2004 DRINKING WATER

QUALITY REPORT
Our Water Treatment and

Distribution System

The DC Water and Sewer Authority (WASA) distributes water to

residences and businesses throughout the District for drinking,

fire fighting and other uses. WASA purchases the drinking water

from the US Army Corps of Engineers Washington Aqueduct.

The Washington Aqueduct (WA) withdraws approximately 180

million gallons of water each day from the Potomac River at the

Great Falls and the Little Falls intakes and then treats the water

at the two water treatment plants, Dalecarlia and McMillan (see

the water treatment scheme). The key treatment processes at

the WA Dalecarlia and McMillan facilities include sedimentation,

filtration, fluoridation, pH adjustment, primary disinfection using

free chlorine, secondary disinfection with chloramines through

the addition of ammonia to convert the chlorine to choloramine,

and finally corrosion control with orthophosphate. This

orthophosphate treatment process began system-wide in August

2004 to help reduce the tendency of water to corrode certain

metals. Compliance water sample analysis through the end of

2004 indicated that the addition of orthophosphate has significantly reduced the corrosive effects of water on service line

pipes and other plumbing fixtures that may contain lead.

Chloramines As Our

Water Disinfectant

As of November 1, 2000, chloramines are used as a disinfectant

to maintain protection against microbial contamination in the

water distribution system. The change in disinfectant from chlorine to chloramines is an effort to reduce the concentrations of

“disinfection byproducts” called trihalomethanes (THMs) and

haloacetic acids (HAAs). This change was an effective response

to more stringent national standards established by the U.S.

Environmental Protection Agency (EPA). Chronic exposure to

high concentrations of these disinfection byproducts is considered potentially carcinogenic. Since the treatment change to

chloramines, we have obtained a significant reduction of THMs

and HAAs in the drinking water. WASA continues to advise facilities providing kidney dialysis treatment, individuals and businesses maintaining fish tanks, and laboratories and businesses

affected by chloraminated water that their pretreatment steps

must remove chloramines. WASA will provide fact sheets on

chloramines upon request.

The Potomac River –

Our Water Supply Source

Drinking water for the District of Columbia comes from the

Potomac River, a “surface water” supply. As water travels over

land and rocks, through creeks, and into the Potomac River, it

Dear Customers,

The District of Columbia Water and Sewer Authority (WASA) is happy

to provide you with the 2004 Consumer Confidence Water Quality

Report. This report has information on our performance under the

national Safe Drinking Water Act and its requirements, as well as the

source of your drinking water, how it is treated and what it contains.

This past year was eventful, and even disturbing, for some members of our community who read about elevated lead levels in drinking water in the District of Columbia. It is important for customers

to understand that although environmental lead exposure can be

very hazardous over a long period of time, large numbers of tests

conducted by the DC Department of Health in 2004 have detected

no measurable health effects from the potential exposure to lead

in drinking water in the District of Columbia.

This complex problem is, nevertheless, a critical concern. It has

been the subject of intensive scientific inquiry because we must

identify the cause, and more importantly, answer the question:

“How do we change the Army Corps of Engineers Washington

Aqueduct water treatment process in order to prevent clean drinking water from corroding the lead service line pipes and plumbing

fixtures serving approximately 23,000 homes in the District?”

In August 2004, this joint inquiry, involving the Washington

Aqueduct (water treatment supplier), WASA, the DC Department

of Health and the Environmental Protection Agency, resulted in a

change to the treatment plan; the Washington Aqueduct now uses

orthophosphate in the treatment process to help prevent drinking

water from corroding pipes. Although lead levels remain over the

federal Lead and Copper Rule regulatory trigger in 2004, compliance testing indicates steady and strong progress in reducing the

lead concentrations in monitoring samples.

Last summer, WASA also issued a public promise – a “Community

Water Pledge” to provide more and better information to the public

about water quality and our efforts to provide the best service we

can. Two examples of our commitment to your high expectations:

• We have created a relationship with the George Washington

University Medical Center – an unprecedented partnership –

that helps ensure that WASA has access to strong analytical

support in understanding potential public health implications

of water quality issues;

• WASA is creating an independent expert working group that will

focus on the District’s distribution system to help WASA and the

Washington Aqueduct anticipate and address any potential technical challenges that may arise if treatment changes are proposed by the Washington Aqueduct in the future.

This 2004 Water Quality Report reflects this renewed effort to continuously improve service and to win back the trust of our customers

by supplying you with clean and affordable drinking water.

I am confident that you will find the 2004 Water Quality Report

informative.

Jerry N. Johnson, General Manager

District of Columbia Water and Sewer Authority

2
dissolves naturally occurring minerals, leaves and vegetation,

and sometimes even radioactive materials. It may also dissolve

animal waste, pesticides, and other debris. Rain or other precipitation may also pick up contaminants as it falls through the

atmosphere and into the river.

Contaminants that may be present in source water (before

treatment) include:

• Microorganisms, such as viruses and bacteria that come from

agricultural livestock, septic systems and wildlife

• Inorganic chemicals, such as salts and metals that can be naturally occurring or result from urban storm water runoff,

industrial or domestic wastewater discharges

• Pesticides and herbicides that may come from agriculture,

urban storm water runoff, and residential uses

• Organic chemicals, including synthetic and volatile organic

chemicals which are by-products of industrial processes and

petroleum products

• Radioactive chemicals that can be naturally occurring or the

result of mining activities

The DC Department of Health conducted a Source Water

Assessment of the Potomac River watershed, upstream of the

water supply intakes for the District. The assessment included

the delineation for the District of Columbia source water area,

the identification of potential contamination sources, a susceptibility analysis for the intakes, and modeling of contaminant

transport within the river system. The key findings of this study

were that the most likely source of potential contamination to

the water supply are urban runoff, toxic spills, agricultural

activities and inadequate wastewater treatment. For more

information on this project, contact the DC Department of

Health at 202-535-1603 or visit www.dchealth.dc.gov/services/

administration_offices/environmental/services2/water_division/

swap.shtm.

Protecting The District

Drinking Water Supply

Protect The Watershed – A watershed is an area of land

surrounding a river from which water eventually drains into the

river. Everyone can help protect the Potomac River from contamination by protecting its watershed:

• Dispose of household wastes and motor oil in a proper manner. You can call the District Recycle Hotline at 202-645-8245

for information regarding proper disposal.

• Never dump anything down a storm drain or catch basin.

• Participate in watershed protection activities by contacting

the Interstate Commission on the Potomac River Basin at

301-984-1908.

Report Fire Hydrant Vandalism – Fire hydrants are used

primarily to supply water for fire protection. WASA also issues

permits for other specific hydrant uses, with mandatory

requirements for the use of a special backflow prevention

device when a permit-holder draws water from a hydrant.

Unauthorized opening of fire hydrants or causing damage to fire

hydrants is a crime punishable by fines and imprisonment.

Opening fire hydrants drains thousands of gallons of fresh

drinking water into streets. The torrent of water is a safety hazard to traffic and pedestrians and damages roads. In addition,

improper use of fire hydrants can increase the flow, causing

mineral sediment in the water mains to come loose, resulting in

discoloration and potential water quality problems in the neighDRINKING WATER QUALITY REPORT

3
DCWASA Serving the Public • Protecting the Environment

borhoods around the hydrant. Most importantly, unauthorized

hydrant use without a backflow preventor can result in the introduction of contaminants into the system. Anyone seeing someone opening a fire hydrant without authorization should call

202-612-3400 immediately.

Conserve Water – Since water is a limited resource, WASA

continues to advocate water conservation activities. There are

many ways to save water and they all start with you, the WASA

customer. To show our customers how to save water, WASA has

adopted the “Water, Use It Wisely” campaign together with

other local water utilities and governments in the Metropolitan

Washington region. Log on to www.wateruseitwisely.com or

www.dcwasa.com to access water saving tips and information.

Changing behavior and installing water efficient fixtures are

among the most effective means of conserving water. The

“Water, Use It Wisely” web site has an inventory of 100 ways you

can save water by making simple changes to your daily routine.

You will also learn how much water can be saved by implementing each tip. For example, running your washing machine and

dishwasher only when they are full could save you 1,000 gallons

a month. The “Water, Use It Wisely” web site also provides

information on plumbing fixture changes. Changing a toilet or a

showerhead to a low volume water fixture is a great way to

reduce water consumption. A low flush toilet could save up

22,000 gallons for a family of four per year. You can save money

and potentially add value to your property with water conservative plumbing fixtures. Please visit the local “Water, Use it

Wisely” website at www.mwcog.org/wisewater to find out about

water conservation activities and events in the D.C. area.

Get Involved – Attend any of the community meetings

WASA periodically conducts with Advisory Neighborhood

Commissions, civic associations, schools, libraries, and other

groups. And, if you would like a speaker from WASA to make a

presentation to your community group, contact the WASA Public

Affairs Office at 202-787-2200, or email us at info@dcwasa.com.

The WASA Board of Directors conducts regular business

meetings that are open to the public, generally on the first

Thursday of each month. If you’d like to attend and learn more

about agency issues, please call the Office of the Board

Secretary at 202-787-2330 to confirm the specific meeting time

and location.

Lead in the Drinking Water

Drinking water for the District is virtually lead-free when it is

delivered from our supplier, the Army Corps of Engineers

Washington Aqueduct. However, water can have a corrosive

effect on pipes and internal plumbing containing lead.

Since the discovery of elevated lead levels in tap water samples

of many District homes, WASA has been under an EPA

Administrative Order (AO). The AO requires WASA to take

measures to comply with the federal Lead and Copper Rule

(LCR). The rule allows no more than ten percent of at-the-tap

water samples, collected during a monitoring period, to exceed

the EPA lead “action level” of 15 parts per billion (ppb).

WASA and the EPA agreed on a set of commitments that WASA

would undertake beyond those required by the federal Lead and

Copper Rule (LCR). In addition, WASA issued the Community

Water Pledgelast August that promises to keep the public fully

informed on progress under the LCR and AO. WASA is fully complying with its commitments under the AO and the Community

Water Pledge. WASA has made reducing lead levels in drinking

water in District homes a top priority.

WASA and the Washington Aqueduct (WA) continue to research

the various chemical treatment techniques and their effects on

corrosion. In November 2000, the Washington Aqueduct began

4
DRINKING WATER QUALITY REPORT

using a different chemical, chloramines, for disinfecting drinking water. Consistent with EPA goals, this change reduced the

levels of disinfection by-products and the public health risks

associated with them (see Chloramines As Our Disinfectant).

However, experts believe that changes in the water chemistry,

that resulted from switching disinfectants in 2000, increased

the rate at which lead leaches into the drinking water.

Orthophosphate was added to the District’s water in 2004 to

control lead leaching. Orthophosphate works by building up a

thin protective coating inside pipes and plumbing fixtures to

prevent water from corroding pipes which causes metals to

leach into the water.

This process takes time, but WASA is already seeing major

reductions in lead concentrations. For example, samples collected from January to April 2004 averaged 28 ppb, while samples collected from January to April 2005 averaged only 7 ppb.

WASA’s most recent test results from 2005 indicate most homes

are below the EPA action level of 15 ppb.

Although most homes have very low levels of lead in their drinking water, a few still have elevated lead levels, consequently, the

District’s tap water is still considered to exceed the action level.

Therefore, WASA continues to encourage customers to follow

the recommended flushing advice and use of filtration devices

as appropriate:

• Homes with lead service lines should flush the tap for

10 minutes before drawing drinking water.

• All other homes should flush the tap for 60 seconds before

drawing drinking water.

• Use only cold water for drinking and cooking.

• Boiling water does not remove lead.

• Remove and clean the strainer/aerator/screen device from

your faucet on a regular basis.

• DC Department of Health recommends the use of filtration

devices for nursing women, pregnant women, and children

under the age of 6. To obtain a filter, call WASA’s Lead

Services Hotline at 202-787-2732.

Health Effects of Lead

Infants and children who drink water containing lead in

excess of the action level could experience delays in their

physical or mental development. Children could show slight

deficits in attention span and learning abilities. Adults who

drink this water over many years could develop kidney problems or high blood pressure.

Lead is a common metal found throughout the environment in

lead-based paint, soil, especially near highways (because lead

was used in gasoline for many years); household dust, especially in older homes with lead-based paint; food to a small

degree; certain types of pottery, porcelain, and pewter; and

water. Lead can pose a significant risk to your health if too

much of it enters your body. The greatest risk is to young children and pregnant women. In addition to drinking water, a

child at play often comes into contact with sources of lead

contamination – like dirt and dust – that rarely affect an adult.

It is important to wash children’s hands and toys often and to

try to make sure they only put food in their mouths.

For more information about the health effects of lead

and how to obtain a blood lead level screening test,

contact the Department of Health at 202-671-0733

or www.dchealth.dc.gov.

5
Lead Service Line Replacement

The EPA Administrative Order (AO) requires WASA to replace

7 percent of the lead service lines in its distribution system

until the District is no longer over the lead action level for two

consecutive six-month sampling periods. In 2004, WASA

replaced the public portion of approximately 1,700 lead service lines, exceeding the federal requirement of 7 percent.

WASA will contact customers before beginning lead service

line replacement work in their neighborhood. WASA encourages residents with lead service lines to consider replacing

the lead piping on their property at the same time. To pay for

private property-side service line and indoor plumbing

replacement, financial assistance is available to income-eligible homeowners through low-interest loans from Wachovia

Bank or grants from the Department of Housing and

Community Development. Contact the WASA Lead Services

Hotline at 202-787-2732 for more information.

To find out if your home has a lead service line, contact the

WASA Lead Services Hotline by calling 202-787-2732 or

e-mailing WQP2003@dcwasa.com.

Water Quality Enhancement

Program

The quality of drinking water is affected as it flows through the

distribution system. The Water Quality Division has undertaken

a number of programs to protect, maintain and enhance water

quality in the distribution system. These programs include

extensive water main flushing, cross connection control, as well

as the following:

• Monitoring the water supply as it enters the

distribution system

• Collecting and analyzing hundreds of samples every month

from various locations in the distribution system, including

residential properties

• Responding rapidly to customer reports of water quality

problems or other water quality episodes

LEAD TESTING

If you would like your water tested

for lead please contact us at

202-787-2732 or WQP2003@dcwasa.com.

DCWASA Serving the Public • Protecting the Environment

6
• Operating small mobile laboratory units to rapidly respond to

water quality complaints and emergencies

• Conducting research in conjunction with EPA and

national experts regarding the water chemistry in our

distribution system

Water Main Flushing – Each spring through fall, WASA

conducts an aggressive program to systematically “flush” water

mains in the distribution system. The water is released by

sequentially opening fire hydrants and flushing water in a unidirectional manner. Some of the water being flushed may flow

into the streams and rivers, but chloramines are neutralized in

the process to protect aquatic life.

Flushing water through the pipes at high velocities removes

potential build-up or “scale” in pipes that may cause discolored water. Sometimes this scale is knocked off the pipe wall

but does not make it out of the system during the flushing.

This may cause short periods of discolored water in customers’ homes. Turning your faucets on for approximately

15 minutes and flushing the toilet can help minimize the problem. WASA distributes notices in neighborhoods where this

work will occur at least 48 hours prior to flushing. You can

also find out when WASA will be flushing in your area by calling 202-612-3440 or checking the flushing schedule on our

website, www.dcwasa.com. The website is continuously

updated throughout the flushing season.

Cross Connection Control Regulation Program –

The purpose of WASA’s cross connection control program is to

eliminate potential “cross connections”—physical links that

could allow contaminants to flow into the District water supply

from customers’ facilities. Backflow of contaminating materials

may cause serious illness. WASA’s cross connection control regulations are published in Chapter 54 Title 21 DCMR under the

heading Cross Connections. To protect public health, WASA is

requiring local businesses to install backflow prevention

devices at the water service connection to prevent contaminants from entering the drinking water supply. WASA is leading

this cooperative effort that includes the DC Department of

Health, the DC Department of Consumer and Regulatory Affairs,

the EPA and consumers.

Cross connection surveyors will conduct inspections of the

drinking water supply in commercial, industrial and apartment

buildings on a schedule prioritized by hazard potential. We

would appreciate your cooperation in assisting our surveyors.

Important Health Information

Certain people may be more vulnerable to microbial

contaminants (disease-causing microorganisms), such as

Cryptosporidium, in drinking water than the general population. Infants, the elderly and immuno-compromised persons,

such as those with cancer undergoing chemotherapy; those who

have undergone organ transplants; or those who have contracted HIV/AIDS or other immune system disorders can be at

greater risk for infection. Persons in these groups should seek

advice about drinking water from their health care providers.

EPA and Centers for Disease Control and Prevention (CDC)

guidelines on reducing the risk of infection by Cryptosporidium

and other microbial contaminants are available from the Safe

Drinking Water Hotline 1-800-426-4791.

Cryptosporidium is a microbial pathogen found in most surface waters in the U.S. The WA routinely monitors the Potomac

River for Cryptosporidium and has not detected any in the

past five years. Although filtration can remove

Cryptosporidium, it cannot guarantee 100-percent removal.

The WA provides a multiple-barrier treatment approach to

minimize the risk of all disease-causing microorganisms to

the public health through chemical treatment, highly efficient

sedimentation and filtration technologies and disinfection.

Ingesting Cryptosporidium may cause cryptosporidiosis, an

abdominal infection. Symptoms of infection include nausea,

diarrhea and abdominal cramps. Cryptosporidium must be

ingested to cause disease, and it may be spread through means

other than drinking water. Most healthy individuals can overcome the disease within a few weeks. However, immuno-compromised people are at greater risk of developing a

life-threatening illness. WASA encourages immuno-compromised individuals to consult their doctor regarding appropriate

precautions to take to avoid infection. EPA and CDC guidelines

on appropriate means to lessen the risk of infection by

Cryptosporidium and other microbial contaminants are available

from the Safe Drinking Water Hotline at 1-800-426-4791.

Compliance with EPA

Drinking Water Standards

Lead and Copper Rule

In 2004, WASA did not meet the EPA Lead and Copper Rule

action level of less than 15 ppb lead in 90 percent of homes

tested. In the first six-month compliance period, 74 of 108

samples (69%) exceeded 15 ppb. In the second six-month

compliance period, the number exceeding the 15 ppb action

level fell to 40 of 133 samples (30%).

DRINKING WATER QUALITY REPORT

7
DCWASA Serving the Public • Protecting the Environment

8

That year, WASA agreed to a negotiated Administrative Order

(AO). The agreement specified additional water quality monitoring and lead line replacements. A copy of the agreement is

located at www.epa.gov/dclead/aowasa617.pdf.

Lead and Copper Rule Violation – The WASA 2003 Water

Quality Annual Report reported the replacement of 7 percent of

the lead service lines for 2003. However, after publication of that

report, WASA was notified by EPA that its testing method did not

follow regulations and therefore, did not meet the 7 percent

requirement for 2003. WASA agreed through a Supplemental

Order, signed in January 2005, to replace an additional 387 lead

service lines. A copy of the agreement is located at

www.epa.gov/dclead/aowasa_supplement_011905.pdf.

Supplemental Monitoring Violation – Beginning

October 2004, WASA initiated a program to enhance its water

quality monitoring in order to optimize the lead corrosion

treatment in the distribution system. WASA conducts over

1,000 additional tests throughout the District on a monthly

basis for this program. It was developed by WASA, but under

the agreed upon Administrative Order, EPA monitors and

ensures WASA compliance. WASA missed 3 percent of the

required tests at the onset of the program due to unexpected

facility closures on Election Day.

Total Coliform Rule (TCR) Violation – In September

2004, WASA exceeded the TCR standard of 5 percent or less

samples negative for coliform growth for this month.

Coliforms were detected in 20 out of 294 samples (7%) in

September. For every sample that tests positive for coliform

growth, WASA must immediately sample that location again as

well as adjacent locations. The repeat samples are also tested

for E.coli and fecal coliforms, in addition to the total coliform

test. All repeat sample tests were negative.

Coliforms are bacteria that are naturally present in the

environment and are used as an indicator that other, potentially-harmful, bacteria may be present. Coliforms were found

in more samples than allowed and this was a warning of

potential problems.

What’s In My Drinking Water?

EPA establishes standards for drinking

water to make sure that it is safe for

you to drink. The table summarizes

District drinking water test results for

the year 2004. The water is tested for

the presence of over 100 prescribed

contaminants; however, for clarity only

those detected are listed in the table.

For a complete list of contaminants tested and the results,

call 202- 612-3440.

The table compares the level of each detected contaminant to

an allowable upper limit (maximum contaminant level, or MCL)

and the ideal goal (maximum contaminate level goal, or MCLG)

set by EPA. Note that the concentrations of nearly all detected

contaminants in District drinking water were considerably below

EPA-established maximum limits.

In addition to the contaminants listed in the table, the

Washington Aqueduct and WASA routinely monitor numerous

water quality parameters to optimize the quality of water delivered to the customer. The “Unregulated Contaminants” section

in the table summarizes some of these contaminants. As part of

the Administrative Order from EPA, WASA monitors water quality at 50 locations each month throughout the District. This program and the water quality results are described in more detail

at www.dcwasa.com.

Drinking water, including bottled water, may reasonably be

expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about

contaminants and potential health effects can be obtained by

calling the EPA Safe Drinking Water Hotline at 1-800-426-4791.
9

Washington, DC Drinking Water Analysis Data for 2004

Regulated Contaminants

Category of

Contaminants

Units EPA Limits DC Drinking Water Typical Sources of

Contaminants

MCLG MCL or TT Highest Range

Water Treatment Plant Performance

Turbidity NTU NA (TT) 5

(maximum)

0.12 0.04 to

0.12

Soil Runoff.

% of

monthly

turbidity

readings ≤

0.3 NTU

NA (TT) 95%

(minimum)

100%

pH NA NA 8.5 7.6 to 8.5

Temperature F NA NA 85 41 to 85

Alkalinity ppm NA NA 90 52 to 90

Total Hardness ppm

gpg

NA NA 148

9

105 to 148

6 to 9

Total Organic Carbon ppm NA TT 2.11 0.97 to

2.11

Naturally present in the

environment.

Orthophosphate (P04) ppm NA NA 3.23 ND to 3.23

Microbiological Indicators

Total Coliform Bacteria % of totalcoliformpositive

samples

0 5%

(maximum)

6.8% 0 to 6.8%1 Naturally present in the

environment.

Disinfectants and Disinfection Byproducts

Chlorine ppm 4

(MRDLG)

4

(MRDL)

3.8 3.3 to 3.8 Water additive that protects

against microbiological

contamination. Chlorine is

combined with ammonia to

form Chloramine.

Total Trihalomethanes ppb

(4-quarter

running

average)

NA 80 30.6

(highest

4-quarter

average)

14.3 to 43.5

(lowest and

highest

single site

result)

Trihalomethanes are a

by-product of drinking water

disinfection.

Haloacetic Acids (5) ppb

(4-quarter

running

average)

NA 60 21.5

(highest

4-quarter

average)

10.3 to

32.4

(lowest and

highest

single site

result)

Haloacetic acids are a

by-product of drinking water

disinfection.

Inorganic Metal

Selenium ppb 50 50 1.0 ND to 1.0 Discharge from petroleum and

metal refineries; erosion of

natural deposits.

Barium ppm 2 2 0.045 .030 to .045 Discharge of drilling waste and

metal refineries; erosion of

natural deposits.

Arsenic ppb 50 50 0.5 ND to 0.5 Erosion of natural deposits.

continued on next page
10

Category of

Contaminants

Units EPA Limits DC Drinking Water Typical Sources of

Contaminants

MCLG MCL or TT Highest Range

Inorganic Metal

Chromium ppb 100 100 1.3 ND to 1.3 Discharge from steel and pulp

mills; erosion of natural

deposits.

Copper

(at the customer’s tap)

(Jan.-June 2004

Monitoring Period)

ppb 1300 1300

(AL)

0

samples

out of

108

above AL

0.5 to 798

90%=116

ppb

Corrosion of household

plumbing systems; erosion of

natural deposits; leaching from

wood preservatives.

(July-Dec. 2004

Monitoring Period)

0

samples

out of

133

above AL

6 to 396

90%=143

ppb

Lead

(at the customer’s tap)

(Jan-June 2004

Monitoring Period)

ppb 0 15

(AL)

74

samples2

out of

108

above AL

0 to 190

90%=59

ppb

Corrosion of household

plumbing systems; erosion of

natural deposits.

(July-Dec. 2004

Monitoring Period)

40

samples2

out of

133

above AL

0 to 265

90%=54

ppb

Inorganic Ions

Fluoride ppm 4 4 0.96 0.71to 0.96 Water additive that promotes

strong teeth.

Nitrate (as N) ppm 10 10 2.63 1.36 to

2.63

Runoff from fertilizer use;

leaching from septic tanks;

erosion of natural deposits.

Chloride ppm 250 42 17 to 42

Synthetic Organic Carbon

Atrazine ppb 3 3 0.18 ND to 0.18 Herbicide runoff

di-(2-Ethylhexyl)adipate ppb NA 400 0.68 ND to 0.68

Metolachlor ppb NA NA 0.06 ND to 0.06

Phenanthrene ppb NA NA 0.03 ND to 0.03

Simazine ppb NA NA 0.10 ND to 0.10

Radionuclides3

Alpha Emitters pCi/L 0 15 2.1 ND to 2.1 Erosion of natural deposits

Beta Emitters4 pCi/L 0 50 3.0 1.2 to 3.0 Decay of natural and manmade deposits

Washington, DC Drinking Water Analysis Data for 2004

Regulated Contaminants (continued)

1. Exceeded Maximum Contaminant Level (MCL). See "TCR Violation" under "Compliance with EPA Drinking Water Standards” for details.

2. EPA regulations require that corrective action be taken if greater than 10 of 100 samples exceed the action level.

3. EPA requirements allow for some contaminants to be monitored less frequently than once per year because the concentrations of these contaminants do not change frequently. The

most recent radionuclides data were obtained in 2002.

4. The MCL for beta particles is 4 millirem per year. EPA considers 50 pCi/L to be the level of concern for beta particles.

5. The Washington Aqueduct (WA) used the EPA-approved method to determine the perchlorate levels reported in the table. The WA conducted additional tests with a new laboratory

method, not yet approved by EPA, and results ranged from ND to 1.8 ppb. For more information pertaining to these results and general information about perchlorate, go to

www.epa.gov/safewater/ccl/perchlorate/perchlorate.html and www.dcwasa.com.
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Contaminant Units Range Detected

Sulfate ppm 34 to 54

Nickel ppb 0.7 to 1.3

Aluminum ppb 25 to 76

Iron ppb ND to 212

Lithium ppb ND to 2.7

Magnesium ppm 6 to 9

Manganese ppb ND to 1.7

Sodium ppm 10 to 24

Strontium ppb 110 to 223

Zinc ppb ND to 8.5

Perchlorate5 ppb <4

Washington, DC Drinking Water Analysis Data for 2004

Unregulated Contaminants

Action Level (AL) = The concentration of

a contaminant which, if exceeded, triggers treatment or other requirements

which a water system must follow.

Other requirements may include additional testing, public notification, or

capital improvements.

CDC = Centers for Disease Control

and Prevention, located in Atlanta,

venting and controlling disease, injury,

and disability. CDC is an agency of

the U.S. Department of Health and

Human Services.

gpg = Grains per gallon.

Haloacetic Acid (5) (HAA5) = The five

haloacetic acid species required to

be monitored by EPA.

MRDL = Maximum Residual

Disinfectant Level. The highest level

of a disinfectant that is allowed in

drinking water. There is convincing

evidence that addition of a disinfectant

is necessary for control of microbial

contaminants.

MRDLG = Maximum Residual

Disinfectant Level Goal. The level of

drinking water disinfectant in water

below which there is no known or

expected risk to health. MDRLGs do

not reflect the benefits of the use of

disinfectants to control microbial contaminants.

MCLG = Maximum Contaminant Level

Goal. The level of a contaminant in

water below which there is no known or

expected risk to health. MCLGs allow

for a margin of safety.

MCL = Maximum Contaminant Level.

The highest level of a contaminant that

is allowed in drinking water. MCLs are

set as close to the MCLGs as feasible

using the best available treatment

technologies.

NA = Not Applicable.

ND = Non-Detectable.

NR = Not regulated by EPA at this time.

NTU = Turbidity is measured with an

instrument called a nephelometer,

which measures the intensity of light

scattered by suspended matter in the

water. Measurements are given in

nephelometric turbidity units (NTUs).

pCi/L = Picocuries per liter (a measure

of radioactivity)

ppm = parts per million

ppb = parts per billion

TT=Treatment Technique. A required

process intended to reduce the level of

a contaminant in drinking water.

Turbidity = A measure of the cloudiness of water. We measure turbidity

because it is a good indicator of the

effectiveness of the water treatment

system. Turbidity in excess of 5 NTU is

just noticeable to the average person.

"<" = Less than. In some cases, the

laboratory’s analytical method was not

capable of measuring at or below

EPA’s minimum detection level. In

these cases, if the contaminant was

not detected, a "less than" result is

reported under the "Highest" detected

level in DC’s drinking water.

ABBREVIATIONS AND DEFINITIONS
DC Water & Sewer Authority

5000 Overlook Ave., SW

Washington, DC 20032

Presorted Std.

U.S. Postage

PAID

Washington, DC

Permit No. 00050

Drinking Water Quality

WASA Water Quality 202-612-3440

Other General Information

WASA Switchboard 202-787-2000

Lead Hotline

WASA Lead Control 202-787-2732

Water Bills

Water Bill Action Line 202-354-3600

To Report Pipe Breaks, Leaks, or Open Hydrants

WASA Water Operations Emergency (24 Hours per Day) 202-612-3400

Information About WASA

WASA Public Affairs Office and WASA’s Programs 202-787-2200

Storm Drain Complaints 202-264-3820

WASA Department of Sewer Services or 202-612-3400

Source Water Protection

DC Department of Health 202-535-2190

Source Water Protection

Interstate Commission on the Potomac River Basin 301-984-1908

Drinking Water Treatment

Washington Aqueduct Division, USACE 202-764-2753

Safe Drinking Water Hotline

EPA 800-426-4791

Visit Our Website - WASA’s annual Water Quality Report and other information about WASA are available on the Internet at: http://www.dcwasa.com

Other web sites with information about drinking

water are listed below:

EPA’s Surf Your Watershed http://www.epa.gov/surf

American Water Works Association http://www.awwa.org

Glenn S. Gerstell – Chairman of the Board

Jerry N. Johnson – General Manager

Comments can also be e-mailed to info@dcwasa.com or faxed

to 202-787-2210

For More Information or Questions concerning this report call Water Quality Division, at 202-612-3440.

For any other aspect please call one of the numbers listed below:

Copias en español de estes folleto están a la disposición en las bibliotecas públicas y en las clínicas del Departamento de Salud del

District of Columbia, o llamando a la Oficina de Asuntos Públicos de

la Autoridad de Agua y Desagües al teléfono 202-787-2200

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