Summary of Ground-Water-Quality Data 

in the Anacostia River Watershed, 

Washington, D.C., September–

December 2005

By Cheryl A. Klohe and Linda M. Debrewer

Prepared in cooperation with the 

District Department of the Environment

Open-File Report 2006–1392

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: 2007

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment:

World Wide Web: http://www.usgs.gov

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U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Klohe, C.A., and Debrewer, L.M., 2007, Summary of ground-water-quality data in the Anacostia River Watershed, 

Washington, D.C., September–December 2005: U.S. Geological Survey Open-File Report 2006–1392, 64 p.
iii

Contents

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

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

Previous Investigations........................................................................................................................4

Purpose and Scope ..............................................................................................................................4

Description of Study Area ...................................................................................................................4

Sample Collection, Analysis, and Quality Control ....................................................................................4

Sample Collection and Analysis.........................................................................................................4

Quality Control.......................................................................................................................................5

Ground-Water Quality and Occurrence and Distribution of Selected Constituents ........................12

Inorganic Water Chemistry ...............................................................................................................12

Nutrients in Ground Water................................................................................................................15

Pesticides in Ground Water..............................................................................................................20

Volatile Organic Compounds, Semivolatile Organic Compounds, and Other Organic 

Compounds in Ground Water..............................................................................................22

Summary........................................................................................................................................................25

Acknowledgments.......................................................................................................................................26

References Cited..........................................................................................................................................26

Appendix 1. List of Chemical Constituents, Reporting Limits, and Methods of Analysis 

Used During the Study...................................................................................................................30

Appendix 2. Concentrations of Inorganic Constituents in Ground Water from Selected 

Wells in the Anacostia River Watershed Within Washington, D.C., September–

December 2005, and Selected Water-Quality Criteria .............................................................38

Appendix 3. Concentrations of Pesticides, Degradates, Volatile Organic Compounds, 

and Semivolatile Organic Compounds in Ground Water from Selected Wells in 

the Anacostia River Watershed Within Washington, D.C., September–

December 2005, and Selected Water-Quality Criteria .............................................................44

Figures

1. Map showing study area and monitoring well locations, Washington, D.C. .....................2

2. Trilinear diagram showing A, general water types for ground water; and 

B, water types for ground-water samples from the Anacostia River watershed in 

Washington, D.C., September–December 2005.....................................................................13

3–9. Maps showing—

3. Spatial distribution of iron concentrations in ground-water samples from 

the Anacostia River watershed within Washington, D.C., September–

December 2005...................................................................................................................16

4. Spatial distribution of manganese concentrations in ground-water samples 

from the Anacostia River watershed within Washington, D.C., September–

December 2005...................................................................................................................17

5. Spatial distribution of arsenic concentrations in ground-water samples 

from the Anacostia River watershed within Washington, D.C., September–

December 2005...................................................................................................................18
iv

Tables

1. Location and construction information for ground-water monitoring wells sampled 

from September through December 2005, Washington, D.C. ...............................................3

2. Estimated uncertainty in reported concentrations of selected constituents in 

ground water from selected wells in the Anacostia River watershed within 

Washington, D.C., September–December 2005.......................................................................6

3. Summary statistics for field parameters measured in ground-water samples 

from the Anacostia River watershed within Washington, D.C., September–

December 2005............................................................................................................................14

4. Summary statistics for major ions measured in ground-water samples from 

the Anacostia River watershed within Washington, D.C., September–

December 2005............................................................................................................................14

5. Summary statistics for trace elements and cyanide measured in ground-water 

samples from the Anacostia River watershed within Washington, D.C., 

September–December 2005......................................................................................................15

6. Summary statistics for nutrients measured in ground-water samples from 

the Anacostia River watershed within Washington, D.C., September–

December 2005............................................................................................................................20

7. Summary statistics for pesticides and degradates detected in ground-water 

samples from the Anacostia River watershed within Washington D.C., 

September–December 2005......................................................................................................22

8. Summary statistics for organic compounds detected in ground-water samples 

from the Anacostia River watershed within Washington D.C., September–

December 2005............................................................................................................................25

6. Spatial distribution of nitrite plus nitrate in ground-water samples from 

the Anacostia River watershed within Washington, D.C., September–

December 2005...................................................................................................................19

7. Spatial distribution of ammonia in ground-water samples from the Anacostia 

River watershed within Washington, D.C., September–December 2005 .................21

8. Spatial distribution of pesticide and degradate detections in ground-water 

samples from the Anacostia River watershed within Washington, D.C., 

September–December 2005.............................................................................................23

9. Spatial distribution of volatile organic compound (VOC) detections in groundwater samples from the Anacostia River watershed within Washington, D.C., 

September–December 2005.............................................................................................24
Conversion Factors and Datums

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square mile (mi2) 259.0 hectare (ha)

square mile (mi2) 2.590 square kilometer (km2) 

Volume

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3) 

gallon (gal) 3.785 cubic decimeter (dm3) 

cubic foot (ft3) 28.32 cubic decimeter (dm3) 

cubic foot (ft3) 0.02832 cubic meter (m3) 

Flow rate

cubic foot per day (ft3/d) 0.02832 cubic meter per day (m3/d)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

gallon per day (gal/d) 0.003785 cubic meter per day (m3/d)

Mass

ounce, avoirdupois (oz) 28.35 gram (g) 

pound, avoirdupois (lb) 0.4536 kilogram (kg) 

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

 °F=(1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

 °C=(°F-32)/1.8

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

(NAVD 88).

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

Altitude, as used in this report, refers to distance above the vertical datum.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius 

(μS/cm at 25°C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).

Abstract

The U.S. Geological Survey, in cooperation with the 

District Department of the Environment (formerly the District 

of Columbia, Department of Health, Environmental Health 

Administration), conducted a ground-water-quality investigation in the Anacostia River watershed within Washington, D.C. 

Samples were collected and analyzed from 17 ground-water 

monitoring wells located within the study area from September through December 2005. Samples were analyzed for a 

variety of constituents including major ions, nutrients, volatile 

organic compounds, semivolatile organic compounds, pesticides and degradates, oil and grease, phenols, total polychlorinated biphenyls, and other selected constituents. The concentrations of major ions in the study area indicate that the ground 

water is predominantly calcium-bicarbonate type water, with 

some wells containing a higher percentage of milliequivalents 

per liter of iron (cation), and chloride or sulfate (anions). Concentrations of nitrogen were generally less than 1 milligram 

per liter, and concentrations of phosphorus were generally 

less than 0.5 milligrams per liter. Twelve of 79 pesticides and 

degradates were detected at 6 out of 17 wells. Volatile organic 

compounds (predominantly gasoline oxygenates and solvents) 

were detected in 9 of the 17 wells. Two semivolatile organic 

compounds, (bis(2-ethylhexyl) phthalate and total phenols), 

out of the 51 analyzed, were detected in the study area.

Introduction

Ground-water quality in the Atlantic Coastal Plain 

Physiographic Province is influenced by the presence of 

soluble ions from natural sources (such as dissolution of 

minerals in the aquifer sediments) and human sources (such 

as road salting), and by geochemical factors that affect the 

mobility and fate of these ions within the aquifer. Additional 

human influences on water quality in the Washington, D.C. 

area include industrial, commercial, and residential land uses 

(Schneider and others, 1993a).

Herbicides, insecticides, and fungicides (collectively 

referred to as pesticides) are used on lawns, gardens, golf 

courses, and cemeteries, as well as in turf maintenance, near 

building foundations, and in the soils surrounding building 

foundations to control termites and other destructive insects. 

Pesticide use in urban areas has changed over the last 

several decades due to the development of new herbicides 

and insecticides and the replacement of organochlorine 

insecticides with alternative compounds (Barbash and Resek, 

1996). Pesticide compounds commonly used in urban settings 

across the Nation were analyzed in the shallow ground-water 

samples from the study area.

Residential and commercial-urban land use contribute 

more volatile organic compounds (VOCs) to ground water 

across the Nation than other land uses (Zogorski and others, 

2006). The presence of VOCs and semivolatile organic 

compounds (SVOCs) in ground water depends on several 

factors, including aquifer properties, stresses on the aquifer 

such as pumping, the relative location of the sampling site, 

and the transport and fate of contaminants. Urban settings 

may have more sources and releases as well as enhanced areas 

of ground-water recharge compared to non-urban settings 

(Zogorski and others, 2006). Possible sources of VOCs in 

urban settings include chemical manufacturing, industrial 

processes (solvents, degreasers, dry cleaning), and gasoline or 

other petroleum-based fuels.

From September through December 2005, the U.S. 

Geological Survey (USGS) collected ground-water-quality 

samples from 17 wells in the Anacostia River watershed, 

within Washington, D.C. (fig. 1, table 1). Field parameters, 

such as pH and specific conductance, were measured at the 

sites at the time of sampling. Samples were collected and 

analyzed for constituents including major ions, nutrients, trace 

elements, VOCs, SVOCs, pesticides and their degradates, oil 

and grease, phenols, total polychlorinated biphenyls (PCBs), 

and cyanide. Sampling was conducted to expand the database 

of baseline concentrations of potential contaminants in ground 

water within the Washington, D.C. part of the Anacostia River 

watershed. The constituents were selected on the basis of 

previous analyses of ground-water samples in the watershed 

as well as constituents currently regulated by the District 

Department of the Environment (DDOE).

Summary of Ground-Water-Quality Data in the 

Anacostia River Watershed, Washington, D.C., 

September–December 2005

By Cheryl A. Klohe and Linda M. Debrewer
Figure 1. Study area and monitoring well locations, Washington, D.C. (modified from Tenbus, 2003).

   Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

L ower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

P

OT

O

M

AC

RI V

E

R

ANACOSTIA

WASHINGTO

N CHANNE L

ANACOSTIA

Beaverdam

Creek

Watts

Branch

RI VE R

RI VE R

WASHINGTON, D.C.

WASHINGTON, D.C.

PRINCE GEORGES

COUNTY,

MARYLAND

PRINCE GEORGES COUNTY,

MARYLAND

U.S.

CAPITOL

Washington

Navy Yard

U.S. NATIONAL

ARBORETUM Kenilworth

Aquatic

Gardens

Kingman L ake

P E N N S Y L V A N I A

P E N N S Y L V A N I A AVE NUE

F L O R ID A

BE NNING R O

A

D

ANAC

OS T IA

ANAC OS T IA

F R E E W A Y

F R E E W A Y

AV E NUE

C O N S T I T U T I O N AV E NUE

NEW Y OR K AV E N UE

INDE P E NDE NC E

50

50

50

295

295

295

4

4

B E N N IN G R O AD

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE Ca 32

WE Cb 8

AC Aa 1

WE Ca 29

WE Ca 33

WE Cb 12

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

MONITORING WELL LOCATION AND IDENTIFIER

EXPLANATION

Base map modified from Tenbus, 2003

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

AV E NUE

A V E N U E

38 52'30" O

38 55'00" O

77 00'00" 76 57'30" O O
Table 1. Location and construction information for ground-water monitoring wells sampled from September through December 2005, Washington, D.C.

[USGS, U.S. Geological Survey; NAVD 88, North American Vertical Datum of 1988; DDOE, District Department of the Environment; unk, unknown; (° ' "), degrees, minutes, seconds]

USGS well 

number

USGS site

identifier

Latitude

( ° ‘ “ )

Longitude

( ° ‘ “ )

Altitude 

of land 

surface, 

in feet 

NAVD 88

Date of

construction Aquifer

Depth 

of well, 

in feet 

below 

land 

surface

Casing 

interval, 

in feet 

below land 

surface

Diameter of casing

(upperlower), in 

inches

Screen 

interval, 

in feet 

below 

land 

surface

Diameter of 

screen 

interval, in 

inches

DDOE well 

number

 AC Aa 1 385225076590101 38°52'25" 76°59'01" 5.7 2/5/1998 Alluvium 30 0–25 2 25–30 1.25 DCMW001-03

 WE Ba 9 385606076584101 38°56'06.5" 76°58'41.4" 81.3 8/15/2005 Potomac Group 18 0.35–8 1 8–18 1 DCMW012-05

 WE Ba 10 385534076582101 38°55'34.4" 76°58'21.4" 74.4 8/18/2005 Alluvium 17 0.35–7 1 7–17 1 DCMW007-051WE Bb 3 385504076563801 38°55'03.6" 76°56'37.7" 12.3 7/24/2002 Alluvium 25 -3.6–15 2 15–25 2 DCMW001-021WE Bb 4 385504076563802 38°55'03.6" 76°56'37.7" 12.4 7/26/2002 Alluvium 32 -3–32 2 22–32 2 DCMW004-02

1WE Ca 29 385238076581501 38°52'38.4" 76°58'15.3" 13.4 7/29/2002 Alluvium 48.5 0.15–38.5 2 38.5–48.5 2 DCMW005-022WE Ca 32 385332076594701 38°53'31.8" 76°59'47.1" 80.0 10/1/1992 Terrace deposits 29 0–19 4 19–29 4 DCMW001-04

 WE Ca 33 385349076592801 38°53'49.8" 76°59'28.3" 67.8 8/5/2005 Terrace deposits 38 0.47–28 2 28–38 2 DCMW006-05

 WE Ca 34 385245076583501 38°52'45.6" 76°58'35.1" 19.6 8/10/2005 Alluvium 33 0.55–13, 33–43 2 13–33 2 DCMW005-051WE Cb 5 385443076562801 38°54'43.5" 76°56'28.4" 18.5 7/24/2002 Terrace deposits 22.6 0.2–12.6 2 12.6–22.6 2 DCMW002-02

1WE Cb 6 385443076562802 38°54'43.5" 76°56'28.4" 18.8 7/25/2002 Terrace deposits 46.3 0.2–36.3 2 36.3–46.3 0.75 DCMW003-022WE Cb 8 385252076572801 38°52'52.3" 76°57'28" 61.0 4/1/1992 Potomac Group 265 0–255 4 255–265 4 DCMW002-04

 WE Cb 11 385332076564101 38°53'32.1" 76°56'41.2" 60.0 7/28/2005 Alluvium 21 0.32–21 1 16–21 1 DCMW003-05 WE Cb 12 385332076564102 38°53'32.1" 76°56'41.2" 60.6 8/3/2005 Potomac Group 39 0.32–29 2 29–39 2 DCMW004-05

 WE Cc 3 385327076544801 38°53'27" 76°54'48.5" 88.7 8/16/2005 Potomac Group 23 0.31–13 1 13–23 1 DCMW008-05

 WW Bc 8 385519077012601 38°55'19.3" 77°01'26.9" 123.4 8/18/2005 Potomac Group 32 0.33–22 1 22–32 1 DCMW009-05

 WW Bc 9 385527077000701 38°55'27.8" 77°00'07.7" 133.6 8/17/2005 Potomac Group 36 0.27–26 1 26–36 1 DCMW011-05

1 Previously sampled in July–August 2002 (Miller and Klohe, 2003).2 Previously sampled in the early 1990s (Schneider and others, 1993a).

Introduction 
Previous Investigations

Previous studies conducted in the Anacostia River 

watershed within Washington, D.C. analyzed ground-water 

samples. Miller and Klohe (2003) analyzed ground-waterquality data from five wells and borehole-sediment-quality 

data from six locations (collected from July through August 

2002) within the watershed. The five wells sampled in 2002 

were re-sampled during the September through December 

2005 study described in this report (WE Bb 3, WE Bb 4, 

WE Cb 5, WE Cb, 6, and WE Ca 29). Ground-water 

samples were analyzed for VOCs, SVOCs, or polyaromatic 

hydrocarbons, organochlorine pesticides, aroclors and total 

PCBs, metals, nutrients, biochemical and chemical oxygen 

demands, total phenols, total cyanide, oil and grease, and 

total suspended and dissolved solids.

Schneider and others (1993a) presented analytical 

results for five wells located in Washington, D.C. Four of the 

five wells are located within the Anacostia River watershed, 

and two of the four were re-sampled by the USGS during 

the September through December 2005 study described 

in this report (WE Ca 32 and WE Cb 8). Schneider and 

others (1993a) analyzed samples for field parameters, major 

ions, trace elements, pesticides, VOCs, SVOCs, and a few 

miscellaneous parameters.

Schneider and others (1993b) presented analytical results 

for eight wells located in Washington, D.C., including three 

wells in the study area; none of these wells were sampled 

for the study described in this report. Schneider and others 

(1993b) analyzed samples for field parameters, major ions, 

trace elements, pesticides, herbicides, and a few miscellaneous 

parameters.

Other selected reports contain ground-water-quality 

analyses for specific areas in the watershed (usually of limited 

geographical extent), such as the Washington Navy Yard, Anacostia Park, the U.S. National Arboretum, and many others.

Purpose and Scope

Analytical results from 17 ground-water-monitoring wells 

located within the Anacostia River watershed within Washington, D.C. are presented in this report. The data include 

analyses from 17 environmental samples, 3 replicate samples 

(corresponding to one of the environmental samples), 3 field 

equipment (all sampling equipment) blanks, 1 equipment 

(pump only) blank, and 8 trip blanks. This report describes the 

site selection and sampling bias, and sample collection and 

analysis methods. Quality control and quality assurance of the 

data also are discussed. The results include all analytical data, 

summary statistics, and a discussion of the results by major 

groups of constituents, ground-water types, and spatial distribution of relative concentrations of constituents.

Description of Study Area

The study area includes the Anacostia River watershed, 

within Washington, D.C. The area is approximately 26 square 

miles within the Atlantic Coastal Plain Physiographic Province 

(fig. 1). Monitoring-well sample locations are shown in 

figure 1. Well location and construction information is 

provided in table 1.

Wells within the study area are screened in various 

aquifers of the Atlantic Coastal Plain unconsolidated 

sediments including: Pleistocene to Holocene alluvium, 

Pleistocene terrace deposits, and undifferentiated units of the 

Potomac Group of Cretaceous age (Cooke, 1952; Johnston 

1964; Tenbus, 2003) (table 1).

Sample Collection, Analysis, and 

Quality Control

From September through December 2005, the USGS 

collected ground-water-quality samples from 17 wells in 

the Anacostia River watershed, within Washington, D.C. 

(fig. 1, table 1). Field parameters including temperature, 

pH, dissolved oxygen, turbidity, alkalinity, and specific 

conductance were measured at the wells. Samples were 

collected and analyzed for constituents including major 

ions, nutrients, trace metals, VOCs, SVOCs, pesticides and 

degradates, oil and gas, phenols, total PCBs, and cyanide.

Sample Collection and Analysis

Ground-water-quality samples were collected from 

17 wells in the Anacostia watershed and processed using 

protocols designed to obtain samples representative of 

the aquifers while minimizing sample contamination and 

measurement variability (U.S. Geological Survey, 1997). 

Wells were purged to remove standing water in the casing 

(a minimum of three well volumes) before samples were 

collected. Purging continued until stabilization of water 

temperature (±0.2oC, degrees Celsius), pH (±0.1 units), 

dissolved oxygen (±0.3 mg/L, milligrams per liter), specific 

conductance (±3 percent), and turbidity (±10 percent). Field 

parameters were measured using a multiple-parameter sonde 

with a flow-through chamber, or a bucket to collect water as it 

was pumped from the well with continuous laminar overflow. 

Water-quality samples were collected using a stainless steel 

submersible pump or a peristaltic pump through Teflon tubing; 

an additional 2 feet of flexible silicon tubing was used in wells 

sampled using the peristaltic pump. Water from a subset of 

samples intended for analysis of dissolved constituents was 

passed through a capsule filter with 0.45-μm (micrometer) 

pores (for inorganic constituents) or a baked glass fiber filter 

with 0.7-μm pores (for pesticides and degradates); selected 

trace elements and major-ion samples were preserved with 

 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
nitric acid or hydrochloric acid to a pH below 2. Selected rawwater samples were preserved with sulfuric acid or nitric acid. 

Bottles were chilled to maintain a temperature of 4oC during 

shipment to the laboratory. Prior to and between collection of 

all samples, all tubing was cleaned following USGS protocols 

(U.S. Geological Survey, 1997) by rinsing with a tap water 

and Liquinox mixture, followed by soaking for 10 minutes in 

10 percent nitric acid, and a final rinse of nanopure deionized 

water (greater than 18 MegaOhms). All other sampling 

equipment was cleaned prior to sampling following USGS 

protocols (U.S. Geological Survey, 1997).

Samples were analyzed for concentrations of major ions, 

trace elements, nutrients, selected pesticides and pesticide 

degradates, VOCs, SVOCs, phenols, PCBs, and oil and grease. 

Bicarbonate concentrations were calculated on the basis of 

field titrations for alkalinity (Radtke and others, 1998). Chemical analyses were conducted at the USGS National WaterQuality Laboratory in Denver, Colorado, following methods 

and procedures described by American Public Health Association (1995, 1998); Fishman (1993); Fishman and Friedman 

(1989); Furlong and others (2001); Garbarino (1999); Garbarino and Damrau (2001); Garbarino and others (2006); Lee and 

others (2002); McLain (1993); Patton and Truitt (1992, 2000); 

Wershaw and others (1987); Zaugg and others (1995), and 

at Severn Trent Laboratory in Arvada, Colorado, following 

methods described in U.S. Environmental Protection Agency 

(1986). A complete list of chemical constituents, reporting 

limits, and methods is provided in appendix 1.

Quality Control

Quality-control samples were collected to provide an 

estimate of sample contamination and measurement variability associated with the data-collection process (Koterba 

and others, 1995; U.S. Geological Survey, 1997). Blank and 

replicate samples were collected, preserved, and analyzed 

using the same methods as those used for the environmental 

samples. Equipment and field blanks were collected to ensure 

that equipment was adequately cleaned to minimize potential 

cross-contamination and to ensure that sample collection and 

processing did not result in contamination. Sequential replicate 

samples were collected immediately following the environmental samples using the same equipment. These samples 

assist in determining the variability of the chemical analyses 

and the consistency of sampling techniques.

Field blanks indicate that reported concentrations of 

selected major ions and trace elements (10 out of 32 compounds analyzed) may contain minimal bias due to sample 

contamination during collection, processing, or shipment 

(table 2), but concentrations detected in the blank samples 

are negligible when compared to typical concentrations in 

environmental samples. In March 2006, after sample collection was completed, the laboratory determined that the blank 

water lot used for equipment blanks for this study was found 

to have higher pH and specific conductance as well as higher 

concentrations of aluminum, barium, and strontium. Laboratory investigations determined that concentrations of aluminum in the blank water ranged from 10 to 70 μg/L, instead of 

less than 1.6 μg/L. The detected blank water concentrations 

may be a result of concentrations in the blank water used, 

rather than sample contamination during collection, processing, or shipping. No other compounds were detected in field 

blanks at concentrations exceeding laboratory reporting levels. 

Replicate analyses indicate minimal variability in laboratory 

and sampling techniques (table 2). Estimated uncertainties in 

reported concentrations exceeded 10 percent only for several 

trace elements (cadmium, copper, uranium, and zinc), nitrite, 

organic nitrogen, and caffeine (table 2).

Sample Collection, Analysis, and Quality Control   
Table 2. Estimated uncertainty in reported concentrations of selected constituents in ground water from selected wells in the 

Anacostia River watershed within Washington, D.C., September–December 2005.—Continued

[BN, number of field blanks; BND, number of blanks in which compound was detected above the laboratory reporting level; BMAX, maximum reported concentration in field blanks; RN, number of replicate sets; RNAGREE, number of replicate sets within which compound was consistently detected or not detected; 

RUNC, median estimated uncertainty in reported concentrations in percent; NC, not computed because no replicate sets had consistent detected concentrations; 

--, not applicable; μg/L, micrograms per liter; mg/L, milligrams per liter; M, presence verified but not quantified; STL, Severn Trent Laboratory; NWQL, 

U.S. Geological Survey National Water Quality Laboratory]

Compound or ion

Contamination bias Sampling uncertainty

BN BND BMAX RN RNAGREE RUNC

1

 (%)

Major ions and trace elements

Aluminum, dissolved 4 3 17 μg/L 3 3 5.30

Antimony, dissolved 4 0 -- 3 3 NC

Arsenic, dissolved 4 0 -- 3 3 6.15

Barium, dissolved 4 1 M 3 3 0.52

Beryllium, dissolved 4 0 -- 3 3 1.24

Cadmium, dissolved 4 0 -- 3 3 16.71a

Calcium, dissolved 4 3 0.16 mg/L 3 3 1.25

Chloride, dissolved 4 0 -- 3 3 1.79

Chromium, dissolved 4 2 0.13 μg/L 3 3 4.37

Cobalt, dissolved 4 0 -- 3 3 0.96

Copper, dissolved 4 2 0.7 μg/L 3 3 14.61a

Cyanide, total 2 0 -- 2 1 NC

Fluoride, dissolved 4 0 -- 3 3 6.91

Iron, dissolved 4 0 -- 3 3 1.13

Lead, dissolved 4 2 0.26 μg/L 3 3 NC

Magnesium, dissolved 4 0 -- 3 3 0.82

Manganese, dissolved 4 0 -- 3 3 0.74

Mercury, dissolved 4 0 -- 3 3 NC

Molybdenum, dissolved 4 0 -- 3 3 4.90

Nickel, dissolved 4 1 0.12 μg/L 3 3 5.48

Potassium, dissolved 4 0 -- 3 3 1.41

Selenium, dissolved 4 0 -- 3 3 NC

Silica, dissolved 4 3 1.6 mg/L 3 3 0.13

Silver, dissolved 4 0 -- 3 3 NC

Sodium, dissolved 4 2 0.31 mg/L 3 3 0.38

Sulfate, dissolved 4 0 -- 3 3 0.82

Thallium, dissolved 4 0 -- 3 3 6.73

Uranium, natural, dissolved 4 0 -- 3 3 10.88b

Zinc, dissolved 4 2 6.2 μg/L 3 3 27.01a

Nutrients

Nitrogen, ammonia + organic nitrogen, total 4 0 -- 3 3 3.80

Nitrogen, ammonia, dissolved 4 0 -- 3 3 3.34

Nitrogen, nitrite + nitrate, dissolved 4 0 -- 3 3 0.33

Nitrogen, nitrite, dissolved 4 0 -- 3 3 12.86b

Phosphorus, dissolved 4 0 -- 3 3 4.07

Phosphorus, total 4 0 -- 3 3 2.13

Pesticides and degradates

2,4-D 4 0 -- 3 3 NC

2,4-D methyl ester 4 0 -- 3 3 NC

2,4-DB 4 0 -- 3 3 NC

2-Chloro-4-isopropylamino-6-amino-s-triazine (CIAT) 4 0 -- 3 3 NC

 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Table 2. Estimated uncertainty in reported concentrations of selected constituents in ground water from selected wells in the 

Anacostia River watershed within Washington, D.C., September–December 2005.—Continued

[BN, number of field blanks; BND, number of blanks in which compound was detected above the laboratory reporting level; BMAX, maximum reported concentration in field blanks; RN, number of replicate sets; RNAGREE, number of replicate sets within which compound was consistently detected or not detected; 

RUNC, median estimated uncertainty in reported concentrations in percent; NC, not computed because no replicate sets had consistent detected concentrations; 

--, not applicable; μg/L, micrograms per liter; mg/L, milligrams per liter; M, presence verified but not quantified; STL, Severn Trent Laboratory; NWQL, 

U.S. Geological Survey National Water Quality Laboratory]

Compound or ion

Contamination bias Sampling uncertainty

BN BND BMAX RN RNAGREE RUNC

1

 (%)

Pesticides and degradates—Continued

2-Chloro-6-ethylamino-4-amino-s-triazine (CEAT) 4 0 -- 3 3 NC

2-Hydroxy-4-isopropylamino-6-ethylamino-s-triazine (OIET) 4 0 -- 3 2 6.06

3(4-Chlorophenyl)-1-methyl urea 4 0 -- 3 3 NC

3-Hydroxycarbofuran 4 0 -- 3 3 NC

3-Ketocarbofuran 4 0 -- 3 3 NC

Acifluorfen 4 0 -- 3 3 NC

Alachlor 2 0 -- 2 2 NC

Aldicarb 4 0 -- 2 2 NC

Aldicarb sulfone 4 0 -- 3 3 NC

Aldicarb sulfoxide 4 0 -- 3 3 NC

Aldrin, total recoverable 4 0 -- 3 3 NC

alpha-Endosulfan, total recoverable 4 0 -- 3 3 NC

Aminomethylphosphonic acid (AMPA), filtered water 4 0 -- 3 3 NC

Atrazine 4 0 -- 3 3 NC

Bendiocarb 4 0 -- 3 3 NC

Benomyl 4 0 -- 3 3 NC

Bensulfuron-methyl 4 0 -- 3 3 NC

Bentazon 4 0 -- 3 3 NC

Bromacil 4 0 -- 3 3 NC

Bromoxynil 4 0 -- 3 3 NC

Carbaryl 4 0 -- 3 3 NC

Carbofuran 4 0 -- 3 3 NC

Chloramben, methyl ester 4 0 -- 3 3 NC

Chlordane, technical mix, total recoverable 4 0 -- 3 3 NC

Chlordiamino-s-triazine (CAAT) 4 0 -- 3 3 NC

Chlorimuron-ethyl 4 0 -- 3 3 NC

Chlorothalonil 4 0 -- 3 3 NC

Clopyralid 4 0 -- 3 3 NC

Cycloate 4 0 -- 3 3 NC

Dacthal monoacid 4 0 -- 3 3 NC

Dicamba 4 0 -- 3 3 NC

Dichlorprop 4 0 -- 3 3 NC

Dieldrin, total recoverable 4 0 -- 3 3 NC

Dinoseb 4 0 -- 3 3 NC

Diphenamid 4 0 -- 3 3 NC

Diuron 4 0 -- 3 3 NC

Endrin, total recoverable 4 0 -- 3 3 NC

Fenuron 4 0 -- 3 3 NC

Flumetsulam 4 0 -- 3 3 NC

Fluometuron 4 0 -- 3 3 NC

Glufosinate, filtered water 4 0 -- 3 3 NC

Sample Collection, Analysis, and Quality Control 
Table 2. Estimated uncertainty in reported concentrations of selected constituents in ground water from selected wells in the 

Anacostia River watershed within Washington, D.C., September–December 2005—Continued

[BN, number of field blanks; BND, number of blanks in which compound was detected above the laboratory reporting level; BMAX, maximum reported concentration in field blanks; RN, number of replicate sets; RNAGREE, number of replicate sets within which compound was consistently detected or not detected; 

RUNC, median estimated uncertainty in reported concentrations in percent; NC, not computed because no replicate sets had consistent detected concentrations; 

--, not applicable; μg/L, micrograms per liter; mg/L, milligrams per liter; M, presence verified but not quantified; STL, Severn Trent Laboratory; NWQL, 

U.S. Geological Survey National Water Quality Laboratory]

Compound or ion

Contamination bias Sampling uncertainty

BN BND BMAX RN RNAGREE RUNC

1

 (%)

Pesticides and degradates—Continued

Glyphosate, filtered water 4 0 -- 3 3 NC

Heptachlor epoxide, total recoverable 4 0 -- 3 3 3.05

Heptachlor, total recoverable 4 0 -- 3 3 NC

Imazaquin 4 0 -- 3 3 NC

Imazethapyr 4 0 -- 3 3 NC

Imidacloprid 4 0 -- 3 3 NC

Lindane, total recoverable 4 0 -- 3 3 NC

Linuron 4 0 -- 3 3 NC

MCPA 4 0 -- 3 3 NC

MCPB 4 0 -- 3 3 NC

Metalaxyl 4 0 -- 3 3 NC

Methiocarb 4 0 -- 3 3 NC

Methomyl 4 0 -- 3 3 NC

Metsulfuron methyl 4 0 -- 3 3 5.52

Mirex, total recoverable 4 0 -- 3 3 NC

Neburon 4 0 -- 3 3 NC

Nicosulfuron 4 0 -- 3 3 NC

Norflurazon 4 0 -- 3 3 NC

Oryzalin 4 0 -- 3 3 NC

Oxamyl 4 0 -- 3 3 NC

p,p'-DDD, total recoverable 4 0 -- 3 3 NC

p,p'-DDE, total recoverable 4 0 -- 3 3 NC

p,p'-DDT, total recoverable 4 0 -- 3 3 NC

p,p'-Methoxychlor, total recoverable 4 0 -- 3 3 NC

Picloram 4 0 -- 3 3 NC

Propham 4 0 -- 3 3 NC

Propiconazole 4 0 -- 3 3 NC

Propoxur 4 0 -- 3 3 NC

Siduron 4 0 -- 3 3 NC

Sulfometuron-methyl 4 0 -- 3 3 NC

Tebuthiuron 4 0 -- 3 3 NC

Terbacil 4 0 -- 3 3 NC

Toxaphene, total recoverable 4 0 -- 3 3 NC

Triclopyr 4 0 -- 3 3 NC

Volatile organic compounds

1,1,1,2-Tetrachloroethane 10 0 -- 2 2 NC

1,1,1-Trichloroethane 10 0 -- 2 2 NC

1,1,2,2-Tetrachloroethane 10 0 -- 2 2 NC

1,1,2-Trichloroethane 10 0 -- 2 2 NC

1,1-Dichloroethane 10 0 -- 2 2 NC

1,1-Dichloroethene 10 0 -- 2 2 NC

   Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Table 2. Estimated uncertainty in reported concentrations of selected constituents in ground water from selected wells in the 

Anacostia River watershed within Washington, D.C., September–December 2005—Continued

[BN, number of field blanks; BND, number of blanks in which compound was detected above the laboratory reporting level; BMAX, maximum reported concentration in field blanks; RN, number of replicate sets; RNAGREE, number of replicate sets within which compound was consistently detected or not detected; 

RUNC, median estimated uncertainty in reported concentrations in percent; NC, not computed because no replicate sets had consistent detected concentrations; 

--, not applicable; μg/L, micrograms per liter; mg/L, milligrams per liter; M, presence verified but not quantified; STL, Severn Trent Laboratory; NWQL, 

U.S. Geological Survey National Water Quality Laboratory]

Compound or ion

Contamination bias Sampling uncertainty

BN BND BMAX RN RNAGREE RUNC

1

 (%)

Volatile organic compounds—Continued

1,1-Dichloropropene 10 0 -- 2 2 NC

1,2,3-Trichlorobenzene 10 0 -- 2 2 NC

1,2,3-Trichloropropane 10 0 -- 2 2 NC

1,2,4-Trichlorobenzene 10 0 -- 2 2 NC

1,2,4-Trimethylbenzene 10 0 -- 2 2 NC

1,2-Dibromoethane 10 0 -- 2 2 NC

1,2-Dichlorobenzene 10 0 -- 2 2 NC

1,2-Dichloroethane 10 0 -- 2 2 NC

1,2-Dichloropropane 10 0 -- 2 2 NC

1,3,5-Trimethylbenzene 10 0 -- 2 2 NC

1,3-Dichlorobenzene 10 0 -- 2 2 NC

1,3-Dichloropropane 10 0 -- 2 2 NC

1,4-Dichlorobenzene 10 0 -- 2 2 NC

2,2-Dichloropropane 10 0 -- 2 2 NC

2-Chlorotoluene 10 0 -- 2 2 NC

4-Chlorotoluene 10 0 -- 2 2 NC

4-Isopropyltoluene 10 0 -- 2 2 NC

Acrylonitrile 10 0 -- 2 2 NC

Benzene 10 0 -- 2 2 NC

Bromobenzene 10 0 -- 2 2 NC

Bromochloromethane 10 0 -- 2 2 NC

Bromodichloromethane 10 0 -- 2 2 NC

Bromomethane 10 0 -- 2 2 NC

Chlorobenzene 10 0 -- 2 2 NC

Chloroethane 10 0 -- 2 2 NC

Chloromethane 10 0 -- 2 2 NC

cis-1,2-Dichloroethene 10 0 -- 2 2 NC

cis-1,3-Dichloropropene 10 0 -- 2 2 NC

Dibromochloromethane 10 0 -- 2 2 NC

Dibromochloropropane 10 0 -- 2 2 NC

Dibromomethane 10 0 -- 2 2 NC

Dichlorodifluoromethane (CFC-12) 10 0 -- 2 2 NC

Dichloromethane 10 0 -- 2 2 NC

Ethylbenzene 10 0 -- 2 2 NC

Hexachlorobutadiene 10 0 -- 2 2 NC

Isopropylbenzene 10 0 -- 2 2 NC

meta- + para-Xylene, total 1 0 -- 1 1 NC

Methyl tert-butyl ether 10 0 -- 2 2 NC

Naphthalene 10 0 -- 2 2 NC

n-Butylbenzene 10 0 -- 2 2 NC

n-Propylbenzene 10 0 -- 2 2 NC

Sample Collection, Analysis, and Quality Control 
Table 2. Estimated uncertainty in reported concentrations of selected constituents in ground water from selected wells in the 

Anacostia River watershed within Washington, D.C., September–December 2005—Continued

[BN, number of field blanks; BND, number of blanks in which compound was detected above the laboratory reporting level; BMAX, maximum reported concentration in field blanks; RN, number of replicate sets; RNAGREE, number of replicate sets within which compound was consistently detected or not detected; 

RUNC, median estimated uncertainty in reported concentrations in percent; NC, not computed because no replicate sets had consistent detected concentrations; 

--, not applicable; μg/L, micrograms per liter; mg/L, milligrams per liter; M, presence verified but not quantified; STL, Severn Trent Laboratory; NWQL, 

U.S. Geological Survey National Water Quality Laboratory]

Compound or ion

Contamination bias Sampling uncertainty

BN BND BMAX RN RNAGREE RUNC

1

 (%)

Volatile organic compounds—Continued

o-Xylene 1 0 -- 1 1 NC

sec-Butylbenzene 10 0 -- 2 2 NC

Styrene 10 0 -- 2 2 NC

tert-Butylbenzene 10 0 -- 2 2 NC

Tetrachloroethene 10 0 -- 2 2 NC

Tetrachloromethane 10 0 -- 2 2 NC

Toluene 10 0 -- 2 2 NC

trans-1,2-Dichloroethene 10 0 -- 2 2 NC

trans-1,3-Dichloropropene 10 0 -- 2 2 NC

Tribromomethane 10 0 -- 2 2 NC

Trichloroethene 10 0 -- 2 2 NC

Trichlorofluoromethane (CFC-11) 10 0 -- 2 2 NC

Trichloromethane 10 0 -- 2 2 NC

Vinyl chloride 10 0 -- 2 2 NC

Xylenes, total 10 0 -- 2 2 NC

Semivolatile organic compounds

2,4,6-Trichlorophenol 2 0 -- 2 2 NC

2,4-Dichlorophenol 2 0 -- 2 2 NC

2,4-Dimethylphenol 2 0 -- 2 2 NC

2,4-Dinitrophenol 2 0 -- 2 2 NC

2,4-Dinitrotoluene 2 0 -- 2 2 NC

2,6-Dinitrotoluene 2 0 -- 2 2 NC

2-Chloronaphthalene 2 0 -- 2 2 NC

2-Chlorophenol 2 0 -- 2 2 NC

2-Methyl-4,6-dinitrophenol (DNOC) 2 0 -- 2 2 NC

2-Nitrophenol 2 0 -- 2 2 NC

3,3-Dichlorobenzidine 2 0 -- 2 2 NC

4-Bromophenyl phenyl ether 2 0 -- 2 2 NC

4-Chloro 3-methylphenol 2 0 -- 2 2 NC

4-Chlorophenyl phenyl ether 2 0 -- 2 2 NC

4-Nitrophenol 2 0 -- 2 2 NC

9H-Fluorene 2 0 -- 2 2 NC

Acenaphthene 2 0 -- 2 2 NC

Acenaphthylene 2 0 -- 2 2 NC

Anthracene 2 0 -- 2 2 NC

Benz(ghi)perylene 2 0 -- 2 2 NC

Benzidine 2 0 -- 2 2 NC

Benzo(a)anthracene 2 0 -- 2 2 NC

Benzo(a)pyrene 2 0 -- 2 2 NC

Benzo(b)fluoranthene 2 0 -- 2 2 NC

Benzo(k)fluoranthene 2 0 -- 2 2 NC

10 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Table 2. Estimated uncertainty in reported concentrations of selected constituents in ground water from selected wells in the 

Anacostia River watershed within Washington, D.C., September–December 2005—Continued

[BN, number of field blanks; BND, number of blanks in which compound was detected above the laboratory reporting level; BMAX, maximum reported concentration in field blanks; RN, number of replicate sets; RNAGREE, number of replicate sets within which compound was consistently detected or not detected; 

RUNC, median estimated uncertainty in reported concentrations in percent; NC, not computed because no replicate sets had consistent detected concentrations; 

--, not applicable; μg/L, micrograms per liter; mg/L, milligrams per liter; M, presence verified but not quantified; STL, Severn Trent Laboratory; NWQL, 

U.S. Geological Survey National Water Quality Laboratory]

Compound or ion

Contamination bias Sampling uncertainty

BN BND BMAX RN RNAGREE RUNC

1

 (%)

Semivolatile organic compounds—Continued

Benzyl n-butyl phthalate 2 0 -- 2 2 NC

bis(2-Chloroethoxy) methane 2 0 -- 2 2 NC

bis(2-Chloroethyl) ether 2 0 -- 2 2 NC

bis(2-Chloroisopropyl) ether 2 0 -- 2 2 NC

bis(2-Ethylhexyl) phthalate 2 0 -- 2 2 NC

Chrysene 2 0 -- 2 2 NC

Dibenz(a,h)anthracene 2 0 -- 2 2 NC

Diethyl phthalate 2 0 -- 2 2 NC

Dimethyl phthalate 2 0 -- 2 2 NC

Di-n-butyl phthalate 2 0 -- 2 2 NC

Di-n-octyl phthalate 2 0 -- 2 2 NC

Fluoranthene 2 0 -- 2 2 NC

Hexachlorobenzene 2 0 -- 2 2 NC

Hexachlorocyclopentadiene 2 0 -- 2 2 NC

Hexachloroethane 2 0 -- 2 2 NC

Indeno(1,2,3-cd)pyrene 2 0 -- 2 2 NC

Isophorone 2 0 -- 2 2 NC

Naphthalene 10 0 -- 2 2 NC

Nitrobenzene 2 0 -- 2 2 NC

N-Nitrosodimethylamine 2 0 -- 2 2 NC

N-Nitrosodi-n-propylamine 2 0 -- 2 2 NC

N-Nitrosodiphenylamine 2 0 -- 2 2 NC

Pentachlorophenol 2 0 -- 2 2 NC

Phenanthrene 2 0 -- 2 2 NC

Phenols, NWQL 3 0 -- 2 2 NC

Phenols, STL 2 0 -- 2 2 NC

Diesel-range, gasoline-range, and other organic constituents

Diesel range organics 2 0 -- 2 1 NC

Gasoline range organics 2 0 -- 2 2 NC

Oil and grease 2 0 -- 2 2 NC

Petroleum hydrocarbons 2 0 -- 2 2 NC

Polychlorinated biphenyls, total recoverable 4 0 -- 3 3 NC

Caffeine 4 0 -- 3 2 14.03b

a

 Estimated uncertainty above 10 percent. Only two replicate sets were used in the calculation.

b

 Estimated uncertainty above 10 percent. Only one replicate set was used in the calculation.

1

 Estimated uncertainty is the median of the relative standard deviation of reported concentrations for replicate sets in which the compound was detected in 

all replicates. The relative standard deviation is the standard deviation divided by the mean.

Sample Collection, Analysis, and Quality Control 11
Ground-Water Quality and Occurrence 

and Distribution of Selected 

Constituents

Results from all environmental, replicate, and blank 

samples are listed in appendix 2 (field parameters and 

inorganics, including trace elements) and appendix 3 

(pesticides and degradates, VOCs, SVOCs, and other organic 

compounds). Concentrations are reported with a remark code 

of ‘<’ (less than symbol) when a constituent is not detected 

in a sample, or may be present but is below the detection 

or reporting level for the constituent. A concentration is 

estimated and reported with a remark code of ‘E’ when the 

presence of a constituent has been confirmed but there is 

greater uncertainty in the concentration.

Many regulations and criteria exist for field parameters 

and concentrations of chemical constituents, such as pH, major 

ions, trace metals, VOCs, SVOCs, pesticides and other constituents in ground water. For comparison purposes, the Washington, D.C. ground-water standards (District of Columbia, 

1993) and surface-water-quality standards (District of Columbia, 2003), U.S. Environmental Protection Agency (USEPA) 

maximum contaminant levels (MCLs) (U.S. Environmental 

Protection Agency, 2006b), and USEPA Region III RiskBased Concentrations (RBCs) (U.S. Environmental Protection Agency Region III, 2006) are listed in appendixes 2 and 

3. Specific details and information regarding the comparison 

of individual values for the listed criteria should be obtained 

from the references or agencies listed. The comparison of data 

from the September through December 2005 samples with the 

Washington, D.C. surface-water-quality regulations and the 

USEPA Region III RBCs should be made with consideration 

of the sources for various standards as well as sample types. 

For example, the ground-water samples may have been analyzed for dissolved constituent concentrations, but the Washington, D.C. surface-water-quality criteria may be reported for 

a whole water sample. Additionally, there may be differences 

in sample collection and processing techniques and caution 

is advised when making direct comparisons between the 

ground-water sample results and the criteria listed in appendixes 2 and 3. Although comparison of ground-water-sample 

concentration data with surface-water criteria is inappropriate 

for most purposes, these criteria are included in appendixes 2 

and 3 because of the potential interaction of ground water and 

surface water in the study area.

Inorganic Water Chemistry

A trilinear diagram is used to classify and compare water 

types based on the ionic composition of the water samples 

(Hem, 1985). Dominant cation (calcium, iron, sodium, and 

potassium) and anion (bicarbonate, sulfate, and chloride) 

concentrations for each ground-water sample are converted to 

total milliequivalents per liter and plotted as percentages of 

their respective totals in two triangles (fig. 2a). The relative 

percentages of cations and anions in each triangle are then 

projected into a quadrilateral polygon that describes the water 

type or hydrochemical facies (Back, 1966). The relative ionic 

composition of ground-water samples collected from the study 

area is plotted on a trilinear diagram (fig. 2b). The samples 

are predominantly calcium-bicarbonate type water; iron is an 

important cation and sulfate or chloride are dominant anions in 

some of the samples (fig. 2b).

Selected field parameters, major-ion, and traceelement concentrations are summarized in tables 3, 4, and 

5. Concentrations of these constituents generally did not 

exceed USEPA standards or Washington, D.C. ground-water 

regulations (appendix 2). Concentrations of dissolved iron 

varied throughout the study area (fig. 3, table 4). Iron was 

detected above the Washington, D.C. ground-water standard 

(300 μg/L, micrograms per liter) in 11 wells and above the 

Washington, D.C. surface-water standard (1,000 μg/L) in 

9 wells (appendix 2). Iron was detected above the USEPA 

Region III RBC (11,000 μg/L) in six wells; the highest 

concentration was detected in well WE Bb 3, just west of the 

Anacostia River south of New York Avenue, N.E. The high 

iron concentrations likely result from reducing conditions in 

the aquifers. Chloride concentrations were detected above 

the Washington, D.C. ground-water standard (250 mg/L) in 

one sample collected from well WE Ca 32, located along 

heavy traffic heavy roads. Manganese was detected above the 

Washington, D.C. ground-water standard (50 μg/L) in 15 wells 

and above the USEPA Region III RBC (730 μg/L) in 5 wells 

(fig. 4); the highest manganese concentrations were detected in 

well WE Ca 33 (6,830 μg/L) and well WE Cb 11 (5,890 μg/L).

Arsenic generally was detected at low levels (median 

value of 0.38 μg/L) in all of the wells (table 5, appendix 2). 

The spatial distribution of arsenic concentrations is shown in 

figure 5. Concentrations of arsenic were above the proposed 

USEPA MCL (10 μg/L) in the sample from well AC Aa 1 

(39.9 μg/L) located between the Anacostia Park Recreation 

Center and the Anacostia River. This concentration was verified by re-analyzing the sample at the laboratory. Cyanide was 

detected in 5 of the 17 wells, but the concentrations were not 

quantified (table 5, appendix 2). Selenium was detected in 9 of 

the 17 wells and thallium was detected in 6 of the 17 wells; all 

of the detections were less than the District of Columbia standards and the USEPA standards (table 5, appendix 2). Mercury 

was detected in 2 of the 17 wells; the detected concentrations 

were less than 0.5 μg/L in both samples (table 5, appendix 2).

12 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Figure 2. Trilinear diagram showing A, general water types for ground water (modified from Back, 1966); and B, water 

types for ground-water samples from the Anacostia River watershed in Washington, D.C., September–December 2005.

Ground-Water Quality and Occurrence and Distribution of Selected Constituents 13

80604020

20406080

20

40

60

80 80

60

40

20

20

40

60

80

20

40

60

80

CHLORIDE + SULFATE

SODIUM + POTASSIUM

IRON

CALCIUM

SULFATE

CHLORIDE

CALCIUM + IRON

BICARBONATE

x

x

x

*

*

*

#

#

EXPLANATION

AC Aa 1

WE Ba 9

WE Ba 10

WE Bb 3

WE Bb 4

WE Ca 32

WE Ca 33

WE Ca 34

WE Ca 29

WE Cb 8

WE Cb 11

WE Cb 12

WE Cb 5

WE Cb 6

WE Cc 3

WW Bc 8

WW Bc 9

x

*

#

#

80604020

20406080

20

40

60

80 80

60

40

20

20

40

60

80

20

40

60

80

CHLORIDE + SULFATE

SODIUM + POTASSIUM

IRON

CALCIUM

SULFATE

CHLORIDE

CALCIUM + IRON

BICARBONATE

IRON

TYPE

CALCIUM

TYPE

SODIUM

TYPE OR

POTASSIUM

TYPE

NO

DOMINANT

TYPE

NO

DOMINANT

TYPE

SULFATE

TYPE

CHLORIDE

BICARBONATE TYPE

TYPE

(a)

(b)

Percentage of total milliequivalents per liter

Percentage of total milliequivalents per liter
Table 3. Summary statistics for field parameters measured in ground-water samples from the 

Anacostia River watershed within Washington, D.C., September–December 2005.

[oC, degrees Celsius; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; CaCO3, calcium carbonate; 

HCO3, bicarbonate; <, less than]

Parameter Units Number of 

samples

Summary statistics

Minimum Median Maximum

Water temperature oC 17 11.5 17.0 18.5

Specific conductance μS/cm @25oC 17 87 355 1,100

Dissolved oxygen mg/L 14 <1.0 1.0 5.8

pH standard units 17 4.8 6.0 7.3

Alkalinity mg/L as CaCO3 17 5 64 317

Bicarbonate mg/L as HCO3 17 7 78 386

Table 4. Summary statistics for major ions measured in ground-water samples from the Anacostia River 

watershed within Washington, D.C., September–December 2005.

[mg/L, milligrams per liter; μg/L, micrograms per liter; <, less than]

Compound or ion Units Number of 

detections

Number of 

samples

Summary statistics

Minimum Median Maximum

Calcium, dissolved mg/L 17 17 2.47 23.7 103

Magnesium, dissolved mg/L 17 17 1.03 10.3 25.9

Sodium, dissolved mg/L 17 17 1.65 9.4 122

Potassium, dissolved mg/L 17 17 1.22 3.82 10.1

Chloride, dissolved mg/L 17 17 2.91 24.2 257

Sulfate, dissolved mg/L 13* 17 <0.2 11.8 81.1

Fluoride, dissolved mg/L 13* 17 <0.1 <0.1 0.4

Iron, dissolved μg/L 15* 17 <6 3,070 54,400

Silica, dissolved mg/L 17 17 6.2 11.8 22.4

*

 One or more detections reported below laboratory reporting level.

14  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Table 5. Summary statistics for trace elements and cyanide measured in ground-water samples from the Anacostia River 

watershed within Washington, D.C., September–December 2005.

[μg/L, micrograms per liter; mg/L, milligrams per liter; <, less than; E, estimated]

Compound or ion Units Number of 

detections

Number of 

samples

Summary statistics

Minimum Median Maximum

Aluminum, dissolved μg/L 10 17 <2 2 172

Arsenic, dissolved μg/L 17* 17 E0.06 0.38 39.9

Barium, dissolved μg/L 17 17 25 136 586

Beryllium, dissolved μg/L 8* 17 <0.06 <0.06 1.44

Cadmium, dissolved μg/L 9* 17 <0.04 <0.04 0.49

Chromium, dissolved μg/L 15 17 <0.04 0.15 1.1

Cobalt, dissolved μg/L 15* 15 E0.02 2.81 61.4

Copper, dissolved μg/L 10* 15 <0.4 <0.4 9.9

Cyanide, total mg/L 5* 17 <0.01 <0.01 <0.01

Lead, dissolved μg/L 6* 17 <0.08 <0.08 7.84

Manganese, dissolved μg/L 17 17 2.8 296 6,830

Mercury, dissolved μg/L 2* 17 <0.01 <0.01 0.33

Molybdenum, dissolved μg/L 9* 17 <0.4 <0.4 4.9

Nickel, dissolved μg/L 14 14 0.62 4.44 29.4

Selenium, dissolved μg/L 9* 17 <0.08 <0.08 2.1

Uranium, natural, dissolved μg/L 6* 17 <0.04 <0.04 0.18

Thallium, dissolved μg/L 6* 17 <0.04 <0.04 0.18

Zinc, dissolved μg/L 15* 17 <0.6 2.0 372

*

 One or more detections reported below laboratory reporting level.

Nutrients in Ground Water

Nutrients are compounds containing nitrogen and 

phosphorus that are necessary for plant growth, but may also 

contribute to eutrophication in surface-water bodies or, in 

high doses, may have human-health effects (Ferrari, 2002). 

Although nutrients occur naturally, concentrations may be 

increased by human-related activity, such as fertilizer or 

manure application, sewage and septic effluent, or atmospheric 

deposition from the burning of coal and petroleum products.

Nitrite plus nitrate was detected in seven wells sampled 

in the study area (fig. 6, table 6), and was above the MCL 

(10 mg/L) in one well (WW Bc 8, 11.2 mg/L) (appendix 2). 

Ammonia was detected in 13 of the 17 wells sampled and 

concentrations were above the RBC (0.21 mg/L) in 7 wells 

(table 6 and appendix 2). The highest ammonia concentrations 

were detected in samples from four wells located along the 

Anacostia River (WE Bb 3, AC Aa 1, WE Ca 34, and 

WE Bb 4) (fig. 7, appendix 2). Phosphorus concentrations 

were low throughout the study area, ranging from 0.02 to 

0.7 mg/L (table 6, appendix 2).

Ground-Water Quality and Occurrence and Distribution of Selected Constituents 15
Figure 3. Spatial distribution of iron concentrations in ground-water samples from the Anacostia River watershed within 

Washington, D.C., September–December 2005.

16  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Lower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

PO

T

O

M

A

C

RIVER

ANACOST IA

WASHINGTON CHANNE L

ANACOSTIA Beaverdam

Creek

Watts

Branch

R VI ER

RIVER

WASHINGTON, D.C .

WASHINGTO N, D.C .

PRINCE GEORGES

C OUNTY,

MARYLAND

PRINCE GEORGES COUNTY ,

M ARYLAND

U.S.

CAPITOL

Washington

Navy Ya rd

U.S.NATIONAL

ARBORETUM

Kenilworth

Aquatic

Gardens

Kingman Lake PE NNS Y LVANIA

PE NNS Y LVANIA

AV E NUE

F LOR IDA AVENUE

BE NNING R OAD

ANACOSTIA

ANACOS T IA

FR E E WAY

FR E E WAY

AVE NUE

C ONS TI TUTIO N AV E NUE

NE W

YOR K AVE NUE

INDE PE NDE NC E AV E NUE

50

50

50

295

295

295

4

4

BE NNING R O AD

38 55'00" O

38 52'30" O

77 00'00" 76 57'30" O O

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE C a 32

WE Cb 8

AC Aa 1

WE C a 29

WE Ca 33

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

EXPLANATION

Base map modified from Tenbus, 2003

301 μg/L TO 1,000 μg/L OF IRON

LESS THAN 6 μg/L OF IRON

GREATER THAN 10,000 μg/L OF IRON

6 μg/L TO 300 μg/L OF IRON

1,001 μg/L TO 10,000 μg/L OF IRON

WE Cb 8 WELL IDENTIFIER
Figure 4. Spatial distribution of manganese concentrations in ground-water samples from the Anacostia River watershed 

within Washington, D.C., September–December 2005.

Ground-Water Quality and Occurrence and Distribution of Selected Constituents 17

Lower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

PO

T

O

M

A

C

RIVER

ANACOSTIA

WASHINGTON CHANNE L

ANACOSTIA Beaverdam

Creek

Watts

Branch

R VI ER

RIVER

WASHINGTON, D.C .

WASHINGTON, D.C .

PRINCE GEORGE S

C OUNTY,

MARYLAND

PRINCE GEORGES COUNTY ,

M ARYLAND

U.S.

CAPITOL

Washington

Navy Ya rd

U.S.NATIONAL

ARBORETUM

Kenilworth

Aquatic

Gardens

Kingman Lake PE NNS Y LVANIA

PE NNS Y LVANIA

AV E NUE

F LOR IDA AV E NUE

BE NNING R OAD

ANACOSTIA

ANACOS T IA

FR E E WAY

FR E E WAY

AVE NUE

CONS TITUTION AV E NUE

NE W

YOR K AVE NUE

INDE PE NDE NC E AV E NUE

50

50

50

295

295

295

4

4

BE NNING R O AD

38 55'00" O

38 52'30" O

77 00'00" 76 57'30" O O

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE C a 32

WE Cb 8

AC Aa 1

WE C a 29

WE Ca 33

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

EXPLANATION

LESS THAN 50 μg/L OF MANGANESE

50 μg/L TO 100 μg/L OF MANGANESE

101 μg/L TO 730 μg/L OF MANGANESE

Base map modified from Tenbus, 2003

GREATER THAN 730 μg/L OF MANGANESE

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

WE Cb 8 WELL IDENTIFIER
Figure 5. Spatial distribution of arsenic concentrations in ground-water samples from the Anacostia River watershed 

within Washington, D.C., September–December 2005.

18 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Lower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

PO

T

O

M

A

C

RIVER

ANACOST IA

WASHINGTON CHANNE L

AN

ACOSTIA Beaverdam

C reek

Watts

Branch

R VI ER

RIVER

WASHINGTON, D.C.

WASHINGTON, D.C .

PRINCE GEORGES

COUNTY,

MARYLAND

PRINCE GEORGES

C OUN TY ,

M ARYLAND

U.S.

CAPITOL

Washington

Navy Ya rd

U.S.NATIONAL

ARBORETUM

Kenilworth

Aquatic

Gardens

Kingman Lake PE NNS Y LVANIA

PE NNS Y LVANIA

AV E NUE

F LOR IDA AV E NUE

BE NNING R OAD

ANACOS TIA

ANAC OS T IA

FR E E WAY

FR E E WAY

AVE NUE

CONSTI TUTIO N AV E NUE

NE W

YOR K AVE NUE

INDE PE NDE NC E AV E NUE

50

50

50

295

295

295

4

4

BE NNING R O AD

38 55'00" O

38 52'30" O

77 00'00" 76 57'30" O O

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE C a 32

WE Cb 8

AC Aa 1

WE C a 29

WE Ca 33

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

EXPLANATION

LESS THAN 1 μg/L OF ARSENIC

1 μg/L TO 10 μg/L OF ARSENIC

GREATER THAN 10 μg/L OF ARSENIC

Base map modified from Tenbus, 2003

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

WE Cb 8 WELL IDENTIFIER
Figure 6. Spatial distribution of nitrite plus nitrate in ground-water samples from the Anacostia River watershed within 

Washington, D.C., September–December 2005.

Ground-Water Quality and Occurrence and Distribution of Selected Constituents 19

Lower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

PO

T

O

M

A

C

RIVER

ANACOST IA

WASHINGTON CHANNE L

ANACOSTIA Beaverdam

Creek

Watts

Branch

R VI ER

RIVER

WASHINGTON, D.C .

WASHINGTON, D.C .

PRINCE GEORGES

COUNTY,

MARYLAND

PRINCE GEORGES COUNTY,

M ARYLAND

U.S.

CAPITOL

Washington

Navy Ya rd

U.S.NATIONAL

ARBORETUM

Kenilworth

Aquatic

Gardens

Kingman Lake PE NNS Y LVANIA

PE NNS Y LVANIA

AV E NUE

F LOR IDA AV E NUE

BE NNING R OAD

ANACOSTIA

ANAC OS T IA

FR E E WAY

FR E E WAY

AVE NUE

CONS TI TUTION AV E NUE

NE W

YOR K AVE NUE

INDE PE NDE NC E AV E NUE

50

50

50

295

295

295

4

4

BE NNING R O AD

38 55'00" O

38 52'30" O

77 00'00" 76 57'30" O O

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE C a 32

WE Cb 8

AC Aa 1

WE C a 29

WE Ca 33

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

5.1 mg/L TO 10 mg/L OF NITRITE PLUS NITRATE

EXPLANATION

LESS THAN 0.06 mg/L OF NITRITE PLUS NITRATE

0.06 mg/L TO 5 mg/L OF NITRITE PLUS NITRATE

GREATER THAN 10 mg/L OF NITRITE PLUS NITRATE

Base map modified from Tenbus, 2003

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

WE Cb 8 WELL IDENTIFIER
Table 6. Summary statistics for nutrients measured in ground-water samples from the Anacostia River watershed within 

Washington, D.C., September–December 2005.

[mg/L, milligrams per liter; <, less than]

Compound or ion1 Units Number of 

detections

Number of 

samples

Summary statistics

Minimum Median Maximum

Nitrogen, ammonia mg/L 13* 17 <0.04 0.13 4.38

Nitrogen, nitrite mg/L 5* 17 <0.008 <0.008 0.009

Nitrogen, ammonia + organic nitrogen mg/L 16* 17 <0.10 0.18 5.0

Nitrogen, nitrite + nitrate mg/L 7 17 <0.06 <0.06 11.2

Phosphorus, unfiltered mg/L 8* 17 <0.04 <0.04 0.7

Phosphorus, filtered mg/L 7* 17 <0.04 <0.04 0.49

1

 Concentrations of nitrogen species are presented in this report as equivalent concentrations of elemental nitrogen.

*

 One or more detections reported below laboratory reporting level.

Pesticides in Ground Water

Several pesticides and degradation products (degradates) 

were detected in ground water in the study area (table 7 and 

appendix 3). The spatial distribution of pesticide and degradate detections is shown in figure 8. Of the 66 pesticides and 

13 pesticide degradates analyzed, 12 compounds (7 pesticides 

and 5 degradates) were detected at low levels in at least one of 

the 17 wells sampled (table 7). Concentrations of pesticides 

and degradates were below 0.2 μg/L and were well below 

established standards (table 7, appendix 3). Of the 17 wells 

sampled, 6 wells had detectable pesticide or degradate concentrations (fig. 8); as many as 7 compounds were detected in 

1 well (WE Ca 32) located on Constitution Avenue, N.E.

Dieldrin, 2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT), and heptachlor epoxide were each detected in 

two ground-water samples (table 7, appendix 3). The use of 

dieldrin, an insecticide, was discontinued in the United States 

for agricultural application in 1970 and for termite control in 

1987. Detection of dieldrin in ground water, surface water, 

rain, and air in both agricultural and residential settings in the 

United States reflects historical application patterns (Gilliom 

and others, 2006; Barbash and Resek, 1996). In fact, dieldrin was the most commonly detected insecticide in shallow 

ground water in urban areas across the Nation (Gilliom and 

others, 2006). CIAT, also known as deethylatrazine, is one of 

the principal degradation products of atrazine, an herbicide 

commonly used for weed control. Atrazine (and deethylatrazine) are also among the most commonly detected herbicides 

in shallow ground water in urban areas across the Nation 

(Gilliom and others, 2006). Atrazine degradates, including 6-amino-2-chloro-4-ethylamino-s-triazine (CEAT) and 

2-hydroxy-4-isopropylamino-t-ethylamino-s-triazine (OIET), 

also were detected in wells WW Bc 9 and WE Cc 3, respectively (fig. 8). Heptachlor epoxide is not produced commercially, but is formed from the chemical and biological transformation of heptachlor, a non-agricultural insecticide. Its use 

was discontinued in 1978 except for fire ant control in buried, 

pad-mounted electric power transformers, and in underground 

cable television and telephone cable boxes (U.S. Environmental Protection Agency, 2006a). Heptachlor epoxide adsorbs 

strongly to soil and is extremely resistant to biodegradation, 

persisting for many years in the upper soil layers. Low levels 

of this compound were detected in shallow wells WE Ca 32 

and WE Cc 3 (appendix 3).

Concentrations of two additional banned compounds 

(Chlordane and DDE) were detected at low levels in groundwater samples from wells WE Ca 32 and WE Ba 9, respectively. Chlordane was commonly used for termite control 

before being banned in the United States in 1988 (Extension 

Toxicity Network, 1996). DDE, a degradation product of 

DDT, which was banned in the 1970s in the United States, was 

detected in one well (WE Ba 9) (fig. 8).

20 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Figure 7. Spatial distribution of ammonia in ground-water samples from the Anacostia River watershed within 

Washington, D.C., September–December 2005.

Ground-Water Quality and Occurrence and Distribution of Selected Constituents 21

Lower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

PO

T

O

M

A

C

RIVER

ANACOST IA

WASHINGTON CHANNE L

ANACOSTIA Beaverdam

Creek

Watts

Branch

R VI ER

RIVER

WASHINGTON, D.C .

WASHINGTON, D.C .

PRINCE GEORGES

COUNTY,

MARYLAND

PRINCE GEORGES

COUN TY ,

M ARYLAND

U.S.

CAPITOL

Washington

Navy Ya rd

U.S.NATIONAL

ARBORETUM

Kenilworth

Aquatic

Gardens

Kingman Lake PE NNS Y LVANIA

PE NNS Y LVANIA

AV E NUE

F LOR IDA AV E NUE

BE NNING R OAD

ANACOS TIA

ANAC OS T IA

FR E E WAY

FR E E WAY

AVE NUE

C ONSTITUTION AV E NUE

NE W

YOR K AVE NUE

INDE PE NDE NC E AV E NUE

50

50

50

295

295

295

4

4

BE NNING R O AD

38 55'00" O

38 52'30" O

77 00'00" 76 57'30" O O

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE C a 32

WE Cb 8

AC Aa 1

WE C a 29

WE Ca 33

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

Base map modified from Tenbus, 2003

EXPLANATION

LESS THAN 0.04 mg/L OF AMMONIA

0.04 mg/L TO 0.21 mg/L OF AMMONIA

0.22 mg/L TO 1 mg/L OF AMMONIA

GREATER THAN 1 mg/L OF AMMONIA

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

WE Cb 8 WELL IDENTIFIER
Volatile Organic Compounds, Semivolatile 

Organic Compounds, and Other Organic 

Compounds in Ground Water

Of the 62 VOCs and 51 SVOCs analyzed in the groundwater samples from the study area, 11 VOCs were detected 

in a total of 9 wells and 2 SVOCs were detected in 3 wells 

(fig. 9, table 8, appendix 3). Six VOCs (gasoline oxygenates) 

were detected in well WE Ca 33 (appendix 3); the well is in a 

grassy triangle near a recently constructed playground and is 

surrounded by multi-unit and single-unit residential buildings. 

Six solvents (five VOCs and one SVOC, bis(2-ethylhexyl) 

phthalate) were detected in well WW Bc 8. One of the 

five VOCs detected in well WW Bc 8, tetrachloroethene 

(68 mg/L), exceeded the Washington, D.C. ground-water 

standard of 5 mg/L. Phenolic SVOCs (phenols) were detected 

in two wells (WE Ca 32 and WE Cb 5). Concentrations of 

phenols were higher in the shallow well at Kenilworth Aquatic 

Gardens (WE Cb 5) than in well WE Ca 32 on Constitution 

Avenue, N.E. (fig. 9, table 8, appendix 3).

Trichloromethane and dichloromethane (both solvents) 

and methyl tert-butyl ether (MTBE), an additive in 

reformulated gasoline, were the most frequently detected 

VOCs in ground water in the study area (table 8, appendix 3). 

These compounds were detected below established USEPA 

MCLs, where applicable. Wells with detections were scattered 

spatially around the study area. Trichloromethane was detected 

in five wells (WE Ca 32, WE Cb 5, WE Cb 12, WW Bc 8, and 

WW Bc 9) with detected concentrations ranging from 0.95 

(estimated value) to 11 μg/L. Dichloromethane was detected 

in four wells (WE Ca 29, WE Bb 3, WE Bb 4, and WW Bc 8), 

with all four detected concentrations greater than the method 

detection level of 0.26 μg/L and less than the laboratory 

reporting level of 5 μg/L. MTBE was detected in samples 

from well WE Ca 33 (6.7 μg/L) and well WE Cb 5 (1.4 μg/L, 

estimated) (fig. 9, table 8, appendix 3).

Concentrations of gasoline-range organics were detected 

in five wells with concentrations 10 times higher in well 

WE Ca 33 (540 μg/L) than in wells AC Aa 1, WE Ca 32, 

WE Cb 12, and WW Bc 8 (ranging from 5.5 to 47 μg/L) 

(appendix 3).

Table 7. Summary statistics for pesticides and degradates detected in ground-water samples from the 

Anacostia River watershed within Washington D.C., September–December 2005.

[CEAT, 2-Chloro-6-ethylamino-4-amino-s-triazine; CIAT, 2-Chloro-4-isopropylamino-6-amino-s-triazine; OIET, 2-Hydroxy-4-isopropylamino-6-ethylamino-s-triazine; μg/L, micrograms per liter; <, less than; E, estimated]

Compound Units Number of 

detections

Number of 

samples

Summary statistics

Minimum Median Maximum

Atrazine μg/L 1 17 <0.008 <0.008 0.02

Bromacil μg/L 1* 17 <0.02 <0.02 <0.02

CEAT μg/L 1* 17 <0.08 <0.08 <0.08

CIAT μg/L 2* 17 <0.03 <0.03 <0.03

Dieldrin μg/L 2 17 <0.001 <0.001 0.065

Heptachlor epoxide μg/L 2 17 <0.001 <0.001 0.007

Imidacloprid μg/L 1 17 <0.020 <0.020 0.301

Metsulfuron μg/L 1 17 <0.03 <0.03 E0.04

OIET μg/L 1* 17 <0.032 <0.032 <0.032

p,p'-DDE μg/L 1 17 <0.002 <0.002 0.004

Chlordane, technical mix μg/L 1 17 <0.1 <0.1 E0.1

Tebuthiuron μg/L 1 17 <0.026 <0.026 0.193

*

 One or more detections reported below laboratory reporting level.

22 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Figure 8. Spatial distribution of pesticide and degradate detections in ground-water samples from the Anacostia River 

watershed within Washington, D.C., September–December 2005.

Ground-Water Quality and Occurrence and Distribution of Selected Constituents 23

Lower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

PO

T

O

M

A

C

RIVER

ANACOST IA

WASHINGTON CHANNE L

ANACOSTIA Beaverdam

Creek

Watts

Branch

R VI ER

RIVER

WASHINGTON, D.C .

WASHINGTON, D.C .

PRINCE GEORGES

COUNTY,

MARYLAND

PRINCE GEORGES COUNTY,

M ARYLAND

U.S.

CAPITOL

Washington

Navy Ya rd

U.S.NATIONAL

ARBORETUM

Kenilworth

Aquatic

Gardens

Kingman Lake PE NNS Y LVANIA

PE NNS Y LVANIA

AV E NUE

F LOR IDA AV E NUE

BE NNING R OAD

ANACOST IA

ANAC OS T IA

FR E E WAY

FR E E WAY

AVE NUE

CONST ITUTION AV E NUE

NE W

YOR K AVE NUE

INDE PE NDE NC E AV E NUE

50

50

50

295

295

295

4

4

BE NNING R O AD

38 55'00" O

38 52'30" O

77 00'00" 76 57'30" O O

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE C a 32

WE Cb 8

AC Aa 1

WE C a 29

WE Ca 33

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

(2)

(2)

(2)

(1)

(0)

(0)

FIVE PESTICIDES DETECTED

EXPLANATION

NO DETECTABLE PESTICIDES

ONE PESTICIDE DETECTED

(2) THE NUMBER OF PESTICIDE DEGRADATES DETECTED

(0)

(0)

(0)

(0)

(0)

(0)

(0)

(0) (0)

(0)

(0)

Base map modified from Tenbus, 2003

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

WE Cb 8 WELL IDENTIFIER
Figure 9. Spatial distribution of volatile organic compound (VOC) detections in ground-water samples from the Anacostia 

River watershed within Washington, D.C., September–December 2005.

24  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Lower

Anacostia

Tidal

Watershed

Study Area

ANACOSTIA

PARK

PO

T

O

M

A

C

RIVER

ANACOST IA

WASHINGTON CHANNE L

ANACOSTIA Beaverdam

Creek

Watts

Branch

R VI ER

RIVER

WASHING TO N, D.C .

WASHINGTON, D.C .

PRINCE GEORGES

COUNTY,

MARYLAND

PRINCE GEORGES

COUNTY,

M ARYLAND

U.S.

CAPITOL

Washington

Navy Ya rd

U.S.NATIONAL

ARBORETUM

Kenilworth

Aquatic

Gardens

Kingman Lake PE NNS Y LVANIA

PE NNS Y LVANIA

AV E NUE

F LOR IDA AV E NUE

BE NNING R OAD

ANACOST IA

ANAC OS T IA

FR E E WAY

FR E E WAY

AVE NUE

CONS TI TUTIO N AV E NUE

NE W

YOR K AVE NUE

INDE PE NDE NC E AV E NUE

50

50

50

295

295

295

4

4

BE NNING R O AD

38 55'00" O

38 52'30" O

77 00'00" 76 57'30" O O

WE Bb 3

WE Bb 4

WE Cb 5

WE Cb 6

WE C a 32

WE Cb 8

AC Aa 1

WE C a 29

WE Ca 33

WE Cb 12

WE Ca 34

WW Bc 8

WE Ba 10

WE Cc 3

WE Cb 11

WW Bc 9

WE Ba 9

GREATER THAN FOUR VOCs DETECTED

EXPLANATION

NO DETECTABLE VOCs

ONE TO FOUR VOCs DETECTED

Base map modified from Tenbus, 2003

0 2,000 4,000 6,000 FEET

0 500 1,000 1,500 METERS

N

WE Cb 8 WELL IDENTIFIER
Summary

This report presents ground-water-quality data collected 

by the U.S. Geological Survey from September through 

December 2005 from 17 monitoring wells in the Anacostia 

River watershed within Washington, D.C. Ground-water 

samples were analyzed for major ions, trace elements, nutrients, pesticides and degradates, volatile organic compounds, 

semivolatile organic compounds, oil and grease, phenols, total 

polychlorinated biphenyls, and other selected constituents. 

Major ion concentrations indicate predominantly calciumbicarbonate type water, with some wells containing a higher 

percentage of milliequivalents per liter of iron (cation), and 

chloride or sulfate (anions). Concentrations of trace elements 

were generally low, with some variability in concentrations of 

arsenic, barium, cobalt, manganese, nickel, selenium, and zinc. 

Concentrations of nutrients were generally low, with concentrations of phosphorus less than 1 milligram per liter, 

ammonia less than 5 milligrams per liter, and a median and 

maximum concentration of nitrite plus nitrate of less than 

0.06 milligrams per liter and 11.2 milligrams per liter, respectively. Concentrations of organic constituents were generally 

less than the laboratory reporting levels. Of the 66 pesticides 

and 13 degradates analyzed, 7 pesticides and 5 degradates 

were detected in 6 wells. The most frequently detected 

pesticides and degradates were dieldrin, 2-chloro-4-isopropylamino-6-amino-s-triazine, and heptachlor epoxide. Of the 

62 volatile organic compounds and 51 semivolatile organic 

compounds analyzed, 11 volatile organic compounds and 2 

semivolatile organic compounds were detected in 9 wells. The 

most frequently detected volatile organic compounds were 

trichloromethane, dichloromethane, and methyl tert-butyl 

ether. The two detected semivolatile organic compounds were 

bis(2-ethylhexyl) phthalate, and total phenols. Constituents 

were generally below the published values for the District of 

Columbia ground-water standards, District of Columbia surface-water standards, U.S. Environmental Protection Agency 

maximum contaminant levels, and U.S. Environmental Protection Agency Region III risk-based concentrations.

Table 8. Summary statistics for organic compounds detected in ground-water samples from the Anacostia River 

watershed within Washington D.C., September–December 2005.

[MTBE, methyl tert-butyl ether; μg/L, micrograms per liter; <, less than; E, estimated; mg/L, milligrams per liter]

Compound Units Number of 

detections

Number of 

samples

Summary statistics

Minimum Median Maximum

Volatile organic compounds

1,2-Dichloroethane μg/L 1* 17 <1.0 <1.0 <1.0

Dichloromethane μg/L 4* 17 <5.0 <5.0 <5.0

Isopropylbenzene μg/L 1 17 <1.0 <1.0 4.4

methyl tert-butyl benzene μg/L 2* 17 <5 <5 6.7

n-Butylbenzene μg/L 1 17 <1.0 <1.0 21

sec-Butylbenzene μg/L 1 17 <1.0 <1.0 19

tert-Butylbenzene μg/L 1* 17 <1.0 <1.0 <2.5

Tetrachloroethene μg/L 1 17 <1.0 <1.0 68

Toluene μg/L 1* 17 <0.50 <0.50 <0.50

Trichloroethene μg/L 1 17 <1.0 <1.0 E1.6

Trichloromethane μg/L 5* 17 <1.0 <1.0 11

Semivolatile organic compounds

bis(2-Ethylhexyl) phthalate μg/L 1* 17 <10 <10 <10

Phenols, total recoverable μg/L 2* 13 <16 <16 E93

Diesel-range/gasoline-range organics

Diesel-range organics mg/L 5* 17 <0.25 <0.25 1.1

Gasoline-range organics μg/L 5* 17 <25 <25 540

Oil and grease mg/L 2* 17 <5.00 <5.00 <5.00

Other

Caffeine μg/L 4* 17 <0.02 <0.02 0.03

*

 One or more detections reported below laboratory reporting level.

Summary 25
Acknowledgments

The authors would like to thank Diane Douglas and 

Alvin Harris of the District Department of the Environment 

for support and input to the study, knowledge of the study 

area, and review comments. The authors would also like to 

thank the U.S. National Park Service and the Washington, 

D.C. Department of Parks and Recreation for their cooperation 

and permission to install and monitor multiple ground-water 

monitoring wells used for this study. Further, the authors 

would also like to thank the U.S. Geological Survey personnel 

that contributed to the preparation, collection, and processing 

of the analytical samples, especially Deborah Bringman, 

George Zynjuk, and Mastin Mount.

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American Public Health Association, 1995, Standard methods 

for the examination of water and wastewater (19th ed.): 

Washington, D.C., American Public Health Association 

Inc., p. 5-36–5-39.

American Public Health Association, 1998, Standard methods 

for the examination of water and wastewater (20th ed.): 

Washington, D.C., American Public Health Association, 

American Water Works Association, and Water Environment Federation, p. 3-37–3-43.

Back, William, 1966, Hydrochemical facies and ground-water 

flow patterns in northern part of Atlantic Coastal Plain: 

U.S. Geological Survey Professional Paper 498-A, 42 p.

Barbash, J.E., and Resek, E.A., 1996, Pesticides in ground 

water: Distribution, trends, and governing factors: Chelsea, 

Michigan, Ann Arbor Press, Pesticides in the Hydrologic 

System series, v. 2, 588 p.

Cooke, C.W., 1952, Sedimentary deposits of Prince Georges 

County and the District of Columbia, in Cooke, C.W., 

Martin, R.O.R., and Meyer, Gerald, Geology and water 

resources of Prince Georges County: Baltimore, Maryland, Maryland Department of Geology, Mines, and Water 

Resources Bulletin 10, 270 p.

District of Columbia, 1993, Water quality standards for ground 

water; District of Columbia Municipal Regulations, Final 

rulemaking published at 40 DCR 4203, 4204 (July 2, 1993); 

renumbered by final rulemaking published at 41 DCR 1075 

(March 4, 1994), Title 21 DCMR, chap. 11, sections 1150–

1158, [variously paged], accessed November 7, 2006, at 

URL http://doh.dc.gov/doh/frames.asp?doc=/doh/lib/doh/

services/administration_offices/environmental/services2/

water_division/pdf/groundwaterquality.pdf&group=1811

District of Columbia, 2003, Water quality standards for surface water; District of Columbia Municipal Regulations, 

49 DCR 3012 with the corrections made to the amendments 

at 49 DCR 4854, Title 21 DCMR, chap. 11, p. 11-1–11-26, 

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standards03.pdf&group=1811

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spectrometry: U.S. Geological Survey Open-File Report 

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contaminants in public drinking-water supplies in the surficial aquifer in Delaware: U.S. Geological Survey Open-File 

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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.

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determination of inorganic substances in water and fluvial 

sediments: U.S. Geological Survey Techniques of WaterResources Investigations, book 5, chap. A1, 545 p.

Furlong, E.T., Anderson, B.D., Werner, S.L., Soliven, P.P., 

Coffey, L.J., and Burkhardt, M.R., 2001, Methods of 

analysis by the U.S. Geological Survey National Water 

Quality Laboratory—Determination of pesticides in water 

by graphitized carbon-based solid-phase extraction and 

high-performance liquid chromatography/mass spectrometry: U.S. Geological Survey Water-Resources Investigations 

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strontium, thallium, and vanadium using inductively 

coupled plasma-mass spectrometry: U.S. Geological Survey Open-File Report 99–093, 31 p.

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mercury in filtered and unfiltered natural water with cold 

vapor-atomic fluorescence spectrometry: U.S. Geological 

Survey Water-Resources Investigations Report 01–4132, 

16 p.

26  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
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samples using collision/reaction cell inductively coupled 

plasma-mass spectrometry: U.S. Geological Survey Techniques and Methods, book 5, section B, chap. 1, 88 p.

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Martin, J.D., Nakagaki, Naomi, Nowell, L.H., Scott, J.C., 

Stackelberg, P.E., Thelin, G.P., and Wolock, D.M., 2006, 

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Nation’s streams and ground water, 1992–2001: U.S. Geological Survey Circular 1291, 172 p.

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113 p.

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of analysis by the U.S. Geological Survey Organic Geochemistry Research Group—Determination of glyphosate, 

aminomethylphosphonic acid, and glufosinate in water 

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liquid chromatography/mass spectrometry: U.S. Geological 

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References Cited 27
Wershaw, R.L., Fishman, M.J., Grabbe, R.R., and Lowe, 

L.E., eds., 1987, Methods for the determination of organic 

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Survey Techniques of Water-Resources Investigations, 

book 5, chap. A3, 80 p.

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K.M., 1995, Methods of analysis by the U.S. Geological 

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capillary-column gas chromatography/mass spectrometry 

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Open-File Report 95–181, 60 p.

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W.W., Moran, M.J., Rowe, B.L., Squillace, P.J., and 

Toccalino, P.L., 2006, The quality of our Nation’s waters—

Volatile organic compounds in the Nation’s ground-water 

and drinking-water supply wells: U.S. Geological Survey 

Circular 1292, 101 p.

28 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Appendixes 1–3.
Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued

[USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automated-segmented flow; EC, electrolytic conductivity]

CASRN® Chemical constituent Reporting level Units Report- ing level type Reference Method ID Method description

7440-70-2 Calcium, dissolved 0.02 mg/L lrl Fishman, 1993 I-1472-87 ICP - atomic emission spectrometry 16887-00-6 Chloride, dissolved 0.2 mg/L lrl Fishman and Friedman, 1989 I-2057-85 Ion chromatography16984-48-8 Fluoride, dissolved 0.1 mg/L lrl Fishman and Friedman, 1989 I-2327-89 ASF, ion-selective electrode7439-89-6 Iron, dissolved 6 μg/L lrl Fishman, 1993 I-1472-87 ICP - atomic emission spectrometry 7439-95-4 Magnesium, dissolved 0.008 mg/L lrl Fishman, 1993 I-1472-87 ICP - atomic emission spectrometry 7439-96-5 Manganese, dissolved 0.6 μg/L lrl Fishman, 1993 I-1472-87 ICP - atomic emission spectrometry 7440-09-7 Potassium, dissolved 0.16 mg/L lrl American Public Health 

Association, 1998

3120-ICP ICP - atomic emission spectrometry 

7631-86-9 Silica, disssolved 0.2 mg/L lrl Fishman and Friedman, 1989 I-2700-89 Colorimetry, ASF, Molybdate blue7440-23-5 Sodium, dissolved 0.2 mg/L lrl Fishman, 1993 I-1472-87 ICP - atomic emission spectrometry 14808-79-8 Sulfate, dissolved 0.18 mg/L lrl Fishman and Friedman, 1989 I-2057-85 Ion chromatography7429-90-5 Aluminum, dissolved 1.6 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-36-0 Antimony, dissolved 0.2 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-39-3 Barium, dissolved 0.2 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-41-7 Beryllium, dissolved 0.06 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-43-9 Cadmium, dissolved 0.04 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-47-3 Chromium, dissolved 0.04 μg/L irl Garbarino and others, 2006; 

or McLain, 1993

I-2020-05 or I-1233-93 Collision/reaction cell ICP-MS or graphite 

furnace atomic absorption spectrometry 

7440-48-4 Cobalt, dissolved 0.04 μg/L lrl Garbarino and others, 2006; 

or Faires, 1993

I-2020-05 or I-2477-92 Collision/reaction cell ICP-MS or ICP MS

7440-50-8 Copper, dissolved 0.4 μg/L lrl Garbarino and others, 2006; 

or Faires, 1993

I-2020-05 or I-2477-92 Collision/reaction cell ICP-MS or ICP MS

7439-92-1 Lead, dissolved 0.08 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7439-96-5 Manganese, dissolved 0.2 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7439-98-7 Molybdenum, dissolved 0.4 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-02-0 Nickel, dissolved 0.06 μg/L lrl Garbarino and others, 2006; 

or Faires, 1993

I-2020-05 or I-2477-92 Collision/reaction cell ICP-MS or ICP MS

7440-22-4 Silver, dissolved 0.2 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-61-1 Uranium, natural, dissolved 0.04 μg/L lrl Faires, 1993 I-2477-92 ICP MS 7440-66-6 Zinc, dissolved 0.6 μg/L lrl Garbarino and others, 2006; 

or Faires, 1993

I-2020-05 or I-2477-92 Collision/reaction cell ICP-MS or ICP MS

7664-41-7 Nitrogen, ammonia, dissolved 0.04 mg/L lrl Fishman, 1993, p. 125 I-2522-90 Salicylate-hypochlorite colorimetry and 

ASF analyzer

17778-88-0 Nitrogen, ammonia + organic 

nitrogen, total

0.1 mg/L lrl Patton and Truitt, 2000 I-4515-91 Colorimetry, ASF, Microkjeldahl digestion

14797-65-0 Nitrogen, nitrite, dissolved 0.008 mg/L lrl Fishman, 1993, p. 143 I-2540-90 Diazotization colorimetry and ASF 

analyzer

30 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued

[USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automated-segmented flow; EC, electrolytic conductivity]

CASRN® Chemical constituent Reporting level Units Report- ing level type Reference Method ID Method description

na Nitrogen, nitrite + nitrate, 

dissolved

0.06 mg/L lrl Fishman, 1993 I-2545-90 Diazotization colorimetry, ASF, cadmium 

reduction 

7723-14-0 Phosphorus, dissolved 0.04 mg/L lrl Pattton and Truitt, 1992 I-2610-99 Colorimetry, ASF, Microkjeldahl digestion7723-14-0 Phosphorus, total 0.04 mg/L lrl Pattton and Truitt, 1992 I-4610-91 Colorimetry, ASF, Microkjeldahl digestion7439-97-6 Mercury, dissolved 0.01 μg/L lrl Garbarino and Damrau, 2001 I-2464-01 Atomic fluorescence cold vapor7440-28-0 Thallium, dissolved 0.04 μg/L lrl Garbarino, 1999 I-2477-92 ICP MS 7440-38-2 Arsenic, dissolved 0.12 μg/L lrl Garbarino, 1999; or 

Garbarino and others, 2006

I-2020-05 or I-2477-92 Collision/reaction cell ICP-MS or ICP MS

7782-49-2 Selenium, dissolved 0.08 μg/L lrl Garbarino, 1999; or 

Garbarino and others, 2006

I-2020-05 or I-2477-92 Collision/reaction cell ICP-MS or ICP MS

108-95-2 Phenols, total recoverable 16 μg/L lrl American Public Health 

Association, 1995

5530

309-00-2 Aldrin, total recoverable 0.001 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors57-74-9 Chlordane, technical mix, 

total recoverable

0.1 μg/L mrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors

60-57-1 Dieldrin, total recoverable 0.001 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors959-98-8 alpha-Endosulfan, total 

recoverable

0.0012 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors

72-20-8 Endrin, total recoverable 0.0019 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors76-44-8 Heptachlor, total recoverable 0.0008 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors1024-57-3 Heptachlor epoxide, total 

recoverable

0.0012 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors

58-89-9 Lindane, total recoverable 0.002 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors72-43-5 p,p'-Methoxychlor, total 

recoverable

0.0028 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors

2385-85-5 Mirex, total recoverable 0.0011 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors72-54-8 p,p'-DDD, total recoverable 0.0024 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors72-55-9 p,p'-DDE, total recoverable 0.0019 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors50-29-3 p,p'-DDT, total recoverable 0.0019 μg/L lrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors1336-36-3 Polychlorinated biphenyls, 

total recoverable 

0.1 μg/L mrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors

8001-35-2 Toxaphene, total recoverable 1 μg/L mrl Wershaw and others, 1987 O-3104-83 GC with electron-capture detectors1066-51-9 Aminomethylphosphonic acid 

(AMPA), filtered water

0.31 μg/L irl Lee and others, 2002 O-2136-01 Solid-phase extraction and HPLC/MS

51276-47-2 Glufosinate, filtered water 0.14 μg/L irl Lee and others, 2002 O-2136-01 Solid-phase extraction and HPLC/MS1071-83-6 Glyphosate, filtered water 0.15 μg/L irl Lee and others, 2002 O-2136-01 Solid-phase extraction and HPLC/MS

Appendix 1  31
Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued

[USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automated-segmented flow; EC, electrolytic conductivity]

CASRN® Chemical constituent Reporting level Units Report- ing level type Reference Method ID Method description

94-75-7 2,4-D 0.038 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1928-38-7 2,4-D methyl ester 0.19 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS94-82-6 2,4-DB 0.02 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS6190-65-4 2-Chloro-4-isopropylamino-6-

amino-s-triazine (CIAT)

0.028 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS

1007-28-9 2-Chloro-6-ethylamino-4-

amino-s-triazine (CEAT) 

0.08 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS

2163-68-0 2-Hydroxy-4-isopropylamino-6-

ethylamino-s-triazine (OIET)

0.032 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS

5352-88-5 3(4-Chlorophenyl)-1-methyl urea 0.036 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS16655-82-6 3-Hydroxycarbofuran 0.008 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS16709-30-1 3-Ketocarbofuran 0.02 μg/L lrl Furlong and others, 2002 O-2060-02 Solid-phase extraction and HPLC/MS50594-66-6 Acifluorfen 0.028 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS116-06-3 Aldicarb 0.15 μg/L mrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1646-88-4 Aldicarb sulfone 0.018 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1646-87-3 Aldicarb sulfoxide 0.1 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1912-24-9 Atrazine 0.008 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS22781-23-3 Bendiocarb 0.08 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS17804-35-2 Benomyl 0.022 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS83055-99-6 Bensulfuron-methyl 0.018 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS25057-89-0 Bentazon 0.024 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS314-40-9 Bromacil 0.018 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1689-84-5 Bromoxynil 0.044 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS58-08-2 Caffeine 0.018 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS63-25-2 Carbaryl 0.018 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1563-66-2 Carbofuran 0.016 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS7286-84-2 Chloramben, methyl ester 0.024 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS3397-62-4 Chlordiamino-s-triazine (CAAT) 0.04 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS90982-32-4 Chlorimuron-ethyl 0.032 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1897-45-6 Chlorothalonil 0.034 μg/L irl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1702-17-6 Clopyralid 0.067 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1134-23-2 Cycloate 0.014 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS887-54-7 Dacthal monoacid 0.028 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1918-00-9 Dicamba 0.036 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS120-36-5 Dichlorprop 0.028 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS88-85-7 Dinoseb 0.038 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS957-51-7 Diphenamid 0.01 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS330-54-1 Diuron 0.016 μg/L mrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS

32 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued

[USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automated-segmented flow; EC, electrolytic conductivity]

CASRN® Chemical constituent Reporting level Units Report- ing level type Reference Method ID Method description

101-42-8 Fenuron 0.1 μg/L mrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS98967-40-9 Flumetsulam 0.04 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS2164-17-2 Fluometuron 0.016 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS81335-37-7 Imazaquin 0.036 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS81335-77-5 Imazethapyr 0.038 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS138261-41-3 Imidacloprid 0.02 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS330-55-2 Linuron 0.014 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS94-74-6 MCPA 0.07 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS94-81-5 MCPB 0.1 μg/L mrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS57837-19-1 Metalaxyl 0.03 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS2032-65-7 Methiocarb 0.034 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS16752-77-5 Methomyl 0.07 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS74223-64-6 Metsulfuron methyl 0.067 μg/L mrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS555-37-3 Neburon 0.012 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS111991-09-4 Nicosulfuron 0.04 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS27314-13-2 Norflurazon 0.02 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS19044-88-3 Oryzalin 0.023 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS23135-22-0 Oxamyl 0.05 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1918-02-1 Picloram 0.032 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS122-42-9 Propham 0.03 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS60207-90-1 Propiconazole 0.01 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS114-26-1 Propoxur 0.008 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS1982-49-6 Siduron 0.02 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS74222-97-2 Sulfometuron-methyl 0.09 μg/L mrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS34014-18-1 Tebuthiuron 0.026 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS5902-51-2 Terbacil 0.026 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS55335-06-3 Triclopyr 0.026 μg/L lrl Furlong and others, 2001 O-2060-01 Solid-phase extraction and HPLC/MS

Appendix 1  33
34  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005 Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued [USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automated- segmented flow; EC, electrolytic conductivity] CASRN® Chemical constituent Laboratory reporting level Units Method detection level Reference Method ID Method description 630-20-6 1,1,1,2-Tetrachloroethane 1 μg/L 0.17 U.S Environmental Protection Agency, 1986 8260B GC/MS 71-55-6 1,1,1-Trichloroethane 1 μg/L 0.18 U.S Environmental Protection Agency, 1986 8260B GC/MS 79-34-5 1,1,2,2-Tetrachloroethane 1 μg/L 0.16 U.S Environmental Protection Agency, 1986 8260B GC/MS 79-00-5 1,1,2-Trichloroethane 1 μg/L 0.24 U.S Environmental Protection Agency, 1986 8260B GC/MS 75-34-3 1,1-Dichloroethane 1 μg/L 0.24 U.S Environmental Protection Agency, 1986 8260B GC/MS 75-35-4 1,1-Dichloroethene 1 μg/L 0.27 U.S Environmental Protection Agency, 1986 8260B GC/MS 563-58-6 1,1-Dichloropropene 1 μg/L 0.14 U.S Environmental Protection Agency, 1986 8260B GC/MS 87-61-6 1,2,3-Trichlorobenzene 1 μg/L 0.34 U.S Environmental Protection Agency, 1986 8260B GC/MS 96-18-4 1,2,3-Trichloropropane 1 μg/L 0.26 U.S Environmental Protection Agency, 1986 8260B GC/MS 120-82-1 1,2,4-Trichlorobenzene 1 μg/L 0.32 U.S Environmental Protection Agency, 1986 8260B GC/MS 95-63-6 1,2,4-Trimethylbenzene 1 μg/L 0.28 U.S Environmental Protection Agency, 1986 8260B GC/MS 96-12-8 Dibromochloropropane 2 μg/L 0.63 U.S Environmental Protection Agency, 1986 8260B GC/MS 106-93-4 1,2-Dibromoethane 1 μg/L 0.2 U.S Environmental Protection Agency, 1986 8260B GC/MS 95-50-1 1,2-Dichlorobenzene 1 μg/L 0.25 U.S Environmental Protection Agency, 1986 8260B GC/MS 107-06-2 1,2-Dichloroethane 1 μg/L 0.12 U.S Environmental Protection Agency, 1986 8260B GC/MS 78-87-5 1,2-Dichloropropane 1 μg/L 0.17 U.S Environmental Protection Agency, 1986 8260B GC/MS 108-67-8 1,3,5-Trimethylbenzene 1 μg/L 0.26 U.S Environmental Protection Agency, 1986 8260B GC/MS 541-73-1 1,3-Dichlorobenzene 1 μg/L 0.21 U.S Environmental Protection Agency, 1986 8260B GC/MS 142-28-9 1,3-Dichloropropane 1 μg/L 0.17 U.S Environmental Protection Agency, 1986 8260B GC/MS 106-46-7 1,4-Dichlorobenzene 1 μg/L 0.2 U.S Environmental Protection Agency, 1986 8260B GC/MS 594-20-7 2,2-Dichloropropane 5 μg/L 0.13 U.S Environmental Protection Agency, 1986 8260B GC/MS 95-49-8 2-Chlorotoluene 1 μg/L 0.25 U.S Environmental Protection Agency, 1986 8260B GC/MS 106-43-4 4-Chlorotoluene 1 μg/L 0.82 U.S Environmental Protection Agency, 1986 8260B GC/MS 99-87-6 4-Isopropyltoluene 1 μg/L 0.22 U.S Environmental Protection Agency, 1986 8260B GC/MS 107-13-1 Acrylonitrile 20 μg/L 2.3 U.S Environmental Protection Agency, 1986 8260B GC/MS 71-43-2 Benzene 1 μg/L 0.15 U.S Environmental Protection Agency, 1986 8260B GC/MS 108-86-1 Bromobenzene 1 μg/L 0.19 U.S Environmental Protection Agency, 1986 8260B GC/MS 74-97-5 Bromochloromethane 1 μg/L 0.2 U.S Environmental Protection Agency, 1986 8260B GC/MS 75-27-4 Bromodichloromethane 1 μg/L 0.15 U.S Environmental Protection Agency, 1986 8260B GC/MS 75-25-2 Tribromomethane 1 μg/L 0.33 U.S Environmental Protection Agency, 1986 8260B GC/MS 74-83-9 Bromomethane 2 μg/L 0.26 U.S Environmental Protection Agency, 1986 8260B GC/MS

56-23-5 Tetrachloromethane 1 μg/L 0.19 U.S Environmental Protection Agency, 1986 8260B GC/MS108-90-7 Chlorobenzene 1 μg/L 0.19 U.S Environmental Protection Agency, 1986 8260B GC/MS75-00-3 Chloroethane 2 μg/L 0.31 U.S Environmental Protection Agency, 1986 8260B GC/MS67-66-3 Trichloromethane 1 μg/L 0.15 U.S Environmental Protection Agency, 1986 8260B GC/MS74-87-3 Chloromethane 2 μg/L 0.25 U.S Environmental Protection Agency, 1986 8260B GC/MS156-59-2 cis-1,2-Dichloroethene 1 μg/L 0.14 U.S Environmental Protection Agency, 1986 8260B GC/MS10061-01-5 cis-1,3-Dichloropropene 1 μg/L 0.12 U.S Environmental Protection Agency, 1986 8260B GC/MS124-48-1 Dibromochloromethane 1 μg/L 0.12 U.S Environmental Protection Agency, 1986 8260B GC/MS
Appendix 1  3

5

Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued[USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automatedsegmented flow; EC, electrolytic conductivity]

CASRN® Chemical constituent Laboratory reporting level Units Method detection level Reference Method ID Method description

74-95-3 Dibromomethane 1 μg/L 0.13 U.S Environmental Protection Agency, 1986 8260B GC/MS75-71-8 Dichlorodifluoromethane 2 μg/L 0.26 U.S Environmental Protection Agency, 1986 8260B GC/MS100-41-4 Ethylbenzene 1 μg/L 0.22 U.S Environmental Protection Agency, 1986 8260B GC/MS87-68-3 Hexachlorobutadiene 1 μg/L 0.33 U.S Environmental Protection Agency, 1986 8260B GC/MS98-82-8 Isopropylbenzene 1 μg/L 0.25 U.S Environmental Protection Agency, 1986 8260B GC/MS1634-04-4 Methyl tert-butyl ether 5 μg/L 0.19 U.S Environmental Protection Agency, 1986 8260B GC/MS75-09-2 Dichloromethane 5 μg/L 0.26 U.S Environmental Protection Agency, 1986 8260B GC/MS91-20-3 Naphthalene 1 μg/L 0.29 U.S Environmental Protection Agency, 1986 8260B GC/MS104-51-8 n-Butylbenzene 1 μg/L 0.27 U.S Environmental Protection Agency, 1986 8260B GC/MS103-65-1 n-Propylbenzene 1 μg/L 0.29 U.S Environmental Protection Agency, 1986 8260B GC/MS135-98-8 sec-Butylbenzene 1 μg/L 0.24 U.S Environmental Protection Agency, 1986 8260B GC/MS100-42-5 Styrene 1 μg/L 0.17 U.S Environmental Protection Agency, 1986 8260B GC/MS98-06-6 tert-Butylbenzene 1 μg/L 0.23 U.S Environmental Protection Agency, 1986 8260B GC/MS127-18-4 Tetrachloroethene 1 μg/L 0.2 U.S Environmental Protection Agency, 1986 8260B GC/MS108-88-3 Toluene 1 μg/L 0.17 U.S Environmental Protection Agency, 1986 8260B GC/MS156-60-5 trans-1,2-Dichloroethene 1 μg/L 0.17 U.S Environmental Protection Agency, 1986 8260B GC/MS10061-02-6 trans-1,3-Dichloropropene 1 μg/L 0.15 U.S Environmental Protection Agency, 1986 8260B GC/MS79-01-6 Trichloroethene 1 μg/L 0.19 U.S Environmental Protection Agency, 1986 8260B GC/MS75-69-4 Trichlorofluoromethane 2 μg/L 0.33 U.S Environmental Protection Agency, 1986 8260B GC/MS75-01-4 Vinyl chloride 1 μg/L 0.28 U.S Environmental Protection Agency, 1986 8260B GC/MS1330-20-7 Xylenes (total) 2 μg/L 0.45 U.S Environmental Protection Agency, 1986 8260B GC/MS120-82-1 1,2,4-Trichlorobenzene 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS95-50-1 1,2-Dichlorobenzene 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS541-73-1 1,3-Dichlorobenzene 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS88-06-2 2,4,6-Trichlorophenol 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS120-83-2 2,4-Dichlorophenol 10 μg/L 1.3 U.S Environmental Protection Agency, 1986 8270C GC/MS105-67-9 2,4-Dimethylphenol 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS51-28-5 2,4-Dinitrophenol 50 μg/L 10 U.S Environmental Protection Agency, 1986 8270C GC/MS121-14-2 2,4-Dinitrotoluene 10 μg/L 1.8 U.S Environmental Protection Agency, 1986 8270C GC/MS606-20-2 2,6-Dinitrotoluene 10 μg/L 1.6 U.S Environmental Protection Agency, 1986 8270C GC/MS91-58-7 2-Chloronaphthalene 10 μg/L 1.7 U.S Environmental Protection Agency, 1986 8270C GC/MS95-57-8 2-Chlorophenol 10 μg/L 1.7 U.S Environmental Protection Agency, 1986 8270C GC/MS88-75-5 2-Nitrophenol 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS91-94-1 3,3'-Dichlorobenzidine 50 μg/L 0.63 U.S Environmental Protection Agency, 1986 8270C GC/MS534-52-1 2-Methyl-4,6-dinitrophenol 50 μg/L 9.8 U.S Environmental Protection Agency, 1986 8270C GC/MS101-55-3 4-Bromophenyl phenyl ether 10 μg/L 2.1 U.S Environmental Protection Agency, 1986 8270C GC/MS59-50-7 4-Chloro-3-methylphenol 10 μg/L 1.3 U.S Environmental Protection Agency, 1986 8270C GC/MS7005-72-3 4-Chlorophenyl phenyl ether 10 μg/L 2 U.S Environmental Protection Agency, 1986 8270C GC/MS
Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued

[USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automatedsegmented flow; EC, electrolytic conductivity]

CASRN® Chemical constituent Laboratory reporting level Units Method detection level Reference Method ID Method description

100-02-7 4-Nitrophenol 50 μg/L 11 U.S Environmental Protection Agency, 1986 8270C GC/MS83-32-9 Acenaphthene 10 μg/L 1.7 U.S Environmental Protection Agency, 1986 8270C GC/MS208-96-8 Acenaphthylene 10 μg/L 1.8 U.S Environmental Protection Agency, 1986 8270C GC/MS15972-60-8 Alachlor 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS120-12-7 Anthracene 10 μg/L 1.9 U.S Environmental Protection Agency, 1986 8270C GC/MS19112-24-9 Atrazine 50 μg/L 13 U.S Environmental Protection Agency, 1986 8270C GC/MS92-87-5 Benzidine 100 μg/L 40 U.S Environmental Protection Agency, 1986 8270C GC/MS56-55-3 Benzo(a)anthracene 10 μg/L 1.7 U.S Environmental Protection Agency, 1986 8270C GC/MS50-32-8 Benzo(a)pyrene 10 μg/L 1.3 U.S Environmental Protection Agency, 1986 8270C GC/MS205-99-2 Benzo(b)fluoranthene 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS191-24-2 Benzo(ghi)perylene 10 μg/L 2 U.S Environmental Protection Agency, 1986 8270C GC/MS207-08-9 Benzo(k)fluoranthene 10 μg/L 2.1 U.S Environmental Protection Agency, 1986 8270C GC/MS111-91-1 bis(2-Chloroethoxy)methane 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS111-44-4 bis(2-Chloroethyl) ether 10 μg/L 1.8 U.S Environmental Protection Agency, 1986 8270C GC/MS108-60-1 bis(2-chloroisopropyl) ether 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS117-81-7 bis(2-Ethylhexyl) phthalate 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS85-68-7 Benzyl n-butyl phthalate 10 μg/L 1.7 U.S Environmental Protection Agency, 1986 8270C GC/MS218-01-9 Chrysene 10 μg/L 2 U.S Environmental Protection Agency, 1986 8270C GC/MS53-70-3 Dibenz(a,h)anthracene 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS84-66-2 Diethyl phthalate 10 μg/L 1.8 U.S Environmental Protection Agency, 1986 8270C GC/MS131-11-3 Dimethyl phthalate 10 μg/L 1.7 U.S Environmental Protection Agency, 1986 8270C GC/MS84-74-2 Di-n-butyl phthalate 10 μg/L 1.9 U.S Environmental Protection Agency, 1986 8270C GC/MS117-84-0 Di-n-octyl phthalate 10 μg/L 1.1 U.S Environmental Protection Agency, 1986 8270C GC/MS206-44-0 Fluoranthene 10 μg/L 1.8 U.S Environmental Protection Agency, 1986 8270C GC/MS86-73-7 9H-Fluorene 10 μg/L 1.7 U.S Environmental Protection Agency, 1986 8270C GC/MS118-74-1 Hexachlorobenzene 10 μg/L 2.1 U.S Environmental Protection Agency, 1986 8270C GC/MS87-68-3 Hexachlorobutadiene 10 μg/L 1.3 U.S Environmental Protection Agency, 1986 8270C GC/MS77-47-4 Hexachlorocyclopentadiene 50 μg/L 5 U.S Environmental Protection Agency, 1986 8270C GC/MS67-72-1 Hexachloroethane 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS193-39-5 Indeno(1,2,3-cd)pyrene 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS78-59-1 Isophorone 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS91-20-3 Naphthalene 10 μg/L 1.5 U.S Environmental Protection Agency, 1986 8270C GC/MS98-95-3 Nitrobenzene 10 μg/L 1.2 U.S Environmental Protection Agency, 1986 8270C GC/MS62-75-9

N-Nitrosodimethylamine 10 μg/L 1.6 U.S Environmental Protection Agency, 1986 8270C GC/MS

621-64-7

N-Nitrosodi-n-propylamine 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS

86-30-6

N-Nitrosodiphenylamine 10 μg/L 2.6 U.S Environmental Protection Agency, 1986 8270C GC/MS

87-86-5 Pentachlorophenol 50 μg/L 10 U.S Environmental Protection Agency, 1986 8270C GC/MS85-01-8 Phenanthrene 10 μg/L 2 U.S Environmental Protection Agency, 1986 8270C GC/MS108-95-2 Phenol 10 μg/L 1.4 U.S Environmental Protection Agency, 1986 8270C GC/MS

36  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Appendix 1  37

Appendix 1. List of chemical constituents, reporting limits, and methods of analysis used during the study.—Continued[USGS, U.S. Geological Survey; CASRN®, Chemical Abstracts Service registry number; na, not applicable; mg/L, milligrams per liter; μg/L, micrograms per liter; lrl, laboratory reporting level; mrl, minimum reporting level; irl, interim reporting level; MS, mass spectrometry; GC, gas chromatography; HPLC, high-performance liquid chromatography; ICP, inductively coupled plasma; ASF, automated-segmented flow; EC, electrolytic conductivity]

CASRN® Chemical constituent

Minimum 

reporting 

level

Units Reference Method ID Method description

na Oil and grease 5 mg/L U.S Environmental Protection Agency, 1986 8270C GC/MSna Petroleum hydrcarbons 5 mg/L U.S Environmental Protection Agency, 1986 8270C GC/MS

CASRN® Chemical constituent

Laboratory 

reporting 

level

Units

Method 

detection 

level

Reference Method ID Method description

na Diesel-range organics 0.25 mg/L 0.013 U.S Environmental Protection Agency, 1986 8015B GC with flame ionization detectorna Gasoline-range organics 0.025 mg/L 0.006 U.S Environmental Protection Agency, 1986 8015B GC with flame ionization detector

CASRN® Chemical constituent

Minimum 

reporting 

level

Units Reference Method ID Method description

na meta- + para-Xylene, total 0.5 μg/L U.S Environmental Protection Agency, 1986 8021B GC using photoionization and/or EC detectors1634-04-4 Methyl tert-butyl ether, total 5 μg/L U.S Environmental Protection Agency, 1986 8021B GC using photoionization and/or EC detectors95-47-6 o-Xylene, total 0.5 μg/L U.S Environmental Protection Agency, 1986 8021B GC using photoionization and/or EC detectors1330-20-7 Xylene, total 0.5 μg/L U.S Environmental Protection Agency, 1986 8021B GC using photoionization and/or EC detectors57-12-5 Cyanide, total 0.01 mg/L U.S Environmental Protection Agency, 1986 9012B Automated colorimetric, with off-line distillation
Appendix 2. Concentrations of inorganic constituents in ground water from selected wells in the Anacostia River watershed within Washington, D.C., 

September–December 2005, and selected water-quality criteria.

[--, no value reported; na, not applicable; gal/min, gallons per minute; NTRU, nephelometric turbidity ratio unit; mm Hg, millimeters of mercury; μS/cm, microsiemens per centimeter 

at 25 degrees Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; N, nitrogen; CaCO3, calcium carbonate; <, less than; E, estimated; M, presence verified but not quantified; d, diluted sample: method high range exceeded; n, value is below the laboratory reporting level and above the long-term method detection level; o, result determined by alternate 

method; NAVD 88, North American Vertical Datum of 1988; CASRN®, Chemical Abstracts Service Registry Number; USGS, U.S. Geological Survey; USEPA, U.S. Environmental 

Protection Agency; ***, Please refer to District of Columbia (2003) for this value; bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample 

results]

USGS well 

number

USGS site 

identifier Date Time Sample type

Flow rate, 

instantaneous, 

gal/min

Pumped 

period prior 

to sampling, 

in minutes

Turbidity, 

NTRU

Barometric 

pressure, 

in mm Hg

Dissolved 

oxygen, 

mg/L

pH, water, 

unfiltered, 

field, 

standard 

units

Specific 

conductance, 

water, 

unfiltered, 

μS/cm

CASRN na na na na na na na

AC Aa 1 385225076590101 9/21/2005 1030 Environmental 0.75 80 7.7 769 3.1 6.7 291

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank -- -- -- -- -- -- --

WE Ba 9 385606076584101 10/12/2005 1230 Environmental 0.17 90 5 765 <1 6.2 765

WE Ba 10 385534076582101 10/12/2005 930 Environmental 0.4 60 2 765 <1 5.4 261

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank -- -- -- -- -- -- --

WE Bb 3 385504076563801 9/20/2005 1000 Environmental 1 90 30 768 1 5.9 363

WE Bb 3 385504076563801 9/20/2005 1010 Replicate -- -- -- -- -- -- --

WE Bb 4 385504076563802 9/20/2005 1430 Environmental 0.66 55 0.8 768 1.6 6 279

WE Ca 29 385238076581501 9/19/2005 1400 Environmental 1 55 12 770 1.1 6 179

WE Ca 32 385332076594701 9/22/2005 1000 Environmental 0.75 90 7.5 765 5.8 5.6 1,100

WE Ca 33 385349076592801 10/14/2005 1030 Environmental 0.75 75 3 762 <1 6.7 710

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank -- -- -- -- -- -- --

WE Ca 34 385245076583501 9/27/2005 1330 Environmental 1 90 1.4 764 <1 7.3 696

WE Cb 5 385443076562801 9/14/2005 1400 Environmental 1 50 1.3 764 4.5 5.2 286

WE Cb 6 385443076562802 9/14/2005 1030 Environmental 1 93 2.3 764 <1 6.2 87

WE Cb 8 385252076572801 12/20/2005 1430 Environmental -- 150 -- 763 -- 6.8 151

WE Cb 8 385252076572801 12/20/2005 1435 Replicate -- -- -- -- -- -- --

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank -- -- -- -- -- -- --

WE Cb 11 385332076564101 12/19/2005 1430 Environmental -- 40 -- 769 -- 6.2 355

WE Cb 12 385332076564102 9/27/2005 1000 Environmental 0.85 75 0.9 764 <1 5.8 164

WE Cc 3 385327076544801 10/6/2005 1000 Environmental 0.4 85 0.4 768 2 5.9 854

WE Cc 3 385327076544801 10/6/2005 1010 Replicate -- -- -- -- -- -- --

WW Bc 8 385519077012601 10/13/2005 1100 Environmental 0.2 50 1 761 1.7 5 482

WW Bc 9 385527077000701 12/19/2005 1100 Environmental 0.18 40 -- 775 -- 4.8 371

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- *** -- -- 6.5–8.5 --

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- *** -- -- 6.0–8.5 --

B -- -- *** -- -- 6.0–8.5 --

C -- -- *** -- 4-5 6.0–8.5 --

D -- -- -- -- -- -- --

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

-- -- -- -- -- -- --

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental Protection Agency Region III, 2006)-- -- -- -- -- -- --

38 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Temperature, air, 

degrees 

Celsius

Temperature, water, 

degrees 

Celsius

Calcium, 

water, 

dissolved, 

mg/L

Magnesium, 

water, 

dissolved, 

mg/L

Potassium, 

water, 

dissolved, 

mg/L

Sodium, 

water, 

dissolved, 

mg/L

Alkalinity, field, 

mg/L as 

CaCO3

Bicarbonate, 

dissolved, 

field, 

mg/L

Chloride, 

water, 

dissolved, 

mg/L

Fluoride, 

water, 

dissolved, 

mg/L

Silica, 

water, 

dissolved, 

mg/L

Sulfate, 

water, 

dissolved, 

mg/L

Ammonia + 

organic 

nitrogen, 

water, total, 

mg/L as N

na na 7440-70-2 7439-95-4 7440-09-7 7440-23-5 na na 16887-00-6 16984-48-8 7631-86-9 14808-79-8 17778-88-0

28 16.5 19.5 8.67 2.66 7.23 131 159 9.39 0.2 10.7 <.2 4.2

-- -- 0.08 <.008 <.16 0.3 -- -- <.20 E.1n 1.6 <.2 <.10

18.5 18.5 91.7 25.9 5.12 11.7 214 260 24.2 0.1 7.4 81.1 0.4

17 18.5 26.3 10.9 1.22 9.45 37 45 11.4 <.1 12.2 61.1 E.07n

-- -- 0.16 E.004n <.16 0.31 -- -- <.20 <.1 1.6 <.2 <.10

31 15.5 12 4.3 2.49 9.02 141 171 23 E.1n 19.1 <.2 5.0d

-- -- 11.8 4.22 2.54 8.81 -- -- 23.3 E.1n 19.1 <.2 4.8

32 16 10.5 4.63 3.33 9.13 101 123 24.2 0.1 16.8 <.2 1.8

32 17 6.05 3.43 1.89 4.97 64 78 17.8 E.1n 15.7 <.2 0.64

25.5 18 57.4 14.3 7.73 122 17 21 257 <.1 7.6 79.7 <.10

19 17.5 28.7 18.7 3.72 39.2 181 220 108d 0.2 6.2 14.1d 0.4

-- -- 0.05 <.008 <.16 E.19n -- -- <.20 <.1 0.5 <.2 <.10

25 16 103 13.8 6.72 13.9 317 386 27.6 0.4 22.4 E.1n 3.6

31 18 34.7 5.21 4.39 9.4 10 12 11.9 <.1 6.4 76.7 0.12

28 17 2.47 1.03 1.25 1.65 27 32 5.58 <.1 11 6.4 0.18

-- 15.2 11.2 6.63 5.53 4.71 58 71 2.91 0.2 11.8 11.8 E.08n

-- -- 11.2 6.6 5.59 4.69 -- -- 3.01 0.1 11.8 11.8 0.11

-- -- E.01n <.008 <.16 <.20 -- -- <.20 <.1 <.2 <.2 <.10

3.5 11.5 23.7 11.6 3.82 7.33 109 133 37 0.2 15.9 2.7d 0.15

21 15 14.4 5.66 3.28 4.21 50 60 9.14 0.1 14 12.5 0.15

22 17.5 55.7 10.3 4.29 85.3 85 104 170 0.1 6.7 46.7 0.16

-- -- 54.1 10.2 4.08 85.7 84 102 174 0.2 6.7 47.7 0.17

15 17.5 27.2 14.6 10.1 25.7 12 15 97.4 E.1n 11.3 11.4 0.56

5.5 15 15.6 10.9 4.51 30.1 5 7 77.3 E.1n 13.1 30.6 E.07n

-- -- -- -- -- -- -- -- 250 4.0 -- 250 --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- 32.2 -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- 4 -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

Appendix 2  39
USGS well 

number

USGS site 

identifier Date Time Sample type

Ammonia, 

water, 

dissolved, 

mg/L as N

Nitrite + 

nitrate, 

water, 

dissolved, 

mg/L as N

Nitrite, 

water, 

dissolved, 

mg/L as N

Phosphorus, 

water, 

dissolved, 

mg/L

Phosphorus, 

water, 

total, 

mg/L

Aluminum, 

water, 

dissolved, 

μg/L

CASRN 7664-41-7 na 14797-65-0 7723-14-0 7723-14-0 7429-90-5

AC Aa 1 385225076590101 9/21/2005 1030 Environmental 3.81d <.06 E.006n 0.43 0.47 <2

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank <.04 <.06 <.008 <.04 <.04 15K

WE Ba 9 385606076584101 10/12/2005 1230 Environmental 0.27 1.36 <.008 <.04 <.04 <2

WE Ba 10 385534076582101 10/12/2005 930 Environmental <.04 1.15 <.008 <.04 <.04 2

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank <.04 <.06 <.008 <.04 <.04 17K

WE Bb 3 385504076563801 9/20/2005 1000 Environmental 4.38d <.06 <.008 0.49 .70d 2

WE Bb 3 385504076563801 9/20/2005 1010 Replicate 4.35d <.06 <.008 0.52 0.72 2

WE Bb 4 385504076563802 9/20/2005 1430 Environmental 1.76d <.06 <.008 0.43 0.48 2

WE Ca 29 385238076581501 9/19/2005 1400 Environmental 0.54 <.06 E.005n E.04n 0.18 <2

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <.04 7.74d <.008 <.04 <.04 4

WE Ca 33 385349076592801 10/14/2005 1030 Environmental 0.24 <.06 <.008 <.20d E.02n <2

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <.04 <.06 <.008 <.04 <.04 6K

WE Ca 34 385245076583501 9/27/2005 1330 Environmental 3.27d <.06 <.008 0.14 0.2 2

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <.04 5.41d <.008 <.04 <.04 2

WE Cb 6 385443076562802 9/14/2005 1030 Environmental 0.11 <.06 0.009 0.13 0.17 <2

WE Cb 8 385252076572801 12/20/2005 1430 Environmental 0.06 <.06 E.006n 0.21 0.29 <2

WE Cb 8 385252076572801 12/20/2005 1435 Replicate 0.07 <.06 E.005n 0.2 0.3 <2

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <.04 <.06 <.008 <.04 <.04 <2K

WE Cb 11 385332076564101 12/19/2005 1430 Environmental 0.13 <.06 <.008 <.04 <.04 <2

WE Cb 12 385332076564102 9/27/2005 1000 Environmental 0.11 <.06 E.006n <.04 <.04 2

WE Cc 3 385327076544801 10/6/2005 1000 Environmental E.03n 3.03 <.008 <.04 <.04 7

WE Cc 3 385327076544801 10/6/2005 1010 Replicate E.02n 3.01 <.008 <.04 <.04 6

WW Bc 8 385519077012601 10/13/2005 1100 Environmental 0.5 11.2d <.008 <.04 <.04 172

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <.04 2.92 <.008 <.04 <.04 107

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- 10 1 -- -- --

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- --

B -- -- -- -- -- --

C *** -- -- -- -- --

D -- -- -- -- -- --

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

-- 10 1 0.00073 0.00073 --

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

0.21 na 3.7 -- -- --

40 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 2. Concentrations of inorganic constituents in ground water from selected wells in the Anacostia River watershed within Washington, D.C., 

September–December 2005, and selected water-quality criteria.—Continued

[--, no value reported; na, not applicable; gal/min, gallons per minute; NTRU, nephelometric turbidity ratio unit; mm Hg, millimeters of mercury; μS/cm, microsiemens per centimeter 

at 25 degrees Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; N, nitrogen; CaCO3, calcium carbonate; <, less than; E, estimated; M, presence verified but not quantified; d, diluted sample: method high range exceeded; n, value is below the laboratory reporting level and above the long-term method detection level; o, result determined by alternate 

method; NAVD 88, North American Vertical Datum of 1988; CASRN®, Chemical Abstracts Service Registry Number; USGS, U.S. Geological Survey; USEPA, U.S. Environmental 

Protection Agency; ***, Please refer to District of Columbia (2003) for this value; bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample 

results]
Antimony, 

water, 

dissolved, 

μg/L

Arsenic, 

water, 

dissolved, 

μg/L

Barium, 

water, 

dissolved, 

μg/L

Beryllium, 

water, 

dissolved, 

μg/L

Cadmium, 

water, 

dissolved, 

μg/L

Chromium, 

water, 

dissolved, 

μg/L

Cobalt, 

water, 

dissolved, 

μg/L

Copper, 

water, 

dissolved, 

μg/L

Cyanide, 

water, 

total, 

mg/L

Iron, 

water, 

dissolved, 

μg/L

Lead, 

water, 

dissolved, 

μg/L

Manganese, 

water, 

dissolved, 

μg/L

Mercury, 

water, 

dissolved, 

μg/L

7440-36-0 7440-38-2 7440-39-3 7440-41-7 7440-43-9 7440-47-3 7440-48-4 7440-50-8 57-12-5 7439-89-6 7439-92-1 7439-96-5 7439-97-6

<.20 39.9o 97 <.06 <.04 0.17 3.9o <.40o <.01 22,500d <.08 63.1 <.01

<.20 E.08no <.2 <.06 <.04 0.11 <.014 0.4 -- <6 0.26 <.2 <.01

<.20 E.10n 58 <.06 E.04n 0.09 2.81o .7o <.01 <6 <.08 554 <.01

<.20 E.06n 25 0.08 E.03n <.04 .364o E.3no <.01 <6 E.04n 176 <.01

<.20 <.12 M <.06 <.04 <.04 <.040o .7o -- <6 0.21 <.2 <.01

<.20 .38o 178 E.03n 0.1 0.75 2.2o E.26no <.01 54,400d <.08 2,330 <.01

<.20 .42o 177 E.03n 0.16 0.8 2.2o E.24no -- 53,600d <.08 2,320 <.01

<.20 .40o 163 E.04n 0.13 0.57 1.9o E.20no <.01 36,900d <.08 1,600 <.01

<.20 3.1o 117 E.03n <.04 0.18 E.02no <.40o <.01 23,900d <.08 141 <.01

<.20 .43o 87 <.06 0.07 1.1 0.423 1.2 M 13 0.14 2.8 <.01

<.20 5.8 142 <.06 <.04 0.26 7.23o <.4o M 37,800d <.08 6,830d <.01

<.20 <.12 <.2 <.06 <.04 0.13 <.040o <.4o <.01 <6 E.04n <.2 <.01

<.20 2.1 404 <.06 <.04 0.15 0.334 E.4n M 7,930 <.08 643 <.01

<.20 E.06no 29 0.07 0.32 .47o -- -- <.01 E3n 0.1 19.3 <.01

<.20 3.4o 72 <.06 <.04 .08o -- -- <.01 5,210 <.08 92 <.01

<.20 E.11n 173 <.06 <.04 0.12 .543o <.4o <.01 3,070 <.08 189 <.01

<.20 0.12 172 <.06 <.04 0.29 .562o <.4o <.01 3,080 <.08 187 <.01

<.20 <.12 <.2 <.06 <.04 <.04 <.040o <.4o <.01 <6 <.08 <.2 <.01

<.20 0.79 535 <.06 <.04 <.04 61.4o <.4o M 17,200d <.08 5,890 <.01

<.20 0.3 136 <.06 <.04 0.12 8.77 E.3n M 3,060 0.13 1,400 <.01

<.20 0.12 63 0.09 0.36 0.05 10.3o .5o <.01 815 <.08 255 <.01

<.20 0.12 63 0.08 0.36 0.05 10.4o E.4no M 797 <.08 244 <.01

<.20 0.28 586 1.44 0.41 0.09 29.6o 9.9o <.01 8 7.84 480 E.01n

<.20 0.2 174 0.28 0.49 0.55 3.20o 1.9o <.01 7 E.07n 296 .33d

-- 50 1,000 -- 5 100A -- 1,000 0.2B 300 50 50 2

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- 150–340 -- -- *** 11–16J -- *** 0.0052–0.022 1,000 *** -- 0.77–1.4G

4,300 0.14 -- -- -- -- -- -- 0.14 -- *** 100 0.15G

 6 10 2,000 4 5 100 -- 1,300C 0.2 -- 15L -- 2D

15 0.045 7,300 73 18 110–55,000E -- 1,500 0.73 11,000 -- 730 --

Appendix 2  41
USGS well 

number

USGS site 

identifier Date Time Sample type

Molybdenum, 

water, 

dissolved, 

μg/L

Nickel, 

water, 

dissolved, 

μg/L

Selenium, 

water, 

dissolved, 

μg/L

Silver, 

water, 

dissolved, 

μg/L

Thallium, 

water, 

dissolved, 

μg/L

Zinc, 

water, 

dissolved, 

μg/L

Uranium, 

natural, 

water, 

dissolved, 

μg/L

CASRN 7439-98-7 7440-02-0 7782-49-2 7440-22-4 7440-28-0 7440-66-6 7440-61-1

AC Aa 1 385225076590101 9/21/2005 1030 Environmental 4.9 1.0o E.06no <.2 <.04 372o <.04

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank <.4 0.12 <.08o <.2 <.04 0.6 <.04

WE Ba 9 385606076584101 10/12/2005 1230 Environmental 0.4 5.71o 0.29 <.2 0.07 3.6o 0.18

WE Ba 10 385534076582101 10/12/2005 930 Environmental <.4 4.71o E.04n <.2 <.04 1.8o E.02n

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank <.4 <.06o <.08 <.2 <.04 6.2 <.04

WE Bb 3 385504076563801 9/20/2005 1000 Environmental E.2n .62o <.08o <.2 <.04 .73o <.04

WE Bb 3 385504076563801 9/20/2005 1010 Replicate E.2n .67o <.08o <.2 <.04 E.34no <.04

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <.4 .98o <.08o <.2 <.04 E.44no <.04

WE Ca 29 385238076581501 9/19/2005 1400 Environmental 0.5 -- <.08o <.2 <.04 E.35no <.04

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <.4 4.22 2.1o <.2 0.08 2 <.04

WE Ca 33 385349076592801 10/14/2005 1030 Environmental 0.8 1.36o <.08 <.2 <.04 <.60 <.04

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <.4 <.06o <.08 <.2 <.04 <.60 <.04

WE Ca 34 385245076583501 9/27/2005 1330 Environmental E.3n 3.49 0.7 <.2 <.04 0.9 E.03n

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <.4 -- .91o <.2 E.02n 2.4o <.04

WE Cb 6 385443076562802 9/14/2005 1030 Environmental E.4n -- <.08o <.2 <.04 .64o <.04

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <.4 .77o <.08 <.2 <.04 <.6o <.04

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <.4 .96o <.08 <.2 <.04 <.6o <.04

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <.4 E.06no <.08 <.2 <.04 <.6o <.04

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <.4 11.9o <.08 <.6d <.04 7.9o <.04

WE Cb 12 385332076564102 9/27/2005 1000 Environmental E.2n 4.65 <.4 <.2 <.04 4.5 <.04

WE Cc 3 385327076544801 10/6/2005 1000 Environmental E.4n 13.1o 1.2 <.2 0.11 13.7 0.14

WE Cc 3 385327076544801 10/6/2005 1010 Replicate 0.4 13.2o 1.2 <.2 0.1 13.2 0.12

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <.4 29.4o 0.23 <.2 0.18 122o 0.05

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <.4 21.1o 0.82 <.2 0.08 37.0o 0.04

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- 50 50 -- 5,000 --

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- --

B -- -- -- -- -- -- --

C -- *** 5–20 *** -- *** --

D -- 4,600 4,200G 65,000 0.47 26,000 --

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

-- -- 50 -- 2 -- 30

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental Protection Agency Region III, 2006)

180 730 180 180 2.6 11,000 7.3–110F

42 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 2. Concentrations of inorganic constituents in ground water from selected wells in the Anacostia River watershed within Washington, D.C., 

September–December 2005, and selected water-quality criteria.—Continued

[--, no value reported; na, not applicable; gal/min, gallons per minute; NTRU, nephelometric turbidity ratio unit; mm Hg, millimeters of mercury; μS/cm, microsiemens per centimeter 

at 25 degrees Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; N, nitrogen; CaCO3, calcium carbonate; <, less than; E, estimated; M, presence verified but not quantified; d, diluted sample: method high range exceeded; n, value is below the laboratory reporting level and above the long-term method detection level; o, result determined by alternate 

method; NAVD 88, North American Vertical Datum of 1988; CASRN®, Chemical Abstracts Service Registry Number; USGS, U.S. Geological Survey; USEPA, U.S. Environmental 

Protection Agency; ***, Please refer to District of Columbia (2003) for this value; bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample 

results]
Appendix 2  43

Appendix 2. Footnotes.

A The District of Columbia has two ground-water standards for chromium: hexavalent chromium is 100 μg/L, and trivalent chromium is 100 μg/L.

B The District of Columbia ground-water standard for cyanide is “free” cyanide, whereas the reported USGS values for cyanide are total or whole values.

C The value listed for copper is a USEPA “action level,” not an MCL.

D The MCL listed for mercury is for inorganic mercury (CASRN 7487-94-7).

E The USEPA Region III RBC value for trivalent chromium is 55,000 μg/L and the value for hexavalent chromium is 110 μg/L.

F

 The USEPA Region III RBCs include two values: a value from the Integrated Risk Information System (IRIS) of 110 μg/L and a “provisional” value of 

7.3 μg/L .

G The District of Columbia surface-water standard for mercury is for total recoverable mercury. The results from the 2005 ground-water samples are for 

dissolved mercury.

H The District of Columbia surface-water standard for selenium is for total recoverable selenium. The results from the 2005 ground-water samples are for 

dissolved selenium.

J

 The District of Columbia surface-water standards contain values of 11 to 16 μg/L for dissolved hexavalent chromium. Please refer to the District of 

Columbia surface-water regulations for the table or equation for the dissolved trivalent chromium value. The results from the 2005 ground-water samples are 

for dissolved chromium.

K In March 2006, the blank water lots used for this sample were found to have concentrations of aluminum between 10 and 70 μg/L instead of less than 

1.6 μg/L.

L This value is a USEPA “action level,” not an MCL.
Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]

USGS well 

number

USGS site 

identifier Date Time Sample type

2,4-D 

methyl 

ester, 

filtered, 

μg/L

2,4-D, 

filtered, 

μg/L

2,4-DB, 

filtered, 

μg/L

CIAT, 

filtered, 

μg/L

CEAT, 

filtered, 

μg/L

OIET, 

filtered, 

μg/L

3-Hydroxycarbofuran, 

filtered, 

μg/L

3-Ketocarbofuran, 

filtered, 

μg/L

CASRN 1928-38-7 94-75-7 94-82-6 6190-65-4 1007-28-9 2163-68-0 16655-82-6 16709-30-1 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <.016 <.08 <.02 <.03 <.08m <.032 <.008 <.02m 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- -- 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate <.016 <.04 <.02 <.03 <.08m 0.044 <.008 <.02m 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <.016 <.04 <.02 E.02n <.08m <.032 <.008 <.02m 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- -- 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <.023 <.04 <.02 <.03 <.08m <.032 <.008 <.09m 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- -- 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <.016 <.04 <.02 <.03 <.08m E.007t <.008 <.02m 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <.016 <.04 <.02 <.03 <.08m E.007t <.008 <.02m 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- -- -- -- 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <.016 <.04 <.02 <.03 <.08m <.032 <.008 <.02m 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- -- -- -- 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <.016 <.04 <.02 E.01t E.01mt <.032 <.008 <.02m 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- -- -- -- 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- 100 -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- -- 

C -- -- -- -- -- -- -- -- 

D -- -- -- -- -- -- -- -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection 

Agency, 2006b)

-- 70 -- -- -- -- -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental Protection Agency Region III, 2006)-- 370 290 -- -- -- -- -- 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

44  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005
Pesticides and degradates

Acifluorfen, 

water, 

filtered, 

μg/L

Alachlor, 

unfiltered, 

μg/L

Aldicarb 

sulfone 

water, 

filtered, 

μg/L

Aldicarb 

sulfoxide, 

filtered, 

μg/L

Aldicarb, 

filtered, 

μg/L

Aldrin, 

unfiltered, 

μg/L

alphaEndosulfan, 

unfiltered, 

μg/L

Aminomethylphosphonic acid, 

filtered, 

μg/L

Atrazine, 

filtered, 

μg/L

Bendiocarb, 

filtered, 

μg/L

Benomyl, 

filtered, 

μg/L

Bensulfuronmethyl, 

filtered, 

μg/L

Bentazon, 

filtered, 

μg/L

Bromacil, 

filtered, 

μg/L

50594-66-6 15972-60-8 1646-88-4 1646-87-3 116-06-3 309-00-2 959-98-8 1066-51-9 19112-24-9 22781-23-3 17804-35-2 99283-01-9 25057-89-0 314-40-9

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 -- <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 -- <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 -- <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 0.02 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022m <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.028 <10.0 <.02 <.022 --r <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

<.028 <10.0 <.02 <.022 --r <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.028 <10.0 <.02 <.022 <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.028 <10.0 <.02 <.022m <.04m <.001 <.001 <.310 <.008 <.02 <.022 <.02 <.01 E.01t

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- 0.4–3.0 0.056–0.22 -- -- -- -- -- -- --

-- -- -- -- -- 0.00005 89 -- -- -- -- -- -- --

-- 2 2 4 3 -- -- -- 3 -- -- -- -- --

-- 0.84 37 -- 37 0.0039 -- -- -- -- -- -- 1,100 --

Appendix 3  45
USGS well 

number

USGS site 

identifier Date Time Sample type

Bromoxynil, 

filtered, 

μg/L

Carbaryl, 

filtered, 

μg/L

Carbofuran, 

filtered, 

μg/L

Chloramben

methyl 

ester, 

filtered, 

μg/L

Chlordane, 

technical 

mix, 

unfiltered, 

μg/L

Chlorimuron, 

filtered, 

μg/L

Chlorodiaminos-triazine, 

filtered, 

μg/L

CASRN 1689-84-5 63-25-2 1563-66-2 7286-84-2 57-74-9 90982-32-4 3397-62-4 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <.03 <.02 <.016 <.02 E.1b <.032m <.04vm 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <.03 <.02 <.016 <.02 <.1 <.032m <.04vm 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- -- -- 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- 

C -- -- -- -- 0.0043–2.4 -- -- 

D -- -- -- -- 0.00081 -- -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

-- -- 40 -- 2 -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

-- 3,700 -- -- 0.19 -- -- 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

46  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Pesticides and degradates—Continued

Chlorothalonil, 

filtered, 

μg/L

Clopyralid, 

filtered, 

μg/L

Cycloate, 

filtered, 

μg/L

Dacthalmonoacid, 

filtered, 

μg/L

Dicamba, 

filtered, 

μg/L

Dichlorprop, 

filtered, 

μg/L

Dieldrin, 

unfiltered, 

μg/L

Dinoseb, 

filtered, 

μg/L

Diphenamid, 

filtered, 

μg/L

Diuron, 

filtered, 

μg/L

Endrin, 

unfiltered, 

μg/L

Fenuron, 

filtered, 

μg/L

Flumetsulam, 

filtered, 

μg/L

Fluometuron, 

filtered, 

μg/L

1897-45-6 1702-17-6 1134-23-2 887-54-7 1918-00-9 120-36-5 60-57-1 88-85-7 957-51-7 330-54-1 72-20-8 101-42-8 98967-40-9 2164-17-2

<.04m <.02 <.01 <.41 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 0.065 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 0.002 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <0.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 0.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02m <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.04m <.02 <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.04m <.02m <.01 <.03 <.04 <.03 <.001 <.04 <.01 <.01v <.002 <.02 <.04 <.02

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- 0.2 -- -- --

-- -- -- -- -- -- -- -- -- -- 0.2 -- -- --

-- -- -- -- -- -- -- -- -- -- 0.2 -- -- --

-- -- -- -- -- -- 0.056–0.24 -- -- -- 0.036–0.086 -- -- --

-- -- -- -- -- -- 0.000054 -- -- -- 0.06 -- -- --

-- -- -- -- -- -- -- 7 -- -- 2 -- -- --

-- -- -- -- 1,100 -- 0.0042 37 -- 73 11 -- -- 470

Appendix 3  47
USGS well 

number

USGS site 

identifier Date Time Sample type

Glufosinate, 

filtered, 

μg/L

Glyphosate, 

filtered, 

μg/L

Heptachlor 

epoxide, 

unfiltered, 

μg/L

Heptachlor, 

unfiltered, 

μg/L

Imazaquin, 

filtered, 

μg/L

Imazethapyr, 

filtered, 

μg/L

Imidacloprid, 

filtered, 

μg/L

CASRN 51276-47-2 1071-83-6 1024-57-3 76-44-8 81335-37-7 81335-77-5 138261-41-3 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate <.140 <.150 <.001 <.001 <.04m <.13 <.020 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <.140 <.150 0.005 <.001 <.04m <.04 0.301 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <.140 <.150 0.007 <.001 <.04m <.04 <.020 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <.140 <.150 0.007 <.001 <.04m <.04 <.020 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <.140 <.150 <.001 <.001 <.04m <.04 <.020 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- -- -- 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- 

C -- -- 0.0038–0.52 0.0038–0.52 -- -- -- 

D -- -- 0.000039 0.000079 -- -- -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

-- 700 0.2 0.4 -- -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental Protection Agency Region III, 2006)-- 3,700 0.0074 0.015 -- 9,100 -- 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

48 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Pesticides and degradates—Continued

Lindane, 

unfiltered, 

μg/L

Linuron, 

filtered, 

μg/L

MCPA, 

filtered, 

μg/L

MCPB, 

filtered, 

μg/L

Metalaxyl, 

filtered, 

μg/L

Methiocarb, 

filtered, 

μg/L

Methomyl, 

filtered, 

μg/L

Metsulfuron 

methyl, 

filtered, 

μg/L

Mirex, 

unfiltered, 

μg/L

3(4-

Chlorophenyl)-

1-methylurea, 

μg/L

Neburon, 

filtered, 

μg/L

Nicosulfuron, 

filtered,

μg/L

Norflurazon, 

filtered, 

μg/L

Oryzalin, 

filtered, 

μg/L

58-89-9 330-55-2 94-74-6 94-81-5 57837-19-1 2032-65-7 16752-77-5 74223-64-6 2385-85-5 5352-88-5 555-37-3 111991-09-4 27314-13-2 19044-88-3

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.07 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 E.04m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 E.04m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020m <.03m <.001 <.04 <.01 <.04 <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.0020 <.01 <.03 <.01 <.01 <.010 <.020 <.03m <.001 <.04 <.01 <.04m <.02 <.01

-- -- -- -- -- -- -- -- -- -- -- -- -- --

<.0020 <.01 <.03 <.01 <.01 <.010 <.020m <.03m <.001 <.04 <.01 <.04 <.02 <.01

-- -- -- -- -- -- -- -- -- -- -- -- -- --

4 -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- -- --

0.08–2.0 -- -- -- -- -- -- -- 0.001 -- -- -- -- --

0.063 -- -- -- -- -- -- -- -- -- -- -- -- --

0.2 -- -- -- -- -- -- -- -- -- -- -- -- --

0.052 -- 18 370 -- -- -- -- 7.3 -- -- -- -- 1,800

Appendix 3  49
USGS well 

number

USGS site 

identifier Date Time Sample type

Pesticides and degradates—Continued 

Oxamyl, 

filtered, 

μg/L

p,p'-DDD, 

unfiltered, 

μg/L

p,p'-DDE, 

unfiltered, 

μg/L

p,p'-DDT, 

unfiltered, 

μg/L

p,p'-

Methoxychlor, 

unfiltered, 

μg/L

Picloram, 

filtered, 

μg/L

Propham, 

filtered, 

μg/L

CASRN 23135-22-0 72-54-8 72-55-9 50-29-3 72-73-5 1918-02-1 122-42-9 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <.03 <.002 0.004 <.002 <.003 <.03 <.030 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.500 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <.03 <.002 <.002 <.002 <.003 <.03 <.500 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <.03 <.002 <.002 <.002 <.003 <.03 <.030 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- -- -- 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- -- -- 100 -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- 

C -- 0.001–1.1 0.001–1.1 0.001–1.1 -- -- -- 

D -- 0.00031 0.00022 0.00022 -- -- -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

200 -- -- -- -- 500 -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

910 0.28 0.2 0.2 180 -- -- 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

50 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Volatile organic compounds

Propiconazole, 

filtered, 

μg/L

Propoxur, 

filtered, 

μg/L

Siduron, 

filtered, 

μg/L

Sulfometuron 

methyl, 

filtered, 

μg/L

Tebuthiuron, 

filtered, 

μg/L

Terbacil, 

filtered, 

μg/L

Toxaphene, 

unfiltered, 

μg/L

Triclopyr, 

filtered, 

μg/L

Xylene, 

unfiltered, 

μg/L

1,1,1,2-

Tetrachloroethane, 

unfiltered, 

μg/L

1,1,1-

Trichloroethane, 

unfiltered, 

μg/L

1,1,2,2-

Tetrachloroethane, 

unfiltered, 

μg/L

1,1,2-

Trichloroethane, 

unfiltered, 

μg/L

1,1-

Dichloroethane, 

unfiltered, 

μg/L

60207-90-1 114-26-1 1982-49-6 74222-97-2 34014-18-1 5902-51-2 8001-35-2 55335-06-3 1330-20-7 630-20-6 71-55-6 79-34-5 79-00-5 75-34-3

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 -- -- -- -- -- --

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

-- -- -- -- -- -- -- -- <2.0 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 -- -- -- -- -- --

-- -- -- -- -- -- -- -- <2.0 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 -- -- -- -- -- --

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 .193v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

-- -- -- -- -- -- -- -- <2.0 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

-- -- -- -- -- -- -- -- <2.0 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

-- -- -- -- -- -- -- -- <2.0 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <2.5d <2.5d <2.5d <2.5d <2.5d

-- -- -- -- -- -- -- -- <2.0 <1.0 <1.0 <1.0 <1.0 <1.0

<.01 <.008 <.02 <.038 <.026v <.016 <1 <.03 <.50 <1.0 <1.0 <1.0 <1.0 <1.0

-- -- -- -- -- -- -- -- <2.0 <1.0 <1.0 <1.0 <1.0 <1.0

-- -- -- -- -- -- 5 -- 10,000 -- 200 -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- 0.0002–0.73 -- -- -- -- -- -- --

-- -- -- -- -- -- 0.00028 -- -- -- -- -- -- --z

-- -- -- -- -- -- 3 -- 10,000 -- 200 -- 5 --

-- 150 -- -- -- -- 0.061 -- 210 0.41 1,700 0.053 0.19 900

Appendix 3  51
USGS well 

number

USGS site 

identifier Date Time Sample type

1,1-Dichloroethene, 

unfiltered, 

μg/L

1,1-Dichloropropene, 

unfiltered, 

μg/L

1,2,3-

Trichlorobenzene, 

unfiltered, 

μg/L

1,2,3-

Trichloropropane, 

unfiltered, 

μg/L

1,2,4-

Trichlorobenzene, 

unfiltered, 

μg/L

1,2,4-

Trimethylbenzene, 

unfiltered, 

μg/L

Dibromochloropropane, 

unfiltered, 

μg/L

CASRN 75-35-4 563-58-6 87-61-6 96-18-4 120-82-1 95-63-6 96-12-8 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate -- -- -- -- -- -- -- 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <2.5d <2.5d <2.5d <2.5d <2d <2.5d <5.0d 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <1 <1.0 <2.0 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) 7 -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- 

C 1,000 -- -- -- -- -- -- 

D 3.2 -- -- -- -- -- -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

7 -- -- -- 70 -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

3,500 -- -- 0.0053 61 -- -- 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

52 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Volatile organic compounds—Continued

1,2-Dibromoethane, 

unfiltered, 

μg/L

1,2-Dichlorobenzene, 

unfiltered, 

μg/L

1,2-Dichloroethane, 

unfiltered, 

μg/L

1,2-Dichloropropane, 

unfiltered, 

μg/L

1,3,5-

Trimethylbenzene, 

unfiltered, 

μg/L

1,3-Dichlorobenzene, 

unfiltered, 

μg/L

1,3-Dichloropropane, 

unfiltered, 

μg/L

1,4-Dichlorobenzene, 

unfiltered, 

μg/L

2,2-Dichloropropane, 

unfiltered, 

μg/L

2-Chlorotoluene, 

unfiltered, 

μg/L

4-Chlorotoluene, 

unfiltered, 

μg/L

4-Isopropyltoluene, 

unfiltered, 

μg/L

Acrylonitrile, 

unfiltered, 

μg/L

106-93-4 95-50-1 107-06-2 78-87-5 108-67-8 541-73-1 142-28-9 106-46-7 594-20-7 95-49-8 106-43-4 99-87-6 107-13-1

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

-- -- -- -- -- -- -- -- -- -- -- -- --

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

-- -- -- -- -- -- -- -- -- -- -- -- --

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

-- -- -- -- -- -- -- -- -- -- -- -- --

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<2.5d <2d E.41d <2.5d <2.5d <2d <2.5d <2d <12d <2.5d <2.5d <2.5d <50d

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

<1.0 <1 <1.0 <1.0 <1.0 <1 <1.0 <1 <5.0 <1.0 <1.0 <1.0 <20

-- -- 5 -- -- -- -- 75 -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- 200 -- 2,000 -- 200 -- 200 -- -- -- -- 700

-- 17,000 -- 15 -- 2,600 -- 2,600 -- -- -- -- 0.25

0.05 600 5 5 -- -- -- -- -- -- -- -- --

0.0053 270 0.12 0.16 -- 18 120 0.47 -- 120 430 -- 0.0037

Appendix 3  53
USGS well 

number

USGS site 

identifier Date Time Sample type

Benzene, 

unfiltered, 

μg/L

Bromobenzene, 

unfiltered, 

μg/L

Bromochloromethane, 

unfiltered, 

μg/L

Bromodichloromethane, 

unfiltered, 

μg/L

Bromomethane, 

unfiltered, 

μg/L

Chlorobenzene, 

unfiltered, 

μg/L

Chloroethane, 

unfiltered, 

μg/L

CASRN 71-43-2 108-86-1 74-97-5 75-27-4 74-83-9 108-90-7 75-00-3 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate -- -- -- -- -- -- -- 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <.50 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <.50 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <.50 <1.0 <1.0 <1.0 <2.0 <.50 <2.0 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <.50 <2.5d <2.5d <2.5d <5.0d <.50 <5.0d 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <.50 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <2.0 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) 5 -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- 

C 1,000 -- -- -- -- -- -- 

D 51 -- -- 22 4,000 21,000 -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

5 -- -- 80A -- 100 -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

0.34 -- -- 0.17 8.5 90 3.6 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

54  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Volatile organic compounds—Continued

Chloromethane, 

unfiltered, 

μg/L

cis-1,2-

Dichloroethene, 

unfiltered, 

μg/L

cis-1,3-

Dichloropropene, 

unfiltered, 

μg/L

Dibromochloromethane, 

unfiltered, 

μg/L

Dibromomethane, 

unfiltered, 

μg/L

Dichlorodifluoromethane, 

unfiltered, 

μg/L

Dichloromethane, 

unfiltered, 

μg/L

Ethylbenzene, 

unfiltered, 

μg/L

Hexachlorobutadiene, 

unfiltered, 

μg/L

Isopropylbenzene, 

unfiltered, 

μg/L

meta- + 

paraXylene, 

unfiltered, 

μg/L

Naphthalene, 

unfiltered, 

μg/L

n-Butylbenzene, 

unfiltered, 

μg/L

74-87-3 156-59-2 10061-01-5 124-48-1 74-95-3 75-71-8 75-09-2 100-41-4 87-68-3 98-82-8 na 91-20-3 104-51-8

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

-- -- -- -- -- -- -- -- -- -- -- -- --

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

E.59 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <1.0 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

-- -- -- -- -- -- -- -- -- -- -- -- --

E.48 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <1.0 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 E.46v <.50 <1 <1.0 <.50 <1 <1.0

-- -- -- -- -- -- -- -- -- -- -- -- --

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 E.40v <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 E.41v <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 4.4 <.50 <1 21

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

E.42 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <1.0 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 E.66 <1.0 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 <.50 <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <1.0 <1 <1.0 -- <1 <1.0

<5.0d <2.5d <2.5d <2.5d <2.5d <5.0d E1.3vd <.50 <2d <2.5d <.50 <2d <2.5d

E.38 <1.0 <1.0 <1.0 <1.0 <2.0 E.94v <1.0 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <.50 <1 <1.0 -- <1 <1.0

<2.0 <1.0 <1.0 <1.0 <1.0 <2.0 <5.0 <1.0 <1 <1.0 -- <1 <1.0

-- 70 -- -- -- -- -- 700 -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- 40 10 -- -- 600 --

-- -- -- 34 -- -- 1,600 2,100 18 -- -- -- --

-- 70 -- 80A -- -- 5 700 -- -- -- --

190 61 -- 0.13 61 350 4.1 1,300 0.86 660 -- 6.5 --

Appendix 3  55
USGS well 

number

USGS site 

identifier Date Time Sample type

n-propylbenzene, 

unfiltered, 

μg/L

o-Xylene, 

unfiltered, 

μg/L

sec-Butylbenzene, 

unfiltered, 

μg/L

Styrene, 

unfiltered, 

μg/L

Methyl tertbutyl ether, 

unfiltered, 

μg/L

tert-Butylbenzene, 

unfiltered, 

μg/L

CASRN 103-65-1 95-47-6 135-98-8 100-42-5 1634-04-4 98-06-6 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank -- -- -- -- -- -- 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate -- -- -- -- -- -- 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <1.0 <.50 19 <1.0 6.7 E.72 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <1.0 <.50 <1.0 <1.0 E1.4 <1.0 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <1.0 <.50 <1.0 <1.0 <5.0 <1.0 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <2.5d <.50 <2.5d <2.5d <5.0 <2.5d 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <1.0 -- <1.0 <1.0 <5.0 <1.0 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank <1.0 -- <1.0 <1.0 <5.0 <1.0 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- 

B -- -- -- -- -- -- 

C -- -- -- -- -- -- 

D -- -- -- -- -- -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

-- -- -- 100 -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

-- -- -- 1,600 2.6 -- 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

56  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Volatile organic compounds—Continued

Tetrachloroethene, 

unfiltered, 

μg/L

Tetrachloromethane, 

unfiltered, 

μg/L

Toluene, 

unfiltered, 

μg/L

trans-1,2-

Dichloroethene, 

unfiltered, 

μg/L

trans-1,3-

Dichloropropene, 

unfiltered, 

μg/L

Tribromomethane, 

unfiltered, 

μg/L

Trichloroethene, 

unfiltered, 

μg/L

Trichlorofluoromethane, 

unfiltered, 

μg/L

Trichloromethane, 

unfiltered, 

μg/L

Vinyl 

chloride, 

unfiltered, 

μg/L

127-18-4 56-23-5 108-88-3 156-60-5 10061-02-6 75-25-2 79-01-6 75-69-4 67-66-3 75-01-4

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

-- -- -- -- -- -- -- -- -- --

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

-- -- -- -- -- -- -- -- -- --

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

-- -- -- -- -- -- -- -- -- --

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 11 <1.0

<1.0 <1.0 M <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 E.95 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 3.9 <1.0

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

68d <2.5d <.50 <2.5d <2.5d <2.5d E1.6d <5.0d 4.2d <2.5d

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

<1.0 <1.0 <.50 <1.0 <1.0 <1.0 <1.0 <2.0 11 <1.0

<1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <2.0 <1.0 <1.0

5 5 11,000 100 -- -- 5 -- -- 2

-- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- --

800 1,000 600 1,000 -- -- 1,000 -- 3,000 --

3.3 1.6 15,000 -- -- 360 30 -- 470 2.4

5 5 1,000 100 -- 80A 5 -- 80A 2

0.1 0.16 2,300 120 -- 8.5 0.026 1,300 0.15 0.015

Appendix 3  57
USGS well 

number USGS site identifier Date Time Sample type

2,4,6-Trichlorophenol, 

unfiltered, 

μg/L

2,4-Dichlorophenol, 

unfiltered, 

μg/L

2,4-Dimethylphenol, 

unfiltered, 

μg/L

2,4-Dinitrophenol, 

unfiltered, 

μg/L

2,4-Dinitrotoluene, 

unfiltered, 

μg/L

2,6-Dinitrotoluene, 

unfiltered, 

μg/L

CASRN 88-06-2 120-83-2 105-67-9 51-28-5 121-14-2 606-20-2 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <10 <10 <10.0 <50 <10 <10 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank -- -- -- -- -- -- 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <10 <10 <10.0 <50 <10 <10 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <10 <10 <10.0 <50 <10 <10 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <10 <10 <10.0 <50 <10 <10 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate -- -- -- -- -- -- 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <10 <10 <10.0 <50 <10 <10 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <10 <10 <10.0 <50 <10 <10 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <10 <10 <10.0 <50 <10 <10 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <10 <10 <10.0 <50 <10 <10 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <10 <10 <10.0 <50 <10 <10 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <10 <10 <10.0 <50 <10 <10 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- -- 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <10 <10 <10.0 <50 <10 <10 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <10 <10 <10.0 <50 <10 <10 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <10 <10 <10.0 <50 <10 <10 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <10 <10 <10.0 <50 <10 <10 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <10 <10 <10.0 <50 <10 <10 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <10 <10 <10.0 <50 <10 <10 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <10 <10 <10.0 <50 <10 <10 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- -- 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <10 <10 <10.0 <50 <10 <10 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <10 <10 <10.0 <50 <10 <10 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- -- 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <10 <10 <10.0 <50 <10 <10 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- -- 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <10 <10 <10.0 <50 <10 <10 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- -- 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- 

B -- -- -- -- -- -- 

C -- 200 200 20 33 -- 

D 2.4 290 850 14,000 3.4 -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

 2006b)

-- -- -- -- -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

6.1 110 730 73 73 37 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

58 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Semivolatile organic compounds

2-Chloronaphthalene, 

unfiltered, 

μg/L

2-Chlorophenol, 

unfiltered, 

μg/L

2-Methyl-

4,6-dinitrophenol, 

unfiltered, 

μg/L

2-Nitrophenol, 

unfiltered, 

μg/L

3,3'-Dichlorobenzidine, 

unfiltered, 

μg/L

4-Bromophenyl 

phenyl 

ether, 

unfiltered, 

μg/L

4-Chloro-3-

methylphenol, 

unfiltered, 

μg/L

4-Chlorophenyl 

phenyl 

ether, 

unfiltered, 

μg/L

4-Nitrophenol, 

unfiltered, 

μg/L

9HFluorene, 

unfiltered, 

μg/L

Acenaphthene, 

unfiltered, 

μg/L

Acenaphthylene, 

unfiltered, 

μg/L

91-58-7 95-57-8 534-52-1 88-75-5 91-94-1 101-55-3 59-50-7 7005-72-3 100-02-7 86-73-7 83-32-9 208-96-8

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <50 <10 <50 <10 <10 <10 <50 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- --

200 100 20 -- 10 -- -- -- -- -- 50 --

1,600 150 765 -- 0.028 -- -- -- -- 5,300 990 --

-- -- -- -- -- -- -- -- -- -- -- --

490 30 -- -- 0.15 -- -- -- -- 240 370 --

Appendix 3  59
USGS well 

number USGS site identifier Date Time Sample type

Anthracene, 

unfiltered, 

μg/L

Atrazine, 

unfiltered, 

μg/L

Benzidine, 

unfiltered, 

μg/L

Benzo-[a]-

anthracene, 

unfiltered, 

μg/L

Benzo-[a]-

pyrene, 

unfiltered, 

μg/L

Benzo-

[b]-fluoranthene, 

unfiltered, 

μg/L

Benzo-

[ghi]-

perylene, 

unfiltered, 

μg/L

CASRN 120-12-7 19112-24-9 92-87-5 56-55-3 50-32-8 205-99-2 191-24-2 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <10 <50.0 <100 <10 <10 <10 <10 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate -- -- -- -- -- -- -- 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <10 <50.0 <100 <10 <10 <10 <10 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <10 <50.0 <100 <10 <10 <10 <10 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <10 <50.0 <100 <10 <10 <10 <10 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <10 <50.0 <100 <10 <10 <10 <10 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <10 <50.0 <100 <10 <10 <10 <10 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- -- -- 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- 

C -- -- 250 -- -- -- -- 

D 40,000 -- 0.0002 0.018 0.018 0.018 -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

-- 3 -- -- 0.2 -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

1,800 0.3 0.0001 0.03 0.003 0.03 -- 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

60 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Semivolatile organic compounds—Continued

Benzo-[k]-

fluoranthene, 

unfiltered, 

μg/L

Benzyl-nbutyl 

phthalate, 

unfiltered, 

μg/L

Bis(2-

chloroethoxy) 

methane, 

unfiltered, 

μg/L

Bis(2-

chloroethyl) ether, 

unfiltered, 

μg/L

Bis(2-

chloroisopropyl) 

ether, 

unfiltered, 

μg/L

Bis(2-

ethylhexyl) 

phthalate, 

unfiltered, 

μg/L

Chrysene, 

unfiltered, 

μg/L

Dibenzo 

[a,h]-anthracene, 

unfiltered, 

μg/L

Diethyl 

phthalate, 

unfiltered, 

μg/L

Dimethylphthalate, 

unfiltered, 

μg/L

Di-nbutyl 

phthalate, 

unfiltered, 

μg/L

Di-noctyl

phthalate, 

unfiltered, 

μg/L

Fluoranthene, 

unfiltered, 

μg/L

207-08-9 85-68-7 111-91-1 111-44-4 108-60-1 117-81-7 218-01-9 53-70-3 84-66-2 131-11-3 84-74-2 117-84-0 206-44-0

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 E3 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 E2 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

<10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- -- --

-- 100 -- 1,000 1,000 100 -- -- 100 100 100 -- 400

0.018 -- -- 1.4 170,000 5.9 0.018 0.018 120,000 2,900,000 12,000 -- 140

-- -- -- -- -- 6 -- -- -- -- -- -- --

0.3 7,300 -- 0.0096 0.26 4.8 3 0.003 29,000 -- 3,700 -- 1,500

Appendix 3  61
USGS well 

number USGS site identifier Date Time Sample type

Semivolatile organic compounds—Continued 

Hexachlorobenzene, 

unfiltered, 

μg/L

Hexachlorocyclopentadiene, 

unfiltered, 

μg/L

Indeno-

[1,2,3-cd]-

pyrene, 

unfiltered, 

μg/L

Isophorone, 

unfiltered, 

μg/L

Nitrobenzene, 

unfiltered, 

μg/L

N-Nitrosodimethylamine, 

unfiltered, 

μg/L

N-Nitrosodi-n-propylamine, 

unfiltered, 

μg/L

CASRN 118-74-1 77-47-4 193-39-5 78-59-1 98-95-3 62-75-9 621-64-7 

AC Aa 1 385225076590101 9/21/2005 1030 Environmental <10 <50 <10 <10 <10 <10 <10 

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 9 385606076584101 10/12/2005 1230 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 930 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank -- -- -- -- -- -- -- 

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Bb 3 385504076563801 9/20/2005 1000 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Bb 3 385504076563801 9/20/2005 1010 Replicate -- -- -- -- -- -- -- 

WE Bb 4 385504076563802 9/20/2005 1430 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Ca 29 385238076581501 9/19/2005 1400 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Ca 32 385332076594701 9/22/2005 1000 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Ca 33 385349076592801 10/14/2005 1030 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank <10 <50 <10 <10 <10 <10 <10 

WE Ca 34 385245076583501 9/27/2005 1330 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cb 5 385443076562801 9/14/2005 1400 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Cb 6 385443076562802 9/14/2005 1030 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Cb 8 385252076572801 12/20/2005 1430 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Cb 8 385252076572801 12/20/2005 1435 Replicate <10 <50 <10 <10 <10 <10 <10 

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank <10 <50 <10 <10 <10 <10 <10 

WE Cb 11 385332076564101 12/19/2005 1430 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Cb 12 385332076564102 9/27/2005 1000 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WE Cc 3 385327076544801 10/6/2005 1000 Environmental <10 <50 <10 <10 <10 <10 <10 

WE Cc 3 385327076544801 10/6/2005 1010 Replicate <10 <50 <10 <10 <10 <10 <10 

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 8 385519077012601 10/13/2005 1100 Environmental <10 <50 <10 <10 <10 <10 <10 

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- -- -- 

WW Bc 9 385527077000701 12/19/2005 1100 Environmental <10 <50 <10 <10 <10 <10 <10 

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- -- -- 

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) -- -- -- -- -- -- -- 

District of Columbia surface-water standards (District of Columbia, 2003)

A -- -- -- -- -- -- -- 

B -- -- -- -- -- -- -- 

C -- 0.5 -- 1,000 1,000 600 600 

D 0.00077 1,100 0.018 960 690 8.1 -- 

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

1 50 -- -- -- -- -- 

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

0.042 220 0.03 70 3.5 0.0013 0.0096 

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

62 Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Miscellaneous compounds

N-Nitrosodi-phenylamine, 

unfiltered, 

μg/L

Pentachlorophenol, 

unfiltered, 

μg/L

Phenanthrene, 

unfiltered, 

μg/L

Phenols, 

STL, 

unfiltered, 

μg/L

Phenols, 

NWQL, 

unfiltered, 

μg/L

Hexachloroethane, 

unfiltered, 

μg/L

Oil and 

grease, 

unfiltered, 

mg/L

Diesel-range 

organic 

compounds, 

unfiltered, 

mg/L

Gasolinerange 

organic 

compounds, 

unfiltered, 

μg/L

Petroleum 

hydrocarbons, 

unfiltered, 

mg/L

PCBs, 

unfiltered, 

μg/L

Caffeine, 

filtered, 

μg/L

86-30-6 87-86-5 85-01-8 108-95-2 108-95-2 67-72-1 na na na na 1336-36-3 58-08-2

<10 <50 <10 <10.0 -- <10 <5.00 <.250 E5.5 <5.0 <.1 <.018

-- -- -- -- -- -- -- -- -- -- <.1 <.018

<10 <50 <10 <10.0 <16 <10 E.85 <.250 <25 <5.0 <.1 <.018

-- -- -- -- -- -- -- -- -- -- -- --

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <25 <5.0 <.1 <.018

-- -- -- -- <16 -- -- -- -- -- <.1 <.018

-- -- -- -- -- -- -- -- -- -- -- --

<10 <50 <10 <10.0 -- <10 <5.00 <.250 <25 <5.0 <.1 <.018

-- -- -- -- -- -- -- -- -- -- <.1 <.018

<10 <50 <10 <10.0 -- <10 <5.00 <.250 <25 <5.0 <.1 <.018

<10 <50 <10 <10.0 -- <10 <5.00 <.250 <25 <5.0 <.1 0.03

<10 <50 <10 <10.0 E3 <10 <5.00 0.41 E11 <5.0 <.1 <.018

<10 <50 <10 <10.0 <16 <10 <5.00 0.39 540 <5.0 <.1 <.018

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <25 <5.0 <.1 E.005t

<10 <50 <10 <10.0 <16 <10 <5.00 E.028 <25 <5.0 <.1 <.018

-- -- -- -- -- -- -- -- -- -- -- --

<10 <50 <10 <10.0 E93 <10 <5.00 <.250 <25 <5.0 <.1 <.018

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <25 <5.0 <.1 <.018

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <10 <5.0 <.1 E.006t

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <10 <5.0 <.1 E.007t

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <10 <5.0 <.1 <.018

<10 <50 <10 <10.0 <16 <10 E1.40 <.250 <10 <5.0 <.1 E.007t

<10 <50 <10 <10.0 <16 <10 <5.00 E.021 47 <5.0 <.1 <.018

-- -- -- -- -- -- -- -- -- -- -- --

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <25 <5.0 <.1 <.018

<10 <50 <10 <10.0 <16 <10 <5.00 E.015 <25 <5.0 <.1 E.017n

-- -- -- -- -- -- -- -- -- -- -- --

<10 <50 <10 <10.0 <16 <10 <5.00 1.1 35 <5.0 <.1 <.018

-- -- -- -- -- -- -- -- -- -- -- --

<10 <50 <10 <10.0 <16 <10 <5.00 <.250 <10 <5.0 <.1 E.007t

-- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- --

-- -- -- -- -- -- -- -- -- -- -- --

600 *** -- -- -- -- -- -- -- -- 0.014 --

16 3 -- 1,700,000 -- -- -- -- -- -- 0.000064 --

-- 1 -- -- -- -- -- -- -- -- 0.5 --

14 0.56 -- 11,000.00 na 4.8 -- -- -- -- 0.033 --

Appendix 3  63
USGS well 

number USGS site identifier Date Time Sample type

Surrogates for laboratory quality control

2,4,5-T 

surrogate, 

filtered, 

percent 

recovery

alpha-HCHd6, surrogate, 

unfiltered, 

percent 

recovery

Barban, 

surrogate, 

filtered, 

percent 

recovery

Caffeine-13C, 

surrogate, 

filtered, 

percent 

recovery

Isdrin, 

surrogate, 

unfiltered, 

percent 

recovery

PCB 207, 

surrogate, 

unfiltered, 

percent 

recovery

CASRN na na na na na na

AC Aa 1 385225076590101 9/21/2005 1030 Environmental E93.1 89.4 162 109 87.2 90.8

AC Aa 1 385225076590101 9/21/2005 1035 Field equipment blank E182 85.2 111 138 80.1 87.7

WE Ba 9 385606076584101 10/12/2005 1230 Environmental E154 E102 E106 108 80.8 E115

WE Ba 9 385606076584101 10/12/2005 2359 STL trip blank -- -- -- -- -- --

WE Ba 10 385534076582101 10/12/2005 930 Environmental 122 E105 124 88.9 76.3 E114

WE Ba 10 385534076582101 10/12/2005 935 Field equipment blank 124 95.6 E102 129 60.7 E94.9

WE Ba 10 385534076582101 10/12/2005 2359 STL trip blank -- -- -- -- -- --

WE Bb 3 385504076563801 9/20/2005 1000 Environmental E152 82.9 110 98.5 75.5 86.7

WE Bb 3 385504076563801 9/20/2005 1010 Replicate E142 50.8 93.8 64.6 56 70

WE Bb 4 385504076563802 9/20/2005 1430 Environmental E111 90.8 104 111 86.6 96.5

WE Ca 29 385238076581501 9/19/2005 1400 Environmental E108 E104 99.6 112 97.2 E114

WE Ca 32 385332076594701 9/22/2005 1000 Environmental E146 92.4 105 106 88.7 93.8

WE Ca 33 385349076592801 10/14/2005 1030 Environmental 104 E105 88.3 83.2 109 E129

WE Ca 33 385349076592801 10/14/2005 800 Field equipment blank 131 96 87 129 87.3 E107

WE Ca 34 385245076583501 9/27/2005 1330 Environmental 87.7 E103 69.2 82.1 97 102

WE Ca 34 385245076583501 9/27/2005 2359 STL trip blank -- -- -- -- -- --

WE Cb 5 385443076562801 9/14/2005 1400 Environmental E128 94.7 119 129 87.7 98.6

WE Cb 6 385443076562802 9/14/2005 1030 Environmental E113 97 104 150 93.3 E110

WE Cb 8 385252076572801 12/20/2005 1430 Environmental 115 87.3 81.8 104 80.8 95.1

WE Cb 8 385252076572801 12/20/2005 1435 Replicate 118 88.8 90.5 104 78 93

WE Cb 8 385252076572801 12/21/2005 1730 Field equipment blank 125 91.3 102 86.1 E90.8 93.5

WE Cb 11 385332076564101 12/19/2005 1430 Environmental 77.4 93.6 75.9 90 90.1 102

WE Cb 12 385332076564102 9/27/2005 1000 Environmental 83.3 E107 84.1 83.2 88.7 E110

WE Cb 12 385332076564102 9/27/2005 2359 STL trip blank -- -- -- -- -- --

WE Cc 3 385327076544801 10/6/2005 1000 Environmental 111 E106 110 63 96.9 E119

WE Cc 3 385327076544801 10/6/2005 1010 Replicate 117 E107 116 72.3 100 E123

WE Cc 3 385327076544801 10/6/2005 2359 STL trip blank -- -- -- -- -- --

WW Bc 8 385519077012601 10/13/2005 1100 Environmental 136 E110 E109 93.8 106 E117

WW Bc 8 385519077012601 10/13/2005 2359 STL trip blank -- -- -- -- -- --

WW Bc 9 385527077000701 12/19/2005 1100 Environmental 101 90.4 124 91.2 83 101

WW Bc 9 385527077000701 12/19/2005 2359 STL trip blank -- -- -- -- -- --

Selected water-quality criteria

District of Columbia ground-water standards (District of Columbia, 1993) na na na na na na

District of Columbia surface-water standards (District of Columbia, 2003)

A na na na na na na

B na na na na na na

C na na na na na na

D na na na na na na

USEPA Maximum Contaminant Levels (U.S. Environmental Protection Agency, 

2006b)

na na na na na na

USEPA Region III Risk-Based Concentrations for tap water (U.S. Environmental 

Protection Agency Region III, 2006)

na na na na na na

ASee USEPA drinking water standards - the total for trihalomethanes (THM) is 80 μg/L.

64  Summary of Ground-Water-Quality Data in the Anacostia River Watershed, Washington, D.C., 2005

Appendix 3. Concentrations of pesticides, degradates, volatile organic compounds, and semivolatile organic compounds in ground water from selected wells in 

the Anacostia River watershed within Washington, D.C., September–December 2005, and selected water-quality criteria.—Continued

[STL, Severn Trent Laboratory; USGS, U.S. Geological Survey; NWQL, USGS National Water Quality laboratory; <, less than; E, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no value reported; na, not applicable; M, presence verified but not quantified; b, value extrapolated at low end; d, diluted sample; m, value is highly variable by this 

method; n, below the laboratory reporting level and above the long-term method detection level; t, below the long-term method detection level; v, analyte detected in laboratory blank; 

r, sample ruined in preparation; CIAT, 2-chloro-4-isopropylamino-6-amino-s-triazine; CEAT, 6-amino-2-chloro-4-ethylamino-s-triazine; OIET, 2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine; CASRN®, Chemical Abstracts Service Registry Number; USEPA, U.S. Environmental Protection Agency; ***, Please refer to District of Columbia (2003) for this value; 

bold, environmental sample results; bold italics, replicate sample results; plain text, blank sample results]
Prepared by Publishing Service Centers 3 and 1.

Edited by Valerie M. Gaine.

Layout by Ann Marie Squillacci.

For additional information, contact:

Director, MD-DE-DC Water Science Center

U.S. Geological Survey

8987 Yellow Brick Road

Baltimore, MD 21237

or visit our Web site at:

http://md.water.usgs.gov