphorus.
I
I
48
I

VI. RECOmKENDATIONS FOR FURTHER RESEARCH
1. Further research is needed to better determine the total mag-
nitude of nutrient inputs from shoreline erosion and to deter-
mine the influence of the shoreline erosion contribution on
the 40% nutrient reduction goal.

2. The relationship of nitrogen concentration with grain size in
deep soil profiles should be investigated to better determine
the cause of the nitrogen increases associated with fine
grained layers.
49


VII. BIBLIOGRA

Biggs, R.B.  1970.  Sources and Distribution of Suspended Sediment in
Northern Chesapeake Bay.	Marine Geology.  9:187-201.
Brown, A.R. and J.C. Price.	[Memorandum to State ASO Committee concern-
ing ACP special project request.] January 22, 1988.
Byrne, R.J. and G.L. Anderson. 1977. Shoreline Erosion in Tidewater
Virginia:   Special Report in Applied Marine Science and Ocean En-
gineering No.111.  Virginia Institute of Marine Science, Gloucester
Point, p. 102.
Byrne, R.J., C.H. Hobbs, III. and M.J. Carron.  1982.  Baseline Sediment
Studies to Determine Distribution, Physical Properties, Sedimenta-
tion Budgets and Rates in the Virginia Portion of the Chesapeake
Bay. U.S. EPA R806001010, Virginia Institute of Marine Science,
Gloucester Point.  p. 155.

Carlo Erba Strumentazione Carbon Nitrogen Analyzer 1500 Instruction Man-
ual.  1986.                                                                       3
1987 Chesapeake Bay Agreement. Final Draft. December 14, 1987.
Chesapeake Executive Council.  1988.  Baywide Nutrient Reduction Strat-
egy.   Chesapeake Bay Program Agreement Commitment Report.
Annapolis, Maryland.
Correll, D.L.  1987.  Nutrients in Chesapeake Bay.  pp. 298-320.  In:
S.K. Majumdar, L.W. Hall, Jr. and H.M. Austin (eds.) Contaminant
Problems and Management of Living Chesapeake Bay Resources.
Easton, PA:  The Pennsylvania Academy of Science Publications.
Flagg, J.M. (personal communication)  Provided list of phosphorus load-
ing rates by county. Virginia Department of Conservation and
Recreation, Division of Soil and Water Conservation.                              3
Laboratory Procedure for the Soil Testing and Plant Analysis Laboratory.
1988. Extension publication 452-881. Virginia Polytechnic Insti-
tute and State University, Agronomy Dept., Blacksburg.                            I
Lukin, C.G.  1983.  Evaluation of Sediment Sources and Sinks:  A Sedi-
ment Budget for the Rappahannock River Estuary. College of William
and Mary, Virginia Institute of Marine Science, Gloucester Point.
Thesis.
Miller, A.J.  1983.  Shore Erosion Processes, Rates, and Sediment
Contributions to the Potomac Tidal River and Estuary.  John Hopkins
University. Dissertation.
Mostaghimi, S. (personal communication)  Virginia Polytechnic Institute
and State University, Agricultural Engineering Dept., Blacksburg.
Mostaghimi, S., U.S. Tim, P.W. McClellan, J.C. Carr, R.K. Byler, T.A.
Dillaha, V.0. Shanholtz and J.R. Pratt.  1989.  Watershed/Water
Quality Monitoring for Evaluating BMP Effectiveness - Nomini Creek

50
I

Watershed, Pre-BMP Evaluation Report No. N-P1-8906, Dept. of Con-
servation and Historic Resources, Div. of Soil of Soil and Water
Conservation, Richmond, VA. p. 211.
Schubel, J.R.  1968.  Shore erosion in northern Chesapeake Bay.  Shore
and Beach. 36:22-26.
Simpson, T.W.  (personal communication)  Virginia Polytechnic Institute
and State University, Department of Crop and Soil Environmental
Sciences, Blacksburg.
Schubel, J.R. and H.H. Carter. 1976. Suspended Sediment Budgets for
Chesapeake Bay. pp. 48-62. In: M.L. Wiley (ed.) Estuarine Pro-
cesses, Vol. II, New York: Academic Press.
Soil survey information for Northampton County, Virginia. Unpublished.
Located at: Soil Conservation Service, Accomack, VA.
Soil survey information for Surry County, Virginia. Unpublished. Lo-
cated at: Virginia Polytechnic Institute & State University, Dept.
of Crop & Soil Environmental Sciences, Blacksburg.

Soil Survey of Isle of Wight County, Virginia. 1986. U.S.D.A., Soil
Conservation Service. p. 105.

Soil Survey of James City and York Counties and the City of Williams-
burg, Virginia. 1985. U.S.D.A., Soil Conservation Service. p.
137.
Soil Survey of Middlesex County, Virginia. 1985. U.S.D.A. , Soil Con-
servation Service. p. 108.
Soil Survey of Northumberland and Lancaster Counties, Virginia.   1963.
U.S.D.A., Soil Conservation Service. p. 52.
Soil Survey of Richmond County, Virginia. 1982. U.S.D.A., Soil Conser-
vation Service. p. 100.
Soil Survey of Westmoreland County, Virginia.   1981.  U.S.D.A., Soil
Conservation Service. p. 96.
U.S. Army Corps of Engineers, Baltimore and Norfolk Districts.   1986.
Chesapeake Bay Shoreline Erosion Study: Final Reconnaissance
Report.
U.S. Environmental Protection Agency.  1982.  Chesapeake Bay Program
Technical Studies: A Synthesis. E.G. Macalaster, D.A. Barker and
M. Kasper (eds.)  U.S. EPA, Washington, D.C.  p. 635.

U.S. Environmental Protection Agency.  1983.  Chesapeake Bay:  A Frame-
work for Action.  D.A. Barker, M. Manganello, D. Pawlowicz and S.
Katsanos (eds.) Philadelphia, Pennsylvania. p. 186.
U.S. Environmental Protection Agency. 1979. Methods for Chemical Anal-
ysis of Water and Wastes. EPA-600/4-79-020. Cincinnati, Ohio. p.
298.
VIMS Shoreline Inventory Computer Database. Unpublished. Virginia
Institute of Marine Science, Gloucester Point, Virginia.
51

I
VIII.  APPENDICES


APPENDIX A

Bank Face Samples
Physical and Chemical Characteristics
I
I
I
Grain Size (%)        Nutrient Concentration (mg/g)
Gravel  Sand  Silt  Clay       TP      IP     TN     PC
Site   Sample #
I
1
NC1
NC2
NC3
NC4
NC5
NC6
2.0
0.0
0.0
0.0
0.0
0.0
74.0
68.8
97.0
34.0
12.7
29.5
14.1
11.9
0.6
39.8
45.4
44.1

40.2
43.5
39.7

55.8
43.4
6.2
9.9
19.3
2.4
26.1
41.8
26.4

12.1
13.3
22.8

24.8
21.2
9.3
0.09
0.05
0.01
0.11
0.56
1.28

0.03
0.01
0.02

0.05
0.07
0.09
0.009
0.002
0.004
0.047
0.100
1.234

0.002
0.000
0.001

0.001
0.004
0.005
0.90
0.30
0.00
0.45
1.11
0.70

0.54
0.20
0.11

0.49
0.25
0.16
16.35
3.07
0.07
3.58
13.80
12.90

13.50
4.93
1.13

5.49
0.98
0.70
I
I
2
GP1
GP2
GP3
0.2	47.5
0.0	43.
1
0.2	37.2
I
3
CB1
CB2
CB3
0.1
0.2
21.6
19.3
35.3
62.9
I
4
FI1
FI2
FI3
9.3	82.0
0.1	36.0
0.0	28.3
5.2
43.4
47.9

9.2
0.3
1.3
20.8
37.2

28.2
2.6
1.4
20.6
40.1
18.5
2.2
6.1
2.6
4.7

11.6
1.9
0.3
1.6
1.5
0.6
2.3
0.3
3.5
20.4
23.8

14.1
1.7
1.9
12.2
12.0

10.3
11.2
3.5
23.8
48.2
45.9
3.8
13.5
0.3
5.9

7.0
5.2
1.2
5.6
2.1
2.8
4.3
1.1
0.06
0.27
0.10

0.09
0.02
0.03
0.04
0.15

0.30
0.04
0.03
0.08
0.08
0.17
0.01
0.10
0.00
0.06

0.19
0.03
0.01
0.06
0.06
0.45
0.08
0.40
0.012
0.174
0.049

0.005
0.002
0.002
0.003
0.102

0.030
0.004
0.002
0.002
0.002
0.004
0.000
0.001
0.000
0.000

0.030
0.006
0.002
0.006
0.011
0.054
0.016
0.054
0.47
1.65
0.48

0.16
0.03
0.04
0.18
0.20

1.30
0.12
0.06
0.17
0.78
3.34
0.00
0.11
0.00
0.01

0.57
0.02
0.00
0.00
0.00
0.00
0.02
0.00
10.80
43.50
8.42
I
5
WE1
WE2
WE3
WE4
WES
1.2
0.9
9.0
1.3
0.0

1.4
0.9
4.9
0.2
1.0
0.0
0.3
0.0
0.0
1.4

0.0
0.0
0.0
0.0
19.8
0.0
5.3
0.8
75.5
97.1
87.8
65.7
50.8

60.1
85.3
90.2
55.4
10.7
35.6
93.7
80.4
97.1
88.0

81.4
92.9
98.5
92.8
76.6
96.6
88.1
97.8
1.34
0.18
0.82
1.24
2.28
I
I
6
CL1
CL2
CL3
CL4
CLS
CL6
CL7
CL8
CL9
CLi10
17.00
0.66
0.79
1.57
5.40
88.30
0.30
1.28
0.14
0.30

6.82
0.67
0.04
0.17
0.11
0.30
0.12
0.17
I
I
I
I
I
I
7
RO1
R02
R03
R04
R05
R06
R07
R08
52
I

Grain Size (%)
Gravel Sand Silt Clay
Nutrient
TP
Concentration (mg/g)
IP     TN     PC
Site  Sample It
8
BP1
BP2
BP3
BP4
BP5
BP6
BP7
BP8
0.0
0.0
0.4
0.1
0.1
0.0
4.8
0.0
84.1
41.3
96.5
98.4
98.6
97.4
92.9
95.7

56.4
47.0
73.6
85.8
76.5
84.0
86.1
83.8
8.5
26.7
1.3
0.3
0.4
0.5
0.7
0.6

31.6
24.3
5.7
1.7
3.8
4.1
6.5
7.4
7.4
31.9
1.8
1.2
0.9
2.1
1.6
3.7

12.0
28.7
20.7
12.5
11.5
11.9
7.4
8.8
0.11
0.14
0.14
0.03
0.03
0.01
0.02
0.11

0.05
0.05
0.03
0.10
0.21
0.15
0.22
0.03
0.006
0.004
0.077
0.017
0.011
0.002
0.002
0.009

0.002
0.001
0.001
0.001
0.002
0.008
0.030
0.006
0.48
0.34
0.04
0.00
0.00
0.00
0.00
0.00

0.07
0.04
0.27
0.20
0.04
0.07
0.09
0.18
7.75
2.70
0.80
0.11
0.10
0.12
0.03
0.15

1.06
2.93
6.21
3.58
0.66
0.15
0.23
1.60
9
SL1
SL2
SL3
SL4
SL5
SL6
SL7
SL8
0.0
0.0
0.0
0.0
8.2
0.0
0.0
0.0
10      PC1
PC2
PC3
PC4
PC5
PC6
PC7

11      CH1
CH2
CH3
CH4
CH5
CH6

12      MB1
MB2
MB3
MB4

13      SB1
SB2
SB3
SB4

14      TB1
TB2
TB3
TB4
2.8
5.0
15.9
0.2
7.3
11.4
0.0
72.2
65.3
68.8
14.6
49.5
75.9
87.1

30.0
58.6
20.7
34.2
62.6
84.6

41.1
45.3
67.9
66.2

69.8
40.5
83.7
97.5

62.6
46.0
74.4
98.9
16.5
18.0
1.4
40.7
13.3
3.2
5.1

50.1
9.4
33.8
25.8
12.2
4.0

24.1
15.6
16.4
19.6

21.7
34.0
0.6
0.2

27.4
27.7
10.7
0.2
8.5
11.7
13.9
44.6
29.8
9.5
7.8

18.7
32.0
45.5
39.9
24.9
7.3

34.2
39.1
15.1
13.0

7.0
25.3
5.3
2.3

10.0
26.3
14.9
0.9
0.05
0.05
0.04
0.28
0.75
0.69
0.17

0.47
0.31
0.09
0.39
0.41
0.44

0.23
0.62
0.55
0.47

0.22
0.06
0.06
0.05

0.60
0.08
0.08
0.04
0.001
0.001
0.001
0.002
0.016
0.121
0.109

0.018
0.002
0.001
0.012
0.367
0.259

0.009
0.052
0.020
0.018

0.150
0.003
0.014
0.025

0.600
0.004
0.014
0.031
0.39
0.15
0.06
0.41
0.23
0.08
0.12

2.20
0.33
0.29
0.28
0.06
0.07

0.64
0.19
0.09
0.22

0.49
0.35
0.21
0.13

0.66
0.33
0.16
0.13
7.59
1.66
0.34
1.59
0.70
12.70
1.11

23.60
1.77
1.57
1.65
1.90
3.90

7.33
0.86
15.70
17.50

5.08
2.02
1.01
0.89

7.83
1.72
0.98
0.62
1.2
0.0
0.0
0.0
0.3
4.1
0.4
0.0
0.6
1.2
1.5
0.2
10.4
0.0

0.0
0.0
0.0
0.0
53

I
APPENDIX B

Shore and Nearshore Samples
Physical and Chemical Characteristics
Grain Size (%)
Site   Sample #   Gravel  Sand  Silt  Clay
Concentration (mg/g)
IP     TN     PC
Nutrient
TP
I
1
NC7
NC8
NC9
79.2
26.4
76.8

0.0
14.5
4.1

8.1
0.0
0.1
18.2
1.9

0.0
32.1
15.6
7.6

0.6
44.0
52.9
18.7
70.3
19.7

98.7
81.8
31.2

88.7
98.5
99.1
80.1
19.2

98.8
67.0
82.8
90.8

98.5
54.9
46.3
1.2	0.9
1.7	1.6
2.0	1.5
0.74
0.46
0.49

0.01
0.04
0.05

0.05
0.05
0.01
0.04
0.09

0.01
0.00
0.01
0.01

0.04
0.11
0.11
0.071
0.232
0.409

0.001
0.011
0.004

0.003
0.001
0.001
0.006
0.001

0.001
0.000
0.001
0.002

0.029
0.097
0.033
0.10
0.13
0.38

0.00
0.09
0.30

0.06
0.07
0.06
0.08
0.46

0.00
0.00
0.00
0.05

0.00
0.01
0.03
1.60
1.83
5.23

0.22
2.27
2.03

0.23
0.18
0.31
0.46
1.57

1.30
0.14
0.30
0.26

0.24
0.35
0.47
1
2
GP4
GP5
GP6
0.2
0.9
22.8

0.6
0.3
0.2
0.3
36,8

0.2
0.1
0.4
0.3
1.1
2.8
41.8

2.6
1.2
0.6
1,4
42.1

1.0
0.8
1.2
1.3
I
3
CB4
CB5
CB6
CB7
CB8
I
[
4
FI4
FI5
FI6
FI7
I
I
5
WE6
WE7
WE8
0.3	0.6
0.3	0.8
0.2	0.6
I
CLll
CL12
CL13

R09
RO10
ROll
RO12
6



7
0.0
26.0
1.9

0.2
52.4
0.0
0.0

0.8
20.0
25.3
99.5
72.7
88.2

98.4
6.5
97.8
11.9

98.4
79.2
74.2
0.2	0.3
0.4	0.9
4.1	5.8
0.02
0.02
0.08

0.02
0.19
0.04
0.10

0.01

0.03
0.000
0.004
0.001

0.011
0.021
0.016
0.008

0.002
0.001
0.003
0.01
0.02
0.25

0.00
0.02
0.02
3.35

0.00
0.00
0.00
0.21
0.40
2.07
I
1.3
0.8
1.8
51.4
0.1
0.3
0.4
36.7
0.18
0.37
0.27
54.60
I
8
BP9
BP10
BPll
0.1	0.7
0.0	0.8
0.0	0.5
0.09
0.10
0.32
I
I
9
SL9
SL10
SL11
0.0	98.5
0.9	93.5
0.2	92.9
0.2	1.3
1.3	4.3
1.9	5.0
0.01
0.06
0.10

0.18
0.32
0.14
0.50
0.002
0.006
0.012

0.089
0.076
0.021
0.010
0.03
0.04
0.07

0.05
0.04
0.06
0.04
0.12
0.20
0.47
I
10       PC8
PC9
PC10
PCll
4.0
0.1
36.9
7.9
94.7
98.9
62.3
90.2
0.1
0.3
0.1
0.2
1.2
0.7
0.7
1.7
0.89
1.18
1.21
10.40
I
I
54
I

Grain Size (%)
Gravel Sand Silt Clay
Nutrient Concentration (mg/g)
TP     IP     TN      PC
Site   Sample #
11      CH7
CH8
CH9
CH10

12      MB5
MB6
MB7
29.5
20.2
3.0
0.8

6.9
11.1
3.8
61.3
76.6
95.6
95.6

91.3
87.4
52.6
2.4
1.4
0.2
1.2

0.4
0.3
26.4
6.8
1.8
1.2
2.4

1.4
1.2
17.2
0.37
0.45
0.26
0.27

0.25
0.16
0.53
0.273
0.232
0.201
0.239

0.108
0.009
0.030
0.04
0.02
0.64
0.09

0.00
0.02
0.27
0.66
0.48
4.36
8.46

6.30
17.80
0.00
13       SB5
SB6
SB7
0.0	98.8
0.1	98.6
0.0	98.7
0.3	0.9
0.3	1.0
0.4	0.9
0.01
0.02
0.01
0.006
0.002
0.005
0.08
0.10
0.15
0.25
0.29
0.41
14      TB5
TB6
TB7
TB8
0.0
0.0
0.5
1.0
99.2
99.3
98.7
97.8
0.2
0.1
0.1
0.3
0.6
0.6
0.7
0.9
0.01
0.01
0.01
0.01
0.002
0.003
0.002
0.007
0.09
0.09
0.07
0.07
0.29
0.30
0.23
0.33
55

APPENDIX C
Nutrient Loading Rates

Site Number/Name: 1 Nomini Cliffs (NC)
Height of Bank (ft): 29.0
Bank Retreat Rate (ft/yr): 3.5
Bank Erosion Volume (cubic feet/yr/ft):
101.5
HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

1.0	0.03	0.09	0.003	0.03	0.04	0.90	0.031	0.29	0.43
6.0	0.21	0.05	0.010	0.10	0.15	0.30	0.062	0.59	0.88
5.0	0.17	0.01	0.002	0.02	0.03	0.00	0.000	0.00	0.00
4.0	0.14	0.11	0.015	0.14	0.21	0.45	0.062	0.59	0.88
6.5	0.22	0.56	0.126	1.18	1.76	1.11	0.249	2.35	3.50
6.5	0.22	1.27	0.285	2.69	4.00	0.70	0.157	1.48	2.20

29.0	1.00	0.441	4.16	6.19	0.561	5.30	7.89
0n
Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 {mg/g)
Pounds/Ton of total phosphorus - 0.881
Pounds/Ton of total nitrogen = 1.122

Site Number/Name: 2 Great Point (GP)
mm mmm   m          _ _ _ m  m

m-  m m  - - m  - - - m







Site Number/Name:   2 Great Point (GP)


Height of Bank (ft): 2.4
Bank Retreat Rate (ft/yr): 10.6
Bank Erosion Volume (cubic feet/yr/ft): 25.4
HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Cone.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr

0.4	0.17	0.03	0.005	0.01	0.01	0.54	0.090	0.21	0.31
1.0	0.42	0.01	0.004	0.01	0.01	0.20	0.083	0.20	0.30
1.0	0.42	0.02	0.008	0.02	0.03	0.11	0.046	0.11	0.16

2.4	1.00	0.018	0.04	0.05	0.219	0.52	0.77
Ll
Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.035
Pounds/Ton of total nitrogen = 0.438

Site Number/Name: 3 Chesapeake Beach (CB)
Height of Bank (ft): 5.8
Bank Retreat Rate (ft/yr): 6.1
Bank Erosion Volume (cubic feet/yr/ft):
35.1
HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr

1.0	0.17	0.05	0.009	0.03	0.04	0.49	0.085	0.28	0.42
2.8	0.48	0.07	0.033	0.11	0.16	0.25	0.120	0.39	0.58
2.0	0.35	0.07	0.024	0.08	0.12	0.11	0.038	0.12	0.18

5.8	1.00	0.066	0.22	0.32	0.243	0.79	1.18
Qn
co
Total

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.133
Pounds/Ton of total nitrogen = 0.486
m m    m m m m mm mm  m m    m mmm     _ -   _ M m

Im   -  m m                                                                           I M   m m               m   -   m m











Site Number/Name: 4 Fleets Island (FI)


Height of Bank (ft): 2.3
Bank Retreat Rate (ft/yr): 7.9
Bank Erosion Volume (cubic feet/yr/ft): 18.1
HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

0.5	0.22	0.06	0.013	0.02	0.03	0.47	0.102	0.28	0.42
0.8	0.35	0.27	0.094	0.16	0.24	1.65	0.574	0.39	0.58
1.0	0.43	0.10	0.043	0.07	0.10	0.48	0.209	0.12	0.18

2.3	1.00	0.150	0.25	0.37	0.885	1.49	2.21

Total
Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.301
Pounds/Ton of total nitrogen = 1.770

Site Number/Name:  5 Wellford (WE)
Height of Bank (ft): 17.5
Bank Retreat Rate (ft/yr): 2.4
Bank Erosion Volume (cubic feet/yr/ft): 42.0

HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

4.5	0.26	0.09	0.023	0.09	0.13	0.16	0.041	0.16	0.24
1.0	0.06	0.02	0.001	0.00	0.00	0.03	0.002	0.01	0.01
5.5	0.31	0.03	0.009	0.04	0.06	0.04	0.013	0.05	0.07
4.5	0.26	0.03	0.008	0.03	0.04	0.18	0.046	0.18	0.27
2.0	0.11	0.14	0.016	0.06	0.09	0.20	0.023	0.09	0.13

17.5	1.00	0.057	0.22	0.32	0.125	0.49	0.72

Totals
Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.115
Pounds/Ton of total nitrogen = 0.249
o0
o~
_   _       _                                _  _     m

- - -- m m  -  -  m  -  - - I  - -







Site Number/Name: 6 Canoe House Landing (CL)
Height of Bank (ft): 36.0
Bank Retreat Rate (ft/yr): 6.5
Bank Erosion Volume (cubic feet/yr/ft):
234.0
HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Cone.	Rel.	Loading	Rates	Cone.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

1.3	0.03	0.30	0.010	0.23	0.34	1.30	0.045	0.98	1.46
7.0	0.19	0.04	0.008	0.17	0.25	0.12	0.023	0.51	0.76
13.8	0.38	0.03	0.011	0.25	0.37	0.06	0.023	0.50	0.74
4.0	0.11	0.08	0.009	0.19	0.28	0.17	0.019	0.41	0.61
2.0	0.06	0.08	0.004	0.10	0.15	0.78	0.043	0.94	1.40
1.5	0.04	0.17	0.007	0.15	0.22	3.34	0.139	3.03	4.51
1.0	0.03	0.01	0.000	0.01	0.01	0.00	0.000	0.00	0.00
1.0	0.03	0.10	0.003	0.06	0.09	0.11	0.003	0.07	0.10
4.5	0.13	0.00	0.000	0.00	0.00	0.00	0.000	0.00	0.00

36.0	1.00	0.052	1.16	1.71	0.295	6.44	9.58
ON
Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.106
Pounds/Ton of total nitrogen = 0.592

Site Number/Name: 7 Rosegill (RO)
Height of Bank (ft): 22.8
Bank Retreat Rate (ft/yr): 2.3
Bank Erosion Volume (cubic feet/yr/ft):
52.3
HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Cone.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr

1.0	0.04	0.19	0.008	0.04	0.06	0.57	0.025	0.12	0.18
3.0	0.13	0.03	0.004	0.02	0.03	0.02	0.003	0.01	0.01
6.0	0.26	0.01	0.003	0.01	0.01	0.00	0.000	0.00	0.00
4.0	0.18	0.06	0.011	0.05	0.07	0.00	0.000	0.00	0.00
3.0	0.13	0.06	0.008	0.04	0.06	0.00	0.000	0.00	0.00
1.8	0.08	0.50	0.038	0.19	0.28	0.00	0.000	0.00	0.00
2.0	0.09	0.08	0.007	0.03	0.04	0.02	0.002	0.01	0.01
2.0	0.09	0.40	0.035	0.17	0.25	0.00	0.000	0.00	0.00

22.8	1.00	0.114	0.55	0.80	0.029	0.14	0.20
rO
Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.228
Pounds/Ton of total nitrogen = 0.059
_m         m   -        '    -  - _  _                  r_  _ I

mm- - --- m - MM-  mm mm    mm








Site Number/Name: 8 Bushy Park Creek (BP)


Height of Bank (ft): 36.3
Bank Retreat Rate (ft/yr): 3.1
Bank Erosion Volume (cubic feet/yr/ft): 112.4
HORIZON
Total Phosphorus                         Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Cone.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr

1.0	0.03	0.11	0.003	0.03	0.04	0.48	0.013	0.14	0.21
5.0	0.14	0.14	0.019	0.20	0.30	0.34	0.047	0.49	0.73
4.0	0.11	0.14	0.015	0.16	0.24	0.04	0.004	0.05	0.07
3.5	0.10	0.03	0.003	0.03	0.04	0.00	0.000	0.00	0.00
4.5	0.12	0.03	0.004	0.04	0.06	0.00	0.000	0.00	0.00
5.5	0.15	0.01	0.002	0.02	0.03	0.00	0.000	0.00	0.00
4.8	0.13	0.02	0.003	0.03	0.04	0.00	0.000	0.00	0.00
8.0	0.22	0.15	0.033	0.35	0.52	0.00	0.000	0.00	0.00

36.3	1.00	0.082	0.86	1.27	0.065	0.68	1.01
Totals
Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.163
Pounds/Ton of total nitrogen = 0.129

Site Number/Name: 9 Sycamore Landing (SL)
Height of Bank (ft): 45.0
Bank Retreat Rate (ft/yr): 1.6
Bank Erosion Volume (cubic feet/yr/ft):
72.0


HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

0.5	0.01	0.05	0.001	0.00	0.00	0.07	0.001	0.01	0.01
6.5	0.14	0.05	0.007	0.05	0.07	0.04	0.006	0.04	0.06
3.0	0.07	0.03	0.002	0.01	0.01	0.27	0.018	0.12	0.18
3.0	0.07	0.10	0.007	0.04	0.06	0.20	0.013	0.09	0.13
1.0	0.02	0.21	0.005	0.03	0.04	0.04	0.001	0.01	0.01
24.0	0.53	0.15	0.080	0.54	0.80	0.07	0.037	0.25	0.37
5.0	0.11	0.22	0.024	0.16	0.24	0.09	0.010	0.07	0.10
2.0	0.04	0.03	0.001	0.01	0.01	0.18	0.008	0.05	0.07

45.0	1.00	0.127	0.84	1.23	0.094	0.64	0.93

Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.254
Pounds/Ton of total nitrogen = 0.188
a0
Ch
m m m m m m m m m m m m m m m m m m m

mm-   - m m m m - -   m m m - - -M








Site Number/Name: 10 Pipsico Camp (PC)


Height of Bank (ft): 53.8
Bank Retreat Rate (ft/yr): 1.8
Bank Erosion Volume (cubic feet/yr/ft): 96.8


HORIZON

Total Phosphorus                        Total Nitrogen

Thick.	Rel.	Cone.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Conce.	lbs/ft/yr	kg/m/yr

0.3	0.01	0.05	0.000	0.02	0.03	0.39	0.002	0.13	0.19
1.0	0.02	0.05	0.001	0.05	0.07	0.15	0.003	0.16	0.24
12.5	0.23	0.04	0.009	0.55	0.82	0.06	0.014	0.82	1.22
1.5	0.03	0.28	0.008	0.46	0.68	0.41	0.011	0.67	1.00
7.5	0.14	0.75	0.105	6.17	9.18	0.23	0.032	1.89	2.81
7.0	0.13	0.69	0.090	5.30	7.89	0.08	0.010	0.61	0.91
24.0	0.45	0.17	0.076	4.48	6.67	0.12	0.054	3.16	4.70

53.8	1.00	0.288	2.59	3.85	0.126	1.14	1.68

Totals
Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.577
Pounds/Ton of total nitrogen = 0.253

Site Number/Name: 11 Chippokes State Park (CH)
Height of Bank (ft): 41.5
Bank Retreat Rate (ft/yr): 1.1
Bank Erosion Volume (cubic feet/yr/ft):
45.7
HORIZON

Total Phosphorus                         Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

1.5	0.04	0.47	0.017	0.07	0.10	2.20	0.080	0.34	0.51
6.0	0.14	0.31	0.045	0.19	0.28	0.33	0.048	0.20	0.30
8.0	0.19	0.09	0.017	0.07	0.10	0.29	0.056	0.24	0.36
8.0	0.19	0.39	0.075	0.32	0.48	0.28	0.054	0.23	0.34
4.0	0.10	0.41	0.040	0.17	0.25	0.06	0.006	0.02	0.03
14.0	0.34	0.44	0.148	0.63	0.94	0.07	0.024	0.10	0.15

41.5	1.00	0.342	1.45	2.15	0.267	1.13	1.69
a%
0%
Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.685
Pounds/Ton of total nitrogen = 0.533
_m m_      m m m m mm m m m  m m

-  - m   m m m -                                                                                -- - m - m m - m










Site Number/Name: 12 Mogarts Beach (MB)


Height of Bank (ft): 24.5
Bank Retreat Rate  (ft/yr):   3.8
Bank Erosion Volume (cubic feet/yr/ft): 93.1
HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

1.5	0.06	0.23	0.014	0.12	0.18	0.64	0.038	0.33	0.49
6.0	0.24	0.62	0.152	1.32	1.96	0.19	0.047	0.40	0.60
6.0	0.24	0.55	0.133	1.16	1.73	0.09	0.022	0.19	0.28
11.0	0.45	0.47	0.210	1.82	2.71	0.22	0.099	0.86	1.28

24.5	1.00	0.510	4.42	6.58	0.206	1.78	2.65
Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 1.019
Pounds/Ton of total nitrogen = 0.411

Site Number/Name: 13 Silver Beach (SB)
Height of Bank (ft): 11.6
Bank Retreat Rate (ft/yr): 5.7
Bank Erosion Volume (cubic feet/yr/ft):
66.1


HORIZON

Total Phosphorus	Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Cone.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Cone.	lbs/ft/yr	kg/m/yr

0.8	0.07	0.22	0.015	0.09	0.13	0.49	0.034	0.21	0.31
1.5	0.13	0.06	0.008	0.05	0.07	0.35	0.045	0.28	0.42
2.3	0.20	0.06	0.012	0.07	0.10	0.21	0.042	0.26	0.39
7.0	0.60	0.05	0.030	0.19	0.28	0.13	0.078	0.48	0.71

11.6	1.00	0.065	0.40	0.58	0.199	1.23	1.83

Totals

Note:

Totat phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)

Pounds/Ton of total phosphorus = 0.130
Pounds/Ton of total nitrogen = 0.398
a
_       _  _  _  _-       -               _  _ -_ _ -

m      m  m
m m  m m m m mm











Site Number/Name: 14 Tankards Beach (TB)


Height of Bank (ft): 7.3
Bank Retreat Rate (ft/yr): 7.0
Bank Erosion Volume (cubic feet/yr/ft): 51.1
HORIZON

Total Phosphorus                         Total Nitrogen

Thick.	Rel.	Conc.	Rel.	Loading	Rates	Conc.	Rel.	Loading	Rates
(feet)	Thick.	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr	(mg/g)	Conc.	lbs/ft/yr	kg/m/yr

1.0	0.14	0.60	0.082	0.39	0.58	0.66	0.090	0.43	0.64
2.3	0.32	0.08	0.025	0.12	0.18	0.33	0.104	0.49	0.73
2.0	0.27	0.08	0.022	0.10	0.15	0.16	0.044	0.21	0.31
2.0	0.27	0.04	0.011	0.05	0.07	0.13	0.036	0.17	0.25

7.3	1.00	0.140	0.66	0.98	0.274	1.30	1.93
0o
tO
Totals

Note:
Total phosphorus detection limit = 0.01 (mg/g)
Total nitrogen detection limit = 0.18 (mg/g)
Pounds/Ton of total phosphorus = 0.281
Pounds/Ton of total nitrogen = 0.548

Phosphoruis vs Grain Size

Concentration (mg/g)
1.4
+                     ~~~~~~~~y = -0O004x + 0.45

2
r= 0. 18











+1~~~~A
+1   I         +1   +    +   I   +   ~~~~~~~--+i
1,2-



,I-i
m






I-I.
0



I-a


Po
0
oq
I1
-
0.8 -
0
0.6


0.4

0.2

0
100
40           60

Grain Size (% sand/gravel)
80
0
20
mmmmm m m m m m m   m m -    m m  m m -

m m m m - m m m m m - - m - - m m m m
Nitrogen vs Grain Size

Concentration (mg/g)
1,2


1


0.8
-I
H-
0.6
0.4


0.2


0
0
20
40           60
Grain Size (% sand/gravel)
80
100