U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2008–1204

Prepared in cooperation with the

U.S. Fish and Wildlife Service (Patuxent Research Refuge)

U.S. Department of Agriculture (Henry A. Wallace Beltsville Agricultural Research Center)

National Park Service (Chesapeake and Ohio Historical Park, Prince William Forest Park,

Rock Creek Park, Shenandoah National Park)

Water-Quality Data at Amphibian Research Sites in 

Maryland, Washington, D.C., and Virginia, 2005–2007

Water-Quality Data at Amphibian Research 

Sites in Maryland, Washington, D.C., and 

Virginia, 2005–2007

By Karen C. Rice

Prepared in cooperation with the

U.S. Fish and Wildlife Service (Patuxent Research Refuge)

U.S. Department of Agriculture (Henry A. Wallace Beltsville Agricultural Research Center)

National Park Service (Chesapeake and Ohio Historical Park, Prince William Forest Park,

 Rock Creek Park, Shenandoah National Park)

Open-File Report 2008–1204

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2008

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Suggested citation:

Rice, K.C., 2008, Water-quality data at amphibian research sites in Maryland, Washington, D.C., and Virginia, 2005–

2007: U.S. Geological Survey Open-File Report 2008–1204, 12 p.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

 Purpose and Scope ..............................................................................................................................1

 Description of Data-Collection Sites .................................................................................................1

Collection and Analysis of Water-Quality Samples..................................................................................3

Field Data-Collection Methods...........................................................................................................3

Laboratory Analytical Methods..........................................................................................................3

Quality Assurance and Quality Control .............................................................................................3

Acknowledgments.........................................................................................................................................4

References Cited............................................................................................................................................4

Figures

1. Map showing location of data-collection sites in Maryland,

Washington, D.C., and Virginia...................................................................................................2

Tables

1. Description of water-quality sampling sites in Maryland, Washington, D.C., 

and Virginia, 2005–2007................................................................................................................5

2. Water-quality data collected from sites in Maryland, 2005–2007 ..................................................7

3. Water-quality data collected from sites in Washington, D.C., 2005–2007.....................................8

4. Water-quality data collected from sites in Virginia, 2005–2007......................................................9
iv

Conversion Factors, Vertical Datum, and 

Abbreviated Water-Quality Units

Multiply By To obtain

Length

millimeter (mm) 0.039 inch

meter (m) 3.28 foot

kilometer (km) 0.62 mile

Volume

liter (L) 0.264 gallon

cubic meter (m3

) 264 gallon

 

Water temperature is reported in degree Celsius (°C), which can be converted to 

degree Fahrenheit (°F) by the following equation: 

°F = 1.8 (°C) + 32

Horizontal coordinate information is referenced to North American Datum of 1983 (NAD 83).

Vertical coordinate information is referenced to the North American Vertical Datum of 1988

(NAVD 88).

Abbreviated water-quality units: Chemical concentration is reported in milligrams per liter (mg/L) or microequivalents per liter (μeq/L). Milligrams per liter 

is a unit expressing the concentration of chemical constituents in solution as 

weight (milligrams) of solute per unit volume (liter) of water. For concentrations 

less than 7,000 mg/L, the numerical value is the same as for concentrations in 

parts per million. Microequivalents per liter is a unit expressing the concentration of chemical constituents in solution as equivalent charges (equivalents) of 

solute per unit volume (liter) of water. Specific electrical conductance of water is 

reported in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 25 °C). 
Abstract

Data on the chemical composition of water were collected at least once from 47 amphibian research sites in 

Maryland, Washington, D.C., and Virginia, from 2005 through 

2007. One hundred twenty-five water samples were collected from vernal pools and streams and analyzed as part 

of long-term monitoring projects of the U.S. Geological 

Survey Amphibian Research and Monitoring Initiative in the 

Northeast Region. Field measurements of water temperature, 

specific conductance, and pH were made. Laboratory analyses 

of the water samples included acid-neutralizing capacity, total 

Kjeldahl nitrogen (ammonium plus organic nitrogen), nitrite 

plus nitrate, total nitrogen, and total phosphorus concentrations. Field and laboratory analytical results of water samples 

and quality-assurance data are presented.

Introduction

Water-quality samples at 47 amphibian research sites in 

Maryland, Washington, D.C., and Virginia were collected and 

analyzed at least once from 2005 through 2007. The samples 

were collected as part of the U.S. Geological Survey (USGS) 

Amphibian Research and Monitoring Initiative (ARMI) in the 

Northeast Region. ARMI was established in 2000 to 

(1) identify a network of Department of Interior lands for 

monitoring the status of and changes in the distribution and 

abundance of amphibian species and communities in the 

United States (U.S.); (2) gather information about environmental conditions that may affect amphibians; (3) document 

the scope of amphibian declines throughout the U.S.; (4) identify possible causes of observed amphibian declines, population changes, malformations, and diseases; and (5) provide 

scientific information to support management decisions 

that address declines, malformations, and diseases in

amphibian populations. 

Water-quality data were collected at vernal pools and 

streams. Water-quality data collected at both types of sites 

included field measurements of water temperature, specific 

conductance, pH, and laboratory analyses of acid-neutralizing 

capacity (ANC), total Kjeldahl nitrogen (ammonium plus 

organic nitrogen), nitrite plus nitrate, total nitrogen (N), and 

total phosphorus (P) concentrations.

Purpose and Scope

This report presents data on the chemical composition 

of 125 water samples collected from 2005 through 2007. The 

methods used to collect water samples are described, as are 

laboratory methods and quality-assurance protocols. Locations 

of the sampling sites and analytical results for the waterquality samples are presented in tables.

Description of Data-Collection Sites

In Maryland, water samples were collected at the U.S. 

Fish and Wildlife Service’s Patuxent Research Refuge; the 

U.S. Department of Agriculture’s Henry A. Wallace Beltsville 

Agricultural Research Center (BARC); and the National Park 

Service’s Chesapeake and Ohio Canal National Historical 

Park (CHOH; fig. 1; tables 1, 2). Patuxent Research Refuge 

and BARC are in the Coastal Plain Physiographic Province, 

approximately 17 kilometers (km) northeast of Washington, 

D.C., and 25 km southwest of Baltimore, MD. The CHOH 

extends northwest from Washington, D.C., to western Maryland, but samples were collected in an area just north of 

Washington, D.C. The CHOH research site is located in the 

Piedmont Physiographic Province.

In Washington, D.C., samples were collected in the 

National Park Service’s Rock Creek Park (ROCR; fig. 1; 

tables 1, 3). ROCR is in the Piedmont Physiographic Province 

and extends from the northern corner of the District of Columbia southward approximately 11 km to the Potomac River. 

In Virginia, samples were collected in the National Park 

Service’s Prince William Forest Park (PRWI) and Shenandoah National Park (SHEN; fig. 1; tables 1, 4). PRWI is in the 

Piedmont Physiographic Province in northeastern Virginia, 

approximately 56 km south of Washington, D.C., SHEN

is in the Blue Ridge Physiographic Province in northcentral Virginia. 

Water-Quality Data at Amphibian Research Sites in 

Maryland, Washington, D.C., and Virginia, 2005–2007

By Karen C. Rice 
2 Water-Quality Data at Amphibian Research Sites in Maryland, Washington, D.C., and Virginia, 2005–2007

COASTAL PLAIN

PIEDMONT

BLUE RIDGE

APPALACHIAN

PLATEAU

VALLEY AND RIDGE

50 100 MILES

00

100 KILOMETERS 50

82o

37o

80o

38o

39o

78o 76o

Shenandoah National Park

Rock Creek Park

Patuxent Research Refuge

Beltsville Agricultural Research Center

Potomac

River

CHESAPEAKE BAY

ATLANTIC OCEAN

Washington, D.C.

Front Royal

Waynesboro

Baltimore

Prince WilliamForest Park

Chesapeake and Ohio Canal National Historical Park

MARYLAND

Base and physiographic province boundaries from U.S. Geological SurveyDigital Line Graph, 1:2,000,000, 1987

Figure 1. Location of data-collection sites in Maryland, Washington, D.C., and Virginia.
Collection and Analysis of Water-Quality Samples 3

Collection and Analysis of

Water-Quality Samples

Water temperature, specific conductance, and pH were 

measured in the field. Water samples were collected and sent 

to laboratories to be analyzed for ANC, total Kjeldahl nitrogen, nitrite plus nitrate, total N, and total P concentrations. 

Field Data-Collection Methods

During each site visit, measurements of water temperature, specific conductance, and pH were made. These properties were measured in 2005 with a Universal Pocket Meter 

Multiline P4 (manufactured by WTW, Weilheim, Germany) 

and in 2006–2007 with a Hanna multiparameter meter 991300. 

Before measuring the physical properties of the water, the pH 

electrode was calibrated by using pH buffers of 4.0 and 7.0 pH 

units, and the conductivity probe was calibrated. The probes 

of the meter were placed directly into the water by reaching 

over the surface of the water from the bank. At sites where 

this method was not practical, a grab sample was collected 

by using a wide-mouth polyethylene bottle, and the probes 

were placed in the bottle. All field analyses were made using 

unfiltered (whole) water. 

Samples for laboratory analyses of selected constituents 

were collected as grab samples. At vernal pools, samples were 

collected approximately 2 meters from the bank and approximately 10 centimeters below the water surface. Care was 

taken to avoid collecting water that contained sediment stirred 

up from the pool bottom. At streams, samples were collected 

from an area of maximum discharge, which generally was near 

the center of the stream channel. In shallow streams, water 

was collected by using a 60-cubic centimeter syringe and 

discharging the sample into a sample bottle. 

The polyethylene sampling bottles with caps were rinsed 

three times with in situ water prior to sampling. At both vernal 

pools and streams, samples for analysis of ANC, total Kjeldahl 

nitrogen, and total P concentrations were collected by holding 

the sample bottle opening below the water surface and allowing the bottle to fill. Water samples for analysis of ANC were 

collected in a 250-milliliter (mL) clear sample bottle filled to 

the top. Water samples for analysis of concentrations of total 

Kjeldahl nitrogen and total P were collected in a 125-mL clear 

sample bottle filled to the top, and 1.0 mL of Baker 4.5-normal 

(1:7) sulfuric acid was added as a preservative. Water samples 

for analysis of concentrations of nitrite plus nitrate and total 

N were collected by using disposable two-piece Norm-Ject 

20-mL syringes (manufactured by Henke Sass Wolf). Each 

syringe was rinsed three times prior to the sample collection. 

Sample water was filtered through a Whatman 0.45-micron 

PES 25-millimeter diameter PP filter into a 125-mL amber 

sample bottle. Samples were chilled and stored until all field 

work was completed, typically about 2 weeks. The samples 

then were shipped on ice in coolers for laboratory analysis. 

Laboratory Analytical Methods

Acid-neutralizing capacity was determined in the USGS 

Water, Energy, and Biogeochemical Budgets (WEBB) Project 

Laboratory in Lakewood, CO, using the automated Gran 

titration (U.S. Environmental Protection Agency test method 

number AERP 05). Because this method is designed to report 

negative values (that is, net acidity), there is no detection limit. 

Concentrations of total Kjeldahl nitrogen, nitrite plus 

nitrate, total N, and total P were determined in the USGS 

National Water-Quality Laboratory in Lakewood, CO. 

Samples for total Kjeldahl nitrogen were analyzed by using a 

microkjeldahl digestion method, which yields a concentration 

of ammonium plus organic nitrogen (Patton and Truitt, 2000). 

The reporting limit for the total Kjeldahl nitrogen method is 

0.14 milligram per liter (mg/L) as N. Samples for nitrite plus 

nitrate concentration were analyzed using a cadmium reduction method with a reporting limit of 0.04 mg/L (Fishman, 

1993). Total N and total P concentrations were determined by 

using an alkaline persulfate digestion method, with reporting 

limits of 0.06 mg/L as N and 0.02 mg/L as P, respectively 

(Patton and Kryskalla, 2003). 

Quality Assurance and Quality Control

All laboratories providing water-quality data for the 

USGS must participate in the Standard Reference Water 

Sample (SRWS) Program, a continuing quality-assurance 

program. A major-ion constituent, a trace-metal constituent, 

a nutrient sample, and a precipitation sample are prepared by 

the USGS Branch of Quality Assurance and distributed to participating laboratories twice a year. Natural waters are used to 

prepare these samples and may be spiked with certain analytes 

to increase the range in concentration. 

In addition to the SRWS Program, the USGS WEBB 

project laboratory voluntarily participates in an ongoing 

laboratory intercomparison study conducted by Environment 

Canada. Two samples of natural waters are sent to participating laboratories each year by Environment Canada (2006). 

Samples are analyzed for concentrations of major cations and 

anions, silica, dissolved-organic carbon, and alkalinity, and for 

values of pH and specific conductance. 

For quality assurance of the data collected, two sequential 

water-quality samples were collected at random sites during 

each sampling trip, and the second sample was the replicate 

sample, which was collected immediately after the first sample 

was collected. The purpose of replicate samples is to evaluate the variability in sampling and analysis processes. Results 

of laboratory analyses of replicate samples are reported in 

tables 2–4.
4 Water-Quality Data at Amphibian Research Sites in Maryland, Washington, D.C., and Virginia, 2005–2007

Acknowledgments

I appreciate the sampling assistance of William Yeaman 

and Kenneth Ferebee at Rock Creek Park, and the logistical 

help provided by James Atkinson at Shenandoah National 

Park and Holliday Obrecht and Marshall Howe at the Patuxent Research Refuge. I thank the following Patuxent Research 

Refuge ARMI staff for field assistance: Andrew Dietrich, 

Sara E. Faust, Lindsay D. Funk, Evan H.C. Grant, Sandra 

Mattfeldt, Priya K. Nanjappa, Clint Otto, Sheera Schneider, 

and Edward J. Schwartzman. I also appreciate the colleague 

reviews of the report provided by Evan H.C. Grant, Patuxent 

Research Refuge, and William A. Battaglin, USGS Colorado 

Water Science Center; the data review by Amy E. Jensen, 

USGS Virginia Water Science Center; and graphics support 

provided by Robert B. Banks, USGS Virginia Water 

Science Center.

References Cited

Environment Canada, 2006, Information and quality management/inorganic analysis laboratory/organic analysis laboratory—National Laboratory for Environmental Testing: 

Environment Canada; accessible online at http://www.nwri.

ca/nletlnee/intro-e.html

Fishman, M.J., ed., 1993, Methods of analysis by the U.S. 

Geological Survey National Water Quality Laboratory—

Determination of inorganic and organic constituents in 

water and fluvial sediments: U.S. Geological Survey OpenFile Report 93–125, 217 p.

Patton, C.J., and Kryskalla, J.R., 2003, Methods of analysis 

by the U.S. Geological Survey National Water Quality 

Laboratory: Evaluation of alkaline persulfate digestion as 

an alternative to Kjeldahl digestion for determination of 

total and dissolved nitrogen and phosphorus in water: U.S. 

Geological Survey Water-Resources Investigations Report 

2003–4174, 33 p.

Patton, C.J., and Truitt, E.P., 2000, Methods of analysis by 

the U.S. Geological Survey National Water Quality Laboratory—Determination of ammonium plus organic nitrogen 

by a Kjeldahl digestion method and an automated photometric finish that includes digest cleanup by gas diffusion: U.S. 

Geological Survey Open-File Report 2000–170, 31 p.
Table 1 5

Table 1. Description of water-quality sampling sites in Maryland, Washington, D.C., and Virginia, 2005–2007.—Continued

[ID, identification number; VP, vernal pool sites; all other sites are streams; na, not applicable]

Station ID Site name Latitude Longitude County

Patuxent Research Refuge, Maryland

390138076522007 Powerline Site 57-68 (VP) 39o 01' 42.0" 76o 52' 22.6" Prince George’s.

390201076512901 Shumate Site (VP) 39o 02' 00.9" 76o 51' 27.9" Prince George’s.

390206076483501 Sam’s Pond (VP) 39o 01' 55.2" 76o 48' 34.2" Prince George’s.

390211076521402 Entomology Back Pond 1 (VP) 39o 02' 08.4" 76o 52' 10.0" Prince George’s.

390211076521403 Entomology Back Pond 2 (VP) 39o 02' 08.1" 76o 52' 10.6" Prince George’s.

390211076521405 Entomology Boards 1-19 (VP) 39o 02' 11.6" 76o 52' 13.8" Prince George’s.

390224076520401 Laura’s Pond (VP) 39o 02' 26.3" 76o 51' 59.3" Prince George’s.

390429076472001 Blue Road (VP) 39o 04' 27.7" 76o 47' 28.2" Anne Arundel.

390440076482401 Red Road (VP) 39o 04' 49.7" 76o 48' 22.3" Anne Arundel.

Henry A. Wallace Beltsville Agricultural Research Center, Maryland

390230076512201 Beltsville 1 (VP) 39o 02' 31.3" 76o 51' 20.1" Prince George’s.

390230076512202 Beltsville 2 (VP) 39o 02' 31.3" 76o 51' 21.7" Prince George’s.

Chesapeake and Ohio Historical Park, Maryland

390032077142201 COST 8 39o 00' 32.7" 77o 14' 22.8" Montgomery.

385939077142801 COST 21 38o 59' 39.9" 77o 14' 28.8" Montgomery.

385929077142101 COST 22 38o 59' 29.3" 77o 14' 21.8" Montgomery.

385936077135501 COST 27 38o 59' 36.7" 77o 13' 55.0" Montgomery.

385929077131501 COST 28 38o 59' 29.8" 77o 13' 15.0" Montgomery.

385913077134301 COST 31 38o 59' 13.2" 77o 13' 43.0" Montgomery.

385920077134501 COST 39 38o 59' 20.2" 77o 13' 45.5" Montgomery.

Rock Creek Park, Washington, D.C.

385716077031201 West Spring 38o 57' 16.0" 77o 03' 12.0" na.

385846077021601 16th Street 38o 58' 46.0" 77o 02' 16.0" na.

385755077023001 Fairway 18 38o 57' 55.8" 77o 02' 30.1" na.

385838077024301 Riley Spring 2 38o 58' 38.7" 77o 02' 43.5" na.

385725077023801 Picnic 21 38o 57' 25.5" 77o 02' 38.7" na.

Prince William Forest Park, Virginia

383442077252601 PRW 101 38o 34' 42.4" 77o 25' 26.1" Prince William.

383458077250801 PRW 114 38o 34' 58.9" 77o 25' 08.2" Prince William.

383512077243601 PRW 127 38o 35' 12.1" 77o 24' 36.7" Prince William.

383655077251301 PRW 146 38o 36' 55.2" 77o 25' 13.4" Prince William.

383635077243901 PRW 157 38o 36' 35.6" 77o 24' 39.2" Prince William.

383712077253401 PRW 172 38o 37' 12.3" 77o 25' 34.1" Prince William.

383543077241601 PRW 226 38o 35' 43.6" 77o 24' 16.7" Prince William.

383542077240001 PRW 227 38o 35' 42.4" 77o 24' 00.2" Prince William.

383456077224901 PRW 247 38o 34' 56.9" 77o 22' 49.1" Prince William.

383521077221001 PRW 262 38o 35' 21.0" 77o 22' 10.7" Prince William.

383528077221001 PRW 263 38o 35' 28.5" 77o 22' 10.4" Prince William.

383614077212401 PRW 301 38o 36' 14.8" 77o 21' 24.4" Prince William.

383639077222201 PRW 314 38o 36' 39.0" 77o 22' 22.4" Prince William.
6 Water-Quality Data at Amphibian Research Sites in Maryland, Washington, D.C., and Virginia, 2005–2007

Table 1. Description of water-quality sampling sites in Maryland, Washington, D.C., and Virginia, 2005–2007.—Continued

[ID, identification number; VP, vernal pool sites; all other sites are streams; na, not applicable]

Station ID Site name Latitude Longitude County

Prince William Forest Park, Virginia—Continued

383638077221201 PRW 315 38o 36' 38.0" 77o 22' 12.8" Prince William.

383534077210601 PRW 331 38o 35' 34.5" 77o 21' 06.1" Prince William.

383436077214001 PRW 370 38o 34' 36.6" 77o 21' 40.7" Prince William.

383436077212901 PRW 371 38o 34' 36.4" 77o 21' 29.1" Prince William.

383505077242801 PRW 424 38o 35' 05.9" 77o 24' 29.0" Prince William.

383657077255101 PRW 516 38o 36' 57.1" 77o 25' 52.0" Prince William.

Shenandoah National Park, Virginia

0166578010 Big Meadows (VP) 38o 30' 54.0" 78o 26' 05.0" Madison.

0166578040 Hogcamp Swamp (VP) 38o 31' 25.0" 78o 26' 04.0" Madison.

0203143670 Pond Ridge (VP) 38o 09' 51.0" 78o 45' 32.0" Albemarle.

01662358 Piney River Tributary 38o 45' 29.0" 78o 16' 24.0" Rappahannock.

0163054075 RAC.35 38o 38' 47.0" 78o 19' 38.0" Page.

0163054107 RAC.36 38o 38' 34.0" 78o 19' 42.0" Page.

01630154 RAC.39 38o 37' 53.0" 78o 20' 35.0" Page.

01630171 RAC.40 38o 37' 46.0" 78o 20' 48.0" Page.

0163054161 RAC.37 38o 38' 20.0" 78o 19' 51.0" Page.

01630577 RAC.03 38o 42' 18.0" 78o 21' 35.0" Page.

01630579 RAC.02 38o 42' 18.0" 78o 21' 49.0" Page.

01630581 RAC.01 38o 42' 15.0" 78o 22' 03.0" Page.

0166235582 RAC.19 38o 45' 25.0" 78o 16' 45.0" Rappahannock.
Table 2 

7

Table 2. Water-quality data collected from sites in Maryland, 2005–2007. [oC, degrees Celsius; μS/cm, microsiemens per centimeter at 25 oC; ANC, acid-neutralizing capacity; TKN, total Kjeldahl nitrogen; NO2 + NO3, nitrite plus nitrate; N, nitrogen; P, phosphorus; mg/L, milligrams per liter; μeq/L, microequivalents per liter; –, no data; <, less than; E, estimated; *, replicate sample]

Site name Date Time

Water 

temperature 

(oC)

Specific 

conductance 

(μS/cm)

pH 

(units)

ANC

 (μeq/L)

TKN 

(mg/L as N)

NO2 + NO3 

(mg/L as N)

Total N 

(mg/L)

Total P 

(mg/L)

Patuxent Research Refuge

Powerline Site 57-68 3-15-2005 1210 7.3 50 5.87 207.3 0.822 <0.060 1.051 0.06Shumate Site 3-14-2005 1715 7.6 124 5.27 22.8 0.624 <0.060 0.71 0.033Sam's Pond 3-15-2005 1330 9.5 35 4.5 16.9 0.875 <0.060 1.196 0.078Entomology Site 1-19 3-15-2005 1018 5.6 691 5.99 355.8 0.922 <0.060 1.003 0.084Entomology Site Backpond 1 3-15-2005 1045 4.8 159 5.36 – 1.034 <0.060 0.982 0.081Entomology Site Backpond 2 3-15-2005 1045 4.8 159 – 53.5 – – – –Laura's Pond B, South side 3-15-2005 1215 7.6 103 5.65 37.8 0.317 <0.060 0.332 0.021Laura's Pond A, North side 3-15-2005 1400 8.4 96 5.61 18.9 0.498 <0.060 0.476 0.039Blue Road (VP) 3-14-2005 1000 5.8 38 5.5 88.7 0.516 <0.060 0.785 0.041Red Road (VP) 3-14-2005 1540 11.5 25 4.37 -20.3 0.351 <0.060 0.365 0.022

Henry A. Wallace Beltsville Agricultural Research Center

Beltsville 1 3-25-2005 1215 8.5 35 5.48 4.4 0.772 0.077 0.982 0.083

*3-25-2005 1220 – – – 3.9 0.589 <0.060 0.638 0.042

Beltsville 2 3-25-2005 1210 8.5 29 4.76 70.4 1.063 <0.060 1.464 0.151

Chesapeake and Ohio Historical Park

COST 8 7-29-2005 1405 13.4 86 6.87 525.6 0.386 6.752 7.306 0.083

*7-29-2005 1415 – – – 524.9 0.224 6.742 7.245 0.082

7-14-2006 1428 13.2 194 5.69 – 0.106 6.667 6.742 0.038

COST 21 7-29-2005 1140 17.1 55 6.42 414.7 0.295 0.144 0.451 0.083

7-17-2006 1259 16.9 62 5.78 – 0.269 0.09 0.354 0.054

COST 22 7-27-2006 1235 14.7 53 6.18 315.9 0.773 <0.060 1.033 0.131

7-17-2006 1137 16.5 87 5.75 – 0.869 E 0.034 1.081 0.423

COST 27 7-25-2006 1342 16.6 195 5.46 461.1 1.089 E 0.072 1.231 E 0.015COST 28 7-25-2006 1325 16.7 248 5.90 159.6 E 0.084 1.56 1.735 E 0.017COST 31 7-26-2006 1058 16.3 108 5.81 445 0.203 0.98 1.349 0.080

7-14-2006 954 13.5 123 5.98 – 0.711 1.17 1.706 0.125

COST 39 7-26-2006 1348 12.7 243 6.31 287.8 0.5 2.273 2.862 0.072

7-14-2006 1152 13.5 286 5.79 – 0.427 2.603 2.894 0.040

*7-14-2006 1153 – – – – 0.257 2.619 2.679 0.024
8 Water-Quality Data at Amphibian Research Sites in Maryland, Washington, D.C., and Virginia, 2005–2007

Table 3. Water-quality data collected from sites in Washington, D.C., 2005–2007. 

[oC, degrees Celsius; μS/cm, microsiemens per centimeter at 25 oC; ANC, acid-neutralizing capacity; TKN, total Kjeldahl nitrogen; NO2 + NO3, nitrite plus nitrate; 

N, nitrogen; P, phosphorus; mg/L, milligrams per liter; μeq/L, microequivalents per liter; –, no data; <, less than; E, estimated; *, replicate sample]

Site name Date Time

Water 

temperature (oC)

Specific 

conductance 

(μS/cm)

pH 

(units)

ANC 

(μeq/L)

TKN 

(mg/L as N)

NO2 + NO3

(mg/L as N)

Total N 

(mg/L)

Total P 

(mg/L)

Rock Creek Park

West Spring 7-21-2005 1236 13 497 5.54 417.9 <0.10 0.695 0.714 0.030

*7-21-2005 1239 – – – 430.3 <0.10 0.681 0.747 0.027

7-24-2006 1011 13 545 5.55 – <0.10 0.842 0.807 0.022

*7-24-2006 1012 – – – – <0.10 0.834 0.809 0.025

16th Street 7-18-2005 1306 20.1 405 6.32 196 0.972 3.019 4.307 0.147

7-21-2006 1033 17.2 475 7.16 – 0.397 3.824 3.845 0.044

Fairway 18 7-24-2005 1520 19.3 153 6.47 554.9 0.149 6.22 6.656 0.039

7-21-2006 1330 18.3 131 4.86 – 0.238 4.896 4.727 E 0.015

Riley Spring 2 7-24-2005 1440 18.1 42 7.02 287.6 0.381 0.309 0.634 0.086

7-24-2006 1437 18.4 56 5.72 – 0.266 <0.060 0.257 0.036

Picnic 21 7-21-2005 1510 12.7 42 5.44 228.8 0.315 0.067 0.466 0.094

7-21-2006 1330 13.3 42 5.38 – E 0.050 0.112 0.137 0.032
Table 4 9

Table 4. Water-quality data collected from sites in Virginia, 2005–2007.—Continued

[oC, degrees Celsius; μS/cm, microsiemens per centimeter at 25 oC; ANC, acid-neutralizing capacity; ANC data for Prince William Forest Park are given in mg/L; TKN, 

total Kjeldahl nitrogen; NO2 + NO3, nitrite plus nitrate; N, nitrogen; P, phosphorus; mg/L, milligrams per liter; μeq/L, microequivalents per liter; –, no data; 

<, less than; E, estimated; *, replicate sample; (VP), vernal pool]

Site name Date Time

Water 

temperature 

(oC)

Specific 

conductance

 (μS/cm)

pH 

(units)

ANC 

(μeq/L)

TKN 

(mg/L as N)

NO2 + NO3

(mg/L as N)

Total N 

(mg/L)

Total P 

(mg/L)

Prince William Forest Park

PRW101 7-19-2006 1603 19.3 96 5.65 6.96 E 0.091 E 0.052 0.118 <–0.02

*7-19-2006 1604 – – – 6.88 0.501 E 0.050 0.179 <–0.02

PRW 114 7-18-2006 1659 21.4 69 5.97 8.4 0.529 < 0.060 0.479 0.086

PRW 127 7-18-2006 1042 13.5 13 7.12 3.36 0.318 < 0.060 0.275 <–0.02

PRW 146 7-10-2006 1549 19.7 32 5.80 6.86 0.296 < 0.060 0.267 <–0.02

PRW 157 7-19-2006 1333 19.9 90 5.94 27.56 0.247 < 0.060 0.197 0.029

PRW 172 7-10-2006 1146 17.7 27 5.11 4.38 0.143 < 0.060 0.124 <–0.02

PRW 226 7-11-2006 957 19.2 24 7.09 8.38 0.291 < 0.060 0.236 E 0.017

PRW 227 7-11-2006 1235 19.6 22 5.52 2.97 0.261 < 0.060 0.148 <–0.02

*7-11-2006 1236 – – – 2.87 0.222 < 0.060 0.181 <–0.02

PRW 247 7-10-2006 1217 16.1 42 5.42 12.61 0.382 < 0.060 0.251 0.055

PRW 262 7-10-2006 1455 19.4 28 7.34 3.11 0.119 < 0.060 0.096 <–0.02

PRW 263 7-19-2006 1036 18.7 44 5.42 6.89 0.167 < 0.060 0.106 0.028

PRW 301 7-19-2006 1120 19 126 5.68 52.33 0.123 0.062 0.134 E 0.010

PRW 314 7-11-2006 1408 16.3 37 5.48 11.01 1.829 E 0.057 1.427 0.435

PRW 315 7-11-2006 1127 17.4 92 7.23 29.28 0.566 < 0.060 0.549 0.117

PRW 331 7-19-2006 1414 19.2 64 5.3 12.28 0.113 < 0.060 0.085 <–0.02

*7-19-2006 1418 – – – 12.51 0.117 < 0.060 0.084 <–0.02

PRW 370 7-18-2006 1405 19.7 23 7.33 4.62 0.167 E 0.057 0.238 0.023

PRW 371 7-18-2006 1620 18.7 26 4.85 3 0.29 E 0.030 0.192 E 0.015

PRW 424 7-18-2006 1504 18.2 32 5.12 7.36 0.32 0.108 0.45 0.1

PRW 516 7-10-2006 1724 19.4 130 6.36 57.99 0.371 < 0.060 0.321 0.049

Shenandoah National Park

Big 

Meadows 

(VP)

4-4-2005 1240 12.4 – 5.53 11.4 0.118 <0.060 0.125 <0.02

Hogcamp 

Swamp 

(VP)

4-4-2005 1358 13.7 – 6.18 93 0.127 0.355 0.485 <0.02

Pond 

Ridge 

(VP)

3-17-2005 1125 3.3 15 5.26 22 0.64 <0.060 0.639 0.075

3-17-2005 1128 24.7 0.701 <0.060 0.649 0.067

Piney 

River 

Tributary

7-17-2007 1033 15.9 8 7.14 65.0 – – – –

RAC.35 6-28-2007 1000 13.9 27 6.10 92.1 – – – –

RAC.36 6-26-2007 1126 12.6 17 5.80 70.8 – – – –
10 Water-Quality Data at Amphibian Research Sites in Maryland, Washington, D.C., and Virginia, 2005–2007

Table 4. Water-quality data collected from sites in Virginia, 2005–2007.—Continued

[oC, degrees Celsius; μS/cm, microsiemens per centimeter at 25 oC; ANC, acid-neutralizing capacity; ANC data for Prince William Forest Park are given in mg/L; TKN, 

total Kjeldahl nitrogen; NO2 + NO3, nitrite plus nitrate; N, nitrogen; P, phosphorus; mg/L, milligrams per liter; μeq/L, microequivalents per liter; –, no data; 

<, less than; E, estimated; *, replicate sample; (VP), vernal pool]

Site name Date Time

Water 

temperature 

(oC)

Specific 

conductance

 (μS/cm)

pH 

(units)

ANC 

(μeq/L)

TKN 

(mg/L as N)

NO2 + NO3

(mg/L as N)

Total N 

(mg/L)

Total P 

(mg/L)

Shenandoah National Park—Continued

RAC.39 6-19-2007 953 12.1 22 6.30 < 0.1 0.194 – –

6-19-2007 954 12.1 22 6.30 89.6 < 0.1 0.196 – –

6-19-2007 1015 12.1 22 6.30 – E 0.075 0.183 – –

6-19-2007 1017 12.1 22 6.30 – < 0.1 0.185 – –

7-25-2007 848 13 26 5.68 – E 0.056 0.149 – –

7-25-2007 849 13 26 5.68 – < 0.10 0.148 – –

7-25-2007 850 13 26 5.68 – E 0.072 0.155 – –

7-25-2007 913 13 26 5.68 – E 0.052 0.112 – –

7-25-2007 914 13 26 5.68 – 0.473 0.108 – –

7-25-2007 915 13 26 5.68 – < 0.10 0.108 – –

9-12-2007 856 15.3 61 6.22 – 0.108 – – –

9-12-2007 857 15.3 61 6.22 – E 0.082 – – –

9-12-2007 858 15.3 61 6.22 – 0.272 – – –

9-12-2007 900 15.3 61 6.22 – 0.132 – – –

9-12-2007 901 15.3 61 6.22 – E 0.087 – – –

9-12-2007 902 15.3 61 6.22 – E 0.071 – – –

RAC.40 6-22-2007 951 11.1 20 5.40 – < 0.10 0.212 – –

6-22-2007 952 11.1 20 5.40 – < 0.10 0.217 – –

6-22-2007 953 11.1 20 5.40 79.9 E 0.059 – – –

6-22-2007 1021 11.1 20 5.40 – 0.153 0.202 – –

6-22-2007 1022 11.1 20 5.40 – 0.197 0.205 – –

6-22-2007 1023 11.1 20 5.40 – 0.243 – – –

7-27-2007 940 14.3 32 5.89 – 0.149 0.232 – –

7-27-2007 941 14.3 32 5.89 – 0.112 0.231 – –

7-27-2007 942 14.3 32 5.89 – 0.128 0.232 – –

7-27-2007 946 14.3 32 5.89 – < 0.10 0.138 – –

7-27-2007 947 14.3 32 5.89 – E 0.052 0.144 – –

7-27-2007 948 14.3 32 5.89 – E 0.079 0.140 – –

9-14-2007 901 15.8 31 6.07 – < 0.10 – – –

9-14-2007 902 15.8 31 6.07 – E 0.070 – – –

9-14-2007 903 15.8 31 6.07 – < 0.10 – – –

9-14-2007 911 15.8 31 6.07 – 0.312 – – –

9-14-2007 912 15.8 31 6.07 – 0.140 – – –

9-14-2007 913 15.8 31 6.07 – 0.381 – – –
Table 4 11

Table 4. Water-quality data collected from sites in Virginia, 2005–2007.—Continued

[oC, degrees Celsius; μS/cm, microsiemens per centimeter at 25 oC; ANC, acid-neutralizing capacity; ANC data for Prince William Forest Park are given in mg/L; TKN, 

total Kjeldahl nitrogen; NO2 + NO3, nitrite plus nitrate; N, nitrogen; P, phosphorus; mg/L, milligrams per liter; μeq/L, microequivalents per liter; –, no data; 

<, less than; E, estimated; *, replicate sample; (VP), vernal pool]

Site name Date Time

Water 

temperature 

(oC)

Specific 

conductance

 (μS/cm)

pH 

(units)

ANC 

(μeq/L)

TKN 

(mg/L as N)

NO2 + NO3

(mg/L as N)

Total N 

(mg/L)

Total P 

(mg/L)

Shenandoah National Park—Continued

RAC.37 6-21-2007 946 10.8 29 6.11 76.1 < 0.10 0.366 – –

6-21-2007 947 10.8 29 6.11 – < 0.10 0.369 – –

6-21-2007 948 10.8 29 6.11 – < 0.10 – – –

6-21-2007 1015 10.8 29 6.11 – < 0.10 0.34 – –

6-21-2007 1016 10.8 29 6.11 – < 0.10 0.347 – –

6-21-2007 1017 10.8 29 6.11 – 0.105 – – –

7-26-2007 902 13.4 21 6.04 – < 0.10 0.314 – –

7-26-2007 903 13.4 21 6.04 – E 0.077 0.308 – –

7-26-2007 904 13.4 21 6.04 – E 0.063 0.318 – –

7-26-2007 921 13.4 21 6.04 – 0.167 0.330 – –

7-26-2007 922 13.4 21 6.04 – 0.193 0.331 – –

7-26-2007 923 13.4 21 6.04 – 0.106 0.337 – –

9-13-2007 930 14.3 25 5.62 – E 0.068 – – –

9-13-2007 931 14.3 25 5.62 – E 0.070 – – –

9-13-2007 932 14.3 25 5.62 – E 0.090 – – –

9-13-2007 945 14.3 25 5.62 – 0.427 – – –

9-13-2007 946 14.3 25 5.62 – E 0.099 – – –

9-13-2007 947 14.3 25 5.62 – E 0.088 – – –

RAC.03 7-20-2007 1122 16.2 18 7.14 48.2 – – – –

RAC.02 7-18-2007 1439 19.1 20 7.00 36.8 – – – –

RAC.01 7-18-2007 1006 15.5 17 5.49 56.7 – – – –

RAC.19 6-18-2007 1608 11.4 36 5.75 34.5 – – – –

6-29-2007 1007 11 14 6.01 42.6 – – – –

Prepared by:

 USGS Enterprise Publishing Network

 Raleigh Publishing Service Center

 3916 Sunset Ridge Road

 Raleigh, NC 27607

For additional infomation regarding this publication, contact:

 Karen C. Rice

 USGS Virginia Water Science Center

 Watershed Studies Section

 900 Natural Resources Drive, Suite 500

 Charlottesville, VA 22903

 Phone: 434-297-0106

 email: kcrice@usgs.gov

Or visit the Virginia Water Science Center website at:

 http://va.water.usgs.gov
Rice—Water-Quality Data at Amphibian Research Sites in Maryland, Washington, D.C., and Virginia, 2005–2007—Open-File Report 2008–1204