Public water system · DC0000002
ActiveD.C. Water and Sewer Authority
At a glance
D.C. Water and Sewer Authority (PWSID DC0000002) is an active community water system in District of Columbia County, District of Columbia. It reports serving 632,323 people through 133,500 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in January 2023.
This page covers its drinking water system only; sewer and wastewater service are not part of EPA's drinking water records.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
632,323
Service connections
133,500
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does D.C. Water and Sewer Authority compare with other water systems in District of Columbia County?
By EPA's size categories, D.C. Water and Sewer Authority is a very large system (more than 100,000 people). District of Columbia County has 5 active public water systems, and D.C. Water and Sewer Authority is the largest of them by population served. Its population served is about 4.7 times the county average of 133,737 people per system, and accounts for 95% of the 668,685 people reported by systems filed under the county. Across District of Columbia, the 12 active systems average 58,113 people each. Nationally, the average active community water system reports serving 6,703 people, so D.C. Water and Sewer Authority is about 94 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. District of Columbia has 4 active community water systems, 33% of the state's 12 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 5 District of Columbia systems (42%) list purchased surface water as their primary source.
Who owns and regulates D.C. Water and Sewer Authority?
EPA lists D.C. Water and Sewer Authority as owned by a local government. The DC state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 1 of the 5 active systems in District of Columbia County (20%) are also owned by a local government.
Does D.C. Water and Sewer Authority have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in January 2023. The violations listed here began between July 2003 and January 2023. By type: 6 monitoring and reporting, 2 monitoring, 2 public notice, recordkeeping or other, 1 required treatment not met and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Revised Total Coliform Rule (2 of them). EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2023-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2022-12-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2022-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | No | Resolved |
| 2005-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2004-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2004-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2004-10-01 | Required treatment not metLead Service Line Replacement (LSLR) · code 64 | Lead and Copper Rulecode 5000 | Yes | Resolved |
| 2004-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-10-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2003-07-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
D.C. Water and Sewer Authority: frequently asked questions
Who runs D.C. Water and Sewer Authority?
D.C. Water and Sewer Authority (PWSID DC0000002) is a community water system owned by a local government. It is regulated by the DC state drinking water program.
How many people does D.C. Water and Sewer Authority serve?
D.C. Water and Sewer Authority reports serving 632,323 people through 133,500 service connections in District of Columbia County, District of Columbia.
Where does D.C. Water and Sewer Authority get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does D.C. Water and Sewer Authority have any drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in January 2023. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is D.C. Water and Sewer Authority's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in January 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the DC state drinking water program.
Where can I find D.C. Water and Sewer Authority's water quality report?
As a community water system, D.C. Water and Sewer Authority must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in District of Columbia County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Joint Base Anacostia - Bolling | District of Columbia | 19,312 | Community | Purchased surface water |
| Naval Station Washington - Wny | District of Columbia | 16,800 | Community | Purchased surface water |
| Naval Observatory | District of Columbia | 250 | Non-transient non-community | Purchased surface water |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “D.C. Water and Sewer Authority, PWSID DC0000002, District of Columbia”, https://aquacensus.com/water-systems/district-of-columbia/d-c-water-and-sewer-authority-dc0000002 (data as of October 1, 2026).