Chesapeake Bay Watershed Model
Application & Calculation of Nutrient
& Sediment Loadings
Appendix B:
Phase IV
Chesapeake Bay
Watershed Model
Water Quality
Calibration
Results
   Prepared by the
 Modeling Subcomittee
     of the
Chesapeake Bay Program

  EPA 903-R-98-003
   CBP/TRS 196/98
February 1998	
Chesapeake Bay Program

-------
    CHESAPEAKE BAY WATERSHED MODEL
     APPLICATION AND CALCULATION OF
     NUTRIENT AND SEDIMENT LOADINGS

  Appendix B: Phase IV Chesapeake Bay Watershed Model
                Water Quality Results
                     A Report of the
                  Chesapeake Bay Program
                  Modeling Subcommittee
                     Annapolis, MD
                     X-SSS&k
                     '"'•.'Y'A " *''; V"",
                Chesapeake Bay Program
                      May 1998


Printed by the U.S. Environmental Protection Agency for the Chesapeake Bay Program

-------
           Principal Authors
             Lewis C. Linker
United States Environmental Protection Agency
      Chesapeake Bay Program Office
              Annapolis, MD
              Gary W. Shenk
United States Environmental Protection Agency
      Chesapeake Bay Program Office
              Annapolis, MD
              Dr. Ping Wang
  Maryland Department of Natural Resources
      Chesapeake Bay Program Office
              Annapolis, MD
            Jennifer M. Storrick
      Chesapeake Research Consortium
      Chesapeake Bay Program Office
              Annapolis, MD

-------
               Modeling Subcommittee Members
James R. Collier
Chairman, Modeling Subcommittee
Program Manager
Water Resources Management Division
Washington, DC

Dr. Joseph Bachman
US Geological Survey
Towson, MD

Mark Bennett
Department of Soil and Water Conservation
Richmond, VA

Dr. Peter Bergstrom
Chesapeake Bay Field Office
US Fish & Wildlife Service
Annapolis, MD

Dr. Arthur Butt
Chesapeake Bay Office
VA Department of Environmental Quality
Richmond, VA

Brian Hazelwood
Metropolitan Washington Council of
Governments
Washington, DC

Dr. Albert Y. Kuo
VA Institute of Marine Science
Gloucester Point, VA

Lewis C. Linker
Coordinator, Modeling Subcommittee
US EPA Chesapeake Bay Program Office
Annapolis, MD
 Dr. Robert Magnien
 MD Department of Natural Resources
 Assessment Administration
 Annapolis, MD

 Dr. Ross Mandel
 Interstate Commission on the Potomac
 River Basin
 Rockville, MD

 Dr. Bruce Parker
 National Oceanic and Atmospheric
 Administration/NOS/OES33
 Coastal & Estuarine Oceanography
 Silver Spring, MD

 Kenn Pattison
 PA Dept. of Environmental Protection
 Bureau of Water Quality Protection
 Harrisburg, PA

 Ron Santos
 US Army Corps of Engineers
 Baltimore, MD

 Dr. Tom Stockton
 MD Dept. of Environmental Resources
 Watershed Modeling & Analysis
Annapolis, MD

Paul Welle
USDA Soil Conservation Service
Northeast National Technical Center
Chester, PA

Dr. Alan Lumb
Hydrologic Analysis Support Section
USGS National Center
Reston, VA

-------
                             Acknowledgments
The writers would like to acknowledge the efforts of several people who contributed
substantially to the compilation of this appendix. We would like to thank the United
States Geological Survey representatives from the states of West Virginia, Virginia,
Pennsylvania and Maryland for the timely processing of our data requests. Finally, the
authors would like to express their appreciation to the scientists and engineers of the
Modeling Subcommittee and the Model Evaluation Group for their guidance and review
of this document. This document and other Chesapeake Bay Program modeling
documents can be found on the Modeling Subcommittee web page:
http://wwwxhesapeakebay.net^ayprogram/committ/nidsc/model.htrn

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                            Appendix Summary
 Appendix B documents the water quality calibration of the Phase IV Watershed
 Model. Simulated and observed concentrations are compared for 8 years of calibration
 (1984-1991) at 15 water quality stations. Calibration data is shown for temperature,
 dissolved oxygen, total suspended sediment, total phosphorus, organic and paniculate
 phosphorus, phosphate, total nitrogen, nitrate, total ammonia, and organic nitrogen.

The following plots are completed for each constituent: (1) observed  and simulated
concentrations; (2) observed and simulated loads (temperature loads are not
calculated); (3) scatter plot and regression of simulated versus observed
concentrations; (4) observed and simulated actual error of paired data (simulated
concentration - observed concentration); (5) frequency distribution of paired simulated
and observed data, i.e. coincident observed and simulated concentrations, and; (6)
frequency distribution of all simulated and observed data.

The daily observed and simulated concentration plots generally show good to excellent
agreement between the model  and data for temperature, dissolved oxygen, and total
suspended sediment and fair to good agreement on other water quality constituents.
Generally, as the number of water quality observations at a station increases the
calibration improves.

The simulated and observed load plots are developed from the observed mean daily
flow and concentration compared to model estimated loads. Overall the load
comparisons range from fair to excellent depending in different cases on the
simulation of flow or the simulation of concentration.

Scatter plots of observed and simulated concentrations are shown with the ideal line
(slope of 1, intercept of zero) drawn to assist interpretation of the plots with changing
x and y axis scales. The actual  regression line slope, intercept, correlation coefficient,
standard error of the slope, standard error of the intercept, and the number of
observations are shown in the plot legend.

The actual error plot is calculated as the difference of the simulated and observed
concentrations plotted against time and is useful for indicating calibration bias and the
actual magnitude of errors. The two frequency distribution plots are useful for
examining the differences between the observed and simulated concentrations with
respect to concentration magnitude and frequency of occurrence. Generally,
calibration is best in the central area of the data and calibration performance is least in
the tails, particularly the 10th and 90th percentiles.

-------
        List of Phase IV Watershed Model Reference Appendices

Appendix A  Phase IV Chesapeake Bay Watershed Model Hydrology Calibration
            Results
Appendix B  Phase IV Chesapeake Bay Watershed Model Water Quality Calibration
Appendix C  Phase IV Chesapeake Bay Watershed Model Nonpoint Source Simulation
Appendix D  Phase IV Chesapeake Bay Watershed Model Precipitation and
            Meteorological Data Development and Atmospheric Nutrient Deposition
Appendix E  Phase IV Chesapeake Bay Watershed Land Use & Model Linkages to the
            Airshed & Estuarine Models
Appendix F  Phase IV Chesapeake Bay Watershed Model Point Source Loads and
            Water Supply Diversions
Appendix G  Observed Water Quality Data Used for Calibration, A Simulation of
            Regression Loads, and a Confirmation Scenario of the Phase IV
            Chesapeake Bay Watershed Model
Appendix H  Development of BMP Input Parameters to Track Nutrient Reduction
            Goals with the Phase IV Chesapeake Bay Watershed Model

-------
                                Table of Contents
Principal Authors	w

Modeling Subcommittee Members	Hi

Acknowledgments	.	iv

Appendix Summary	v

List of Phase IV Watershed Model Reference Appendices	vi

Table of Contents	vii

List of Figures	ix

List of Tables	x

B.1.0   Susquehanna River.	I

  B. 1.1   East Branch Susquehanna River near Danville, PA at Segment 40 (Monitoring
  Station: 1540500) (Above Fall Line Basin Segments: 10, 20,700, 30, and 40)	3
  B. 1.2   West Branch Susquehanna River near Lewisburg, PA at Segment 70 (Monitoring
  Station: 1553500) (Above Fall Line Basin Segments: 50, 60, and 70)	45

  B. 1.3   Juniata River at Newport, PA near Segment 100 (Monitoring Station: 1567000)
  (Above Fall Line Basin Segments: 90 and 100)	87
  B. 1.4   Lower Susquehanna River at Harrisburg, PA Segment 110 (Monitoring Station:
  1576000) (Above Fall Line Basin Segments: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 700
  and 710)	129
  B. 1.5   Susquehanna River near Conowingo, MD At Segment 140 (Monitoring Station:
  1578310) (Above Fall Line Basin Segments: 120,140, and 720)	167

5.2.0   Patuxent River	209

  B.2.1   Patuxent River near Bowie, MD at Segment 340 (Monitoring Station: 1594440)
  (Above Fall Line Basin Segments: 330,340,500, and 900)	211

B.3.0  Potomac River.	253
  B.3.1  Mid Potomac River near Shepardstown, WV at Segment 740 (Monitoring Station:
  1613000) (Above Fall Line Basin Segments: 160,170,175,730, and 740)	255
  B.3.2   Shenandoah River near Millville, WV at Segment 200 (Monitoring Station: 1636500)
  (Above Fall Line Basin Segments: 190 and 200)	297
  B.3.3  Lower Potomac River at Chain Bridge near Washington, DC at Segment 220
  (Monitoring Station: 1646580) (Above Fall Line Basin Segments: 160,170, 175, 180, 190,
  200,210, 220,730, 740, and 750)	339

B.4.0  Rappahannock River  Basin	381
                                 vii

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  B.4.1    Rappahannock River near Fredericksburg, VA at Segment 230 (Monitoring Station:
  1668000) (Above Fall Line Basin Segments: 230)	383

B.5.0  York River Basin	425

  B.5.1    Mattaponi River near Beulahville, VA at Segment 240 (Monitoring Station: 1674500)
  (Above Fall Line Basin Segments: 235 and 240)	427

  B.5.2    Pamunkey River near Hanover, VA at Segment 260 (Monitoring Station: 1673000)
  (Above Fall Line Basin Segments: 250 and 260)	469

B.6.0 James River Basin	577

  B.6.1    James River at Gartersville, VA at Segment 280 (Monitoring Station: 2035000)
  (Above Fall Line Basin Segments: 265,270, 280, and 290)	513

  B.6.2    Appomattox River at Matoaca, VA at Segment 310 (Monitoring Station: 2041650)
  (Above Fall Line Basin Segments: 300 and 310)	555

B.7.0  Choptank River Basin	597

  B.7.1    Choptank River near Greensboro, MD at Segment 770 (Monitoring Station: 1491000)
  (Above Fall Line Basin Segments: 770)	,	599
                                 viii

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                               List of Figures
 Figure                                                          Page




 B.O    Major Basins of the Chesapeake Bay Watershed	xi




 B. 1    Monitoring Stations in the Susquehanna River Basin	2




 B.2    Monitoring Stations in the Patuxent River Basin	210




 B.3    Monitoring Stations in the Potomac River Basin	254




 B.4    Monitoring Stations in the Rappahannock River Basin	382




 B.5    Monitoring Stations in the York River Basin	426




B.6    Monitoring Stations in the James River Basin	512




B.7    Monitoring Stations hi the Choptank River Basin	598
                               ix

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                                List of Tables
Table
                                                                    ze
B .0    Table of Phase IV Watershed Model Segments by Basin	xii

B. 1    Characteristics of Stations used in Hydrology Calibration	xiii

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Major Basins of the  Chesapeake Bay Watershed
          LOCATION MAP
             OF THE
       Chesapeake Bay Watershed
       NY,PA,MD,D.C,DE,
         WVANDVA
   Susquehanna River Basin
[   Potomac River Basin
   Western Shore Maryland
   Patuxent River Basin
   Western Shore Virginia
  {Rappahannock River Basin
   York River Basin
   Eastern Shore Maryland
   Eastern Shore Virginia
   James River Basin
                                                 Source: U.S. E.P.A. Chesapeake Bay Program

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 Table B.O

        PHASE IV CHESAPEAKE BAY MODEL

                SEGMENTS BY BASIN


 SUSQUEHANNA RIVER BASIN:
 AFL--10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 140, 700, 720

 POTOMAC RIVER BASIN:
 AFL- 160, 170, 175, 180, 190, 200, 210, 220, 730, 740, 750
 BFL - 540, 550, 890, 900, 910, 920, 970, 980

 JAMES RIVER BASIN:
 AFL - 265, 270, 280, 290, 300, 310
 BFL-600, 610, 620, 630

 RAPPAHANNOCK RIVER BASIN:
 AFL-230
 BFL-560

 PATUXENT RIVER BASIN:
 AFL - 330, 340
 BFL - 500, 990

 YORK RIVER BASIN:
 AFL-235, 240,250, 260
 BFL-590

 WESTERN SHORE MARYLAND:
 AFL - 650, 760
 BFL - 470, 480, 490, 510, 850, 860. 870, 880

 EASTERN SHORE MARYLAND:
 BFL - 370, 380, 390, 400, 410, 420, 430, 450, 770, 780, 800, 820, 830, 840

WESTERN SHORE VIRGINIA:
BFL - 580, 930, 940, 950, 960

EASTERN SHORE VIRGINIA:
BFL-440
                          xii

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                                                                Table B.I

                                         Characteristics of Stations Used in Hydrology Calibration
Phase IV
Model
Segment
40



70







100



710




Station
No.

1540500



1553500







1567000



1576000




Location


Montour County, PA, on right bank 200 ft
upstream from Mill Street bridge on State
Highway 54 at Danville and 0.8 mi
upstream from Mahoning Creak.
Northumberland County, PA, at down-
stream side of left abutment of Market
Street bridge on State Highway 45 at
Lewisburg, 0.2 mi downstream from
Buffalo Creek and 7.4 mi upstream from
mouth.


Perry County, PA, on right bank at
downstream side of bridge on State
Highway 34 at Newport and 1 ,000 ft
upstream from Little Buffalo Creek.
Dauphin County, PA, on east bank of City
Island, 60 ft downstream from Market
Street bridge in Harrisburg, 3,670 ft
upstream from sanitary dam, and 1 .7 mi
upstream from Paxton Creek.
Latitude


40°57'29"



40058'05"







40°28'42"



40°15'17"




Longitude


76°37'10"



76°52'25"







77°07'46"



76°53'11"




Drainage
Area
(mi2)
11220



6847







3354



24100




Gauge
(ft. above
NGVD)
431.29



428.20.
10/20/87 -
9/30/88,
nonrecord-
ing gauge
at same
site and
datum.
363.93



290.01




Average
Discharge

89 years,
1 5,270 cfs,
18.48 in/yr
as 1988.*
62 years,
757 cfs,
23.21 in/yr
as 1991.*




89 years,
4,280 cfs,
17.37 in/yr
as 1988.
98 years,
34,220 cfs,
19.28 in/yr
as 1988.

H-
H-
H-

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Phase IV
» mr -\ K
Model
Segment
175







140



220



200


780




Station
No.
1613000







1578310



1646580



1636500


1487000




Location

Washington County, MD, on left bank,
0.2 mi downstream from Little
Tonoloway Creek, 0.5 mi downstream
from bridge on US Highway 522 at
Hancock, 1 . 1 mi upstream from
Tonoloway Creek (formerly called Great
or Big Tonoloway Creek), and at mile
239.
Harford County, MD, on downstream side
of Conowingo Dam, 1.0 mi southwest of
Conowingo, and 9.9 mi upstream from
mouth.
Arlington County, DC, under right
downstream side of bridge on Virginia
State Highway 123, and at river mile
115.9.
Jefferson County, WV, on left bank 0.4
mi downstream from Cattail Run, 1 .0 mi
upstream from Millville, 5.0 mi upstream
from Harpers Ferry, and at mile 5.0.
Bridgeville, DE, on left bank at
downstream side of highway bridge, 800
ft downstream from Gum Branch, 2.5 mi
southeast of Bridgeville, and 50.5 mi
upstream from mouth.
Latitude

39°41'49"







39039'3r'



38°55'46"



39°16'55"


38°43'42"




Longitude

78°10'39"







76°10'28"



77°07'02"



77°47'22"


75°33'44"




Drainage
Area
(mi2)
4073







27100



11570



3040


75




Gauge
(ft. above
NGVD)
383.68







5.00



N/A



293.00


13.64




Average
Discharge
56 years,
4,154cfs,
13.85 in/yr
as 1988.




19 years,
41,870cfs,
20.98 in/yr
as 1986.
N/A



71 years,
2699 cfs,
12.06 in/yr
as 1986.
45 years,
89.8 cfs,
16. 17 in/yr
as of 1988.


-------
Phase IV
Model
Segment
280




760




310






230




240




Station
No.

2035000




1589000




2041650






1668000




1674500




Location


Goochland County, VA, on left bank, 200
ft downstream from bridge at State
Highway 45 between Pemberton and
Cartersville, 1.8 mi downstream from
Willis River and at mile 156.4.
Baltimore County, on left bank at
downstream side of highway bridge at
Hollofield, 0.3 mi downstream from
Dogwood Run, 3.0 mi north of Ellicott
City and 28 mi upstream from mouth.
Chesterfield County, VA, on left bank at
upstream side of bridge on State Highway
600, 0.2 mi south of Matoaca, 2.0 mi
upstream from Rohoic Creek, 2.8 mi
downstream from Lake Chesdin, 3.5 mi
west of Petersburg, and at mile 15.9.

Spotsylvania County, VA, on right bank
1.6 mi upstream from dam of Virginia
Power, 2.2 mi downstream from Motts
Run, and 3.8 mi upstream from
Fredericksburg.
King and Queen County, VA, on left bank
0.4 mi upstream from bridge on State
Highway 628, 2.4 mi north of Beulahville,
and 2.7 mi downstream from Maracossic
Creek.
Latitude


37°40'15"




39°18'36"




37°13'28"






38°19'20"




37°53'16"




Longitude


78005'10"




76°47'34"




77°28'32"






77°31'05"




77°09'48"




Drainage
Area
(mi2)
6257




285




1344






1596




601




Gauge
(ft. above
NGVD)
163.90




187.70




68.30






55.18




12.43




Average
Discharge

89 years,
7,087 cfs,
15.38 in/yr
as 1988.

N/A




18 years,
1,476 cfs,
14.91 in/yr
as 1987.
(minimum,
41 cfs, Oct.
4, 1981.)
80 years,
1,660 cfs,
14. 12 in/yr
as 1988.

46 years,
591 cfs,
13.35 in/yr
as 1987.


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Phase IV
Model
Segment
260
340
770
Station
No.
1673000
1594440
1491000
Location
Hanover County, VA, on right bank 100 ft
downstream from bridge on State
Highway 614, 0.3 mi upstream from
Mechumps Creek, 2.0 mi east of Hanover,
and 7.0 mi upstream from Millpond
Creek.
Anne Arundel County, MD, on left bank
45 ft upstream from bridge on U.S.
Highway 50, 3.0 mi west of Bowie City
Hall, 3.1 mi downstream from mouth of
Little Patuxent River, 4.2 mi northwest of
Davidsonville, and 60 mi upstream from
mouth.
Caroline County, MD, on left bank at
highway bridge, 0. 1 mi upstream from
Gravelly Branch, 2.0 mi northeast of
Greensboro, and 60 mi upstream from
mouth-
Latitude
37°46'03M
38°57'21"
38°59'50"
Longitude
77019'57"
76°41'36"
75047-09..
Drainage
Area
(mi2)
1081
348
113
Gauge
(ft. above
NGVD)
14.72
13.10
3.51
Average
Discharge
46 years,
l,006cfs,
12.64 in/yr
as 1988.
1 1 years,
362 cfs,
14.13 in/yr
as 1988.
41 years,
130 cfs,
15.62 in/yr
as 1989.
*: Datum of gauge, above National Geodetic Vertical Datum of 1929; Water-stage recorder, if not otherwise indicated.

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                     B.1.0 Susquehanna River
Basin Segments:
       Above Fall Line Basin Segments: 10, 20,30,40, 50, 60, 70, 80,90, 100,
       110, 110, 120, 140, 700, 710, and 720

Section Contents:
       B. 1.0 Monitoring Stations in the Susquehanna River Basin (Figure B.1.0)
       B.I.I East Branch Susquehanna River (Monitoring Station: 1540500)
       B.1.2 West Branch Susquehanna River (Monitoring Station: 1553500)
       B.I.3 JuniataRiver (Monitoring Station:  1567000)
       B.1.4 Lower Susquehanna River (Monitoring Station: 1576000)
       B.1.5 Susquehanna River at Conowingo Dam  (Monitoring Station:  1578310)

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                                     Figure B.1
     Monitoring Stations
               in the
 Susquehanna River Basin
 Susquehanna River Basin in
The Chesapeake Bay Watershed
                               Calibration Stations
                               • 1540500
                               m 1553500
                               A 1567000
                               ^ 1576000
                               m 1578310
                               /V Streams
                               |"l Model Segments
    * Bar Program

  Map Date: Apnl 1998
Source: USGS and USEPA Chesapeake Bay Program
                              KJH

-------
 B.LI  East Branch Susquehanna River near Danville, PA at Segment 40 (Monitoring
 Station: 1540500) (Above Fall Line Basin Segments: 10, 20, 700, 30, and 40)	

 Section Summary;

 The East Branch Susquehanna basin is largely rural in character and influenced by
 agricultural loads as well as loads from several cities including Binghamton, Scranton,
 and Wilkes Barre. An unusual feature of the East Branch Susquehanna is the decreasing
 population in the basin over the 1984-1995 simulation period. This is the only
 Chesapeake Bay basin with a decreasing population.

 The East Branch Susquehanna basin above the gaged site covers an area of 11,522 square
 miles.  At the midpoint of the simulation, 1990, the land use for the basin was composed
 of 59% forest land, 7% cropland, 27% other agricultural areas, 6% urban areas, and 1%
 water (river and lake) surface area.

 Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
 Reduction Progress scenario, estimated total nitrogen delivered to the gage decreased
 from 47.9 million pounds in 1985 to 46.7 million pounds in 1996. Total phosphorus
 loads over the same time period decreased from 2.1 million pounds to 1.6 million pounds.
 In general, point source loads above the gage site are low. In 1996, the total nitrogen
 point source load was 12% of the total load and the total phosphorus point source load
 was 29% of the total load. Estimated septic system total nitrogen loads increased 6%,
 from 1.35 million pounds in 1985 to 1.44 million pounds in 1996.

 Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
 estimated cropland total nitrogen loads by 7%, and other agricultural loads (primarily
pasture and manure loads) by 7%. Total phosphorus decreased for these land uses by
 10% and 24% respectively. Urban loads were estimated to have increased over the 1985
to 1996 period by 5% for total nitrogen and 5% for total phosphorus due to increases in
population and urban land use area.

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 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date — Temperature

-------
Ut
    o-t
        East Branch Susquehanna River at Segment 40
                Observed and Simulated versus Time
                        Temperature-C
                         (*=Observed, -=Simulated)
                               Date

-------
 East Branch Susquehanna at Segment 40
        Scatter Plot and Regression of Simulated
          versus Observed with Ideal Line
         Temperature-C: 01JAN84 - 01JAN92
                   SioiuUttd-Tcmp-C
East Branch Susquehanna at Segment 40
          Actual Error versus Time
              Temperarure-C

1 •
•s
3 "'
" -S
-7-
•11 ;



'










IT
l<







j





•





i






ft i
1





T
1






f

•



j,
11






"tl
1




I,
'J





i
il«






F





T
11




•
Iji


1
•


': . .; J , i

Jr
,



                     Date

-------
          East Branch Susquehanna at Segment 40
                         Temperature-C
               Frequency Distribution - FAIRED Simulated and Observed Data
2
j 1.000
o
                             30 Percent ofPoptiktion *°
         East Branch Susquehanna at Segment 40
                         Temperature-C
               Frequency Distribution - All Simulated and Observed Data
                             Pwcwit of Population

-------
00
         East Branch Susquehanna River at Segment 40
                Observed and Simulated versus Time
                      Dissolved Oxygen
                        (*=Observed, -=Simulated)

-------
          East Branch Susquehanna River at Segment 40

         Dissolved Oxygen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
     4000000
     3000000 -
vo
   t
    2000000-
    1000000 -
                                   Date

-------
         East Branch Susquehanna at Segment 40
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                 Dissolved Oxygen: 01JAN84 - 01JAN92
f,
S  7
3
                            SunuUted-mgfl
        East Branch Susquehanna at Segment 40
                   Actual Error versus Time
                     Dissolved Oxygen
11
10
9
S
t
5
3-
t •
1 •
3-







ll I I





Jj
1





. 1 i if I il ,
Ml * A 1
                                         XXX
                         10

-------
 East Branch Susquehanna at Segment 40

              Dissolved Oxygen
     Frequency Distribution - PAIRED Simulated and Observed Data
               30    tectnto/iPopiiUlion   TO
                                           90
East Branch Susquehanna at Segment 40

             Dissolved Oxygen
      Frequency Distribution - All Simulatedand Observed Data
                   Porontol Population
                  11

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    soo -:
    700
ro
        East Branch Susquehanna Kiver at Segment 40
                Observed and Simulated versus Time
                  Total Suspended Sediment
                        (*=Observed, -=Simulated)
                               Date

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      East Branch Susquehanna River at Segment 40

 Total Suspended Sediment Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 1.50E+08




 1.40E+08




 1.30E+08




 1.20E+08




 1.10E+08




 l.OOE+08
                                Date
.
*V2«JANM IS

-------
         East Branch Susquehanna at Segment 40
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
              Total Suspended Sediment: 01JAN84 - 01JAN92
                            Simulated-mgfl
-wo
.100
         East Branch Susquehanna at Segment 40
                   Actual Error versus Time
                  Total Suspended Sediment
                                          .L-L
                             DaU
                          14

-------
 East Branch Susquehanna at Segment 40
          Total Suspended Sediment
     Frequency Distribution - PAIRED Simulated and Observed Data
                   Percent on*ojniUtion
East Branch Susquehanna at Segment 40
          Total Suspended Sediment
      Frequency Distribution - All Simulated and Observed Data
                  15

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East Branch Susquehanna River at Segment 40
       Observed and Simulated versus Time
              Total Phosphorus
                (*=Observed, -=Simulated)
                       Qife

-------
       East Branch Susquehanna River at Segment 40

      Total Phosphorus Observed and Simulated Load vs Time
                       (line = simulated, O = observed)
  60000 -:
                               Date
6r2l JWI.MI duulon2
 ..d» 2UAN9*

-------
           East Branch Susquehanna at Segment 40
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                   Total Phosphorus: 01JAN84 - 01JAN92
ssssassss...
                               SimuUted-mgfl
  0.11

  O.H

  0.14

  0.12

  0.10

  O.M
          East Branch Susquehanna at Segment 40
                    Actual Error versus Time
                        Total Phosphorus
 *0.
 4.14

 -O.U

 •0.11



 •0.22-

 •OJ4 •

 -u«-

 -»J»-

 •OJO-
,ll
.

TTfl
i i
ll,

T ll
1
i
1

r^l'
%

t Tr

1


^Tt.TT.1


11. if

1
rri
L kfl
,* u, r
                                                    X    X
                                Dite
                            18

-------
1.00
        East Branch Susquehanna at Segment 40

                      Total Phosphorus
             Frequency Distribution - PAIRED Simulated and Observed Data
        East Branch Susquehanna at Segment 40

                     Total Phosphorus
             Frequency Distribution - All Simulated and Observed Data
                          19

-------
East Branch Susquehanna River at Segment 40
       Observed and Simulated versus Time
     Organic and Particulate Phosphorus
                (*=Observed, -^Simulated)
                       Date

-------
      East Branch Susquehanna River at Segment 40

Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 60000-:
                                Date
»-•<*• 2«J*NW

-------
 East Branch Susquehanna at Segment 40
        Scatter Plot ana Regression of Simulated
           versus Observed with Ideal Line
  Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
                    Simulated, ngfl
East Branch Susquehanna at Segment 40
          Actual Error versus Time
     Organic and Particulate Phosphorus
0.12
0.10
04)8
O.M
044
002
0.00
•a -OJS
£ -OJH
O 4.0*
1 4.01 *
3 4.10'
(«•
I *;;;
-».!••
4J2-
•0.14 •
4-Zf
-OJO-

Tf









X /


111









f


lit
1







1
•
fl TT
T

i
n








^ «i»


i.
r1,




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* TT 1
1-1
1 '

1
,




/ /
Date

I T
1


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,
-

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Hi i|
.'!







•
s /


i



•
f, f 1 1 rli
f '"•§ T * i ll^*i * '
•







/• /•

                22

-------
         East Branch Susquehanna at Segment 40

               Organic and Farticulate Phosphorus
             Frequency Distribution - PAIRED Simulated and Observed Data  ,
0.00001-
                            30 Penxnt depopulation *°
        East Branch Susquehanna at Segment 40

              Organic and Farticulate Phosphorus
              Frequency Distribution - All Simulated and Observed Data
                             PwMnt o( Population
                            23

-------
N)
         East Branch Susquehanna River at Segment 40
                Observed and Simulated versus Time
                    Dissolved Phosphorus
                        (*=Observed, -=Simulated)
                               Dile

-------
to
Ul
           East Branch Susquehanna River at Segment 40

       Dissolved Phosphorus Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
     19000
     18000
     17000
     16000
     15000
     14000 -
     13000'
     12000
    «"
     11000
.£

•o
     10000
     9000 -
     8000-
     7000
     6000-
     5000-
     4000-
     3000-
     2000-
     1000
                                      Date

-------
          East Branch Susquehanna at Segment 40
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                 Dissolved Phosphorus: 01JAN84 - 01JAN92
                             Simulated-mg/I
 0.0*

 0.05

 0.04

 tJO
 4JO
' 4*7

 JIM

 •CM

 •4.10

 •4.11

 •O.U

 -O.U

 -0.14-
         East Branch Susquehanna at Segment 40
                    Actual Error versus Time
                     Dissolved Phosphorus
     TT
VT^I
                         I
TI
4
^k
             Jut
1
                          26

-------
          East Branch Susquehanna at Segment 40
                       Dissolved Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
 0.010"
                               Percent
          East Branch Susquehanna at Segment 40
                      Dissolved Phosphorus
                Frequency Distribution - All Simulated and Observed Data
 0.17
 o.it
 o.is
 O.M
 0.13 •
 0.12 •
- 0.11 •
 0.10 •
 0.07-
 0.06'
 0.05-
 o.o« •
 am-
 O.OZ-
 o.oo
                            *     «?     #
                               Pwcmt of Population
                             27

-------
     7- :
          East Branch Susquehanna River at Segment 40
                  Observed and Simulated versus Time
                          Total Nitrogen
                           (*=Observed/ -=Simulated)
N)
00
•	*-.	3<--:
   -ulc *  •  *
    0-Li
                                  Date
                                                              * *;

                                                            * * * * :
                                                          ...**.*....*....
                                                             * * •
                                                                I

-------
     500000
     400000
10

VO
    >, 300000 1
    CO
    .c

    TJ
     200000 -
     100000
          East Branch Susquehanna River at Segment 40
           Total Nitrogen Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
                                      Date
 _..
(•butt.ddnt 04FCBM Otllfnc i»».mod«l y.i)
          «B*MlM
          i»».mod«l y

-------
          East Branch Susquehanna at Segment 40
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Total Nitrogen: 01JAN84 - 01JAN92
                             *   t
                             Simubud-m(/I
tsssx
         East Branch Susquehanna at Segment 40
                    Actual Error versus Time
                        Total Nitrogen
    I.  IljlftlltlH  j{.l.frl
                                                  X     X
                                                             J
                          30

-------
East Branch Susquehanna at Segment 40

                Total Nitrogen
     Frequency Distribution - PAIRED Simulated and Observed Data
                  30 hnxnt o%>puUlioii
East Branch Susquehanna at Segment 40

               Total Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                   PmwitofPopuMion
                  31

-------
OJ
N>
    3-:
    oi
         East Branch Susquehanna River at Segment 40
                Observed and Simulated versus Time
                              NO3
                         (*=Observed, -=Simulated)
                                Date
  eer.

-------
 180000
 170000
 160000
 150000 -
 140000
 130000'
 120000
 110000 '
w 100000-
s.
s
o
      East Branch Susquehanna River at Segment 40
            NO3 Observed and Simulated Load vs Time
                       (line = simulated, O = observed)
                                 Date

-------
 East Branch Susquehanna at Segment 40
        Scatter Plot and Regression of Simulated
          versus Observed with Ideal Line
             NO3:01JAN84 - 01JAN92
East Branch Susquehanna at Segment 40
          Actual Error versus Time
                  NO3
                34

-------
I    C 0.10 •
   Bsssssrar1
             East Branch Susquehanna at Segment 40

                                 N03
                  Frequency Distribution - FAIRED Simulated and Observed Data
     10.00 • 	
             East Branch Susquehanna at Segment 40

                                 N03
                   Frequency Distribution - All Simulated and Observed Data
                                 Pwctnt of Popuwlwn
    assess"
                                35

-------
    0.9- :
CO
    0.1 -
    0.0
         East Branch Susquehanna River at Segment 40
                Observed and Simulated versus Time
                        Total Ammonia
                         (*=Observed, -=Simulated)
                                Date

-------
          East Branch Susquehanna River at Segment 40
          Total Ammonia Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
     80000
     70000- :
     60000-
     50000 -
u>
•o
I
£

I
     40000 -
     30000
     20000
     10000
                                    Date
     .
    Klrv 2U«NM 1>:

-------
           East Branch Susquehanna at Segment 40
                    Scatter Plot aim Regression of Simulated
                       versus Observed with Ideal Line
                     Total Ammonia: 01JAN84 - 01JAN92
  OJl
  OJO
  OJ9
  (US
  0.27
  0.26
  0.2S
  0.24
  0.23
  0.22
  0.21
  0.20
  O.J9
5, 1-U
E 0.17
i O.M
| 0.15
i 0.14
0 0.13
  0.12
  0.11
  0.10
  o.o»
  0.08
  0.07'
  0.06-
  0.05'
  0.04-
  0.03-
  0.02-
  0.01-
  0.00-
                                  SimuUUd-ntgfl
          East Branch Susquehanna at Segment 40
                      Actual Error versus Time
                           Total Ammonia
 o.u
 0.14
 0.11
 0.10
 0.0»
 0.0*
 0.04
 0.02
 0.00 '
 4.02"
-o.io-
JIM-
-d.il-
-010
•002
»T. . I
 irj
-OJ8 j
JIM -
il
                                         II
                                   Dam
                              38

-------
 I


 s
 1
          East Branch Susquehanna at Segment 40

                         Total Ammonia
               Frequency Distribution - PAIRED Simulated and Observed Data
                                 ofpoptiUtiai
  0.1 -:
          East Branch Susquehanna at Segment 40

                         Total Ammonia
                Frequency Distribution - All Simulated and Observed Data
scrsssw

                             39

-------
East Branch Susquehanna at Segment 40
     Observed and Simulated versus Time
           Organic Nitrogen
             (*=Observed, -=Simulated)
                    Date

-------
          East Branch Susquehanna at Segment 40

      Organic Nitrogen Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
  400000
  300000-
I
I
  200000-
  100000-
(ySI Jlo* ui maWMfewra d| MU.)

   vl 23FEBM OMl«f« r.g.m<
                                  Date

-------
           East Branch Susquehanna at Segment 40
                  Scatter Plot ana Regression of Simulated
                     versus Observed with Ideal Line
                   Organic Nitrogen: 01JAN84 - 01JAN92
                                                            of Row
                              Simulated-mg/1
          East Branch Susquehanna at Segment 40
                    Actual Error versus Time
                        Organic Nitrogen
           r
fr-
™
Miki
                                                     Jtl
                                     lfl
essssav—
                            42

-------
 East Branch Susquehanna at Segment 40

              Organic Nitrogen
     Frequency Distribution - PAIRED Simulated and Observed Data
East Branch Susquehanna at Segment 40

              Organic Nitrogen
     Frequency Distribution - All Simulatedand Observed Data
                  43

-------
 East Branch Susquehanna River at Segment 40
        Relative Error versus Percentile Sample Population
                     Organic Nitrogen
          Frequency Distribution - All Simulated and Observed Data
                        Percent of Population
East Branch Susquehanna River at Segment 40
   Actual error versus Percentile Sample Population
                  Organic Nitrogen
          Frequency Distribution - All Simulated and Observed Data
                       Percent of Population
                      44

-------
 B.1.2  West Branch Susquehanna River near Lewisburg, PA at Segment 70
 (Monitoring Station: 1553500) (Above Fall Line Basin Segments: SO, 60, and 70)

 Section Summary;

 The West Branch Susquehanna basin is dominated by the large areas of forest. Total
 nitrogen and total phosphorus loads are generally low.

 The West Branch Susquehanna basin above the gaged site covers an area of 7,014 square
 miles.  At the midpoint of the simulation, 1990, the land use for the basin was composed
 of 80% forest land, 6% cropland, 11% other agricultural areas, 2% urban areas, and 1%
 water (river and lake) surface area.

 Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
 Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
 from 26.1 million pounds in 1985 to 22.2 million pounds in 1996. Total phosphorus
 loads over the same time period decreased from 0.8 million pounds to 0.5 million pounds.
 In general, point source loads above the gage site are low. In 1996, the total nitrogen
 point source load was 7% of the total load and the total phosphorus point source load was
 23% of the total load. Estimated septic system total nitrogen loads increased 9%, from
 0.50 million pounds in 1985 to 0.55 million pounds in 1996.

 Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
 estimated cropland total nitrogen loads by 3%, and other agricultural loads (primarily
 pasture and manure loads) by 10%. Total phosphorus increased for cropland by 1% and
 decreased for other agricultural loads by 19%.  Urban loads were estimated to have
 increased over the 1985 to 1996 period by 7% for total nitrogen and 9% for total
phosphorus due to increases in population and urban land use area.

-------
 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
 Parameters

 Temperature
 Dissolved Oxygen
 Total Suspended Sediment
 Total Phosphorus
 Organic and Paniculate Phosphorus
 Phosphate
 Total Nitrogen
 Nitrate
 Total Ammonia
 Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date — Temperature
                               46

-------
  40 :
  30-
  20 -
  10
  0-tl
         West Branch Susquehanna at Segment 70
              Observed and Simulated versus Time
                       Temperature-C
                       (*=Observed, -=Simulated)
                               Date
(»2I j*» t«i
     M ptotoiM • on*™)

-------
West Branch Susguehanna at Segment 70
        Scatter Plot andllegression of Simulated
           versus Observed with Ideal Line
          Temperature-C: 01JAN84 - 01JAN92
                   Simulated-T«np-C
West Branch Susquehanna at Segment 70
           Actual Error versus Time
               Temperature-C

r
i*
                     thte
                  48

-------
          West Branch Susquehanna at Segment 70
                         Temperature-C
               Frequency Distribution - PAIRED Simulated and Observed Data
                             30 Percent J^opiUtion T0
BSSsssssr
          West Branch Susquehanna at Segment 70
          Actual error versus Percentile Sample Population
                         Temperature-C
                Frequency Distribution - All Simulated and Observed Data
                             49

-------
        West Branch Susauehanna at Segment 70
             Observed and Simulated versus Time
                    Dissolved Oxygen
                      (*=Observed/ -=Simulated)
 is-:
 15-
 14
 13 -
 12
I
 11-
 10-
  9-
  7-
  5-L
                              Date

-------
          West Branch Susquehanna at Seement 70

      Dissolved Oxygen Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
 1800000
 1700000
 1600000-
 1500000
 1400000
 1300000
 1200000-
 1100000
s-
w 1000000-
8.
 **>.*** mo*U*(p«Mng.dl| MM)
 i.d.cfcvl 30FESM 0*4e,proc i*9,mod«t y-i)
                                     Date

-------
 West Branch Susquehanna at Segment 70
        Scatter Plot and Degression of Simulated
          versus Observed with Ideal Line
        Dissolved Oxygen: 01JAN84 - 01JAN92
West Branch Susquehanna at Segment 70
          Actual Error versus Time
             Dissolved Oxygen
±1
                   ,
i_L
                 52

-------
         West Branch Susquehanna at Segment 70
                        Dissolved Oxygen
              Frequency Distribution - PAIRED Simulated and Observed Data
r

1
M
O
                          30
                                 ofFopuli
                              Pciccnt ofropulation
                                                      90
  •ssas"
         West Branch Susquehanna at Segment 70
         Actual error versus Percentile Sample Population
                        Dissolved Oxygen
                Frequency Distribution - All Simulated and Observed Data
                              Fttctnt of Population
                              53

-------
600
       West Branch Susquehanna at Segment 70
            Observed and Simulated versus Time
              Total Suspended Sediment
                    (*=Observed, —Simulated)
                           D»te

-------
          West Branch Susquehanna at Segment 70

  Total Suspended Sediment Observed and Simulated Load vs Time
           JL             /« •    •  1 4 •• ^-^   1   J V
                         (line = simulated, O = observed)
  60000000
  50000000
  40000000-
I
  30000000
  20000000
  10000000
Iy2l j** JM moiM3
-------
        West Branch Susquehanna at Segment 70
               Scatter Plot and Kegression of Simulated
                  versus Observed with Ideal Line
             Total Suspended Sediment: 01JAN84 - 01JAN92
       West Branch Susquehanna at Segment 70
                  Actual Error versus Time
                 Total Suspended Sediment
100
100
    -j	1 i>t**\r***^1" **
                                        LJ
                             Ditt
                         56

-------
          West Branch Susquehanna at Segment 70
                    Total Suspended Sediment
               Frequency Distribution - FAIRED Simulated and Observed Data
                              PeKtnt on*opuUtion
                                      70
                                              90
          West Branch Susquehanna at Segment 70
          Actual error versus Percentile Sample Population
                    Total Suspended Sediment
                Frequency Distribution - All Simulated and Observed Data
sssssssar-
                             57

-------
oo
          West Branch Susguehanna at Segment 70
               Observed and Simulated versus Time
                      Total Phosphorus
                        (*=Observed, -^Simulated)
                               Date

-------
           West Branch Susquehanna at Segment 70
        Total Phosphorus Observed and SimulatedLoad vs Time
    30000- :•
    20000-
Ui

    10000-
                         (line = simulated, O = observed)
                      O
                                             O
                                  Date
: O
   l_pUt>»l

-------
         West Branch Susquehanna at Segment 70
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                 Total Phosphorus: 01JAN84 - 01JAN92
                         A  & i*  <» i*
                        &  & <&  «" y


                             Simulated-mg/1
        West Branch Susquehanna at Segment 70
                   Actual Error versus Time
                       Total Phosphorus
 016

 024



 020

 0.11

 0.1*

 0.14

 0.11

 0.10
•0.02-
•0.10

•0.12

•0.14

-0.lt

-a if

* A i
T
'I
T» CT * 	 .
IT '
1
i*
i

ll
,1

'1
!

.'

i
T 1
Jl'



:J
r T/Tw.


,
1A
                                                    X     X
                           60

-------
West Branch Susquehanna at Segment 70
              TotalPhosphorus
     Frequency Distribution - PAIRED Simulated and Observed Data
West Branch Susquehanna at Segment 70
Actual error versus Percentile Sample Population
              Total Phosphorus
      Frequency Distribution - All Simulated and Observed Data

                  61

-------
cr>
          West Branch Susguehanna at Segment 70
               Observed and Simulated versus Time
             Organic and Particulate Phosphorus
                        (*=Observed, -^Simulated)

-------
             West Branch Susquehanna at Segment 70
   Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
     30000-
    20000
to
I
I
s
    10000-
                       : O
                                                 O
                                                             i O
   !l J4o* u. mod*Wlpw«>g dl| Mb.)
    • • I 20FEBW otMjxoc ngjmxW yn)
                                     Date

-------
         West Branch Susquehanna at Segment 70
                 Scatter Plot andTRegression of Simulated
                    versus Observed with Ideal Line
           Organic and Participate Phosphorus; 01JAN84 - 01JAN92
                              Simulated-
         West Branch Susquehanna at Segment 70
                    Actual Error versus Time
               Organic and Particulate Phosphorus
 0.17
 O.M
 0.11
 0.14
 0.13
 0.12
 0.11
 0.10
 0.09
 O.M
 0.07
 0.0t
 0.05
0.01
-0.01
-0.02
•0.09-
•0.10-
-0.11-
-0.12-

•O.M-
•O.W-
•O.K-
-0.17-
iL
iLi,
JU
1
                                    TO
J
                                                    Tu.
                  Tjr
JJJL
                X     /
                 XX
                            64

-------
          West Branch Susquehanna at Segment 70
                Organic and Particulate Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
          West Branch Susquehanna at Segment 70
          Actual error versus Percentile Sample Population
                Organic and Particulate Phosphorus
                Frequency Distribution - All Simulated and Observed Data
                              Percent of Population
eassiaaua*
                             65

-------
CT>
          West Branch Susquehanna at Segment 70
               Observed and Simulated versus Time
                   Dissolved Phosphorus
                        (*=Observed/ -=Simulated)
                               Date

-------
          West Branch Susquehanna at Segment 70
    Dissolved Phosphorus Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
  4000-
  3000
  2000
 c
 •o
  1000
                                 Date
Ml JMUM m
-------
        West Branch Susquehanna at Segment 70
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
               Dissolved Phosphorus: 01JAN84 - 01JAN92
0.03
0.01"
         '*•? ••••*:

     [g;£f >.-"„ :="•>. *   f\
                                                          .ofPoi I
                            SimuUlnl-ini/1
       West Branch Susquehanna at Segment 70
                  Actual Error versus Time
                   Dissolved Phosphorus
0.11
0.10
0.09
(UM
0.07
0.0*
0.05
0.04-
0.03-
0.02'
0.01-
0.00-
-O.OT
•0.02 •
41.01-
-0.04 *
-4.0S
•QM '
•am-








" -ir1
'
i











mj,'%i 11 I'TI i"iff*t?'*iTi i iJWti^r«-fT t-t
"^|J| i^Ij^'TJ



.
i

!


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11
,










J








'; . tJ.J. I - T
\lF - * *i "M4 * ill




                         68

-------
West Branch Susquehanna at Segment 70
            Dissolved Phosphorus
     Frequency Distribution - FAIRED Simulated and Ol
lated and Observed Data
West Branch Susquehanna at Segment 70
Actual error versus Percentile Sample Population
            Dissolved Phosphorus
      Frequency Distribution • All Simulated and Observed Data
                                               *     


-------
West Branch Susauehanna at Segment 70
     Observed and Simulated versus Time
             Total Nitrogen
              (*=Observed/ -^Simulated)

-------
         West Branch Susquehanna at Segment 70

       Total Nitrogen Observed and Simulated Load vs Time
                       (line = simulated, O = observed)
  400000
                                 Date
fell j** ... mo
-------
        West Branch Susquehanna at Segment 70
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                  Total Nitrogen: 01JAN84 - 01JAN92
                                                         .of F>oio
                         •v           •»

                            SimuUI«l - mg/1
-I"
        West Branch Susquehanna at Segment 70
                   Actual Error versus Time
                       Total Nitrogen
                                                     n
                          72

-------
SSZSSISSI*
          West Branch Susquehanna at Segment 70
                          Total Nitrogen
               Frequency Distribution - FAIRED Simulated and Observed Data
                      10
                             30 Percent ofPopuUtran TO
                                               90
          West Branch Susquehanna at Segment 70
          Actual error versus Percentile Sample Population
                          Total Nitrogen
                Frequency Distribution - All Simulated and Observed Data
                              Percent of Population
                             73

-------
4-
       West Branch Susquehanna at Segment 70
            Observed and Simulated versus Time
                         NO3
                    (*=Observed, -=Simulated)
                           Date

-------
  120000-
  110000-
         West Branch Susquehanna at Segment 70
            NO3 Observed and Simulated Load vs Time
                       (line = simulated, O = observed)
                                 Date
Ar2l_pk
     -
  I 20FEBM OtMfiK ragjnxM y«|

-------
        West Branch Susquehanna at Segment 70
               Scatter Plot and Regression of Simulated
                 versus Observed with Ideal Line
                    NO3:01JAN84 - 01JAN92
                          Simulated-mg/1
sssaaiK
       West Branch Susquehanna at Segment 70
                 Actual Error versus Time
                          NO3
           fl.
Ubfl
rVTj
4
                                          T It'll Tr»
                                    j
                           DM*
                        76

-------
West Branch Susquehanna at Segment 70
                    N03
     Frequency Distribution - PAIRED Simulated and Observed Data
West Branch Susquehanna at Segment 70
Actual error versus Percentile Sample Population
                    NO3
      Frequency Distribution - All Simulated and Observed Data
                    PMcmtofPapulltiim
                     77

-------
    0.7-:
    0.6
00
    0.01
           West Branch Susquehanna at Segment 70
                Observed and Simulated versus Time
                       Total Ammonia
                         (*=Observed, -=Simulated)
                                Date

-------
        West Branch Susquehanna at Segment 70
     Total Ammonia Observed and Simulated Load vs Time
                     (line = simulated, O = observed)
50000-
40000
30000
                 :  O
20000-
10000-
                               Date
    .
 20FEBH Oi:Wjme rigjIKxM r->)

-------
  West Branch Susquehanna at Segment 70
          Scatter Plot and regression of Simulated
            versus Observed with Ideal Line
           Total Ammonia: 01JAN84 - 01JAN92
                      Simulittd-ntfl
 West Branch Susquehanna at Segment 70
            Actual Error versus Time
                Total Ammonia
IP
                    +-•}
T
•*•. T •Li*"".

                     80

-------
          West Branch Susquehanna at Segment 70
                          Total Ammonia
               Frequency Distribution - PAIRED Simulated and Observed Data
                             30    SO    70
                               Percent ofPopuUtion
          West Branch Susquehanna at Segment 70
          Actual error versus Percentile Sample Population
                         Total Ammonia
                Frequency Distribution - All Simulated and Observed Data
                              Percent of PopuUKon
ssxts
                               81

-------
oo
S3
          West Branch Susquehanna at Segment 70
               Observed and Simulated versus Time
                      Organic Nitrogen
                        (*=Observed, -=Simulated)
                               Date

-------
oo
    170000
    160000
            West Branch Susquehanna at Segment 70
           ;anic Nitrogen Observed and Simulated]
                         (line = simulated, O = observed)
Load vs Time
                                  Date
  («k.u«_cl drvl 20FEBM H

-------
          West Branch Susquehanna at Segment 70
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                  Organic Nitrogen: 01JAN84 - 01JAN92
                              Sinuhttd-mt/l
                                                          VN  #
         West Branch Susquehanna at Segment 70
                    Actual Error versus Time
                        Organic Nitrogen
  i-


IT
J i
*T


11


i'

•IJ:
l mfu-fl


Jit.
[1
[1,



i
i
inn.
•
JJH

II lit
'I
Li
[ r
|nf|
1
f,Tt,t,,lT
1
                s     /
s     s
                               Dak
ssrsassr-
                              84

-------
West Branch Susquehanna at Segment 70
               Organic Nitrogen
     Frequency Distribution - PAIRED Simulated and Observed Data
of^PopuUt
                     PcnxntofopuUtum
West Branch Susquehanna at Segment 70
Actual error versus Percentile Sample Population
               Organic Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                    Ft rent of Population
                    85

-------
86

-------
B.1.3  Juniata River at Newport, PA near Segment 100 (Monitoring Station: 1567000)
(Above Fall Line Basin Segments: 90 and 100)	

Section Summary;

The Juniata basin is primarily rural and forested.  The Raystown Reservoir, which
intercepts drainage of 28% of the basin, has long hydrologic residence times which result
in decreased total nitrogen and total phosphorus loads for this portion of the basin.

The Juniata basin above the gaged site covers an  area of 3,355 square miles. At the
midpoint of the simulation, 1990, the land use for the basin was composed of 69% forest
land, 10% cropland, 18% other agricultural areas, 3% urban areas, and 1% water (river
and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage increased from
11.2 million pounds in 1985 to 11.3 million pounds in 1996. Total phosphorus loads over
the same time period decreased from 0.5 million  pounds to 0.4 million pounds. In
general, point source loads above the gage site are low. In  1996, the total nitrogen point
source load was 7% of the total load and the total phosphorus point source load was 12%
of the total load. Estimated septic system total nitrogen loads increased 14%, from 0.32
million pounds in  1985 to 0.37 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 9%, and other agricultural loads (primarily
pasture and manure loads) by 2%. Total phosphorus decreased for these land uses by 4%
and 9% respectively.  Urban loads were estimated to have increased over the 1985 to
1996 period by 11% for total nitrogen and 8% for total phosphorus due to increases in
population and urban land use area.
                                 87

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date - Temperature
                                 88

-------
00
VO
                  Juniata River at Segment 100
                 Observed and Simulated versus Time
                         Temperature-C
                          (*=Observed, -=Simulated)
                                 Date

-------
Juniata River at Segment 100
 Scatter Plot and Regression of Simulated
    versus Observed with Ideal Line
   Temperarure-C: 01JAN84 - 01J AN92
              Simulated-T«mp*C
Juniata River at Segment 100
    Actual Error versus Time
         Temperature-C
                D.lt
              90

-------
       Juniata River at Segment 100
                Temperature-C
     Frequency Distribution - PAIRED Simulated and Observed Data
                                                 98
       Juniata River at Segment 100
Actual error versus Percentile Sample Population
                Temperature-C
      Frequency Distribution - All Simulated and Observed Data
                    PtlrortafPopublfon
                     91

-------
vo
                  Juniata River at Segment 100
                 Observed and Simulated versus Time
                       Dissolved Oxygen
                         (*=Observed, -=Simulated)
                                 Date

-------
VD

CO
                     Juniata River at Segment 100

          Dissolved Oxygen Observed and Simulated Load vs Time
                             (line = simulated, O = observed)
     1000000
      900000
      800000
      700000
    >, 600000
    td
    •a
      500000-
      400000 -
      300000
      200000 ~
      100000 -
                                        Date

-------
                Juniata River at Segment 100
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                 Dissolved Oxygen: 01JAN84 - 01JAN92
•J-t
   ir
               Juniata River at Segment 100
                   Actual Error versus Time
                      Dissolved Oxygen
                            94

-------
                   Juniata River at Segment 100
                           Dissolved Oxygen
                Frequency Distribution - PAIRED Simulated and Observed Data
                                 Ferant ofPopulttion
                                              70
                                                          90
 w
 I -I
                  Juniata River at Segment 100
           Actual error versus Percentile Sample Population
                          Dissolved Oxygen
                  Frequency Distribution - All Simulated and Observed Data
                                 Pnctnl of Population
SfSZmJmi*,' •••*••
                                 95

-------
VO
    700-:
    600
                  Juniata River at Segment 100
                 Observed and Simulated versus Time
                   Total Suspended Sediment
                         (*=Observed, -=Simulated)
                                Date

-------
                  Juniata River at Segment 100

  Total Suspended Sediment Observed and Simulated Load vs Time
       ^___	    Uine = simulated, O = observed)
  50000000





  40000000





 >, 30000000
 CO
 •o
 
 Q.
 3


 I
  20000000
                      : O


                      :        : O
                                                O
  10000000
  .
(»«<*.. dry MSEM7U 17jHoc..,/««l.iK.'l
                                     Date

-------
                Juniata River at Segment 100
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
               Total Suspended Sediment: 01JAN84 - 01JAN92
                              Simulated-mg/l
 IN
•100
-200-
                Juniata River at Segment 100
                    Actual Error versus Time
                   Total Suspended Sediment
    TV   +..4. ifi - If J
        i   *
                             98

-------
               Juniata River at Segment 100
                   Total Suspended Sediment
             Frequency Distribution - FAIRED Simulated and Observed Data
                             Percent
MO:
               Juniata River at Segment 100
        Actual error versus Percentile Sample Population
                  Total Suspended Sediment
              Frequency Distribution - All Simulated and Observed Data
                             P«rceiito< Population
                             99

-------
o
o
    0.8
    0.7-
                  Juniata River at Segment 100

                 Observed and Simulated versus Time

                        Total Phosphorus
                          (*=Observed, -=Simulated)
                                 Date

-------
  18000-
  17000
  16000-
  15000-
  14000
  13000
  12000
  11000
f
r loooo
01
o.
3
.E


i
9000
8000
                  Jvmiata River at Segment 100

      Total Phosphorus Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
tr*IJ*>«.««
   0«S£P»7 1«lt.pfoc
                                     Date

-------
 Juniata River at Segment 100
  Scatter Plot and Regression of Simulated
     versus Observed with Ideal Line
   Total Phosphorus: 01JAN84 - 01JAN92
               StauUfed-mg/l
Juniata River at Segment 100
    Actual Error versus Time
        Total Phosphorus
                D
-------
       Juniata River at Segment 100
                Total Phosphorus
     Frequency Distribution - PAIRED Simulated and Observed Data
                    30 PHtwitofPopuUHoB
                                                  98
       Juniata River at Segment 100
Actual error versus Percentile Sample Population
                Total Phosphorus
      Frequency Distribution - All Simulated and Observed Data
                      F«iw»t
-------
o
*-
                 Juniata River at Segment 100

                Observed and Simulated versus Time

              Organic and Participate Phosphorus
                         (*=Observed, -=Simulated)
                                Date

-------
                 Juniata River at Segment 100
Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
 17000
 16000
 15000
 14000
 13000
 12000
 11000
£
•o
I
 10000
 9000
                                   Date

-------
               Juniata River at Segment 100
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
          Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
                                                            of Pot I
                                                        J ** 
-------
                 Juniata River at Segment 100
                Organic and Participate Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
1
1
 o.ooo«-L
                             30
                                               90
                Juniata River at Segment 100
         Actual error versus Percentile Sample Population
               Organic and Participate Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                              107

-------
                  Juniata River at Segment 100
                Observed and Simulated versus Time
                     Dissolved Phosphorus
                         (*=Observed, -=Simulated)
o
00
                                Date

-------
O

VO
                    Juniata River at Segment 100

       Dissolved Phosphorus Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
     1300
     1200
     1100
   .E
                                    Date
     nFtBM »Mjme
         >IIIMJM)

         ratine*) y.

-------
                  Juniata River at Segment 100
                   Scatter Plot and Regression of Simulated
                      versus Observed with Ideal Line
                  Dissolved Phosphorus: 01JAN84 - 01JAN92
i*.
                                                                    of Point
                                   ^>   <&


                                 Simulated - a^n
 • 14
 0.15
 o.u
 a.]]
 o.u
 0.11
 o.u
 O.M
 0.00
 0.07
 O.M
 0.05
 0.02 •
 0.01-
 0.00
 -0.01-
 •O.R-
 jua-
 -O.M-
 •O.OS-
 -o.i*-
 -0417-
 -OJ16-
 •0.00-
                 Juniata River at Segment 100
                      Actual Error versus Time
                        Dissolved Phosphorus

11



J]

Ff

1

i
T T . .
f'llf
v

I
f

IJ
"II1 1
I
i
.1
:&.. *
pry
                                 110

-------
       Juniata River at Segment 100
             Dissolved Phosphorus
     Frequency Distribution - FAIRED Simulated and Observed Data
                        ofPopuUHon
       Juniata River at Segment 100
Actual error versus Percentile Sample Population
             Dissolved Phosphorus
      Frequency Distribution • All Simulated and Observed Data
                     PncentofPopulMio.
                      Ill

-------
                  Juniata River at Segment 100
                 Observed and Simulated versus Time
                          Total Nitrogen
                          ("^Observed, -=Simulated)
    s-;
to
   1
    1-
    o-ti
                           I
                                  Date
    tfe^l UPEBM 11MI

-------
  200000


  190000
  180000
  170000 -
  160000
  150000-


  140000-
  130000 -


>, 120000

«
fc 110000
Q.

2> 100000
                   Juniata River at Segment 100
        Total Nitrogen Observed and Simulated Load vs Time
                            (line = simulated/ O = observed)
                                        Date
Ml JMIJM MailonlJ'Vtpa JMMI.IM) UtMj
jrta.tdnrl MFEBM aMfUX ngjnoM ».«!

-------
easwasfisssau
                 Juniata River at Segment 100
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                    Total Nitrogen: 01JAN84 - 01JAN92
                Juniata River at Segment 100
                     Actual Error versus Time
                         Total Nitrogen
                                1 Tt.t
                                Dak
                              114

-------
                  Juniata River at Segment 100
                            Total Nitrogen
                Frequency Distribution - PAIRED Simulated and Observed Data
                               30 Percent J¥opuUtion 7°
                                                  90
sasssrsr"
                  Juniata River at Segment 100
           Actual error versus Percentile Sample Population
                            Total Nitrogen
                 Frequency Distribution - All Simulated and Observed Data
                                PcirattofroptiUtioci
                                 115

-------
              Juniata River at Segment 100
            Observed and Simulated versus Tim
                           NO3
                      (*=Observed, -=Simulated)
                             Date
frtitt.tt)

-------
  60000
  50000
  40000
I


I
 30000-
•3
Q
 20000
 10000
                 Juniata River at Segment 100

            NO3 Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
                                 Dale

-------
 Juniata River at Segment 100
  Scatter Plot and Regression of Simulated
     versus Observed with Ideal Line
       NO3: 01JAN84 - 01JAN92
              SimuUttd-mg/l
Juniata River at Segment 100
    Actual Error versus Time

             l!
              J 111
l
               Dak
             118

-------
       Juniata River at Segment 100
                     NO3
     Frequency Distribution - FAIRED Simulated and Observed Data
                     PcntnlofhpuUtion
                                                 99
       Juniata River at Segment 100
Actual error versus Percentile Sample Population
                      NO3
      Frequency Distribution - All Simulated and Observed Data

                      119

-------
0.01
              Juniata River at Segment 100
             Observed and Simulated versus Time
                     Total Ammonia
                      (*=Observed, -=Simulated)
                             Dare

-------
19000
18000
17000
               Juniata River at Segment 100
     Total Ammonia Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
                               Date

-------
                 Juniata River at Segment 100
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                    Total Ammonia: 01JAN84 - 01JAN92
  O.U


  0.15


  0.14


  0.13


  0.12


  0.11


  0.10


fu.



1-

o «•""

  0.06


  0.05


  0.04


  O.W


  0.02


  0.01


  0.00 •
                                Simulated-ni(fl
                Juniata River at Segment 100
                     Actual Error versus Time
                         Total Ammonia
OJC
US
024
023
022
Oil
tM
0.1*
O.U
0.17
0.1*
0.15
0.14-
O.U-
o.u-
Ml-
o.w •
o.o»-
0.01 '
M>-
o.o* -
045-
044 '
O.OJ-
042-
041-
•041-
•042-
-0.03-
444"
•O.W-
-OJ7-
•041-
•0.10-























*
I '


























|[



'
.1
1

•
























f,
1

,























'


























1






































ft
'll



























1



TT»'











.
II





















j
*






1






11'



1

ft III '



























T












*"' i



         /     X
                              122

-------
                 Juniata River at Segment 100
                          Total Ammonia
               Frequency Distribution - PAIRED Simulated and Observed Data
                              30 PwttBl ofRtpuUtion
 StTMBW"
                 Juniata River at Segment 100
          Actual error versus Percentile Sample Population
                          Total Ammonia
                 Frequency Distribution - All Simulated and Observed Data
stsz.
                                 123

-------
N>
    01
                  Juniata River at Segment 100
                 Observed and Simulated versus Time
                        Organic Nitrogen
                          (*=Observed, -^Simulated)
  BOX
                                 Date

-------
KJ
     130000
     120000
                    Juniata River at Segment 100

         Organic Nitrogen Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
                                     Date
   MUM I ui dMMouIfrtM (.3

   (•noh.l *v MSEP*7 U: 17j»oe

-------
                 Juniata River at Segment 100
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                   Organic Nitrogen: 01JAN84 - 01JAN92
1
 Ot
         r-  *•**
                                                              ,<*Poil)
                              Simulated -mg/I

         I  i
                Juniata River at Segment 100
                    Actual Error versus Time
                        Organic Nitrogen
J.
,1
                               Drt.
                              126

-------
ifl
1
                 Juniata River at Segment 100
                         Organic Nitrogen
               Frequency Distribution - PAIRED Simulated and Observed Data
                                                          99
                Juniata River at Segment 100
         Actual error versus Percentile Sample Population
                         Organic Nitrogen
                Frequency Distribution - All Simulated and Observed Data
                               127

-------
128

-------
B.1.4  Lower Susquehanna River at Marietta, PA Segment 110 (Monitoring Station:
1576000) (Above Fall Line Basin Segments: 10,20, 30, 40, 50, 60, 70, 80, 90,100,110,
700, and 710) 	

Section Summary;

Water quality at the Lower Susquehanna water quality gaging station reflects the water
quality of the upstream basins of the East Branch Susquehanna, West Branch
Susquehanna, and the Juniata as well as changes in land use, point source loads, and
nonpoint source management practices of the Lower Susquehanna basin. The Lower
Susquehanna basin is largely rural, and influenced by the upstream agricultural loads and
forest loads, as well as lower basin agricultural loads and point sources from the cities of
Harrisburg, York,  and Hershey.


The Lower Susquehanna basin above the gaged site covers an area of 26,184 square
miles. At the midpoint of the simulation, 1990, the land use for the basin was composed
of 64% forest land, 10% cropland, 20% other agricultural areas, 5% urban areas, and 1%
water (river and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 122 million pounds in 1985 to 115 million pounds in 1996. Total phosphorus loads
over the same time period decreased from 4.8 million pounds to 3.9 million pounds. In
general, point source loads above the gage site are low. In 1996, the total nitrogen point
source load was 11% of the total load and the total phosphorus point source load was
22% of the total load. Estimated septic system total nitrogen loads increased 9%, from
3.5 million pounds in 1985 to 3.8 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 9%, and other agricultural loads (primarily
pasture and manure loads) by 10%. Total phosphorus decreased for these land uses by
5% and 22% respectively. Urban loads were estimated to have increased over the 1985
to 1996 period by 7% for total nitrogen and 9% for total phosphorus due to increases in
population and urban land use area.
                                 129

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Particulate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date - Temperature
Observed and Simulated Loads versus Date - Dissolved Oxygen
                                 130

-------
             Susquehanna River at Segment 110
               Observed and Simulated versus Time
                       Temperature-C
                        (*=Observed, -=Simulated)
  40-:
  30-
V
a,
  20-
  10
tft\jta**l* m«W3dlp<»iii|
}o«»_d.*vl 23FE8M 1*13)
                                Date

-------
 Susquehanna River at Segment 110
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
       Temperature-C: 01JAN84 - 01JAN92
                Simulated -Tcotp-C
Susquehanna River at Segment 110
       Actual Error versus Time
            Temperature-C
                                              r
                132

-------
             Susquehanna River at Segment 110
                         Temperature-C
              Frequency Distribution - PAIRED Simulated and Observed Data
1
£
                            30 Ptnw.1 copulation ^
             Susquehanna River at Segment 110
          Actual error versus Percentile Sample Population
                         Temperature-C
               Frequency Distribution - All Simulated and Observed Data
                              Percent of Population
                               133

-------
              Susquehanna River at Segment 110
                Observed and Simulated versus Time
                       Dissolved Oxygen
                         (*=Observed, -^Simulated)
    16-:
    is -
    14
    13-
    12-
u>
   •3,
    11-
    10-
    6
                                Date

-------
OJ
    800
    700
    600-
    500-
    400-
    300-
    200-
    100
               Susquehanna River at Segment 110
                 Observed and Simulated versus Time
                   Total Suspended Sediment
                          (*=Observed/ -=Simulated)
                                 Date
   ''-!**••••»!*'**
   l_d*vl 13FEIM 13:31)

-------
CO
ON
               Susquehanna River at Segment 110
    Total Suspended Sediment Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    1.60E+08 -
    1.50E+08 -
    1.40E+08 -
                                  Date

-------
             Susquehanna River at Segment 110
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
               Total Suspended Sediment: 01JAN84 - 01JAN92
  too-
                                                           .Of Poll!
sxszssxsxx,
                              Simul.fcd.mgfl
  200
            Susquehanna River at Segment 110
                    Actual Error versus Time
                   Total Suspended Sediment
r^
                                 tr
                                      . M«
f
                X     /
                 LJL
                                                 »p
                             137

-------
    Susquehanna River at Segment 110
           Total Suspended Sediment
      Frequency Distribution - FAIRED Simulated and Observed Data
                   30    so
                    Percent efPopulation
   Susquehanna River at Segment 110
Actual error versus Percentile Sample Population
          Total Suspended Sediment
      Frequency Distribution - All Simulated and Observed Data
                    138

-------
              Susquehanna River at Segment 110
                Observed and Simulated versus Time
                       Total Phosphorus
                         (*=Observed/ -=Simulated)
    0.9
CO
VO
    0.8-
    0.7
    0.6-
0.5-
   I
    0.4-
    0.3-
    0.2
    0.1
    0.0
                                                §
                                 Date

-------
             Susquehanna River at Segment 110

      Total Phosphorus Observed and Simulated Load vs Time
                       (line = simulated, O = observed)
I
2
.£
 90000
 80000
 70000
 60000
 50000-
 40000
 30000
 20000
 10000
                                 Date
    -MM**.

-------
            Susquehanna River at Segment 110
                 Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                 Total Phosphorus: 01JAN84 - 01JAN92
SfSS
            Susquehanna River at Segment 110
                    Actual Error versus Time
                       Total Phosphorus
w
                                               • JT/
                             LTlTlTl
                               DUt
                                            X     X
                             141

-------
    Susquehanna River at Segment 110
                Total Phosphorus
              ribution - PAIRED Simulated and Observed Data
Frequency Distribution •
                   30 Pmcnlo^opublkm
   Susquehanna River at Segment 110
Actual error versus Percentile Sample Population
               Total Phosphorus
      Frequency Distribution - All Simulated and Observed Data
           +
                       #

                    Percent 0c ropitutian
                    142

-------
U)
    0.0 i
              Susquehanna River at Segment 110
                Observed and Simulated versus Time
             Organic and Particulate Phosphorus
                        (*=Observed, -=Simulated)
                               Date

-------
            Susquehanna River at Segment 110

Organic and Particufate Phosphorus Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 80000
 70000-
                               Date

-------
 (US
 94t
 044
 042
 040
 OJ8
 OJ<
 OJ4
 0.32
 OJO

C
i 024
I 0.22
1 OJO
 o.is-
 0.1C
 o.u-
 0.12
 O.M-
 O.DI-
 o.ot-
 O.M-
 0.02'
 0.00 '
               Susquehanna River at Segment 110
                    Scatter Plot and Regression of Simulated
                       versus Observed with Ideal Line
              Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
                                                                  0*Po(lt
                            *>       #
                                 Simulated-
              Susquehanna River at Segment 110
                       Actual Error versus Time
                 Organic and Particulate Phosphorus
                             Viiifr
                                     IT . rTr
                                        "-rtr
                                   Data
*«aj«w< uWnfr**
                                 145

-------
    1.00000
  S ojnom
   0.00100
               Susquehanna River at Segment 110
                  ^•^     •     -3 T^  • •  1 •  W^l ^^  1
                  Organic and Participate Phosphorus
                 requency Distribution - FAIRED Simulated and Observed Da
Frequency 1
Data
                              30 Promt o&tpubtion
              Susquehanna River at Segment 110
           Actual error versus Percentile Sample Population
                 Organic and Particulate Phosphorus
                 Frequency Distribution - All Simulated and Observed Data
essr
                               146

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0.16-
0.15
0.14
          Susquehanna River at Segment 110
            Observed and Simulated versus Time
                Dissolved Phosphorus
                     (*=Observed, -=Simulated)
                            Date

-------
              Susquehanna River at Segment 110

      Dissolved Phosphorus Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
    12000
CO
                                 Date
      ftniS*v*i*i*t

-------
Susquehanna River at Segment 110
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
    Dissolved Phosphorus: 01JAN84 - 01JAN92
                 Simulated • mgfl
Susquehanna River at Segment 110
       Actual Error versus Time
         Dissolved Phosphorus
                   Dale
                149

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              Susquehanna River at Segment 110
                       Dissolved Phosphorus
                Frequency Distribution - PAIRED Simulated and Ol
lated and Observed Data
 C 0.100
 E
  0001-
                      10

                               Pncmt
                                        70
                                                90
essssssnr*
             Susquehanna River at Segment 110
          Actual error versus Percentile Sample Population
                      Dissolved Phosphorus
                Frequency Distribution - All Simulated and Observed Data
                              Fttcrat of Population
                              150

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 •3,,-
             Susquehanna River at Segment 110
               Observed and Simulated versus Time
                        Total Nitrogen
                         (*=Observed, -^Simulated)
                                Date
M1 J**.HI nodil3dlp««g *| plolKM - oo*m.)
|bw.d.
-------
                Susquehanna River at Segment 110

          Total Nitrogen Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
    1000000
    900000-
     800000
     700000-
     600000
cn
   I
   I
   & 500000
     400000
     300000
     200000
     100000
                                      Date

-------
 |
  1-
             Susquehanna River at Segment 110
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
            	   Total Nitrogen: 01JAN84 - 01JAN92
                             SimuUttd-mgrt
!•
            Susquehanna River at Segment 110
                    Actual Error versus Time
                        Total Nitrogen

1
U i.
n
IT


UT

1
l!
i

;
It
T

|ii<
lit

11
M

"

                                                   s     s
                              Da*
                             153

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   Susquehanna River at Segment 110
               Total Nitrogen
              Uion - PAIRED Simulated and Observed Data
Frequency Distributio
                    Fnttnt
   Susquehanna River at Segment 110
Actual error versus Percentile Sample Population
                Total Nitrogen
      Frequency Distribution - All Simulated and Observed Data

-------
01
Lrt
   •s,,.
               Susquehanna River at Segment 110
                 Observed and Simulated versus Time
                              NO3
                          (*=Observed/ -=Simulated)
                                 Date
    \ 13FEBW1JSJ)

-------
    400000
    300000
   t
r  I
Ul
    200000
    100000
               Susguehanna River at Segment 110

              NO3 Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
                                  Date

-------
              Susquehanna River at Segment 110
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                        NO3:01JAN84 - 01J AN92
   2.1


   2.0


   19

   IS


   1.7


   U


   l.S


   1.4
1.1

10

0.9

OJ

0.7-

0.6-

OJ-
                                                             .olPeii)
                               Simulated-ng/I
             Susquehanna River at Segment 110
                     Actual Error versus Time
                              NO3
2
1
O
i .-
3
1
j
•i •
•i-


1
J




!
fl
Pi




1,
1




|]





! I.T
1 1




1




"


fill





}
II
*
I? IT IT TTTt
t
r
'
1
•

                                             X     X
sas
                              157

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Bssrssstsr1
              Susquehanna River at Segment 110
                                N03
               Frequency Distribution - PAIRED Simulated and Observed Data
                               Percent ofpopwktion
             Susquehanna River at Segment 110
          Actual error versus Percentile Sample Population
                               NO3
                Frequency Distribution - All Simulated and Observed Data
                              Percent o< Population
                               158

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    0.8 -:
Ul
VO
    0.01
              Susquehanna River at Segment 110
                Observed and Simulated versus Time
                        Total Ammonia
                         (*=Observed, -=Simulated)
                                Date

-------
             Susquehanna River at Segment 110
       Total Ammonia Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
 140000

 130000

 120000-

 110000

 100000

  90000
&
•8 80000
I
& 70000
c
1
q 60000
  50000
                                  Date
    l»»imM m)

-------
            Susquehanna River at Segment 110
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Total Ammonia: 01JAN84 - 01JAN92
                               Simulated-mg/1
002
OJl
(L20
o.w
0.1S
0.17
O.M
0.15
0.14
0.13
0.12
0.11
0.10
0.09
0.05
0.04
0.01
0.00
4.01
4.02
4.03
-0.04
•0.05-
4.M
4.07
•OM
449
4.10
4.11
4.12
4.13
            Susquehanna River at Segment 110
                    Actual Error versus Time
                         Total Ammonia
                           B
                            i,


                /      /
                              161

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            Susquehanna River at Segment 110
                       Total Ammonia
             Frequency Distribution - PAIRED Simulated and Observed Data
1.000
0.001-
           Susquehanna River at Segment 110
        Actual error versus Percentile Sample Population
                       Total Ammonia
              Frequency Distribution - All Simulated and Observed Data
                            162

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Susquehanna River at Segment 110
  Observed and Simulated versus Time
         Organic Nitrogen
           (*=Observed/ -=Simulated)



1 :
1


4c : 1 ;
f : 	 :
ij* i||i
i \: * i F H 1 •'
i "*T^" ~^< •
: # **:
-••>(< 	 •-
i i i1 1 	 	
                        ^ T-«f     ' >|C
                         •Xiy'' "^t^"   '*¥''  ^li*
                       	sf^j T?1>   *tTr   . ^sL-
                              "	 *>T< -----	
                                               C^l
                                               S
                  Date

-------
          Susquehanna River at Segment 110

    Organic Nitrogen Observed and Simulated Load vs Time
                    (line = simulated, O = observed)
500000-
                             Date

-------
Susquehanna River at Segment 110
    Scatter Plot and Regression of Simulated
       versus Observed with Ideal Line
     Organic Nitrogen: 01JAN84 - 01JAN92
2
1
1.-
! !
w
1
-1-
•a •
Susquehanna River at Segment 110
Actual Error versus Time
Organic Nitrogen

t
1






f
i


ifli



HIM
"
,,,

T.1
Ij
•

|




I



'

iLill


                165

-------
    Susquehanna River at Segment 110
               Organic Nitrogen
     Frequency Distribution - PAIRED Simulated and Observed Data
   Susquehanna River at Segment 110
Actual error versus Percentile Sample Population
              Organic Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                    166

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B.I.5  Susquehanna River near Conowingo, MD At Segment 140 (Monitoring Station:
1578310) (Above Fall Line Basin Segments: 120,140, and 720)	

Section Summary:

Water quality at the Conowingo water quality gaging station reflects water quality of the
upstream basins of the East Branch Susquehanna, West Branch Susquehanna, Juniata,
and the Lower Susquehanna basins as well as local changes in land use, point source
loads, and nonpoint source management practices. The Conowingo gage station is the
largest basin in the Chesapeake watershed. The Conowingo basin is largely rural, with
particularly high agricultural loads from areas in the basin like the Conestoga watershed.
Water quality at the Conowingo gage station is influenced by three reservoirs on the
Conowingo mainstem, the Holtwood, Safe Harbor, and Conowingo reservoirs.

The Conowingo basin above the gaged site covers an area of 27,155 square miles. At the
midpoint of the simulation, 1990, the land use for the basin was composed of 47% forest
land, 23% cropland, 22% other agricultural areas, 8% urban areas, and 2% water (river
and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 134 million pounds in 1985 to 130 million pounds in 1996.  Total phosphorus loads
over the same time period decreased from 5.5 million pounds to 4.5 million pounds. In
general, point source loads above the gage site are low. In 1996, the total nitrogen point
source  load was 11% of the total load and the total phosphorus point source load was
20% of the total load. Estimated septic system total nitrogen loads increased 13%, from
3.8 million pounds in 1985 to 4.3 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 9%, and other agricultural loads (primarily
pasture and manure loads) by 11%. Total phosphorus decreased for these land uses by
5% and 23% respectively. Urban loads were estimated to have increased over the 1985
to 1996 period by 9% for total nitrogen and 10% for total phosphorus due to increases in
population and urban land use area.
                                  167

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Particulate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date — Temperature
                                 168

-------
            Susquehanna River at Segment 140
              Observed and Simulated versus Time
                      Temperature-C
                       (*=Observed, -=Simulated)
                              Date
Ml J*» u>
(•no.*. MFEBM

-------

40



V
1
7 M


10-





:
<


Susquehanna River at Segment 140
Scatter Plot and Regression of Simulated
versus Observed with Ideal Line
Temperature-C: 01JAN84 - 01JAN92
: ; ! * * ',
: : ; - jr*2*
: : « „» ~ Bi/liiTii i'i;ZL : :



• »« « *ysfZ»^m**«* * : ;
'''...*"!>Z'--m'rr-J'-i'r-- «•
•All • MWMVMMMMIi * * ! [ ;
	 * 	 i i nil rjiii^iii <•»*«»> ^ . . Unjui^M^rui«iHi bl PCM




mmZtlilmSmi^''*** '

> 4 4 * *
Simulated -Temp-C










1
1
1










Susquehanna River at Segment 140
       Actual Error versus Time
          Temperature-C
                DIM
               170

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100
1
1
1
i 10"
I
i
£
\
\
1-



Susquehanna River at Segment 140
Temperature-C
Frequency Distribution - PAIRED Simulated and Observed Data

X

J

A


S


****-







O.1 1 10 3Q fip 70 90 99 90



a

   Susquehanna River at Segment 140
Actual error versus Percentile Sample Population
               Temperature-C
      Frequency Distribution - All Simulated and Observed Data
                    171

-------
K)
              Susquehanna River at Segment 140
                Observed and Simulated versus Time
                      Dissolved Oxygen
                        (*=Observed, -^Simulated)
                               Date

-------
              S usque harm a River at Segment 140
      Dissolved Oxygen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
 7000000-
 6000000-
 5000000
Sr
•8 4000000
<5
Q.
 3000000
 2000000
 1000000
                                    Date
     .
  24FEBM »:47jnoe ragjnoW ».«)

-------
 Susquehanna River at Segment 140
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
      Dissolved Oxygen: 01JAN84 - 01JAN92
Susquehanna River at Segment 140
       Actual Error versus Time
          Dissolved Oxygen
                  D.1.
                174

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              Susquehanna River at Segment 140
                         Dissolved Oxygen
                Frequency Distribution - PAIRED Simulated and Observed Data
              Susquehanna River at Segment 140
          Actual error versus Percentile Sample Population
                        Dissolved Oxygen
                Frequency Distribution - All Simulated and Observed Data
assess-"—•
                              175

-------
400-
          Susquehanna River at Segment 140
            Observed and Simulated versus Time
              Total Suspended Sediment
                    <*=Observed, -^Simulated)
                           Date

-------
           Susquehanna River at Segment 140

Total Suspended Sediment Observed and Simulated Load vs Time
                     (line = simulated, O = observed)
1.40E+08




1.30E+08




1.20E+08
                              Date

-------
 Susquehanna River at Segment 140
     Scatter Plot and Regression of Simulated
       versus Observed with Ideal Line
  Total Suspended Sediment: 01JAN84 - 01JAN92
Susquehanna River at Segment 140
       Actual Error versus Time
      Total Suspended Sediment
                  Dale
                  178

-------
           Susquehanna River at Segment 140
                  Total Suspended Sediment
            Frequency Distribution - PAIRED Simulated and Observed Data
        0.1
400
           Susquehanna River at Segment 140
        Actual error versus Percentile Sample Population
                  Total Suspended Sediment
              Frequency Distribution - All Simulated and Observed Data
                            tyrant of rof«l>ti€«t
                              179

-------
Susquehanna River at Segment 140
  Observed and Simulated versus Time
        Total Phosphorus
          (*=Observed, -=Simulated)
                  Date

-------
           Susquehanna River at Segment 140

    Total Phosphorus Observed and Simulated Load vs Time
                     (line = simulated, O = observed)
120000
noooo-
100000
                                                          #
                                                          &
  ll:47«ne nfjnoiM y.t)

-------
 Susquehanna River at Segment 140
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
      Total Phosphorus: 01JAN84 - 01JAN92
Susquehanna River at Segment 140
       Actual Error versus Time
          Total Phosphorus
                  Date
                182

-------
    Susquehanna River at Segment 140
               Total Phosphorus
     Frequency Distribution - PAIRED Simulated and Observed Data
   Susquehanna River at Segment 140
Actual error versus Percentile Sample Population
              Total Phosphorus
      Frequency Distribution - All Simulated and Observed Data
                    P«c*nt of Population
                    183

-------
00
             Susquehanna River at Segment 140
               Observed and Simulated versus Time
             Organic and Particulate Phosphorus
                        (*=Observed, -=Simulated)
                               Date

-------
00
                Susguehanna River at Segment 140

   Organic and Participate Phosphorus Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
    120000
    110000
                                    Date
    MfCMI i*47tm i^m«M y.»

-------
              Susquehanna River at Segment 140
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
             Organic and Participate Phosphorus: 01JAN84 - 01JAN92
                               SimuUtad-mg/I
             Susquehanna River at Segment 140
                     Actual Error versus Time
                Organic and Particulate Phosphorus
                                0.1.
assess—•
                              186

-------
           Susquehanna River at Segment 140
              Organic and Particulate Phosphorus
            Frequency Distribution - PAIRED Simulated and Observed Data
i.ooo-
                           30 Ptranto&piiUtioti n

           Susquehanna River at Segment 140
        Actual error versus Percentile Sample Population
              Organic and Particulate Phosphorus
              Frequency Distribution - All Simulated and Observed Data
                             187

-------
    0.09-:
    0.08
    0.07
    0.06
oo
00
0.05
   I
    0.04^
    0.03 J
    0.02 H
    0.01
    0.00 i
               Susquehanna River at Segment 140
                 Observed and Simulated versus Time
                      Dissolved Phosphorus
                          <*=Observed, -=Simulated)
                                  Date
  jtanutv,
    HftBHtlUT)

-------
oo
               Susquehanna River at Segment 140

      Dissolved Phosphorus Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
    9000-
                                 Date
  Wl>
  (conow.

-------
 Susquehanna River at Segment 140
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
    Dissolved Phosphorus: 01JAN84 - 01JAN92
Susquehanna River at Segment 140
       Actual Error versus Time
        Dissolved Phosphorus
                190

-------
 i
 1
 i
  o.ooio-
sstssrar-
             Susquehanna River at Segment 140
                      Dissolved Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
                               Percent arPopulltion
                                               80
             Susquehanna River at Segment 140
          Actual error versus Percentile Sample Population
                      Dissolved Phosphorus
                Frequency Distribution - All Simulated and Observed Data
                               191

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              Susquehanna River at Segment 140
                Observed and Simulated versus Time
                        Total Nitrogen
                         (*=Observed, -^Simulated)
\O
NJ
    1 -
    oi:
                                Date

-------
\o
               Susquehanna River at Segment 140
          Total Nitrogen Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
    1300000
    1200000
                                   Date
        .
    .*, 24FEBM I3J7jxoe nftno
-------
              Susquehanna River at Segment 140
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                    Total Nitrogen: 01JAN84 - 01JAN92
                              SimuUl.d-mg/1

             Susquehanna River at Segment 140
                     Actual Error versus Time
                         Total Nitrogen
esssswr-1—••
                              194

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   Susquehanna River at Segment 140
                Total Nitrogen
     Frequency Distribution - FAIRED Simulated and Observed Data
   Susquehanna River at Segment 140
Actual error versus Percentile Sample Population
               Total Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                    195

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    5-
VO
              Susquehanna River at Segment 140
                Observed and Simulated versus Time
                             NO3
                         (*=Observed, -=Simulated)
                                Date

-------
    500000
    400000
    300000
VO
Q.




C
    200000
    100000
               Susquehanna River at Segment 140

              NO3 Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
                                   Date

-------
            Susquehanna River at Segment 140
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                     NO3:01JAN84 - 01JAN92
I
                            Simulated-mgfl

           Susquehanna River at Segment 140
                  Actual Error versus Time
                           NO3
                             Date
                           198

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              Susquehanna River at Segment 140
                                N03
               Frequency Distribution - PAIRED Simulated and Observed Data
                               Percent ofTofwUtian
              Susquehanna River at Segment 140
          Actual error versus Percentile Sample Population
                               N03
                Frequency Distribution - All Simulated and Observed Data
                              Ptnxntirf Population
eesssaar
                               199

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              Susquehanna River at Segment 140
                Observed and Simulated versus Time

                        Total Ammonia
                         (*=Observed, -=Simulated)
    0.8 -:
    0.7
    0.6-
    0.5
O
o
   •5,
    0.4
    0.3
                                 Date

-------
ISJ

O
                 Susquehanna River at Segment 140

          Total Ammonia Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
     noooo-
     100000
I
i
     90000
     80000-
     70000-
     60000 -:
     50000-
     40000 -
     30000
     20000-
     10000-
        ;O
                        : O
   HI jHkttt H«»UU1f*~V<» MUl)
    v 23FEBM 12:l4
                                       Date

-------
            Susquehanna River at Segment 140
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                  Total Ammonia: 01JAN84 - 01JAN92
f
                                                          , of Point
                             Simulated- o>|/l
            Susquehanna River at Segment 140
                   Actual Error versus Time
                       Total Ammonia
                              Data
                            202

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     Susquehanna River at Segment 140
                 Total Ammonia
      Frequency Distribution - PAIRED Simulated and Observed Data
    Susquehanna River at Segment 140
 Actual error versus Percentile Sample Population
                Total Ammonia
       Frequency Distribution - All Simulated and Observed Data
-s>
      •*>
            *
                     Ptmat«f Population
                     203

-------
           Susquehanna River at Segment 140
             Observed and Simulated versus Time
                    Organic Nitrogen
                      (*=Observed, -^Simulated)
f
 1 1
                             Date

-------
               Susquehanna River at Segment 140

        Organic Nitrogen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    800000
    700000
N)

O
                                 Date

-------
              Susquehanna River at Segment 140
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                   Organic Nitrogen: 01JAN84 - 01JAN92
                              Simulated-m«/l
             Susquehanna River at Segment 140
                    Actual Error versus Time
                        Organic Nitrogen
5KSS
                             206

-------
    Susquehanna River at Segment 140
               Organic Nitrogen
     Frequency Distribution - FAIRED Simulated and Observed Data
   Susquehanna River at Segment 140
Actual error versus Percentile Sample Population
              Organic Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                    207

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208

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                         B.2.0  Patuxent River
Basin Segments:
      Above Fall Line Basin Segments: 330, and 340
      Below Fall Line Basin Segments: 500, and 990

Section Contents:
      B.2.0 Monitoring Stations in the Patuxent River Basin (Figure B.2.0)
      B.2.1 Patuxent River, near Bowie, MD (Monitoring Station: 1594440)
                              209

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                                    Rgure B.2
    Monitoring Stations
              in the
   Patuxent River Basin
    Patuxent River Basin in
   The Chesapeake Bay Watershed
Chesapeake Bay Program

Map Date: April 1998
                   Calibration Stations
                    % 1594440
                   /V Streams
                   fi Model Segments
Source: USGS and USEPA Chesapeake Bay Program
     210
                                        N

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B.2.1  Patuxent River near Bowie, MD at Segment 340 (Monitoring Station: 1594440)
(Above Fall Line Basin Segments: 330, 340, 500, and 990)	

Section Summary;

The Patuxent basin is the most urbanized of the major Chesapeake Bay Program basins.
The water quality time series reflects the urban, hydrologically "flashy" character of the
basin.  Basin water quality is dominated by point source discharges. Changes in point
source discharges over the simulation period including the phosphorus detergent ban in
January, 1984, and Biological Nutrient Removal (BNR) treatment in the 1990s have
resulted in large step-wise changes in water quality in both the observed and simulated
water quality data.

The Patuxent basin above the gaged site covers an area of 902 square miles. At the
midpoint of the simulation, 1990, the land use for the basin was composed of 45% forest
land, 19% cropland,  11% other agricultural areas, 24% urban areas, and 2% water (river
and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996  Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 5.7 million pounds in 1985  to 5.1 million pounds in 1996. Total phosphorus loads
over the same time period decreased from 0.53 million pounds to 0.35 million  pounds. In
general, point source loads above the gage site decreased.  In 1996, the total nitrogen
point source load was 22% of the total load and the total phosphorus point source load
was 28% of the total load. Estimated septic system total nitrogen loads increased 30%,
from 0.31 million pounds in 1985 to 0.41 million pounds in  1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 15%, and other agricultural loads (primarily
pasture and manure loads) by 34%. Total phosphorus decreased for these land uses by
16% and 44% respectively. Urban loads were estimated to have increased over the 1985
to 1996 period by 22% for total nitrogen and 23% for total phosphorus due to increases in
population and urban land use area.
                                  211

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 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date - Temperature
                                 212

-------
CO
                 Patuxent River at Segment 340
                Observed and Simulated versus Time
                         Temperature-C
                         (*=Observed, -^Simulated)
                                Date

-------
                Patuxent River at Segment 340
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Temperature-C: 01JAN84 - 01JAN92
 20
s
t
                                                             ofPoir:
                             Siaiulltad-Tonp-C
                                                              —r
                                                               •f
               Patuxent River at Segment 340
                    Actual Error versus Time
                         Temperature-C
                             214

-------
looi-
              Patuxent River at Segment 340
                        Temperature-C
            Frequency Distribution - PAIRED Simulated and Observed Data
             Patuxent River at Segment 340
       Actual error versus PercentUe Sample Population
                       Temperature-C
              Frequency Distribution - All Simulated and Observed Data
                            FucntofFopiiklian
                             215

-------
Patuxent River at Segment 340
Observed and Simulated versus Time
      Dissolved Oxygen
         (*=Observed, -=Simulated)
                Date

-------
             Patuxent River at Segment 340

    Dissolved Oxygen Observed and Simulated Load vs Time
                    (line = simulated, O = observed)
40000-
                              Date

-------
 Patuxent River at Segment 340
  Scatter Plot and Regression of Simulated
     versus Observed with Ideal Line
   Dissolved Oxygen: 01JAN84 - 01JAN92
                                              etPw:
               SimuUrtd-mg/l
                                               ••—r
                                                •9
Patuxent River at Segment 340
     Actual Error versus Time
        Dissolved Oxygen
              218

-------
                 Patuxent River at Segment 340
                         Dissolved Oxygen
                Frequency Distribution - PAIRED Simulated and Observed Data
                Patuxent River at Segment 340
          Actual error versus Percentile Sample Population
                         Dissolved Oxygen
                Frequency Distribution - All Simulated and Observed Data
ssszssssr--•
                               219

-------
    3000-
    2000
NJ
to
O
    1000
                Patuxent River at Segment 340
                Observed and Simulated versus Time
                  Total Suspended Sediment
                         (*=Observed, -=Simulated)
                                Date

-------
ro
(0
                      Patuxent River at Segment 340
     Total Suspended Sediment Observed and Simulated Load vs Time
                                (line =B simulated, O = observed)
     19000000-
     18000000
     17000000
     16000000-
     15000000-
     14000000
  13000000

  12000000-

.g iioooooo-
w
§• 10000000
s
.£ 90000001
      80000001
      7000000
     6000000-
     5000000-
     4000000
     3000000
     2000000-
     1000000
                                            Date

-------
              Patuxent River at Segment 340
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
             Total Suspended Sediment: 01JAN84 - 01JAN92
                            SinuUM-ing/l
3000
    T, . - T
             Patuxent River at Segment 340
                  Actual Error versus Time
                 Total Suspended Sediment
              /     /
                           222

-------
                Patuxent River at Segment 340
                     Total Suspended Sediment
               Frequency Distribution - PAIRED Simulated and Observed Data
                                Penpal of Population
 SKSW
J
o
                Patuxent River at Segment 340
          Actual error versus Percentile Sample Population
                    Total Suspended Sediment
                Frequency Distribution - All Simulated and Observed Data
    »      <>     &     4>
                                         #      
-------
to
                Patuxent River at Segment 340
                Observed and Simulated versus Time
                       Total Phosphorus
                         (*=Observed, -=Simulated)
                                Date

-------
                    Patuxent River at Segment 340
          Total Phosphorus Observed and Simulated Load vs Time
                             (line = simulated, O = observed)
      11000
      10000-
      9000
      8000-
      7000-
ro
    &
    £
      6000
      5000
      4000-
      3000-
      2000
      1000
                     .O.
    MIX*
    HMUX340
                                       Date

-------
 1"
   
-------
      Patuxent River at Segment 340
               Total Phosphorus
     Frequency Distribution - FAIRED Simulated and Observed Data
                                                99
      Patuxent River at Segment 340
Actual error versus Percentile Sample Population
               Total Phosphorus
      Frequency Distribution - All Simulated and Observed Data
                     PtKtnt of Population
                     227

-------
    3--:
N>
N>
00
                Patuxent River at Segment 340
                Observed and Simulated versus Time
             Organic and Particulate Phosphorus
                         (»=Observed, -=Simulated)
                                Dile

-------
NJ
N>
vo
                    Patuxent River at Segment 340
    Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                             (line = simulated, O = observed)
     11000
     10000
     9000
     8000
   *
     7000-
     60001
     50001
     4000-
     3000-
     2000
     1000-
                                       Date

-------
                 Fatuxent River at Segment 340
                   Scatter Plot and Regression or Simulated
                      versus Observed with Ideal Line
             Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
      '•f *
                                Simulated-ing/I
Ml.*** «•••*•*•>,
  LI

  1.0

  M

  OJ

  0.7

  04

  OS

  04


  °-3

  03

  0.1-
 -OJ

 -04-

 •OJ-
                Patuxent River at Segment 340
                     Actual Error versus Time
                Organic and Particulate Phosphorus
                                               'f JT^f" "T'J>t''1
T
                                 Date
                               230

-------
              Patuxent River at Segment 340
              Organic and Particulate Phosphorus
             Frequency Distribution - PAIRED Simulated and Observed Data
1.0000
                              Percent o^opulibon ™
              Patuxent River at Segment 340
        Actual error versus Percentile Sample Population
              Organic and Particulate Phosphorus
              Frequency Distribution - All Simulated and Observed Data
                             Percent of Potation
                             231

-------
 0.9-
 0.8-
 0.7-
 0.6-
 0.5-
1
 0.4
 0.3-
 0.2-
 0.1-
 0.0-L.
              Patuxent River at Segment 340
              Observed and Simulated versus Time
                   Dissolved Phosphorus
                       (*=Observed, -^Simulated)
                               Date

-------
                  Patuxent River at Segment 340

      Dissolved Phosphorus Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
    400
    300
w  a
w  & 200
   c
    100-
                                  Date
       al MM)

-------
Patuxent River at Segment 340
  Scatter Plot and Regression of Simulated
     versus Observed with Ideal Line
 Dissolved Phosphorus: 01JAN84 - 01JAN92
               Simulated-nf/1
Patuxent River at Segment 340
     Actual Error versus Time
      Dissolved Phosphorus
                Dale
              234

-------
                 Patuxent River at Segment 340
                       Dissolved Phosphorus
                Frequency Distribution - PAIRED Simulated and Ol
Dated and Observed Data
                                Percent oTPopuUliait
                 Patuxent River at Segment 340
           Actual error versus Percentile Sample Population
                       Dissolved Phosphorus
                 Frequency Distribution - All Simulated and Observed Data
fmf-jam.jp
                                235

-------
    14-
ro
                 Patuxent River at Segment 340
                Observed and Simulated versus Time
                         Total Nitrogen
                         (*=Observed, -=Simulated)
                                Date

-------
KJ

10

•vl
     70000-
     60000
     50000-
   •3 40000:
s.
s
     30000
     20000:
     10000-
                    Patuxent River at Segment 340

           Total Nitrogen Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
                                       Date
         .
     20TEBM WMnae r»j,mo
-------
 Patuxent River at Segment 340
   Scatter Plot and Regression of Simulated
     versus Observed with Ideal Line
    Total Nitrogen: 01JAN84 - 01JAN92
Patuxent River at Segment 340
     Actual Error versus Time
          Total Nitrogen
              238

-------
                 Patuxent River at Segment 340
                           Total Nitrogen
                Frequency Distribution - FAIRED Simulated and Observed Data

                 Patuxent River at Segment 340
           Actual error versus Percentile Sample Population
                           Total Nitrogen
                 Frequency Distribution - All Simulated and Observed Data
                               PtrttntofPopuUtian
BSSSSSSS"
                                239

-------
10
-p>
o
                 Patuxent River at Segment 340
                Observed and Simulated versus Time

                              NO3
                         (*=Observed, -=Simulated)
                                Dale

-------
 8000
 7000
 6000
 5000-
I
 4000-
I
 3000-
 2000-
 1000
                Patuxent River at Segment 340

            NO3 Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
                                 Date

-------
               Patuxent River at Segment 340
                 Scatter Plot and Regression or Simulated
                    versus Observed with Ideal Line
                      NO3:01JAN84 - 01JAN92
SSKtm
               Patuxent River at Segment 340
                    Actual Error versus Time
                             NO3
                               D.H
                             242

-------
  rssasr-
                 Patuxent River at Segment 340
                                 N03
                Frequency Distribution - PAIRED Simulated and Observed Data
                                 Percent ofPopulttton
                 Patuxent River at Segment 340
           Actual error versus Percentile Sample Population
                                 NO3
                 Frequency Distribution - All Simulated and Observed Data
                                PtrctntofPopuktioti
SBssssstsr-
                                 243

-------
    3-:
ro
-e-
   I
                 Patuxent River at Segment 340

                Observed and Simulated versus Time

                        Total Ammonia
                         (*=Observed, -=Simulated)
                                Date

-------
              Patuxent River at Segment 340
     Total Ammonia Observed and Simulated Load vs Time
800
700
                      (line = simulated, O = observed)
                               Date
dry 20FEBH 0*44*rac ragjno

-------
                Patuxent River at Segment 340
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Total Ammonia: 01JAN84 - 01JAN92
 o-t
                              SunuUtcd - mgfl
               Patuxent River at Segment 340
                    Actual Error versus Time
                         Total Ammonia
 03

 OX

 0.1

 OJ)

-0.1

-0.2


-OJ
-Oi

-0.7
•14-

-is-
                                Date
                             246

-------
      Patuxent River at Segment 340
                Total Ammonia
     Frequency Distribution - PAIRED Simulated and Observed Data
                      Percent orropuUtion
                                       90
      Patuxent River at Segment 340
Actual error versus Percentile Sample Population
                Total Ammonia
      Frequency Distribution - All Simulated and Observed Data
                     Peicoil of Population
                      247

-------
    13-:
to
•C-
00
                 Patuxent River at Segment 340
                Observed and Simulated versus Time
                       Organic Nitrogen
                         (*=Observed, -=Simula ted)
                                Date

-------
to
                    Patuxent River at Segment 340

          Organic Nitrogen Observed and Simulated Load vs Time
                             (line = simulated, O = observed)
     60000-
     50000-
     40000

     30000-
     20000
     10000-
   M1 jMb.M> m14«.dr> MFCMi WMfms
     MFCMi WMfms Ittmaitl yd
                                       Date

-------
 Patuxent River at Segment 340
   Scatter Plot and Regression or Simulated
     versus Observed with Ideal Line
    Organic Nitrogen: 01JAN84 - 01JAN92
               <•    A    *


               SimuUM-ng/l
                                              .olPoii:
Patuxent River at Segment 340
     Actual Error versus Time
         Organic Nitrogen
              250

-------
                 Patuxent River at Segment 340
                          Organic Nitrogen
               Frequency Distribution - PAIRED Simulated and Observed Data
                                Ptnxnt ofPopuUHon
sssssssssr*
                 Patuxent River at Segment 340
          Actual error versus Percentile Sample Population
                          Organic Nitrogen
                 Frequency Distribution - All Simulated and Observed Data
                                Percent o< Population
                                251

-------
252

-------
                        B.3.0  Potomac River
Basin Segments:
      Above Fall Line Basin Segments: 160,170, 175, 180,190, 200, 210, 220, 730,
                                  740, and 750
      Below Fall Line Basin Segments: 540,550, 890, 900, 910, 920, 970, and 980

Section Contents:
      B.3.0  Monitoring Stations in the Potomac River Basin (Figure B.3.0)
      B.3.1  Mid Potomac River (Monitoring Station: 1613000)
      B.3.2  Shenandoah River (Monitoring Station: 1636500)
      B.3.3  Lower Potomac River (Monitoring Station: 1646500)
                              253

-------
      Monitoring Stations
                 in  the
      Potomac River Basin
                                          Figure B.3
             Calibration Stations
              0 1613000
              m 1636500
               1646500
             /V Streams
             I  i Model Segments
Chesapeake Bay Program
Ma? Date: April 1998
                           Potomac River Basin in
                         The Chesapeake Bay Watershed
                                             N
Source: USGS and USEPA Chesapeake Bay Program
           254
KJH

-------
B.3.1  Mid Potomac River near Shepardstown, WV at Segment 740    (Monitoring
Station: 1613000) (Above Fall Line Basin Segments: 160,170,175, 730, and 740)

Section Summary;

The mid-Potomac gage at Shepardstown, WV, is downstream of a largely forested basin
which is rural in nature and is dominated by agricultural loads.  The mid-Potomac basin
above the gage covers an area of 5,961 square miles. At the midpoint of the simulation
period, 1990, the land use for the basin was composed of 67% forest land, 7% cropland,
23% other agricultural areas, 3% urban areas, and 1% water (river and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage increased from
18.8 million pounds in 1985 to 19.3 million pounds in 1996.  Total phosphorus loads over
the same time period decreased from 2.0 million pounds to 1.9 million pounds. In
general, point source loads above the gage site decreased.  In 1996, the total nitrogen
point source load was 8% of the total load and the total phosphorus point source load was
21% of the total load. Estimated septic system total nitrogen loads increased 19%, from
0.5 million pounds in 1985 to 0.7 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation increased
estimated cropland total nitrogen loads by 2%, and decreased other agricultural loads
(primarily pasture and manure loads) by 10%. Total phosphorus increased for cropland
by 9% and decreased for other agricultural loads by 6%. Urban loads were estimated to
have increased over the 1985 to 1996 period by 12% for total nitrogen and 13% for total
phosphorus due to increases in population and urban land use area.
                                  255

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date - Temperature
                                 256

-------
Isi
              Mid Potomac River at Segment 740
                Observed and Simulated versus Time
                       Temperature-C
                        (*=Observed, -^Simulated)
                               Date

-------
 Mid Potomac River at Segment 740
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
       Temperature-C: 01JAN84 - 01JAN92
                Simakted-Tatp-C
                                               of Pa* I
Mid Potomac River at Segment 740
       Actual Error versus Time
            Temperature-C
5
4
3
2
1
r
i;
p "^
.3 •
i
1 4'
-5-
-«•
-7-
4-




T









>





L


1 i






«








•






/






^











J















1

1










'







,

II


m





*
! i ll , 1 1 ,
J1 111 1 ' ' 'I'll'
*
A A
1 1 *

A




////// X
Dit*
SttSSWT— '
                258

-------
* 1.000
o
1
1
X
^
I!
I
             Mid Potomac River at Segment 740
                         Temperature-C
              Frequency Distribution - PAIRED Simulated and Observed Data
                     10
                            30
             Mid Potomac River at Segment 740
         Actual error versus Percentile Sample Population
                         Temperature-C
               Frequency Distribution - All Simulated and Observed Data
              •e
                    *
KMSS!
                              259

-------
16-:


15-


14


13


12 -


11 -


10


 9


 8


 7


 6-


 5-


 4-
            Mid Potomac River at Segment 740
              Observed and Simulated versus Time
                    Dissolved Oxygen
                       (*=Observed, -=Simulated)
I
 3-L
                              Date

-------
               Mid Potomac River at Segment 740

        Dissolved Oxygen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    3000000
    2000000
   I
to
    1000000
                                  Date

-------
              Mid Potomac River at Segment 740
                  Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Dissolved Oxygen: 01JAN84 - 01JAN92
 SHT
 j.



 \

 I
sasssx
             Mid Potomac River at Segment 740
                    Actual Error versus Time
                       Dissolved Oxygen
                               D.t.
                             262

-------
            Mid Potomac River at Segment 740
                       Dissolved Oxygen
              Frequency Distribution - PAIRED Simulated and Observed Data
                    10
                           30
                                             90
I1
 •i-
            Mid Potomac River at Segment 740
         Actual error versus Percentile Sample Population
                       Dissolved Oxygen
               Frequency Distribution - All Simulated and Observed Data
                              263

-------
    5000-
    4000
10
    3000-
    2000
    1000
              Mid Potomac River at Segment 740
                Observed and Simulated versus Time
                  Total Suspended Sediment
                         (*=Observed, -=Simulated)
                                Date

-------
ro
                Mid Potomac River at Segment 740
    Total Suspended Sediment Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
     7.00E+08 - :
     6.00E+08
 5.00E+08




•8 4.00E+08
I
2
.£

| 3.00E+08-




 2.00E+08 -




 l.OOE+08 :
    O.OOE+00 -ttl
             e
                       &      ^      A*      A^
                      /      /      /     /


                                      Date

-------
              Mid Potomac River at Segment 740
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
               Total Suspended Sediment: 01JAN84 - 01JAN92
SSSSBTB
                              Simulated-ng/l
  TOO


  «M


  500


  400


  300


  ZOO


  100
 -MO
             Mid Potomac River at Segment 740
                    Actual Error versus Time
                   Total Suspended Sediment
                                                    IJLL
                             266

-------
            Mid Potomac River at Segment 740
                   Total Suspended Sediment
              Frequency Distribution • PAIRED Simulated and Observed Data
            Mid Potomac River at Segment 740
        Actual error versus Fercentile Sample Population
                   Total Suspended Sediment
               Frequency Distribution - All Simulated and Observed Data
TOO:

soo-

soo:

400-

300'



100-

 o-

-100-

-MO-

-300-
                             PemntofrcpuUtion
                              267

-------
               Mid Potomac River at Segment 740
                Observed and Simulated versus Time

                        Total Phosphorus
                          (*=Observed, -=Simulated)
10
<^
oo
    1-
  fcttjfcfciiMififlMfriPiMltliHiiil.
                                 Date

-------
VO
             Mid Potomac River at Segment 740

      Total Phosphorus Observed and Simulated Load vs Time
     	         (line = simulated, O = observed)
  500000





  400000





t  300000
^


.5

 200000





 100000
     X     X
                             ^^
                        /     X
X
                                   Date

-------
            Mid Potomac River at Segment 740
                 Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                 Total Phosphorus: 01JAN84 - 01JAN92
o
-2-
            Mid Potomac River at Segment 740
                   Actual Error versus Time
                      Total Phosphorus
        - * *
                      * * .. • «
'- I .r
                                          X     S
                             Data
                           270

-------
             Mid Potomac River at Segment 740
                        Total Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
             Mid Potomac River at Segment 740
         Actual error versus Percentile Sample Population
                        Total Phosphorus
               Frequency Distribution • All Simulated and Observed Data
I-;-
                            Pmtnlo< Population
                             271

-------
              Mid Potomac River at Segment 740
                Observed and Simulated versus Time
             Organic and Particulate Phosphorus
                        (*=Observed/ -=Simulated)
to
«»j
10
   •5,
    2-
                               Dtte

-------
                 Mid Potomac River at Segment 740

   Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                            (line = simulated, O = observed)

     500000 -p                   ~






     400000






   >, 300000


5  &
   _c


   J  200000-






     100000
                                          o p> o
fp 
-------
  1
  r
  o
              Mid Potomac River at Segment 740
                   Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
             Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
    -* « I » *
              Mid Potomac River at Segment 740
                     Actual Error versus Time
                Organic and Particulate Phosphorus
                       »*-•*  «-
                                         . . T »
                                Da*
sax
                                                           tJL.
                              274

-------
              Mid Potomac River at Segment 740
                Organic and Participate Phosphorus
               Frequency Distribution - FAIRED Simulated and Observed Data
 I
 I  •

 I-.-
             Mid Potomac River at Segment 740
          Actual error versus Percentile Sample Population
                Organic and Participate Phosphorus
                Frequency Distribution -All Simulated and Observed Data
                              PncnvtcrfPopuUlion
ssssrr
                               275

-------
    0.7 -:
    0.6
to
    0.01
              Mid Potomac River at Segment 740
                Observed and Simulated versus Time
                    Dissolved Phosphorus
                         (*=Observed, -^Simulated)
                                Date
 vu&ss

-------
               Mid Potomac River at Segment 740

      Dissolved Phosphorus Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    5000
    4000
    3000
10
   2
   c
    2000-
    1000
                                  Date

-------
Mid Potomac River at Segment 740
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
    Dissolved Phosphorus: 01JAN84 - 01JAN92
O.ff

i OA>
t ••"
1
i
0.01
i
i
fl.7-
tf
•5-
10J-
W
1
0.1-

•
-0.1 -r
X

111 [ ! i ; ; 	

I / 1 ! 1 i i


ij i i i | | p-
	 	 	 , 	 ,..,,. 	 1 1 I I 1
Mid Potomac River at Segment 740
Actual Error versus Time
Dissolved Phosphorus





T T * T T. . T T ft T.I TT t T.
1 j, I'll "1* * " * ** * •*»"' ' ' • j • ' -' * '
Date





sgftk ^
w :
•* 	 :
1 ' ' • i r






f
i



1















                278

-------
              Mid Potomac River at Segment 740
                       Dissolved Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
SSCWSB
              Mid Potomac River at Segment 740
          Actual error versus Percentile Sample Population
                      Dissolved Phosphorus
                Frequency Distribution • All Simulated and Observed Data
srwr
                               279

-------
    11
    10-
    8-:
    7-:
K>
00
O
   I
    1-
              Mid Potomac River at Segment 740
                Observed and Simulated versus Time
                        Total Nitrogen
                         <*=Observed, -=Simulated)
                                 \ '
                                Dtte

-------
                Mid Potomac River at Segment 740

          Total Nitrogen Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
     700000
     600000
    500000
to
00

<5
o.
    400000
   .5
    300000-
    200000-
    100000
                                     Date

-------
 Mid Potomac River at Segment 740
     Scatter Plot and Regression of Simulated
       versus Observed with Ideal Line
       Total Nitrogen: 01JAN84 - 01JAN92
Mid Potomac River at Segment 740
       Actual Error versus Time
            Total Nitrogen
5
4
3
2'
»'

-2'
•3-





III
1 |' I'll


•
H'l







1
,








1
















T T












h i i
r 11 Jjiiir '



         /      X     X     /
                282

-------
10.0
            Mid Potomac River at Segment 740
                        Total Nitrogen
             Frequency Distribution - PAIRED Simulated i
I and Observed Data
                            PercMitofPopuUKon
           Mid Potomac River at Segment 740
        Actual error versus Percentile Sample Population
                        Total Nitrogen
              Frequency Distribution - All Simulated and Observed Data
                            283

-------
    10-:
    9 -1
ro
oo
   •5,
              Mid Potomac River at Segment 740

                Observed and Simulated versus Time

                              NO3
                         (*=Observed, -=Simulated)
                                Date

-------
00
in
    130000
    120000
                Mid Potomac River at Segment 740

              NO3 Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
  Ml EM.** IKNM
  (rmiSi2f EMTn
                                   Date

-------

 2-0


 1.9


 U


 17


 1.6


 IS


 1A


 U
i

: u
>
 u


 u>


 «.»•


 flj-


 4.7 •


 04-


 as-
              Mid Potomac River at Segment 740
                   Scatter Plot and Regression of Simulated
                      versus Observed with Ideal Line
                        NO3:01JAN84 - 01JAN92
                                                              .

                               Simulated-
tSgtOmlfJt "-
              Mid Potomac River at Segment 740
                     Actual Error versus Time
                              NO3
                                Dtt>
                              286

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    Mid Potomac River at Segment 740
                     NO3
     Frequency Distribution - PAIRED Simulated and Observed Data
   Mid Potomac River at Segment 740
Actual error versus Percentile Sample Population
                     N03
      Frequency Distribution - All Simulated and Observed Data
                    P.™* .< Population
                     287

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    0.9 -:
    0.8 -
    0.7-:
    0.6
N>
OO   „_ .
oo   0.5 -
   •s,
   g
    0.4
    0.3
    0.2-
    0.1 -
    0.0 i
               Mid Potomac River at Segment 740
                 Observed and Simulated versus Time
                         Total Ammonia
                          (*=Observed, -^Simulated)
                                  Date

-------
00
SO
     120000
     110000
     100000
     90000
     80000
     70000-
   J? 60000
   .5
     50000
     40000
     30000
     20000-
     10000
                 Mid Potomac River at Segment 740
          Total Ammonia Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
                      O'f
                                      Date

-------
 Mid Potomac River at Segment 740
     Scatter Plot and Regression of Simulated
       versus Observed with Ideal Line
      Total Ammonia: 01JAN84 - 01JAN92
                 Simulated-m|fl
Mid Potomac River at Segment 740
        *  -  f in          m»^


OJ-
0.1
on-
•o.i-
o
I*3'
| -04-
I
•oj-
44 "
•°-7"
-OJ-


1 IT*
1 U ' A

.






Actual error versus 1 ime
Total Ammonia

1

1








IMllli*** -1 *'|ii|A * \i
*
i







                        XXX
                  Dttt
                290

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1
£ 0.010-
             Mid Potomac River at Segment 740
                        Total Ammonia
              Frequency Distribution - PAIRED Simulated and Observed Data
             Mid Potomac River at Segment 740
          Actual error versus Percentile Sample Population
                         Total Ammonia
               Frequency Distribution - All Simulated and Observed Data
eaawsr-
                              291

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to
vo
              Mid Potomac River at Segment 740
                Observed and Simulated versus Time

                       Organic Nitrogen
                         <*=Observed, -=Simulated)
                               Date

-------
                Mid Potomac River at Segment 740
         Organic Nitrogen Observed and Simulated Load vs Time
            v^         ^^    /•* •   •   i * i ^^  ••   •• \
     500000
    400000
    300000
NJ
VO
U>

-------
        Mid Potomac River at Segment 740
            Scatter Plot and Regression of Stimulated
               versus Observed with Ideal Line
             Organic Nitrogen: 01JAN84 - 01JAN92
                        Simulated-m|fl
       Mid Potomac River at Segment 740
              Actual Error versus Time
                  Organic Nitrogen
1 1 *
     IT-
                         Dili
                       294

-------
  •Jii
££•£••* LU "•*
             Mid Potomac River at Segment 740
                         Organic Nitrogen
               Frequency Distribution • PAIRED Simulated and Observed Data
             Mid Potomac River at Segment 740
          Actual error versus Percentile Sample Population
                        Organic Nitrogen
                Frequency Distribution • All Simulated and Observed Data
                              295

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296

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B.3.2  Shenandoah River near Millville, WV at Segment 200 (Monitoring Station:
1636500) (Above Fall Line Basin Segments: 190 and 200)	

Section Summary:
The Shenandoah basin is largely rural and is dominated by agricultural loads of the
Shenandoah Valley.  The Shenandoah basin above the gaged site covers an area of 3,033
square miles.  At the midpoint of the simulation, 1990, the land use for the basin was
composed of 51% forest land, 6% cropland, 34% other agricultural areas, 8% urban
areas, and 1% water (river and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 9.1 million pounds in 1985 to 8.4 million pounds in 1996. Total phosphorus loads
over the same time period  decreased from 1.5 million pounds to 1.2 million pounds. In
general, point source loads above the gage site decreased.  In  1996, the total nitrogen
point source load was 16% of the total load and the total phosphorus point source load
was 32% of the total load.  Estimated septic system total nitrogen loads increased 28%,
from 0.30 million pounds in 1985 to 0.38 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 32%, and other agricultural loads (primarily
pasture and manure loads) by 11 %. Total phosphorus decreased for these land uses by
23% and 25% respectively. Urban loads were estimated to have increased over the 1985
to 1996 period by 35% for total nitrogen and 30% for total phosphorus due to increases in
population and urban land use area.
                                  297

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date ~ Temperature
                                 298

-------
N)
VO
VO
    40 j
               Shenandoah River at Segment 200
                Observed and Simulated versus Time
                        Temperature-C
                         (*=Observed, -=Simulated)
                                Date

-------
 Shenadoah River at Segment 200
   Scatter Plot and Regression ofbimulated
      versus Observed with Ideal Line
     Temperature-C: 01JAN84 - 01J AN92

               SimuUM-Tcmp-C
Shenadoah River at Segment 200
      Actual Error versus Time
          Temperature-C
            uu
J-TT^
                              X     X
                 DMt
              300

-------
SSSSf
              Shenadoah River at Segment 200
                         Temperature-C
              Frequency Distribution - PAIRED Simulated and Observed Data
                                  offopuktion
              Shenadoah River at Segment 200
          Actual error versus Percentile Sample Population
                          Temperature-C
                Frequency Distribution - All Simulated and Observed Data
                               301

-------
OJ
o
              Shenandoah River at Segment 200
               Observed and Simulated versus Time
                      Dissolved Oxygen
                        (*=Observed, -=Simulated)
                               Date

-------
                Shenandoah River at Segment 200

       Dissolved Oxygen Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
 I

 2
 c
   900000
   800000
   700000
  600000
  500000
  400000
  300000
  200000
  100000
                                     Date
(111 jM\ in dMMonl (r»«»I IHIKI utl MiM)
(»<(«_. dn »AUOt7 17:<0j>..|

-------
Shenadoah River at Segment 200
   Scatter Plot and Regression ofSimulated
      versus Observed with Ideal Line
    Dissolved Oxygen: 01JAN84 - 01JAN92
                                             .olPoii

Shenadoah River at Segment 200
      Actual Error versus Time
         Dissolved Oxygen
                 D.I.
               304

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              Shenadoah River at Segment 200
                        Dissolved Oxygen
              Frequency Distribution - PAIRED Simulated and Observed Data
5
I  »

i
iZ
                    10
                            30
                                      70
                                              90
              Shenadoah River at Segment 200
         Actual error versus Percentile Sample Population
                       Dissolved Oxygen
               Frequency Distribution - All Simulated and Observed Data
        •5>
                    •f
                             PnemlofPqnhlM.
                              305

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          Shenandoah River at Segment 200
            Observed and Simulated versus Time
              Total Suspended Sediment
                    (*=Observed, -=Simulated)
1900
                           Date

-------
              Shenandoah River at Segment 200
  Total Suspended Sediment Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
  3.00E+081:
 2.00E+08
                   O
T3

I
2
.£
 l.OOE+08 -
 O.OOE+00 -
i  '       '
f1^ r>^>^^ f^ ^^ ^^ ^"^ <^~
                                                     o<
                                 Date

-------
              Shenadoah River at Segment 200
                 Scatter Plot and Regression ofSimulated
                    versus Observed with Ideal Line
               Total Suspended Sediment: 01JAN84 - 01JAN92
             Shenadoah River at Segment 200
                    Actual Error versus Time
                   Total Suspended Sediment
  soo
o
                    T-   pr
                                         .   T    I.
                           308

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               Shenadoah River at Segment 200
                    Total Suspended Sediment
               Frequency Distribution - PAIRED Simulated and Observed Data
               Shenadoah River at Segment 200
          Actual error versus Percentile Sample Population
                    Total Suspended Sediment
                Frequency Distribution • All Simulated and Observed Data
  500-



  400-



  MO-



  200-


  100;



   •'


  -loo :



  -200-
  -300 1:
ssessas
                               309

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Shenandoah River at Segment 200
 Observed and Simulated versus Time
        Total Phosphorus
          (*=Observed, -=Simulated)

-------
                Shenandoah River at Segment 200

         Total Phosphorus Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
     3000001
    200000
u>
I
a
s
    100000
      o-tia
     X     X
                     O
                                                    -B$ ft) H)O (^-Q£V-
                                 /.<$>
                               /
X     X
                                   Date

-------
              Shenadoah River at Segment 200
                 Scatter Plot and Regression otSimulated
                   versus Observed with Ideal Line
                  Total Phosphorus: 01JAN84 - 01JAN92
             Shenadoah River at Segment 200
                   Actual Error versus Time
                      Total Phosphorus
• -u-
1

1-o.M
Si
 -04'
   FTT
"T
IT
                 iL
^
                         iL
                           312

-------
 10.00-
I
  0.10
              Shenadoah River at Segment 200
                        Total Phosphorus
              Frequency Distribution - FAIRED Simulated and Observed Data
              Shenadoah River at Segment 200
         Actual error versus Percentile Sample Population
                        Total Phosphorus
               Frequency Distribution - All Simulated and Observed Data
KOSS
                              313

-------
1.8-
           Shenandoah River at Segment 200
            Observed and Simulated versus Time
          Organic and Particulate Phosphorus
                     (*=Observed, -=Simulated)
               ..ir*^.Trr.*.*  *.r...***.**:..*.* *^.*.*.*^0'^^^^r*^^.^.,-
                             Date

-------
Ui
                 Shenandoah River at Segment 200

    Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
     300000
    200000
   .
   Q)
   a
    100000
      oi
                     O
o-no ^onnr^ooon
                                                                    '<
    .
  Ituph.lHrv 2UUO>7 l
                                     Date

-------
             Shenadoah River at Segment 200
                Scatter Plot and Regression ofSimulated
                   versus Observed with Ideal Line
           Organic and Participate Phosphorus: 01JAN84 - 01JAN92
                             Simulittd - mg/1
             Shenadoah River at Segment 200
                   Actual Error versus Time
              Organic and Particulate Phosphorus
0.1
-OJ-
-04-
IT  tit  1.  ItT     llllIlT  T^   T,  ,T_l,t
                               Oil*
                            316

-------
              Shenadoah River at Segment 200
               Organic and Particulate Phosphorus
              Frequency Distribution - FAIRED Simulated and Observed Data
                             30 P«rc«T,lo$opuUtion ^
!«•
              Shenadoah River at Segment 200
         Actual error versus Percentile Sample Population
               Organic and Particulate Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                           #
                              Nrcn.tofPop.WHm
                              317

-------
               Shenadoah River at Segment 200
               Observed and Simulated versus Time
                    Dissolved Phosphorus
                        (*=Observed, -^Simulated)
00

-------
             Shenadoah River at Segment 200

   Dissolved Phosphorus Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 12000
 11000
I
                              Date

-------
 Shenadoah River at Segment 200
    Scatter Plot and Regression orSimulated
       versus Observed with Ideal Line
   Dissolved Phosphorus: 01JAN84 - 01JAN92
                  SimuUttd • mg/1
Shenadoah River at Segment 200
       Actual Error versus Time
        Dissolved Phosphorus
 0.07
 0.04
 0.05
 O.M
 OJ13
 0.02
i 0.01
j O.M

| -0.02
[ -0.03

i -0.05-

 -0.07
 •0.08
 •0.09
 •0.10
 -0.11
 •0.12
 •0.13
 •0.14
T
                   Y
                          /"      J      f
                          &       V       &
                320

-------
               Shenadoah River at Segment 200
                       Dissolved Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
               Shenadoah River at Segment 200
          Actual error versus Percentile Sample Population
                      Dissolved Phosphorus
                Frequency Distribution - All Simulated and Observed Data
Sire
                              321

-------
ts>
               Shenadoah River at Segment 200
                Observed and Simulated versus Time
                        Total Nitrogen
                         (*=Observed, -=Simulated)
                               Date

-------
     eooooo
                  Shenadoah River at Segment 200

          Total Nitrogen Observed and Simulated Load vs Time
                           (line = simulated, O = observed)

     500000
                     o ••
Ul
    400000-
   t
    300000
    200000
    100000
                                    Date

-------
              Shenadoah River at Segment 200
                 Scatter Plot and Regression orSimulated
                    versus Observed with Ideal Line
                   Total Nitrogen: 01JAN84 - 01JAN92
                             Simulated-m(/l
  1-
I
              Shenadoah River at Segment 200
                    Actual Error versus Time
                        Total Nitrogen
L
                                   T T
JL
                      /     X
                               D.I.
                            324

-------
S2SSS
              Shenadoah River at Segment 200
                         Total Nitrogen
              Frequency Distribution - PAIRED Simulated and Observed Data
              Shenadoah River at Segment 200
          Actual error versus Percentile Sample Population
                         Total Nitrogen
                Frequency Distribution - All Simulated and Observed Data
                               325

-------
u>
              Shenandoah River at Segment 200
                Observed and Simulated versus Time
                             NO3
                        (*=Observed, -^Simulated)

-------
CO
ho
    100000-
     90000
     80000
     70000
     60000
   c
     50000-
     40000-
     30000-
     20000
     10000
                 Shenandoah River at Segment 200

               NO3 Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
                                      Date

-------
     Shenadoah River at Segment 200
        Scatter Plot and Regression otSimulated
           versus Observed with Ideal Line
              NO3:01JAN84 - 01JAN92
                    Simulated-mg/1
     Shenadoah River at Segment 200
           Actual Error versus Time
                    NO3
      1   ll
r     i
                      D.I.
                   328

-------
               Shenadoah River at Segment 200
                               NO3
               Frequency Distribution - PAIRED Simulated and Observed Data
               Shenadoah River at Segment 200
          Actual error versus Percentile Sample Population
                               N03
                Frequency Distribution - All Simulated and Observed Data
SrtSKS"
                              Ptrcmtot Population
                               329

-------
U)
o
              Shenandoah River at Segment 200
                Observed and Simulated versus Time

                        Total Ammonia
                        (*=Observed, -=Simulated)
                               Date

-------
OJ
00
    60000
    50000
    40000
    30000
    20000-
    10000-
     Oi
                Shenandoah River at Segment 200
         Total Ammonia Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
                    o;
                    A*
ODD
no
00 no-*
                                   Date

-------
 Shenadoah River at Segment 200
    Scatter Plot and Regression ofSimulated
      versus Observed with Ideal Line
     Total Ammonia: 01JAN84 - 01JAN92
Shenadoah River at Segment 200
      Actual Error versus Time
          Total Ammonia
-  -T L  T   III.
                          n
                             TT T,
                              X     X
                 Due
              332

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     Shenadoah River at Segment 200
                Total Ammonia
     Frequency Distribution - PAIRED Simulated and Observed Data
     Shenadoah River at Segment 200
Actual error versus Percentile Sample Population
               Total Ammonia
      Frequency Distribution - All Simulated and Observed Data
                    333

-------
to
to
               Shenandoah River at Segment 200
                Observed and Simulated versus Time
                       Organic Nitrogen
                         <*=Observed, -^Simulated)
                               Date
 KtSffi

-------
                 Shenandoah River at Segment 200
         Organic Nitrogen Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
     400000
     300000
10
I
I
5? 200000
    100000

  b2ljW1.MKWnloiOtvtf3
  jgnph.» in lfMXM717i4ejw
                      O •
                           Q.
                                 £L
                     /
                                     Date

-------
 Shenadoah River at Segment 200
    Scatter Plot and Regression ofSimulated
       versus Observed with Ideal Line
     Organic Nitrogen: 01JAN84 • 01JAN92
                Simulated-mg/1

Shenadoah River at Segment 200
      Actual Error versus Time
          Organic Nitrogen
        !l....  I
11
                              X     X    X
                 D.I.
              336

-------
     Shenadoah River at Segment 200
               Organic Nitrogen
     Frequency Distribution1- PAIRED Simulated and Observed Data
     Shenadoah River at Segment 200
Actual error versus Percentile Sample Population
              Organic Nitrogen
      Frequency Distribution - All Simulated and Observed Data
    *
                    337
                                                        	i

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338

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B.3.3  Lower Potomac River at Chain Bridge near Washington, DC at Segment 220
(Monitoring Station: 1646580) (Above Fatt Line Basin Segments: 160,170,175,180,
190,200,210,220, 730, 740, and 750)	

Section Summary:

The Potomac River at the fall line is primarily rural, with the lowest portions of the basin
changing to the urban character of the Washington Metropolitan region. Land use
upstream is predominantly forest with agricultural loads from the Piedmont and the Great
Valley the primary influence on water quality.  The upstream basins of the upper
Potomac and Shenandoah contribute to the water quality characteristics at the Potomac
fall line. Nitrate comprises the greatest part of total nitrogen and is highly seasonal with
nitrate concentrations highest in winter and lowest in summer. An unusual feature of the
water quality time series at the Potomac is a 100-year storm in November, 1985.  Total
suspended sediment increased to  about 4,500 mg/1 at the Shepardstown gage, the highest
observed total suspended sediment concentrations recorded in the Chesapeake watershed.

The Potomac basin above the gaged site covers an area of 8,744 square miles. At the
midpoint of the simulation period, 1990, the land use for the basin was composed of 36%
forest land, 22% cropland, 30% other agricultural areas, 11 % urban areas, and 1 % water
(river and lake) surface area.

Based on an average hydrology used hi a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 42.8 million pounds in 1985 to 41.1 million pounds hi 1996. Total phosphorus
loads over the same tune period decreased from 5.0 million pounds to 4.3 million pounds.
In general, point source loads above the gage site decreased. In 1996, the total nitrogen
point source load was 11% of the total load and the total phosphorus point source load
was 25% of the total load. Estimated septic system total nitrogen loads increased 28%,
from  1.5 million pounds hi 1985  to 1.9 million pounds hi 1996.

Over the  1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 18%, and other agricultural loads (primarily
pasture and manure loads) by 12%. Total phosphorus decreased for these land uses  by
10% and 17% respectively.  Urban loads were estimated to have increased over the 1985
to 1996 period by 24% for total nitrogen and 26% for total phosphorus due to increases in
population and urban land use area.
                                  339

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date ~ Temperature
                                 340

-------
            Lower Potomac River at Segment 220
                Observed and Simulated versus Time
                        Temperature-C
                         (*=Observed/ -^Simulated)
  o l
                                Date
(til jktt ut nuuaiafrr, p3 |»m«t.i.t| note*
(»«(«|,. 
-------
            Lower Potomac River at Segment 220
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Temperature-C: 01JAN84 - 01JAN92
BBSBS
                             Simulated-T«mp-C
            Lower Potomac River at Segment 220
                    Actual Error versus Time
                        Temperature-C
                               DOt
ex
                             342

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  Lower Potomac River at Segment 220
               Temperature-C
     Frequency Distribution - FAIRED Simulated and Observed Data
                   30 Percent o^opuUtkm 70
  Lower Potomac River at Segment 220
Actual error versus Percentile Sample Population
               Temperature-C
      Frequency Distribution - All Simulated and Observed Data
                    343

-------
OJ
*-
.C-
             Lower Potomac River at Segment 220
                Observed and Simulated versus Time
                      Dissolved Oxygen
                        (*=Observed, -=Simulated)
                              Dtte

-------
              Lower Potomac River at Segment 220

        Dissolved Oxygen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    3000000
    2000000
L/l
   s
   C
   (0
   O
    1000000
                                  Date

-------
 Lower Potomac River at Segment 220
      Scatter Plot and Regression of Simulated
         versus Observed with Ideal Line
      Dissolved Oxygen: 01JAN84 - 01JAN92
Lower Potomac River at Segment 220
        Actual Error versus Time
           Dissolved Oxygen
                   Da,
                 346

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           Lower Potomac River at Segment 220
                       Dissolved Oxygen
              Frequency Distribution - PAIRED Simulated and Observed Data
  10.000
E
3  0.100
                     10
                            30

           Lower Potomac River at Segment 220
         Actual error versus Percentile Sample Population
                       Dissolved Oxygen
               Frequency Distribution - All Simulated and Observed Data
                             347

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             Lower Potomac River at Segment 220
                Observed and Simulated versus Time
                  Total Suspended Sediment
                        (*=Observed, -=Simulated)
    3000
    2000
oo
   1
    1000
                               Date

-------
          Lower Potomac River at Segment 220

Total Suspended Sediment Observed and Simulated Load vs Time
                    (line = simulated, O = observed)
9.00E+08 1.
8.00E+08 -
                             Date

-------
o
 1000-
           Lower Potomac River at Segment 220
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
              Total Suspended Sediment: 01JAN84 - 01JAN92
                            Simulated-ngfl
          Lower Potomac River at Segment 220
                   Actual Error versus Time
                  Total Suspended Sediment
                              Dite
                           350

-------
          Lower Potomac River at Segment 220
                 Total Suspended Sediment
            Frequency Distribution - PAIRED Simulated and Observed Data
                                                    99.9
1000-
1000
          Lower Potomac River at Segment 220
        Actual error versus Percentile Sample Population
                 Total Suspended Sediment
             Frequency Distribution - All Simulated and Observed Data
                           351

-------
         Lower Potomac River at Segment 220
            Observed and Simulated versus Time
                  Total Phosphorus
                    (*=Observed, -=Simulated)
i :
                          Date

-------
Ln
OJ
            Lower Potomac River at Segment 220
      Total Phosphorus Observed and Simulated Load vs Time
                       (line = simulated, O = observed)
 700000 -fT
    •••       ;      °:
 600000:

 SODOM-

'S 400000:
I   '•
c
I 300000:


 200000 :

    ::O
 looooo:
                                    Date

-------
            Lower Potomac River at Segment 220
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                  Total Phosphorus: 01JAN84 - 01JAN92

                             SimuUMd-mg/I
eesasssfsgszff
           Lower Potomac River at Segment 220
                    Actual Error versus Time
                       Total Phosphorus
                             354

-------
KSST3S*—'•
            Lower Potomac River at Segment 220
                        Total Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
                              Pnctnt
            Lower Potomac River at Segment 220
          Actual error versus Percentile Sample Population
                        Total Phosphorus
                Frequency Distribution - All Simulated and Observed Data
                           *
assay
                              355

-------
             Lower Potomac River at Segment 220
                Observed and Simulated versus Time
             Organic and Participate Phosphorus
                        (*=Observed, -=Simulated)
CO
C/i
  I
   o -tl
                               Date

-------
u>
01
vj
            Lower Potomac River at Segment 220


 Organic and Particulate Phosphorus Observed and Simulated Load vs Time

                         (line = simulated, O = observed)


  700000




                   O


  600000






  500000





SI-
'S 400000
CD
Q.

S
C

H
  300000






  200000-





     O
  100000
                                  Date

-------
            Lower Potomac River at Segment 220
                  Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
            Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
                             SimuUted-mg/1
Kfl
            Lower Potomac River at Segment 220
                    Actual Error versus Time
               Organic and Particulate Phosphorus


j
JLr -LJ
TTFJf* 1"" 71""*"


                            358

-------
soars*
           Lower Potomac River at Segment 220
               Organic and Particulate Phosphorus
              Frequency Distribution - PAIRED Simulated and Observed Data
            Lower Potomac River at Segment 220
          Actual error versus Percentile Sample Population
               Organic and Particulate Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                              359

-------
           Lower Potomac River at Segment 220
              Observed and Simulated versus Time
                  Dissolved Phosphorus
                       (*=Observed, -=Simulated)
                              Date
J&ttfltf

-------
            Lower Potomac River at Segment 220

    Dissolved Phosphorus Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
  10000
                              Date
 .
fodiv»>f EM

-------
            Lower Potomac River at Segment 220
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                Dissolved Phosphorus: 01JAN84 - 01JAN92
KiSSSS
           Lower Potomac River at Segment 220
                    Actual Error versus Time
                     Dissolved Phosphorus
                            362

-------
  Lower Potomac River at Segment 220
            Dissolved Phosphorus
     Frequency Distribution - PAIRED Simulated and Observed Data
  Lower Potomac River at Segment 220
Actual error versus Percentile Sample Population
            Dissolved Phosphorus
      Frequency Distribution - All Simulated and Observed Data
                    363

-------
CO
CT>
  •3,
    o 1
             Lower Potomac River at Segment 220
                Observed and Simulated versus Time
                        Total Nitrogen
                        (*=Observed, -=SimuIated)
                               Date

-------
              Lower Potomac River at Segment 220

          Total Nitrogen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    3000000
f
                    o;
    2000000
w
ON
   .§»
    1000000
                                  Date

-------
             Lower Potomac River at Segment 220
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                    Total Nitrogen: 01JAN84 - 01JAN92
                               Simulated -mgfl
 szstxssszssss?
            Lower Potomac River at Segment 220
                     Actual Error versus Time
                          Total Nitrogen
                                                    x     x
                                Oak
RflBWST"
                              366

-------
           Lower Potomac River at Segment 220
                        Total Nitrogen
             Frequency Distribution - PAIRED Simulated and Observed Data
           Lower Potomac River at Segment 220
         Actual error versus Percentile Sample Population
                         Total Nitrogen
               Frequency Distribution - All Simulated and Observed Data
casaui" " ' '
                              367

-------
U)
o>
00
             Lower Potomac River at Segment 220
                Observed and Simulated versus Time
                             NO3
                         (*=Observed, -=Simulated)
                               Date

-------
   300000
  200000 -
 i
 $
  100000
             Lower Potomac River at Segment 220

             NO3 Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
                                 Date

-------
            Lower Potomac River at Segment 220
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                      NO3: 01JAN84 - 01JAN92
                             SimuUted • m|/l
            Lower Potomac River at Segment 220
                    Actual Error versus Time
                             NO3
                                                  X     X
                              Dttt
XfSSX
                            370

-------
  Lower Potomac River at Segment 220
                    N03
     Frequency Distribution - FAIRED Simulated and Observed Data
  Lower Potomac River at Segment 220
Actual error versus Percentile Sample Population
                    N03
      Frequency Distribution - All Simulated and Observed Data
                   371

-------
u>
    1.0
    0.9
    0.8
    0.7
    0.6
   •3.
    0.5
             Lower Potomac River at Segment 220
                Observed and Simulated versus Time
                        Total Ammonia
                         (*=Observed, -=Simulated)
                                Date

-------
              Lower Potomac River at Segment 220
         Total Ammonia Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    300000-
                    O :
    200000
OJ
-o
u>
   0>
   i
    100000-
     o-l
       :O
                                  Date

-------
           Lower Potomac River at Segment 220
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                  Total Ammonia: 01JAN84 - 01JAN92
 9.7
I
                                                         .ofPoit
                f  &  «>" *>* **  >?  & f J  &  J  &
          Lower Potomac River at Segment 220
                   Actual Error versus Time
                       Total Ammonia
                                                 X     X
                           374

-------
           Lower Potomac River at Segment 220
                        Total Ammonia
             Frequency Distribution • PAIRED Simulated and Observed Data
           Lower Potomac River at Segment 220
         Actual error versus Percentile Sample Population
                        Total Ammonia
               Frequency Distribution - All Simulated and Observed Data
 1 -04-
 3

 r
  •at

  •OJ
  -OJ


  -LO
                     •f
catta
                              375

-------
u>
^J
Ox
             Lower Potomac River at Segment 220
                Observed and Simulated versus Time

                       Organic Nitrogen
                         <*=Observed, -=Simulated)
                               Date
   taMocm Seat *'r

-------
              Lower Potomac River at Segment 220

        Organic Nitrogen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    3000000
     f
    2000000
to
•vj
vj
*
I
8
c

1
    1000000
                    o;
                                  Date

-------
             Lower Potomac River at Segment 220
                  Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Organic Nitrogen: 01JAN84 - 01JAN92
                              Simvbted-nc/1
            Lower Potomac River at Segment 220
                    Actual Error versus Time
                       Organic Nitrogen
                               Drt.
ttfSSR
                            378

-------
           Lower Potomac River at Segment 220
                        Organic Nitrogen
              Frequency Distribution - PAIRED Simulated and Observed Data
j 0.1000
o
1
S 0.0100
                      10
                                  oTPopaUtion
                                       70
tasssss*
            Lower Potomac River at Segment 220
          Actual error versus Percentile Sample Population
                         Organic Nitrogen
                Frequency Distribution - All Simulated and Observed Data
                              379

-------
380

-------
                B.4.0  Rappahannock River Basin
Basin Segments:
      Above Fall Line Basin Segments: 230
      Below Fall Line Basin Segments: 560

Section Contents:
      B.4.0  Monitoring Stations in the Rappahannock River Basin (Figure B.4.0)
      BA1  Rappahannock River (Monitoring Station:  1668000)
                              381

-------
                                      Figure R4
        Monitoring Stations
                  in the
   Rappahannock River Basin
Chesapeake Bay Program

 Map Date: April 1998
             Rappahannock River Basin in
            The Chesapeake Bay Watershed
                              Calibration Stations
                               1668000
                              A/ Streams
                              C_J Model Segments
Source: USGS and USEPA Chesapeake Bay Program
  382
                                          Ktf

-------
B.4.1 Rappahannock River near Fredericksburg, VA at Segment 230 (Monitoring
Station: 1668000) (Above Fall Line Basin Segments: 230)	

Section Summary;

The Rappahannock basin is largely rural in character and is dominated by agricultural
loads. Concentrations of total nitrogen, total phosphorus, and total suspended solids are
generally low.  Water quality observations increased and were oriented toward storm
weighted sampling after 1989.  Model calibration focused primarily on the refined, storm
weighted sampling after 1989.

The Rappahannock basin above the gaged site covers an area of 2,582 square miles. At
the midpoint of the simulation, 1990, the land use for the basin was composed of 55%
forest land, 12% cropland, 26% other agricultural areas, 6% urban areas, and 1% water
(river and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 5.3 million pounds in 1985 to 5.0 million pounds in 1996. Total phosphorus loads
over the same time period decreased from 0.55 million pounds to 0.46 million pounds. In
general, point source loads above the gage site decreased. In 1996, the total nitrogen
point source load was 4% of the total load and the total phosphorus point source load was
7% of the total load. Estimated septic system total nitrogen loads increased 38%, from
0.13 million pounds in 1985 to 0.18  million pounds in 1996.

Over the 1985 to 1996 period, changes hi the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 18%, and other agricultural loads (primarily
pasture and manure loads) by 5%. Total phosphorus decreased for these land uses  by
25% and 2% respectively. Urban loads were estimated to have increased over the  1985
to 1996 period by 23% for total nitrogen and 25% for total phosphorus due to increases in
population and urban land use area.
                                 383

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date - Temperature
                                384

-------
00
Ul
             Rappahannock River at Segment 230
                Observed and Simulated versus Time
                        Temperature-C
                         (*=Observed, -=Simulated)
                               Date

-------
 sa-
           Rappahannock River at Segement 230
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                  Temperature-C: 01JAN84 - 01JAN92
                             Simulated .T«np-C
sssssx
 I1
 I-
 i.
 i
           Rappahannock River at Segement 230
                    Actual Error versus Time
                        Temperature-C

ILJ
1
Jj
                                                   X    X
                               Djle
                            386

-------
  Rappahannock River at Segement 230

               Temperature-C
     Frequency Distribution - PAIRED Simulated and Observed Data
  Rappahannock River at Segement 230

Actual error versus Percentile Sample Population

               Temperature-C

      Frequency Distribution • All Simulated and Observed Data
                   387

-------
CO
00
    17-:
             Rappahannock River at Segment 230
               Observed and Simulated versus Time
                      Dissolved Oxygen
                        (*=Observed, -^Simulated)
                               Date

-------
u>
oo
VO
               Rappahannock River at Segment 230

        Dissolved Oxygen Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
    600000
    500000
    400000
   Q.
    300000
    200000
    100000 -
                                   Date

-------
          Rappahannock River at Segement 230
                Scatter Plot and Regression of Simulated
                  versus Observed with Ideal Line
                Dissolved Oxygen: 01JAN84 - 01JAN92
                           SimuUlcd-ni/l
                                                       .OfPoi
1:

1
          Rappahannock River at Segement 230
                  Actual Error versus Time
                     Dissolved Oxygen
      11
r^l
          TI
                            Date
                         390

-------
sstx
          Rappahannock River at Segement 230
                      Dissolved Oxygen
             Frequency Distribution - PAIRED Simulated and Observed Data
                           30
           Rappahannock River at Segement 230
          Actual error versus Percentile Sample Population
                       Dissolved Oxygen
                Frequency Distribution - Ail Simulated and Observed Data
                             391

-------
CO
\o
ro
             Rappahannock River at Segment 230
               Observed and Simulated versus Time

                 Total Suspended Sediment
                        (*=Observed/ -=Simulated)
                              Date

-------
               Rappahannock River at Segment 230

     Total Suspended Sediment Observed and Simulated Load vs Time
                         . (line = simulated, O = observed)
     40000000
    30000000
VO

U>
I



I
    20000000
   .£


   1
    10000000
       o •*
                     C
                   jnnnnnnn rl
o
                                                     O
                                                          o
                                                  o
                                    Date

-------
             Rappahannock River at Segement 230
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                Total Suspended Sediment: 01JAN84 - 01JAN92
                               SimuUltd-nf/l
S£i
            Rappahannock River at Segement 230
                     Actual Error versus Time
                    Total Suspended Sediment
  wo


  500
  MO


  200
 !
 « -200
  -SOD'
                                Dirt
ssssstsr——•
                             394

-------
 van-
          Rappahannock River at Segement 230
                  Total Suspended Sediment
             Frequency Distribution - PAIRED Simulated and Observed Data
           Rappahannock River at Segement 230
         Actual error versus Fercentile Sample Population
                   Total Suspended Sediment
               Frequency Distribution • All Simulated and Observed Data
8HSKW—"
                            395

-------
Rappahannock River at Segment 230
   Observed and Simulated versus Time
         Total Phosphorus
           (*=Observed, -=Simulated)
                  Date

-------
              Rappahannock River at Segment 230

        Total Phosphorus Observed and Simulated Load vs Time
                        /•*»   •   1 •  1 >™v  <    ••v
                        (line = simulated, O = observed)
    60000-:
u>
<£>
-J
                                 Date

-------
            Rappahannock River at Segement 230
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                  Total Phosphorus: 01JAN84 - 01JAN92
                              Simulated-n(/l
           Rappahannock River at Segement 230
                    Actual Error versus Time
                        Total Phosphorus
  OJ



  02



  0.1-



  0.0



  -0.1



  •9X



  4J



  •QA-



  •OJ



  •04
t _ . T , t *. , T Ttr XT

.T.tf .IT
• i \i ' *
T-. ...
1




(Jfft^t. Jt 1
7
>
!

'^
i-

111
J- i
                                Dtte
esss
                            398

-------
  W.OO- '

SffSSC
           Rappahannock River at Segement 230
                       Total Phosphorus
              Frequency Distribution - PAIRED Simulated and Observed Data
           Rappahannock River at Segement 230
          Actual error versus Percentile Sample Population
                        Total Phosphorus
               Frequency Distribution - All Simulated and Observed Data
SOU
                             399

-------
             Rappahannock River at Segement 230

                 Organic and Particulate Phosphorus
                         (*=Observed/ -^Simulated)
    10
    9- :
    7 '•
o
o
    4 :
    3 :
    2
•*-

-------
          Rappahannock River at Segement 230

Organic and Paniculate Phosphorus Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 40000
                               Date

-------
           Rappahannock River at Segement 230
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
           Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
  10-:
I
          Rappahannock River at Segement 230
                   Actual Error versus Time
              Organic and Particulate Phosphorus
                          402

-------
  0.0001
SMWSSST
           Rappahannock River at Segement 230
               Organic and Particulate Phosphorus
              Frequency Distribution - PAIRED Simulated and Observed Data
           Rappahannock River at Segement 230
          Actual error versus Percentile Sample Population
               Organic and Particulate Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                    —r~
                     *
—r—
 *
                             403

-------
         Rappahannock River at Segement 230
                   Dissolved Phosphorus
                      (*=Observed, -=Simiflated)
0.26-

0.25-

0.24-
0.22-
                             Date

-------
4S
O
Oi
             Rappahannock River at Segement 230
      Dissolved Phosphorus Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
    i4oo-
    1300:
                                Date

-------
             Rappahannock River at Segement 230
                   Scatter Plot and Regression of Simulated
                      versus Observed with Ideal Line
                  Dissolved Phosphorus: 01JAN84 - 01JAN92
                               Simul>tnl-mi/l
            Rappahannock River at Segement 230
                     Actual Error versus Time
                       Dissolved Phosphorus
  0.14
  0.13
  0.12
  0.11
  0.10
  0.09
  O.OS
  tun-
I O.M-

° 0.04-

I »•«
f 0.01-
  •0.01-
  •ojn-
  •0.04-
  -0.05-
    1
TT
              qii
                         T    tT
                                 Date
ssts
                             406

-------
           Rappahannock River at Segement 230
                      Dissolved Phosphorus
              Frequency Distribution - PAIRED Simulated and Observed Data
 3
 2
  0.001 -
SS3X.US "
                                             90
           Rappahannock River at Segement 230
         Actual error versus Percentile Sample Population
                     Dissolved Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                            407

-------
    8-:
o
00
             Rappahannock River at Segement 230

                          Total Nitrogen
                         (*=Observed, -=Simiflated)
                               Date

-------
           Rappahannock River at Segement 230

       Total Nitrogen Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 300000 -:
 200000
t
i
2
s
 100000-
                               Date

-------
Rappahannock River at Segement 230
      Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
       Total Nitrogen: 01JAN84 - 01JAN92
                  Simulated
Rappahannock River at Segement 230
         Actual Error versus Time
              Total Nitrogen
      u
                    Data
                  410

-------
 Rappahannock River at Segement 230
               Total Nitrogen
    Frequency Distribution - PAIRED Simulated and Observed Data
  Rappahannock River at Segement 230
Actual error versus Percentile Sample Population
               Total Nitrogen
      Frequency Distribution • All Simulated and Observed Data
                   411

-------
K3
   0 1
              Rappahannock River at Segment 230
                Observed and Simulated versus Time
                             NO3
                         (*=Observed, -=Simulated)

                               Date

-------
  17000
  16000
  15000
             Rappahannock River at Segment 230
             NO3 Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
                                Date
Ml J*t\
Irwk jf
  *• twoaw ii »

-------
            Rappahannock River at Segement 230
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                        NO3:01JAN84 - 01JAN92
 E

 I"

  04-
                                                           innofPoio
                               SimulaM-oig/l
            Rappahannock River at Segement 230
                     Actual Error versus Time
                              NO3
  1.1


  1JI

  O.f

  OJ

  OJ


  04


  OJ


 • M-

  OJ-
 i
 ! 02-

  0.1

  0.0-


  -«.i-

  •42-


  -OJ-
n-rp
SCUS35T
                            414

-------
BSS—JS?"*"
            Rappahannock River at Segement 230
                              N03
               Frequency Distribution - PAIRED Simulated and Observed Data
                              Patent
            Rappahannock River at Segement 230
          Actual error versus Percentile Sample Population
                              NO3
                Frequency Distribution - All Simulated and Observed Data
SSSSB..J " ' '
                             415

-------
Rappahannock River at Segment 230
   Observed and Simulated versus Time
           Total Ammonia
           (*=Observed, -=Simulated)

-------
            Rappahannock River at Segment 230

       Total Ammonia Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
  8000
  7000
  6000
  5000
  4000
 3
                                Date
MI »MI i«4 «iimi'«»
toWh.a^nr 91MM9J tr

-------
            Rappahannock River at Segement 230
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                   Total Ammonia: 01JAN84 - 01JAN92
           Rappahannock River at Segement 230
                    Actual Error versus Time
                        Total Ammonia
 0.1S

 0.1C

 0.14

 0.15

 0.10
0.05

0.00

4.02
-0.10

-0.12

•0.14

-O.

-O.H

•WO-

-O22-
       TrT, t ,rr,TT
           r
n
l
                                     il
                               Dn>
                           418

-------
1.0000
          Rappahannock River at Segement 230
                       Total Ammonia
             Frequency Distribution • PAIRED Simulated and Observed Data
0.11
          Rappahannock River at Segement 230
        Actual error versus Percentile Sample Population
                       Total Ammonia
              Frequency Distribution - All Simulated and Observed Data
                           419

-------
Rappahannock River at Segment 230
   Observed and Simulated versus Time
         Organic Nitrogen
           (*=Observed, -^Simulated)
                  Date

-------
              Rappahannock River at Segment 230

         Organic Nitrogen Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
    300000
    200000
IS)
   2
   s
    100000
                                   Date
   ._• *v 17AUOI7 1I3I«M n»M*l r-4

-------
           Rappahannock River at Segement 230
                 Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                  Organic Nitrogen: 01JAN84 - 01JAN92	
 !
 i
                                                         ,<***>
gaaasssaasa
  1-
 -21
           Rappahannock River at Segement 230
                    Actual Error versus Time
                       Organic Nitrogen
                T
                  J.
V
fa
Ji
f H
                             X     X     X     X
                              Dak
                           422

-------
            Rappahannock River at Segement 230
                         Organic Nitrogen
               Frequency Distribution - PAIRED Simulated and Observed Data
                              Percent
STSi
            Rappahannock River at Segement 230
          Actual error versus Percentile Sample Population
                        Organic Nitrogen
                Frequency Distribution - All Simulated and Observed Data
grass?
                             423

-------
424

-------
                      B.5.0  York River Basin
Basin Segments:
      Above Fall Line Basin Segments: 235, 240,250, and 260
      Below Fall Line Basin Segments: 590

Section Contents:
      B.5.0  Monitoring Stations in the York River Basin (Figure B.5.0)
      B.5.1  Mattaponi River (Monitoring Station:  1674500)
      B.5.2  Pamunkey River (Monitoring Station:  1673000)
                              425

-------
                                         Figure B.5
   Monitoring Stations
               in  the
      York River Basin
                York River Basin in
             The Chesapeake Bay Watershed
Chetapeake Bay Program
Map Date: April 1998
                                 Calibration Stations
                                 9 1673000
                                 H 1674500
                                 /V Streams
                                 f~l Model Segments
                                           N
Source: USGS and USEPA Chesapeake Bay Program
KJH

-------
B.5.1  Mattaponi River near Beulahville, VA at Segment 240 (Monitoring Station:
1674500) (Above Fall Line Basin Segments: 235 and 240)	

Section Summary;

The Mattaponi basin together with the Pamunkey form the above fall line portion of the
York River.  The Mattaponi is similar to the Rappahannock in its rural character
dominated by agricultural loads. Concentrations of total nitrogen, total phosphorus, and
total suspended sediment are generally low at the Mattaponi gage station. Water quality
observations increased and were oriented toward storm weighted sampling after 1989.
Model calibration focused primarily on the refined, storm-weighted sampling after 1989.

The Mattaponi basin above the gaged site covers an area of 594 square miles. At the
midpoint of the simulation, 1990, the land use for the basin was composed of 72% forest
land, 11% cropland, 8% other agricultural areas, 7% urban areas, and  1% water (river and
lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage increased from
0.64 million pounds in 1985 to 0.67 million pounds in 1996. Total phosphorus loads over
the same time period decreased from 58 thousand pounds to 49 thousand pounds. In
general, point source loads above the gage site decreased. Estimated septic system total
nitrogen loads increased 39%, from 41 thousand pounds in 1985 to 58 thousand pounds
in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 2%, and other agricultural loads (primarily
pasture and manure loads) by 28%. Total phosphorus decreased for these land uses by
22% and 54% respectively. Urban loads  were estimated to have increased over the 1985
to 1996 period by 32% for total nitrogen and 29% for total phosphorus due to increases in
population and urban land use area
                                427

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
 Parameters

 Temperature
 Dissolved Oxygen
 Total Suspended Sediment
 Total Phosphorus
 Organic and Particulate Phosphorus
 Phosphate
 Total Nitrogen
 Nitrate
 Total Ammonia
 Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date — Temperature
                               428

-------
to
VO
    -10 i
                Mattaponi River at Segment 240
                Observed and Simulated versus Time
                         Temperature-C
                         (*=Observed, -=Simulated)
                                Date

-------
 Mattaponi River at Segment 240
    Scatter Plot and Regression ofSimulated
       versus Observed with Ideal Line
      Temperature-C: 01JAN84 - 01JAN92
                                               .ofPoiil
                  •f

               SunuUled.
Mattaponi River at Segment 240
      Actual Error versus Time
           Temperature-C
9
•
7
«
5
4
I '
0 I'
1 '•
a •*'
-i-
•3
•4'
•i-
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                 Date
             430

-------
0.10:
            Mattaponi River at Segment 240
                      Temperature-C
            Frequency Distribution - PAIRED Simulated and Observed Data
            Mattaponi River at Segment 240
       Actual error versus Percentile Sample Population
                      Temperature-C
             Frequency Distribution - All Simulated and Observed Data
                           431

-------
    18-
    17
OJ
N9
                Mattaponi River at Segment 240
                 Observed and Simulated versus Time
                       Dissolved Oxygen
                          (*=Observed, -=Simulated)
    ZMOOf? I/

-------
            Mattaponi River at Segment 240

    Dissolved Oxygen Observed and Simulated Load vs Time
                J °   (line = simulated, O = observed)
100000
90000
                               Date

-------
              Mattaponi River at Segment 240
                 Scatter Plot and Regression orSimulated
                    versus Observed with Ideal Line
                  Dissolved Oxygen: 01JAN84 - 01JAN92
O |.
1
I
              Mattaponi River at Segment 240
                    Actual Error versus Time
                       Dissolved Oxygen
TTTT
                             x     x
                         X     X
                              Data
                           434

-------
               Mattaponi River at Segment 240
                        Dissolved Oxygen
               Frequency Distribution - PAIRED Simulated and Observed Data
w
1
                           30
              Mattaponi River at Segment 240
         Actual error versus Percentile Sample Population
                       Dissolved Oxygen
               Frequency Distribution - All Simulated and Observed Data
                            435

-------
OJ
ON
                Mattaponi River at Segment 240
                Observed and Simulated versus Time
                  Total Suspended Sediment
                        (*=Observed, -=Simulated)
                               Date

-------
u>
                   Mattaponi River at Segment 240

     Total Suspended Sediment Observed and Simulated Load vs Time
                             (line = simulated, O = observed)
     800000
     700000
     600000
 500000



t


I

2 400000
     300000
    200000
    looooo-

                                                          O
  (fit jun u> dMMot.94nM pi (MM

  llftHt.t *v >MUO«> 1J >»««*
                                       Date

-------
               Mattaponi River at Segment 240
                  Scatter Plot and Regression ofSimulated
                     versus Observed with Ideal Line
               Total Suspended Sediment: 01JAN84 - 01JAN92
                               SimUt.d-mgfl
ssrs
  100
 •100-
              Mattaponi River at Segment 240
                     Actual Error versus Time
                    Total Suspended Sediment
                                          * J'**r»4
                              X     X
                                Date
                            438

-------
              Mattaponi River at Segment 240
                   Total Suspended Sediment
              Frequency Distribution - PAIRED Simulated and Observed Data
              Mattaponi River at Segment 240
         Actual error versus Percentile Sample Population
                   Total Suspended Sediment
               Frequency Distribution - All Simulated and Observed Data
  300
  KK
I
i

1
 -100
                     •?
                                       #
                             439

-------
Mattaponi River at Segment 240
Observed and Simulated versus Time
       Total Phosphorus
         (*=Observed, -=Simulated)
                 Date


-------
             Mattaponi River at Segment 240

     Total Phosphorus Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 looo-'
 900
                               Date
 .
**» tuuon 17

-------
                  Mattaponi River at Segment 240
                     Scatter Plot and Regression ofSimulated
                        versus Observed with Ideal Line
                      Total Phosphorus: 01JAN84 - 01JAN92
   021
   020
   O.U
   O.U
   0.17
   0.16
   0.15
   0.14
   0.13
   0.12
   0.11
   0.10
   o.w
   0.08
   5.07
 7  O.OC
 £  0.05
 *  0.04
 O  OJO
• 7  QJtt
 •J  OJM
 £  OJ»
  •0.08
  -0.09
  •0.10
  -0.11
  -0.12
  -O.U
  -0.lt
  -0.1S
  -a.i<
  -0.17
  •0.16
  X>.»-
  •4UO
  -OJ1
                 Mattaponi River at Segment 240
                        Actual Error versus Time
                            Total Phosphorus
1.  -J
T.
I  ,  .   I  1
                                        T T,
                                     Date
                                 442

-------
 1.000
oooi-i
              Mattaponi River at Segment 240
                        Total Phosphorus
              Frequency Distribution - PAIRED Simulated an
Simulated and Observed Data
                              ftacmtarKopdilmi
             Mattaponi River at Segment 240
        Actual error versus Percentile Sample Population
                       Total Phosphorus
              Frequency Distribution - All Simulated and Observed Data
                            443

-------
  Mattaponi River at Segment 240
  Observed and Simulated versus Time
Organic and Particulate Phosphorus
           (*=Observed, -=Simulated)
                  Date

-------
Ui
                 Mattaponi River at Segment 240
   Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
    9oo-:
    800
                                  Date
   *y HAUMT 17

-------
                Mattaponi River at Segment 240
                   Scatter Plot and Regression oFSimulated
                      versus Observed with Ideal Line
             Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
                                 SunuUttd -
  0.11

  041
  041
  047
  04t
  O.OS
  044
  041
  041
               Mattaponi River at Segment 240
                      Actual Error versus Time
                 Organic and Particulate Phosphorus
      v
| -044
| -0.01
; 441
 -0.07
 441
 441 •
 4.10-

 4.1J-
 4.U-
 4.14-
 4.15-
T   T
                                                X     X     X
                                  Oak
                             446

-------
              Mattaponi River at Segment 240
               Organic and Particulate Phosphorus
              Frequency Distribution - PAIRED Simulated and Observed Data
0.11
             Mattaponi River at Segment 240
        Actual error versus Percentile Sample Population
              Organic and Particulate Phosphorus
              Frequency Distribution - All Simulated and Observed Data
                           447

-------
00
    0.18
    0.17
                 Mattaponi River at Segment 240
                 Observed and Simulated versus Time
                      Dissolved Phosphorus
                          (*=Observed, -=Simulated)
  (tr>l.«lglllM4
-------
          Mattaponi River at Segment 240

Dissolved Phosphorus Observed and Simulated Load vs Time
                   (line as simulated, O = observed)
                          Date

-------
              Mattaponi River at Segment 240
                 Scatter Plot and Regression ofSimulated
                    versus Observed with Ideal Line
                 Dissolved Phosphorus: 01JAN84 - 01JAN92
  «+   **  **  +*  «*  **  »*  +*  »•
             J  J  J
          f  s
J  f
 o.u
 0.10
 Mt
 O.OJ
 043
 0.01
 040
•041
441
••.If
•o.u-
•o.u-
•o.u-
-o.u-
              Mattaponi River at Segment 240
                    Actual Error versus Time
                     Dissolved Phosphorus

TJ'  T"
"FIT
               x

           xx
                     X     X
                           450

-------
     Mattaponi River at Segment 240
            Dissolved Phosphorus
     Frequency Distribution - PAIRED Simulated and Ol
dated and Observed Data
     Mattaponi River at Segment 240
Actual error versus Percentile Sample Population
            Dissolved Phosphorus
      Frequency Distribution - All Simulated and Observed Date
                   451

-------
•P-
Wl
10
   •5,,:
                Mattaponi River at Segment 240
                 Observed and Simulated versus Time
                         Total Nitrogen
                          (*=Observed/ -=Simulated)
                                 Date

-------
                Mattaponi River at Segment 240

          Total Nitrogen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    5000
in
                                 Date

-------
                Mattaponi River at Segment 240
                   Scatter Plot and Regression oFSimulated
                     versus Observed with Ideal Line
                    Total Nitrogen: 01JAN84 - 01JAN92
                                                            itqnof P«o
                               Simukted - mg/1
               Mattaponi River at Segment 240
                     Actual Error versus Time
                          Total Nitrogen
       rrn
                i ii i—ii' '*
ssrsser"-1
HT
                                  A
                                Due
                             454

-------
1

I
^
               Mattaponi River at Segment 240
                          Total Nitrogen
               Frequency Distribution - PAIRED Simulated and Observed Data
30 P«»nt.ffLp»U«i.n n
                                               90
              Mattaponi River at Segment 240
         Actual error versus Percentile Sample Population
                         Total Nitrogen
               Frequency Distribution - All Simulated and Observed Data
                             455

-------
    3-:
Ui
   I
                Mattaponi River at Segment 240
                Observed and Simulated versus Time
                              NO3
                         (*=Observed, -=Simulated)
                                Date

-------
 3000
              Mattaponi River at Segment 240

           NO3 Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
                               Date
> *v ttFEBtt OM7«rae ngmxM y.i|

-------
             Mattaponi River at Segment 240
                Scatter Plot and Regression oFSimulated
                  versus Observed with Ideal Line
                     NO3:01JAN84 - 01JAN92
M
0.0 t
                                                         ofPoio
            Mattaponi River at Segment 240
                  Actual Error versus Time
                           NO3


T JT k 1 !

1
t. T.
M
I
. T T
I
J ' 11

If,

' ' }W* I
1 1
\
1
W|f " T
                                                 s     /
                            Dak
                         458

-------
      Mattaponi River at Segment 240
                      N03
      Frequency Distribution - PAIRED Simulated and Observed Data
                         ofFopnUtion
     Mattaponi River at Segment 240
Actual error versus Percentile Sample Population
                     N03
      Frequency Distribution - All Simulated and Observed Data
                    459

-------
             Mattaponi River at Segment 240
             Observed and Simulated versus Time
                      Total Ammonia
                       (*=Observed, -=Simulated)
0.9 -:
0.8
0.7-
0.6-
0.5-
0.4-
0.3
0.2
0.1
0.0 1
                               Date

-------
            Mattaponi River at Segment 240

     Total Ammonia Observed and Simulated Load vs Time
                     (line = simulated, O = observed)
600-:
                             Date

-------
             Mattaponi River at Segment 240
                Scatter Plot and Regression oFSimulated
                   versus Observed with Ideal Line
                  Total Ammonia: 01JAN84 - 01JAN92
             Mattaponi River at Segment 240
                  Actual Error versus Time
                       Total Ammonia
00
     i f
                   *« t	.
                                          X    X
                             Data
                          462

-------
                 Mattaponi River at Segment 240
                            Total Ammonia
                 Frequency Distribution - PAIRED Simulated and Observed Data
                Mattaponi River at Segment 240
           Actual error versus Percentile Sample Population
                           Total Ammonia
                 Frequency Distribution - All Simulated and Observed Data
nssr*u!Lu*"n
                              463

-------
               Mattaponi River at Segment 240
               Observed and Simulated versus Time
                      Organic Nitrogen
                        (*=Observed, -=Simulated)
                                Date
fmutu^r OfUtt tun

-------
                 Mattaponi River at Segment 240

         Organic Nitrogen Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
    4000
in
                                   Date
  Ml _jto»*M
  jm«M40.*>

-------
               Mattaponi River at Segment 240
                 Scatter Plot and Regression oFSimulated
                    versus Observed with Ideal Line
                  Organic Nitrogen: 01JAN84 - 01JAN92
I

1

I
                                                             ofPoiM
                                ' I ' ' ' ' I
                                A
                             SimuliMd - mg/l
              Mattaponi River at Segment 240
                    Actual Error versus Time
                       Organic Nitrogen
                     T  , T . , ,T
                               Dlte
                            466

-------
                 Mattaponi River at Segment 240
                           Organic Nitrogen
                 Frequency Distribution - FAIRED Simulated and Observed Data
                               30    SO    70
                                 PeitntofPopuUtioit
90
  -I-
                Mattaponi River at Segment 240
           Actual error versus Percentile Sample Population
                          Organic Nitrogen
                 Frequency Distribution • All Simulated and Observed Data
sssrasssr
                               467

-------
468

-------
£.5.2  Pamunkey River near Hanover, VA at Segment 260 (Monitoring Station:
1673000) (Above Fall Line Basin Segments: 250 and 260)	

Section Summary:

The Pamunkey basin together with the Mattaponi form the above fall line portion of the
York River. The Pamunkey basin is largely rural. The Lake Anna Reservoir influences
water quality in this basin contributing to the low concentrations of total nitrogen, total
phosphorus, and total suspended sediment at the Pamunkey gage station.  Water quality
observations increased and were oriented toward storm weighted sampling after 1989.
Model calibration focused primarily on the refined, storm-weighted sampling after 1989.

The Pamunkey basin above the gaged site covers an area of 1,070 square miles. At the
midpoint of the simulation, 1990, the land use for the basin was composed of 67% forest
land, 8% cropland, 17% other agricultural areas, 6% urban areas,  and 3% water (river and
lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage increased from
1.7 million pounds in 1985 to 1.9 million pounds in 1996.  Total phosphorus loads over
the same time period did not change at 0.15 million pounds.  In general, point source
loads above the gage site decreased. In 1996, the total nitrogen point source load was 9%
of the total load and the total phosphorus point source load was 11 % of the total load.
Estimated septic system total nitrogen loads increased 36%, from 61 thousand pounds in
1985 to 83 thousand pounds in  1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation resulted in no
change in the estimated cropland total nitrogen loads, and decreased other agricultural
loads (primarily pasture and manure loads) by 6%. Total phosphorus decreased for
cropland by 10% and increased for other agriculture by 2%. Urban loads were estimated
to have increased over the 1985 to 1996 period by 36% for total nitrogen and 44% for
total phosphorus due to increases in population and urban land use area
                                469

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date — Temperature
                                470

-------
Pamunkey River at Segment 260
Observed and Simulated versus Time
        Temperature-C
         (*=Observed, -=Simulated)
                Date

-------
               Pamunkey River at Segment 260
                  Scatter Plot and Regression ofSimulated
                    versus Observed with Ideal Line
                   Temperature-C: 01JAN84 - 01JAN92
 I
 I
                                                            otPoir:
                             Simulated-Tcmp-C
                                                             —r
                                                             •f
sax
        n
              Pamunkey River at Segment 260
                    Actual Error versus Time
                        Temperature-C
     U  I  I   I
                               Date
                           472

-------
 1
 3
saxssxsr
               Pamunkey River at Segment 260
                          Temperature-C
               Frequency Distribution - PAIRED Simulated and Observed Data
                            30
                                              80
              Pamunkey River at Segment 260
          Actual error versus Percentile Sample Population
                         Temperature-C
               Frequency Distribution - All Simulated and Observed Data
                            473

-------
17
16
            Pamunkey River at Segment 260
            Observed and Simulated versus Time
                  Dissolved Oxygen
                    (*=Observed, -=Simulated)
                           Date

-------
                 Pamunkey River at Segment 260

         Dissolved Oxygen Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
    300000
    200000-
ui  ex

   $
   TJ
   a
   o
    100000
                                    Date
 (y21 ploiV
 (9«»ph_» *v 27AU097 1

-------
Pamunkey River at Segment 260
   Scatter Plot and Regression otSimulated
      versus Observed with Ideal Line
    Dissolved Oxygen: 01JAN84 - 01JAN92
m. ««JL*.B. «A A. K.A'm^v W A-*.* • ^A. •«*> kaT ^ fc
Actual Error versus 1
KA.&&^«.
rime
&«•
«H»^^^^



Dissolved Oxygen
s
4
3-
I"
! ^
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r









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                 Date
             476

-------
  100
3>
              Pamunkey River at Segment 260
                        Dissolved Oxygen
              Frequency Distribution - PAIRED Simulated and Observed Data
                                             90
              Pamunkey River at Segment 260
         Actual error versus Percentile Sample Population
                       Dissolved Oxygen
               Frequency Distribution - All Simulated and Observed Data
                            Fount of PopiiUtioii
                           477

-------
    1300-;
    1200
    1100
    1000
00
                Pamunkey River at Segment 260
                Observed and Simulated versus Time
                  Total Suspended Sediment
                         (*=Observed, -=Simulated)
                                Date

-------
                     Pamunkey River at Segment 260

     Total Suspended Sediment Observed and Simulated Load vs Time
                                (line = simulated, O = observed)
     17000000
     16000000
     15000000
     14000000
     13000000
     12000000
     11000000
    t
^J   Si
«>   s.
10000000
      9000000
    5  8000000
      7000000
     6000000
     5000000
     4000000
     3000000-
     2000000 -
     1000000
                                           Date
  (9f*ph_»*v2;AUG*7 I

-------
              Pamunkey River at Segment 260
                 Scatter Plot and Regression ofSimulated
                    versus Observed with Ideal Line
               Total Suspended Sediment: 01JAN84 - 01JAN92
                              SimuUted.ms/1
aagasessa.-
             Pamunkey River at Segment 260
                    Actual Error versus Time
                   Total Suspended Sediment
 «00


 100
100


 *
-300


-400


-500
JU.
                               Ditc
                            480

-------
               Pamunkey River at Segment 260

                    Total Suspended Sediment
               Frequency Distribution - FAIRED Simulated and Observed Data
 1000
 0




-100-




-MO




•300-
                           *     *      #

                              PtTcnlofPepuUtlan
CSSSSi





•a MO'
snsr
Pamunkey River at Segment 260
Actual error versus Percentile Sample Population
Total Suspended Sediment
Frequency Distribution - All Simulated and Observed Data

: 	 ; 	 ; 	 i 	 :.: 	 ; 	 : 	 i 	 } 	 ; 	 1
i 	 i 	 i 	 i 	 j 	 j 	 I 	 l 	 i 	 i 	 ~'T\
\ 	 i i i i ; 	 : 	 ; 	 } 	 T^T";
: 	 ; 	 : 	 i 	 i 	 i::::i:::r::j^^::n







                             481

-------
    0.6 - :
00
N>
    o.o
                Pamunkey River at Segment 260
                Observed and Simulated versus Time
                       Total Phosphorus
                         (*=Observed, -=Simulated)
                                Date

-------
-P-
oo
u>
                Pamunkey River at Segment 260

        Total Phosphorus Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    9000
    8000
                                 Date

-------
 Pamunkey River at Segment 260
   Scatter Plot and Regression otSimulated
      versus Observed with Ideal Line
    Total Phosphorus: 01JAN84 - 01JAN92
                Simulated-mgn
Pamunkey River at Segment 260
      Actual Error versus Time
         Total Phosphorus
0.2*
1 0.24
0.22
OJO
0.18
O.U
0.14
0.12
0.10-
O.M-
OJK-
0.04-
0.02-
4.02-
-0.04-
_A A£ "
"OJI»
-o.o«-
-0.10-
•0.12-
-0.14-
-o.u-
•0.20 -
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                 Dale
             484

-------
     Pamunkey River at Segment 260
              Total Phosphorus
     Frequency Distribution - PAIRED Simulated an
nutated and Observed Data
     Pamunkey River at Segment 260
Actual error versus Percentile Sample Population
              Total Phosphorus
      Frequency Distribution - All Simulated and Observed Data
                   485

-------
00
ON
    0.0
               Pamunkey River at Segment 260
                Observed and Simulated versus Time
              Organic and Participate Phosphorus
                         (*=Observed, -=Simulated)
                               Date

-------
                  Pamunkey River at Segment 260

   Organic and Particulate Phosphorus Observedand Simulated Load vs Time
                           (line = simulated, O = observed)
     8000
     7000
    6000
    5000
oo
•3

I
   2 4000
   1
    3000
    2000
    1000-
       D
    
-------
   Pamunkey River at Segment 260
      Scatter Plot and Regression ofSimulated
        versus Observed with Ideal Line
Organic and Paniculate Phosphorus: 01JAN84 - 01JAN92
 Pamunkey River at Segment 260
       Actual Error versus Time
  Organic and Particulate Phosphorus
0.1
0.14
0.13
0.12
0.11
0.10
0.0!
O.M
osn
0.0*
O.OS
0.04
0.03
0.01
0.01
-0.01
-0.02 •
•90S-
^1.04 "
-OJB-
-O.M-
•907-
-0.08-
-009-
-o.io-
-0.11-
-0.1I-
•0.13-
•0.14-
-0.15-
-O.W
•O.U-
-«.l»-
•0.20-
•9M-
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              488

-------
              Pamunkey River at Segment 260
               Organic and Participate Phosphorus
              Frequency Distribution - PAIRED Simulated and Observed Dab
 1.000
0.100
0.010
0001
             Pamunkey River at Segment 260
        Actual error versus Percentile Sample Population
              Organic and Participate Phosphorus
              Frequency Distribution - All Simulated and Observed Data
                          489

-------
VD
O
               Pamunkey River at Segment 260
               Observed and Simulated versus Time
                    Dissolved Phosphorus
                        (*=Observed, -=Simulated)
                               Date

-------
                Pamunkey River at Segment 260

      Dissolved Phosphorus Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    1000
VO
                                  Date
    dn QVtVM 14 44ftae t

-------
                Pamunkey River at Segment 260
                  Scatter Plot and Regression orSimulated
                     versus Observed with Ideal Line
                  Dissolved Phosphorus: 01JAN84 - 01JAN92
                               Simukml. mg/1
sassssxaszA~
               Pamunkey River at Segment 260
                     Actual Error versus Time
                      Dissolved Phosphorus
  o.io

  em
  OJS

  0.04
1 IU2

Jr1
1 4.04-

 -O.OJ-
 4.09-

 •o.io-
     'l
                           '  I
I1
                                        .  T
r
                                Data
                             492

-------
5
£
              Pamunkey River at Segment 260
                      Dissolved Phosphorus
              Frequency Distribution - FAIRED Simulated and Observed Data
                                ofPopulition
              Pamunkey River at Segment 260
         Actual error versus Percentile Sample Population
                     Dissolved Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                             Front of ropuUli«.
                            493

-------
Pamunkey River at Segment 260
Observed and Simulated versus Time
        Total Nitrogen
         (*=Observed, -^Simulated)
                Date

-------
    40000
VO
Ol
                Pamunkey River at Segment 260

         Total Nitrogen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
                                 Date

-------
            Pamunkey River at Segment 260
              Scatter Plot and Regression ofSimulated
                 versus Observed with Ideal Line
                Total Nitrogen: 01JAN84 - 01JAN92
                         SimuUUd-ms/1
           Pamunkey River at Segment 260
                Actual Error versus Time
                     Total Nitrogen
I I. IT. t  T. Irl

jVi'i   y'li "-]ij 'i    "ill"
                          Date
                       496

-------
     Pamunkey River at Segment 260
                Total Nitrogen
     Frequency Distribution - FAIRED Simulated and Observed Data
     Pamunkey River at Segment 260
Actual error versus Percentile Sample Population
                Total Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                    PmmtofPtpiiUlimi
                    497

-------
Pamunkey River at Segment 260
Observed and Simulated versus Time
              NO3
         (*=Observed/ -=Simulated)
                Date

-------
    sooo-:
vo
VO
                Pamunkey River at Segment 260
             NO3 Observed and Simulated Load vs Time
                        (line = simulated, O = observed)
                                Date

-------
             Pamunkey River at Segment 260
                Scatter Plot and Regression ofSimulated
                   versus Observed with Ideal Line
                     NO3:01JAN84 - 01JAN92
                            SlmuUlcd.a«/I
 10


 o.«


 04


 0.7


 M


 OJ


 
-------
5
I
1
  O.DOJ i
               Pamunkey River at Segment 260
                              N03
               Frequency Distribution - FAIRED Simulated and Observed Data
                              Fetccnl ofPopulition
              Pamunkey River at Segment 260
         Actual error versus Percentile Sample Population
                              NO3
               Frequency Distribution - All Simulated and Observed Data
                             501

-------
    0.7 -:
    0.6
    0.5
Ui
O
    0.4 -
   1
    0.3-
    0.2-
    0.1-
    0.0 i
                 Pamunkey River at Segment 260
                 Observed and Simulated versus Time
                          Total Ammonia
                           (*=Observed, -^Simulated)
-    •'^ ^ ..i,  *.   *>
                                  Date

-------
900-:
800
            Pamunkey River at Segment 260
     Total Ammonia Observed and Simulated Load vs Time
                    (line = simulated/ O = observed)
                             Date

-------
              Pamunkey River at Segment 260
                 Scatter Plot and Regression oraimulated
                   versus Observed with Ideal Line
                  Total Ammonia: 01JAN84 - 01JAN92
 Mi
 0.17
 0.1*
 0.15
 0.14
 M
 0.12
 0.11
 0.10
 tM
 Ml
 M7
**'
•tM-
•M7-
-0.10
*n
             Pamunkey River at Segment 260
                   Actual Error versus Time
                       Total Ammonia


llljfl I

11




JIT' ' I'JM '
11
i
t



ill

'
IT
it »i
1*
 /     /
                           504

-------
     Pamunkey River at Segment 260
                Total Ammonia
     Frequency Distribution - FAIRED Simulated and Observed Data
                        ofKopiilaticii
     Pamunkey River at Segment 260
Actual error versus Percentile Sample Population
               Total Ammonia
      Frequency Distribution - All Simulated and Observed Data
                    505

-------
Pamunkey River at Segment 260
Observed and Simulated versus Time
       Organic Nitrogen
         (*=Observed, -=Simulated)
 r
                          f
                              i	• ' •

                Date

-------
            Pamunkey River at Segment 260

    Organic Nitrogen Observed and Simulated Load vs Time
                    (line = simulated, O = observed)
40000
                             Date

-------
 Pamunkey River at Segment 260
    Scatter Plot and Regression ofSimulated
       versus Observed with Ideal Line
     Organic Nitrogen: 01JAN84 - 01JAN92
                                             .olPoifl
               Sunuhtcd-mg/l
Pamunkey River at Segment 260
      Actual Error versus Time
         Organic Nitrogen
                   IL
r-r
             508

-------
SXSSXZ"
             Pamunkey River at Segment 260
                       Organic Nitrogen
             Frequency Distribution - PAIRED Simulated and Observed Data
             Famunkey River at Segment 260
        Actual error versus Percentile Sample Population
                       Organic Nitrogen
              Frequency Distribution - All Simulated and Observed Data
                            509

-------
510

-------
                      B.6.0  James River Basin
Basin Segments:
      Above Fall Line Basin Segments: 265, 270,280, 290,300, and 310
      Below Fall Line Basin Segments: 600, 610,620, and 630

Section Contents:
      B.6.0  Monitoring Stations in the James River Basin (Figure B.6.0)
      B.6.1  James River (Monitoring Station:  2035000)
      B.6.2  Appomattox River (Monitoring Station: 2041650)
                             511

-------
     Monitoring Stations
               in the
      James River Basin
  Calibration Stations
   • 2035000
   H 2041650
     Streams
     Model Segments
Chesapeake Bay PW""

Map Date: April1998
             janes River Basin in
           The Chesapeake Bay Watershed
                                         N
Source: USGSand USEPA Chesapeake Bay Program
        512

-------
B.6.1  James River at Cartersvitte, VA at Segment 280 (Monitoring Station: 2035000)
(Above Fall Line Basin Segments: 265,270,280, and 290)	

Section Summary:

The James basin water quality gage is at Cartersville, VA, about 40 miles above the fall
line at Richmond, VA. Above the gage at Cartersville, the James basin is largely rural
and forested. Water quality observations increased and were oriented toward storm
weighted sampling after 1989. Model calibration focused primarily on the refined, storm
weighted sampling after 1989.

The James basin above the gaged site covers an area of 6,810 square miles. At the
midpoint of the simulation, 1990, the land use for the basin was composed of 75% forest
land, 2% cropland, 16% other agricultural areas, 6% urban areas, and 1% water (river and
lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 8.2 million pounds in 1985 to 7.9 million pounds in 1996. Total phosphorus loads
over the same time period decreased from 2.4 million pounds to 2.3 million pounds. In
general, point source loads above the gage site decreased.  In  1996, the total nitrogen
point source load was 14% of the total load and the total phosphorus point source  load
was 20% of the total load. Estimated septic system total nitrogen loads increased  13%,
from 0.41 million pounds in 1985 to 0.46 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 13%, and other agricultural loads (primarily
pasture and manure loads) by  12%. Total phosphorus decreased for these land uses by
10% and 7% respectively. Urban loads were estimated to have increased over the 1985
to 1996 period by 14% for total nitrogen and 11% for total phosphorus due to increases in
population and urban land use area.
                                513

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
 Parameters

 Temperature
 Dissolved Oxygen
 Total Suspended Sediment
 Total Phosphorus
 Organic and Paniculate Phosphorus
 Phosphate
 Total Nitrogen

 Nitrate
 Total Ammonia
 Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date — Temperature
                                514

-------
Ol
H-•
cn
                  James River at Segment 280
                Observed and Simulated versus Time
                        Temperature-C
                         (*=Observed, -=Simulated)
                                Dale
   .• *v tlMXMr )

-------
 James River at Segment 280
 Scatter Plot and Regression of Simulated
    versus Observed with Ideal Line
   Temperature-C: 01JAN84 - 01JAN92
                                           olPoi
James River at Segment 280
    Actual Error versus Time
        Temperature-C
rJ.J IllT.T
1
1
1 1
•


i,,f,
11
>
_


•
•


i
i

I
n1
1

T
' 1

P
i|i 1 1

              DM*
          516

-------
                  James River at Segment 280
                           Temperature-C
                Frequency Distribution - PAIRED Simulated and Observed Data
SfSSS
                  James River at Segment 280
          Actual error versus Percentile Sample Population
                          Temperature-C
                Frequency Distribution - All Simulated and Observed Data
SfSSSS,
                              517

-------
oo
    16
    15
                  James River at Segment 280
                Observed and Simulated versus Time
                      Dissolved Oxygen
                         (*=Observcd/ -^Simulated)
                                Date

-------
                    James River at Segment 280

         Dissolved Oxygen Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
     3000000
    2000000
Cn
>—>
\o
I"
I
s
.5

I
    1000000
                                    Date
      • |*» ft v~~ >M MM

-------
                 James River at Segment 280
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                  Dissolved Oxygen: 01JAN84 - 01JAN92
                                                           .
-------
        James River at Segment 280
              Dissolved Oxygen
     Frequency Distribution - PAIRED Simulated and Observed Data
                    POCTHI offof.il Miai TO
       James River at Segment 280
Actual error versus Percentile Sample Population
              Dissolved Oxygen
      Frequency Distribution - All Simulated and Observed Data
                   521

-------
Oi
Isi
to
    1800


    1700
                  James River at Segment 280
                Observed and Simulated versus Time
                  Total Suspended Sediment
                         (*=Observed, -=Simulated)
                                Date

-------
                     James River at Segment 280

     Total Suspended Sediment Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
     4.00E+08
     3.00E+08
U>
   I
   S 2.00E+08

   .5
    l.OOE+08
    O.OOE+00
                      O
                            n
                                                          /     y
                                     Date
    .••vn/tUOtl It

-------
                James River at Segment 280
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
              Total Suspended Sediment 01JAN84 - 01JAN92
               James River at Segment 280
                   Actual Error versus Time
                  Total Suspended Sediment
-VXf
-foo-


\ T
I
1 ,1
• * • • "* •] — -•* * • • •* i • •» — n 1 • 	 *- f-i


!



1
'nr-
                                           /
                          524

-------
 i
                 James River at Segment 280
                    Total Suspended Sediment
               Frequency Distribution - FAIRED Simulated and Observed Data
sasssr
                 James River at Segment 280
          Actual error versus Percentile Sample Population
                    Total Suspended Sediment
                Frequency Distribution • All Simulated and Observed Data
                             525

-------
  James River at Segment 280
Observed and Simulated versus Time
       Total Phosphorus
         (*=Observed, -^Simulated)
                Date

-------
                    James River at Segment 280
         Total Phosphorus Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
     300000
     200000
Ln
to
f

I
&
£
    100000
                     •(J
                                   Date

-------
 I


 •J

 §,
     LI
                 James River at Segment 280
                  Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                  Total Phosphorus: 01JAN84 - 01JAN92
                James River at Segment 280
                    Actual Error versus Time
                       Total Phosphorus
          TIT
.. T
                   T .
s     /    s
                s     s     s     s
                          528

-------
  lo.oo-
                 James River at Segment 280
                        Total Phosphorus
                     Distribution - PAIRED Simulated and Observed Data
Frequency Distribution •
SSSBTS
                  James River at Segment 280
          Actual error versus Percentile Sample Population
                         Total Phosphorus
                Frequency Distribution - All Simulated and Observed Data
                              529

-------
                  James River at Segment 280
                Observed and Simulated versus Time
              Organic and Participate Phosphorus
                         (*=Observed, -=Simulated)
    1.5-
    1.4-
    1.2
    1.1
    1.0
    0.9-
    0.8
    0.7-
to
O
                                Date

-------
                   James River at Segment 280
 Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
   300000
  200000
 I
  100000
                    'O'f
                                     Date
rJ1J>k».«««mo*tWfc««ngdl|WU«|
&.*V2*EB»» 113-   •• '

-------
     James River at Segment 280
      Scatter Plot and Regression of Simulated
         versus Observed with Ideal Line
Organic and Particulate Phosphorus: 01JAN84 - 01JAN92

                                                 of POJI
    James River at Segment 280
        Actual Error versus Time
   Organic and Particulate Phosphorus
04
OJ
0.1
04
| -44-
I •"'
j«:
1
3j -tu-
tu -OS-
-0.4 '
•0.7'
-OJ
•o.*-
-IJ>-


1









T Tit t» t T» 1 _. » t. , TV
• t • ' ' '•«

«










•




Tlfl
T


i











i
T

l|*ttl»t ikwt'J* * t*..




•
1 |i*' |1" *|

i
1 i





                532

-------
                 James River at Segment 280
                Organic and Particulate Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
                             30 p««.J¥^.«« n
SBSKSS*
                 James River at Segment 280
          Actual error versus Percentile Sample Population
                Organic and Particulate Phosphorus
                Frequency Distribution - All Simulated and Observed Data
                                                               •»*
                             533

-------
0.44-
0.42-
0.40-
0.38-
              James River at Segment 280
            Observed and Simulated versus Time
                 Dissolved Phosphorus
                     (*=Observed, -=Simulated)
                             Date

-------
    40000
                   James River at Segment 280
      Dissolved Phosphorus Observed and Simulated Load vs Time
        	             dine = simulated, O = observed)               «««=
Oi
co
C/i
                                 Date

-------
 Tames River at Segment 280
 Scatter Plot and Regression of Simulated
    versus Observed wi"1 Ideal Line
Dissolved Phosphorus: 01JAN84 - 01JAN92

James River at Segment 280
    Actual Error versus Time
     Dissolved Phosphorus
/
                                           /•
               Date
           536

-------
        James River at Segment 280
             Dissolved Phosphorus
      Frequency Distribution - PAIRED Simulated and Observed Data
                     Percent oTPoptiUtion TO
       James River at Segment 280
Actual error versus Percentile Sample Population
            Dissolved Phosphorus
      Frequency Distribution - All Simulated and Observed Data
                   537

-------
   3-:
    2
Oi
w
oo
  I
   Oil
                  James River at Segment 280
                Observed and Simulated versus Time

                         Total Nitrogen
                         (*=Observed, -=Simulated)
                                Date

-------
                    James River at Segment 280
          Total Nitrogen Observed and Simulated Load vs Time
    600000
    500000
    400000
Ln
U>
vo
   t
    300000
    200000
    looooo-
                           (line = simulated, O = observed)
                     O :
                                    Date

-------
 James River at Segment 280
 Scatter Plot and Regression of Simulated
    versus Observed with Ideal Line
   Total Nitrogen: 01JAN84 - 01JAN92
            SinuUM - mftl
James River at Segment 280
   Actual Error versus Time
        Total Nitrogen
             rrr1
                                       il
           540

-------
                    James River at Segment 280
                            Total Nitrogen
                 Frequency Distribution - PAIRED Simulated and Observed Data
                                 P.rwntofi'opuUtioe.
                   James River at Segment 280
           Actual error versus Percentile Sample Population
                            Total Nitrogen
                 Frequency Distribution - All Simulated and Observed Data
                                FMcoil of Imputation
eaex
                               541

-------
  James River at Segment 280
Observed and Simulated versus Time
             NO3
         (*=Observed, -=Simulated)

-------
     60000
     50000-
In

*-

U)
    40000
I

I

& 30000
.c
TJ
    20000
    10000
                    James River at Segment 280

               NO3 Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
                                   Date

-------
                  James River at Segment 280
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                        NO3: 01JAN84 - 01JAN92
 RRM7
  •1.0-t
  X
                 James River at Segment 280
                     Actual Error versus Time
                              NO3
X     X     X
stssa
                            544

-------
                  James River at Segment 280
                                N03
               Frequency Distribution - FAIRED Simulated and Observed Data
  10.000
 I
gasesr—"
                  James River at Segment 280
          Actual error versus Percentile Sample Population
                               N03
                Frequency Distribution - All Simulated and Observed Data
SK3SW
                               545

-------
               James River at Segment 280
             Observed and Simulated versus Time
                     Total Ammonia
                      (*=Observed, -=Simulated)
                              Date
JK*"*"»*»

-------
   70000
   60000
                    James River at Segment 280
         Total Ammonia Observed and Simulated Load vs Time
                           (line = simulated, O = observed)
                     O !
   50000 -
 •8 40000-
  (1)
  a.
 _c
 •o
   30000-
   20000-
   10000
   4*
    &
     ^
(r?l J*»l ui
tl 
-------
 James River at Segment 280
  Scatter Plot and Regression of Simulated
    versus Observed with Ideal Line
   Total Ammonia: 01JAN84 - 01JAN92
James River at Segment 280
    Actual Error versus Time
        Total Ammonia
1.1
M!
0.01
M7
MJ
M]
MI-
MI-
MO-
•J -Ml-
i •*•*'
i -0.03-
0 -OJ4-
1 -tar
i 4M-
| -04* •
J -8-11'
-O.U-
•O.M-
-O.W
•0.17-
-t.lt
•fl.W
•OJ1-
-OJJ-
-OJJ-






















X

KSSBSS*—





I—



,














•4





UT ITT 1 M T 1 ,. T.T _ _ T T















.
1 1 1 * M 11'
1 «

1












/ X X X X X X X
DMl

           548

-------
                  James River at Segment 280
                          Total Ammonia
               Frequency Distribution - PAIRED Simulated and Observed Data
                      10
                             30
                                               90
SW3SKS
                 James River at Segment 280
          Actual error versus Percentile Sample Population
                          Total Ammonia
                Frequency Distribution - All Simulated and Observed Data
fffSSS,
                              549

-------
Ui
o
                  James River at Segment 280
                Observed and Simulated versus Time
                       Organic Nitrogen
                         (*=Observed, -=Simulated)

-------
                 James River at Segment 280
      Organic Nitrogen Observed and Simulated Load vs Time
                        (line = simulated, O = observed)     «-w*»w. v u M. IIAL^
 500000-
 400000
 300000-
8.
_c
o
 200000-
  100000
                  O :
       O
                 JJ
OOP
                                 Date

-------
 James River at Segment 280
 Scatter Plot and Regression of Simulated
    versus Observed with Ideal Line
  Organic Nitrogen: 01JAN84 - 01JAN92
James River at Segment 280
    Actual Error versus Time
       Organic Nitrogen

1
T T . t . T . IT 1 1. T It I , T I? L T
r
1 1J U
/     X
              Drtt
                           X     X
          552

-------
   James River at Segment 280

            Organic Nitrogen
Frequency Distribution - PAIRED Simulated and Observed Data
1
«E? ^*® '
|




^ 	


^—S

___^ — •
x~~

r^

^-— ^-

y
»•»*


•

James River at Segment 280
Actual error versus Percentile Sample Population
Organic Nitrogen
 Frequency Distribution - All Simulated and Observed Data

                P«rmitofPepuUli
-------
554

-------
B.6.2  Appomattox River at Matoaca, VA at Segment 310 (Monitoring Station:
2041650) (Above Fall Line Basin Segments: 300 and 310)
Section Summary:

The Appomattox basin water quality gage is below a series of reservoirs, which influence
water quality at the gage. As with other Virginia tributaries, water quality observations
increased and were oriented toward storm weighted sampling after 1989. Model
calibration focused primarily on the refined, storm weighted sampling after 1989.

The Appomattox basin above the gaged site covers an area of 1,352 square miles.  At the
midpoint of the simulation, 1990, the land use for the basin was composed of 70% forest
land, 8% cropland, 16% other agricultural areas, 6% urban areas, and 1% water (river and
lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 2.3 million pounds in 1985 to 2.1 million pounds in 1996. Total phosphorus loads
over the same time period decreased from 0.20 million pounds to 0.18 million pounds. In
general, point source loads above the gage site decreased.  In 1996, the total nitrogen
point source load was 2% of the total load and the total phosphorus point source load was
4% of the total load. Estimated septic system total nitrogen loads increased 11%, from
0.10 million pounds in 1985  to 0.11 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 16%, and other agricultural loads (primarily
pasture and manure loads) by 11%. Total phosphorus decreased for these land uses by
26% and 12% respectively. Urban loads were estimated to have increased over the 1985
to 1996 period by 12% for total nitrogen and 14% for total phosphorus due to increases in
population and urban land use area.
                                555

-------
 Graphs

 Observed and Simulated Concentrations versus Date
 Observed and Simulated Loads versus Date
 Scatter Plot and Regression of Simulated versus Observed
 Actual Error versus Date
 Relative Error versus Percentile Sample Population
 Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date - Temperature
                               556

-------
             Appomattox River at Segment 310
               Observed and Simulated versus Time
                       Temperature-C
                        (*=Observed, -=Simulated)
                               Dale
hit.**I u<*u>Hn!*v«rli
(»•(*.• *v ttMKMI II Ml

-------
 Appomattox River at Segment 310
    scatter Plot and Regression of Simulated
       versus Observed with Ideal Line
      Temperature-C: D1JAN84 - 01JAN92
                Simulated- Temp-C
Appomattox River at Segment 310
       Actual Error versus Time
           Temperature-C
                 Oat
              558

-------
    Appomattox River at Segment 310
                Temperature-C
     Frequency Distribution - PAIRED Simulated and Observed Data
                   30 Ptrc.nl o^PopuUtion TO
    Appomattox River at Segment 310
Actualerror versus Percentile Sample Population
               Temperature-C
      Frequency Distribution - All Simulated and Observed Data
                   559

-------
15
14
           Appomattox River at Segment 310
            Observed and Simulated versus Time
                  Dissolved Oxygen
                    (*=Observed, -=Simula ted)
                           Date

-------
               Appomattox River at Segment 310

       Dissolved Oxygen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
   200000
   190000
   180000
   170000
   160000
   150000
  140000
 I

 &
 s
 .5
                                  Dale
Ml jte>lM«
Awl. . *» i

-------
 Appomattox River at Sejgment 310
     scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
     Dissolved Oxygen: 01JAN84 - 01JAN92
                 Simulated, ngfl
Appomattox River at Segment 310
       Actual Error versus Tune
2
1
o-
•1-
,v










•




1



'
•1 TM T '


M1
,



1

•



J



-JO-

T T
ill










ill
f
I
•



f
I)



,
A
1
]

hi

i

•



ui




1 /


                                      s     /
                  D.I.
              562

-------
             Appomattox River at Segment 310
                       Dissolved Oxygen
              Frequency Distribution - PAIRED Simulated and Observed Data
in
•o
i
                    10
                            30
                                      n
                                              90
                                                        99
             Appomattox River at Segment 310
          Actual error versus Percentile Sample Population
                        Dissolved Oxygen
               Frequency Distribution - All Simulated and Observed Data
                              563

-------
    140
    130
in
              Appomattox River at Segment 310
               Observed and Simulated versus Time
                 Total Suspended Sediment
                        (*=Observed, -^Simulated)
                               Dale

-------
                Appomattox River at Segment 310

    Total Suspended Sediment Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    3000000
    2000000
in
   I
   J?

   .£
    1000000
                                  Dale

-------
 Appomattox River at Segment 310
     scatter Plot and Regression of Simulated
       versus Observed with Ideal Line
  Total Suspended Sediment: 01JAN84 - 01JAN92
Appomattox River at Segment 310
       Actual Error versus Tune
      Total Suspended Sediment
40
JO
a
10
1 *'
| -w
I*:
•30-
•40'
•50 •
•M-



T
• T






,' ' , , - IT T T t,I . T I I T .1
— I p * | * '[ ' ' ' ' ii ' j,*1 ^
(





I _; 	 ••- ' 	 •; 	 • '• 	 -• • 	 •• 	
Jr jP5 jf ^r xr JT ^T j#* j«v
DlK
             566

-------
    Appomattox River at Segment 310
          To^1 Suspended Sediment
     Frequency Distribution - PAIRED Simulated and Observed Data
    Appomattox River at Segment 310
ActuaTerror versus Percentile Sample Population
          Total Suspended Sediment
      Frequency Distribution • All Simulated and Observed Data
                  567

-------
Ln
CT>
00
               Appomattox River at Segment 310
                Observed and Simulated versus Time
                       Total Phosphorus
                         (*=Observed, -^Simulated)
                                Date

-------
5000
           Appomattox River at Segment 310

    Total Phosphorus Observed and Simulated Load vs Time
                    (line = simulated, O = observed)
                            Date

-------
Appomattox River at Segment 310
    Scatter Plot and Regression of Simulated
       versus Observed with Ideal Line
     Total Phosphorus: 01JAN84 - 01JAN92

Appomattox River at Segment 310
Actual Error versus Tune
Total Phosphorus
i



i
;
i



«.n
«.u
«••
f If •
Ut'
tM-
r
! Ml'
•43 '
IB
Ml'
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•«Jl-
-M3
•oi-
^ n* •






Illll
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•*J*^I 	 t • '
X X






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i

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nit
T

I,
I
i

X






T
1


i
1
ill
1

X
               570

-------
    Appomattox River at Segment 310
              Total Phosphorus
     Frequency Distribution - PAIRED Simulated and Observed Data
    Appomattox River at Segment 310
Actualerror versus Percentile Sample Population
              Total Phosphorus
      Frequency Distribution - All Simulated and Observed Data
                   571

-------
10
              Appomattox River at Segment 310
                Observed and Simulated versus Time
              Organic and Particulate Phosphorus
                        (*=Observed/ -^Simulated)
                                Dale

-------
tn
                Appomattox River at Segment 310

    Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                          (line = simulated,, O = observed)
     4000
                                  Data


-------
  Appomattox River at Segment 310
      scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
Organic and Particulate Phosphorus: 01JAN84 • 01JAN92
 Appomattox River at Segment 310
        Actual Error versus Time
   Organic and Particulate Phosphorus
                                      /•    /•
              574

-------
    Appomattox River at Segment 310
       Organic and Participate Phosphorus
     Frequency Distribution - PAIRED Simulated and Observed Data
    Appomattox River at Segment 310
Actualerror versus Percentile Sample Population
      Organic and Particulate Phosphorus
      Frequency Distribution - All Simulated and Ob*err*d Data
                   575

-------
01
-J
ON
    0.07 -:
    0.06
    0.05
    0.04
   I
    0.03 -
    0.02 -
    0.01 -
    0.00 i
               Appomattox River at Segment 310
                 Observed and Simulated versus Time
                     Dissolved Phosphorus
                          (*=Observed, -=Simulated)
                                 Date

-------
               Appomattox River at Segment 310
      Dissolved Phosphorus Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    600
Ul
N*|
-4
                                 Date

-------
           Appomattox River at Segment 310
               scatter Plot and Regression of Simulated
                  versus Observed with Ideal Line
              Dissolved Phosphorus: 01JAN84 - 01JAN92
                            Sin.uUt.d-mj/1
MZ
I

           Appomattox River at Segment 310
                  Actual Error versus Time
                   Dissolved Phosphorus
        11

Ml  1   111
11

                     /     /
                         578

-------
rsssw"
             Appomattox River at Segment 310
                     Dissolved Phosphorus
              Frequency Distribution - PAIRED Simulated and Observed Data
                             Percent
            Appomattox River at Segment 310
        Actualerror versus Percentile Sample Population
                     Dissolved Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                          J
•&A2" '.'
                                      #     
                            Percent of PopiUtion
                            579

-------
               ADpomattox River at Segment 310
                Observed and Simulated versus Time
                        Total Nitrogen
                         (*=Observed/ -^Simulated)
CO
o
    oi
       KXpk*.
                                Date

-------
             Appomattox River at Segment 310

       Total Nitrogen Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 30000
 20000
»  8.
   s
   .£
3
 10000
                               Date

-------
             Appomattox River at Segment 310
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                  Total Nitrogen: 01JAN84 - 01JAN92
!
                           Sionil.rtd-mg/1
•I-
            Appomattox River at Segment 310
                  Actual Error versus Time
                       Total Nitrogen
     r^
        i	i
... t I I  . i
                            Date
                         582

-------
    Appomattox River at Segment 310
               Total Nitrogen
     Frequency Distribution - PAIRED Simulated and Observed Data
    Appomattox River at Segment 310
Actualerror versus Percentile Sample Population
               Total Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                    583

-------
00
               Appomattox River at Segment 310
                Observed and Simulated versus Time
                             NO3
                         (*=Observed, -^Simulated)
                                Date

-------
in
00
Cn
     6000
                Appomattox River at Segment 310
              NO3 Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
                                  Dal*

-------
           Appomattox River at Segment 310
               Scatter Plot and Regression of Simulated
                 versus Observed with Ideal Line
                    NO3:01JAN84 - 01JAN92
           Appomattox River at Segment 310
                 Actual Error versus Time
                          NO3
0.1-
 II
       S     S
/     s     /    /     s
                            Dtu
                         586

-------
    Appomattox River at Segment 310
                    N03
     Frequency Distribution • PAIRED Simulated and Observed Data
    Appomattox River at Segment 310
Actualerror versus Percentile Sample Population
                   N03
      Frequency Distribution - All Simulated and Observed Data
                   587

-------
               Aopomattox River at Segment 310
                Observed and Simulated versus Time
                        Total Ammonia
                         (*=Observed, -^Simulated)
00
00
                                Dale

-------
               Appomattox River at Segment 310

         Total Ammonia Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    woo-:
    1200
    1100
    1000-
    900-
oo
t

&
2
s
                                  Dal*

-------
              Appomattox River at Segment 310
                  Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                   Total Ammonia: 01JAN84 - 01JAN92
             Appomattox River at Segment 310
                    Actual Error versus Tune
                        Total Ammonia
  tM



  tM



  0.01
J -0.01
o
•3
 4.02
 •OM


 -o.ot-


 -0.07-
/•     /
                                                   s     /
                               Da,
                           590

-------
0.04
            Appomattox River at Segment 310
                       Total Ammonia
             Frequency Distribution - PAIRED Simulated and Observed Data


0.010000
c
J 0.001000
o
S
I
£
£
5 o.oowoo-
I
£
o.ooooio-
1
0.000001 -
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           Appomattox River at Segment 310
        Actualerror versus Percentile Sample Population
                      Total Ammonia
             Frequency Distribution - All Simulated and Observed Data

-------
Appomattox River at Segment 310
 Observed and Simulated versus Time
        Organic Nitrogen
          (*=Observed, -^Simulated)
                 Date

-------
               Appomattox River at Segment 310
        Organic Nitrogen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    30000-
    20000
Ln
   8.
   2
   s
    10000

-------
            Appomattox River at Segment 310
               scatter Plot and Regression of Simulated
                  versus Observed with Ideal Line
                Organic Nitrogen: 01JAN84 - 01JAN92
 M


 «J

i

: M


 0.1


 co


 -0.1
•O2


-OJ


•04


-Of


•n*-
           Appomattox River at Segment 310
                  Actual Error versus Time
                     Organic Nitrogen
llLJI
                                  x    x     x

                        594

-------
     Appomattox River at Segment 310
               Organic Nitrogen
      Frequency Distribution - PAIRED Simulated and Observed Data
                                          n
    Appomattox River at Segment 310
Actual error versus Percentile Sample Population
              Organic Nitrogen
      Frequency Distribution - All Simulated and Observed Data
                   595

-------
596

-------
                   B.7.0  Choptank River Basin
Basin Segments:
      Above Fall Line Basin Segments: 770
      Below Fall Line Basin Segments: 400

Section Contents:
      B.7.0  Monitoring Stations in the Choptank River Basin (Figure B.7.0)
      B.7.1  Choptank River (Monitoring Station: 1491000)
                              597

-------
   Monitoring Stations
              in the
  Choptank River Basin
                                     Figure B.7
   Choptank River Basin in
 The Chesapeake Bay Watershed
Chesapeake Bay Program

 Map Date: April 1998
                      Calibration Stations
                      •  1491000
                      /\y Streams
                      fi Model Segments
Source: USGS and USEPA Chesapeake Bay Progran
   598
                                       N
                                         KJH

-------
B. 7.1  Choptank River near Greensboro, MD at Segment 770 (Monitoring Station:
1491000) (Above Fall Line Basin Segments: 770)	
Section Summary;

The Choptank basin water quality gage is in the upper reaches of the Choptank river in
land characterized as poorly drained and with less agriculture than in the downstream
areas of the Choptank. The Choptank basin above the gaged site covers an area of 582
square miles. At the midpoint of the simulation period, 1990, the land use for the basin
was composed of 31 % forest land, 54% cropland, 10% other agricultural areas, 4% urban
areas, and 1% water (river and lake) surface area.

Based on an average hydrology used in a 1985 Reference scenario and a 1996 Nutrient
Reduction Progress scenario estimated total nitrogen delivered to the gage decreased
from 4.0 million pounds in 1985 to 3.6 million pounds in 1996. Total phosphorus loads
over the same time period decreased from 0.36 million pounds to 0.28 million pounds. In
general, point source loads above the gage site decreased. In 1996, the total nitrogen
point source load was 5% of the total load and the total phosphorus point source load was
17% of the total load. Estimated septic system total nitrogen loads increased 16%, from
0.11 million pounds in 1985 to 0.12 million pounds in 1996.

Over the 1985 to 1996 period, changes in the land use and BMP simulation decreased
estimated cropland total nitrogen loads by 20%, and other agricultural loads (primarily
pasture and manure loads) by 32%. Total phosphorus decreased for these land uses by
21% and 43% respectively. Urban loads were estimated to have increased  over the 1985
to 1996 period by 10% for both total nitrogen and total phosphorus due to increases in
population and urban land use area.
                                 599

-------
Observed and Simulated Concentrations versus Date
Observed and Simulated Loads versus Date
Scatter Plot and Regression of Simulated versus Observed
Actual Error versus Date
Relative Error versus Percentile Sample Population
Actual Error versus Percentile
Parameters

Temperature
Dissolved Oxygen
Total Suspended Sediment
Total Phosphorus
Organic and Paniculate Phosphorus
Phosphate
Total Nitrogen
Nitrate
Total Ammonia
Organic Nitrogen
Exceptions

Observed and Simulated Loads versus Date - Temperature
                                 600

-------
             CKoptank River at Segment 770
             Observed and Simulated versus Time
                     Temperature-C
                      (*=Observed, -=Simulated)
                             D«te
-'	•«*—•-*••

-------
 CHOPTANK RIVER at Segment 770
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
       Temperature-C: 01JAN84 - 01JAN92
                                              ofPoirr
CHOPTANK RIVER at Segment 770
        Actual Error versus Time
            Temperature-C
   XXX
X
               602

-------
   CHOPTANK RIVER at Segment 770
               Temperature-C
     Frequency Distribution - PAIRED Simulated >
• Simulated and Observed Data
  CHOPTANK RIVER at Segment 770
Actual error versus Percentile Sample Population
               Temperature-C
      Frequency Distribution - All Simulated and Observed Data
                  603

-------
Choptank River at Segment 770
Observed and Simulated versus Time
      Dissolved Oxygen
         (*=Observed/ -=Simulated)
                Date

-------
  30000 -f :•
     ^.   ,    Choptank River at Segment 770

     Dissolved Oxygen Observed and Simulated Load vs Time
                       (line = simulated, O = observed)               «««-
 2000
o>
a.
 10000
                                Date
dr» MKBM 11 :»J»OC ,t,m
-------
             CHOPTANK RIVER at Segment 770
                  Scatter Plot and Regression of Simulated
                     versus Observed with Ideal Line
                   Dissolved Oxygen: 01JAN84 - 01JAN92
ff1 "".Ljagg^^'y^y |
                              Sun«Ut«|.m«fl
                                                           wn o( Poii t
            CHOPTANK RIVER at Segment 770
                    Actual Error versus Time
                       Dissolved Oxygen
-T . . T 	
i
111
1

lilt
11
t

1

1 ^
J 'I
1
IJ
1
J
T
1,


'
1
i
I
i

t
1
1
li

1 1
if
IT
i
                                                           s
                           606

-------
           CHOPTANK RIVER at Segment 770
                      Dissolved Oxygen
             Frequency Distribution - PAIRED Simulated and Observed Data
fsssssr
          CHOPTANK RIVER at Segment 770
        Actual error versus Percentile Sample Population
                     Dissolved Oxygen
             Frequency Distribution - All Simulated and Observed Data
                          Potent of Popaltfioa
                          607

-------
ON
O
00
                t^noptank River at Segment 770
                Observed and Simulated versus Time
                  Total Suspended Sediment
                         (*=Observed, -^Simulated)
                               Date

-------
              Choptank River at Segment 770

 Total Suspended Sediment Observed and Simulated Load vs Time
                      (line = simulated, O = observed)
 3000000
 2000000-
i

2
.£
 1000000
   oi
                        /
                                Dale

-------
 CHOPTANK RIVER at Segment 770
      Scatter Plot and Regression of Simulated
         versus Observed with Ideal Line
    Total Suspended Sediment: 01JAN84 - 01JAN92
CHOPTANK RIVER at Segment 770
        Actual Error versus Time
       Total Suspended Sediment
              610

-------
   CHOPTANK RIVER at Segment 770
          Total Suspended Sediment
     Frequency Distribution - PAIRED Simulated and Obser
I Observed Data
                      «ffi| ihlii
  CHOPTANK RIVER at Segment 770
Actual error versus Fercentile Sample Population
         Total Suspended Sediment
      Frequency Distribution • All Simulated and Obfcrred Data
                   611

-------
i.o-:
0.01
             Choptank River at Segment 770
             Observed and Simulated versus Time
                   Total Phosphorus
                     (*=Observed, -=Simulated)
                            Date

-------
              Choptank River at Segment 770
     Total Phosphorus Observed and Simulated Load vs Time
                      (line =* simulated, O = observed)
 3000
 2000
 »
3
i
2
.c
 1000

-------
       CHOPTANK RIVER at Segment 770
            Scatter Plot and Regression of Simulated
               versus Observed with Ideal Line
             Total Phosphorus: 01JAN84 - 01JAN92
u


• I


M-


•0.1


•OJ
X
      CHOPTANK RIVER at Segment 770
              Actual Error versus Time
                 Total Phosphorus
T T  J Tr
          . .
X
                            X     X
                                      4

                                                   X
                     614

-------
  CHOPTANK RIVER at Segment 770
             Total Phosphorus
    Frequency Distribution - PAIRED Simulated and Observed DaU
  CHOPTANK RIVER at Segment 770
Actual error versus Percentile Sample Population
             Total Phosphorus
      Frequency Distribution - Ail Simulated and Obw
I Data
                   615

-------
ON
I—«
ON
   •3,
    0.9 -:
    0.8 -:
    0.7- •
    0.6-
0.5-
    0.4-
    0.3-
    0.2-
    0.1-
    0.0-
    -o.i i:
              CHOPTANK RIVER at Segment 770
                 Observed and Simulated versus Time
              Organic and Participate Phosphorus
                          (*=Observed, -=Simulated)
                                         §
                                         o
                                 Date

-------
            CHOPT ANK RIVER at Segment 770

Organic and Particulate Phosphorus Observed and Simulated Load vs Time
                       (line = simulated, O = observed)
  3000
  2000
I
Q)
a.
i? 1000
 •1000

-------
                CHOPTANK RIVER at Segment 770
                      Scatter Plot and Regression of Simulated
                         versus Observed with Ideal Line
               Organic and Particulate Phosphorus: 01JAN84 - 01JAN92
     0.24
     0.23
     0.22
     0.21
     0.20
     0.19
     0.18
     0.17
     O.li
     0.15
     0.14
     0.13
     0.12
     0.11
   i  o.io
   =  0.09
   \  0.09
   I  0.87
   ;  0.06
   >  0.05
     0.04-
     0.03
    0.02:
    0.01-
    0.00:
   •0.01-
   •0.02-
   •0.03-
   •0.04:
   •0.05:
   •O.M:
   •0.0?:
   -O.M:
                                    Simulated. n(/l
 3 «
 i
               CHOPTANK RIVER at Segment 770
                        Actual Error versus Time
                   Organic and Particulate Phosphorus
            ir
.Trr I.
  TjUi. »T Jljiwi
"1  1
                                     Date
SSSSSSSf
                                 618

-------
0.00001
          CHOPTANK RIVER at Segment 770
              Organic and Participate Phosphorus
             Frequency Distribution - PAIRED Simulated and Observed Data
                            Pcrc.nl
          CHOPTANK RIVER at Segment 770
        Actual error versus Percentile Sample Population
              Organic and Particulate Phosphorus
              Frequency Distribution - All Simulated and Observed Data
                            619

-------
             CHOPTANK RIVER at Segment 770
                Observed and Simulated versus Time
                    Dissolved Phosphorus
                         <*=Observed, -^Simulated)
ON
NJ
O
                                Date
    *• ZVEM 0*12)

-------
              CHOPTANK RIVER at Segment 770

    Dissolved Phosphorus Observed and Simulated Load vs Time
                          (line = simulated, O = observed)
  180



  170



  160



  150



  140



  130



  120



  110



* 100



  90
O)

,c

TJ
5 8°


  70



  60



  50



  40



  30



  20



  10



   0
Ml Jtoft.u. modtUdtpwing «] Ddnu)

(chwUi* Orv 23FEBM Ol:32.p
-------
             CHOPTANK RIVER at Segment 770
                 Scatter Plot and Regression of Simulated
                    versus Observed with Ideal Line
                 Dissolved Phosphorus: 01JAN84 - 01JAN92
SJSSS
            CHOPTANK RIVER at Segment 770
                    Actual Error versus Time
                     Dissolved Phosphorus
                              Date
                           622

-------
             CHOPTANK RIVER at Segment 770
                      Dissolved Phosphorus
               Frequency Distribution - PAIRED Simulated and Observed Data
szszssxss
            CHOPTANK RIVER at Segment 770
         Actual error versus Percentile Sample Population
                     Dissolved Phosphorus
               Frequency Distribution - All Simulated and Observed Data
                            623

-------
Choptank River at Segment 770
Observed and Simulated versus Time
        Total Nitrogen
         (*=Observed/ -^Simulated)
                Date

-------
17000
16000
             Choptank River at Segment 770

     Total Nitrogen Observed and Simulated Load vs Time
                     (line = simulated, O = observed)
                             Date

-------
CHOPTANK RIVER at Segment 770
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
       Total Nitrogen: 01JAN84 - 01JAN92
                                                 otPoifl
                  Simul>tcd-mt/l
CHOPTANK RIVER at Segment 770
        Actual Error versus Time
             Total Nitrogen
*
1
7
i
5
4'
2'
I-
•I-
2-
3-






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                                                /•
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                626

-------
 100.0	
I
£ i-ol
            CHOPTANK RIVER at Segment 770
                         Total Nitrogen
              Frequency Distribution - PAIRED Simulated and Observed Data



saxssf

1

B-M

i



a 3



Percent o/



P^U^ *



0 9



0 9



9






            CHOPTANK RIVER at Segment 770
         Actual error versus Percentile Sample Population
                         Total Nitrogen
               Frequency Distribution - All Simulated and Observed Data
                            627

-------
to
OO
    12
    11
                 Choptank River at Segment 770
                 Observed and Simulated versus Time
                              NO3
                          (*=Observed, -=Simulated)
                                 Date

-------
     5000
cr.
to
                   Choptank River at Segment 770

                NO3 Observed and Simulated Load vs Time
                            (line = simulated, O = observed)
                                     Date
       . pi j»m.. ui| Ulu)

  {c»Of>Ui*.div 04FEBM 1 l:23j»oc ni.nxxM »•»)

-------
           CHOPTANK RIVER at Segment 770
                Scatter Plot and Regression of Simulated
                   versus Observed with Ideal Line
                      NO3:01JAN84 - 01JAN92
                                                         of foil
                             SinuUtad-ms/1
           CHOPTANK RIVER at Segment 770
                   Actual Error versus Time
                            NO3
ess
                           630

-------
   CHOPTANK RIVER at Segment 770
                     N03
     Frequency Distribution - PAIRED Simulated and Observed Data
   CHOPTANK RIVER at Segment 770
Actual error versus Percentile Sample Population
                    N03
      Frequency Distribution - All Simulated and Observed Data
                   631

-------
u>
to
    0.0 -t
               CHOPTANK RIVER at Segment 770
                 Observed and Simulated versus Time

                          Total Ammonia
                          (*=Observed, -^Simulated)
                                  Date
  fWi^Bdu^f MF£0M VMB)

-------
          CHOPTANK RIVER at Segment 770

     Total Ammonia Observed and Simulated Load vs Time
                    (line = simulated, O = observed)
600
                           Oat*

-------
                 Choptank River at Segment 770

         Total Ammonia Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
    500
    400-
U>
   f
   S 300

   £
                                  Date

-------
CHOPTANK RIVER at Segment 770
     Scatter Plot and Regression of Simulated
        versus Observed with Ideal Line
       Total Ammonia: 01JAN84 - 01J AN92
CHOPTANK RIVER at Segment 770
        Actual Error versus Time
            Total Ammonia
          x     x     x     x
               635

-------
           CHOPTANK RIVER at Segment 770
                        Total Ammonia
             Frequency Distribution - PAIRED Simulated and Observed Data
o.wi-1
          CHOPTANK RIVER at Segment 770
        Actual error versus Percentile Sample Population
                       Total Ammonia
              Frequency Distribution - All Simulated and Observed Data
                           636

-------
ON
U)
    0 1
              CHOPTANK RIVER at Segment 770
                 Observed and Simulated versus Time
                        Organic Nitrogen
                          (*=Observed, -^Simulated)
                                 Dale
   •>

-------
oo
    16000
              CHOPTANK RIVER at Segment 770

        Organic Nitrogen Observed and Simulated Load vs Time
                         (line = simulated, O = observed)
                                 Date
    UFEM MatjMt MfxwM rul

-------
 CHOPTANK RIVER at Segment 770
      Scatter Plot and Regression of Simulated
         versus Observed with Ideal Line
	Organic Nitrogen: 01JAN84 - 01JAN92
CHOPTANK RIVER at Segment 770
        Actual Error versus Time
           Organic Nitrogen
1-
1
1.-
(11
-1-


'

X
T T



'|M


/
nfh


M


/
4il


I
41

1
,




/
liii
li
*
jJ L[ J
li tot

li
1
1

s /

f

r


11
i
y-r
•

/
VI -T !l



\

•



X /
                639

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J 0.1000
o
 S3SK5T
            CHOPTANK RIVER at Segment 770
                        Organic Nitrogen
              Frequency Distribution - FAIRED Simulated an
I and Observed Data
                     10
                              Ftrecnl ofPopuUtion
                                       70
                                              90
            CHOPTANK RIVER at Segment 770
         Actual error versus Percentile Sample Population
                        Organic Nitrogen
               Frequency Distribution - All Simulated and Observed Data
                             640

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641

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