Public water system · MD0180007
ActiveLexington Park
At a glance
Lexington Park (PWSID MD0180007) is an active community water system in St. Mary's County, Maryland. It reports serving 43,030 people through 15,820 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
43,030
Service connections
15,820
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Lexington Park compare with other water systems in St. Mary's County?
By EPA's size categories, Lexington Park is a large system (10,001 to 100,000 people). St. Mary's County has 194 active public water systems, and Lexington Park is the largest of them by population served. Its population served is about 67 times the county average of 642 people per system, and accounts for 35% of the 124,635 people reported by systems filed under the county. Across Maryland, the 2,992 active systems average 1,947 people each. Nationally, the average active community water system reports serving 6,703 people, so Lexington Park is about 6.4 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. Maryland has 422 active community water systems, 14% of the state's 2,992 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,870 Maryland systems (96%) list groundwater as their primary source.
Who owns and regulates Lexington Park?
EPA lists Lexington Park as owned by a local government. The MD state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 47 of the 194 active systems in St. Mary's County (24%) are also owned by a local government.
Does Lexington Park have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025. The violations listed here began between November 1991 and July 2025. By type: 10 monitoring and reporting, 1 reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (3 of them). EPA lists 11 as resolved and 1 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2023-06-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2020-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2004-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 1994-01-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1991-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
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.
Lexington Park: frequently asked questions
Who runs Lexington Park?
Lexington Park (PWSID MD0180007) is a community water system owned by a local government. It is regulated by the MD state drinking water program.
How many people does Lexington Park serve?
Lexington Park reports serving 43,030 people through 15,820 service connections in St. Mary's County, Maryland.
Where does Lexington Park get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Lexington Park have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025. 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 Lexington Park'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, one is health-based, and the most recent began in July 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the MD state drinking water program.
Where can I find Lexington Park's water quality report?
As a community water system, Lexington Park 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 St. Mary's County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Patuxent Naval Air Station (Navfac-Wash) | St. Mary's | 22,000 | Community | Groundwater |
| Town of Leonardtown | St. Mary's | 5,000 | Community | Groundwater |
| Country Lakes | St. Mary's | 3,016 | Community | Groundwater |
| Cedar Cove | St. Mary's | 2,728 | Community | Groundwater |
| Saint Marys College | St. Mary's | 2,200 | Community | Groundwater |
| Chopticon High School | St. Mary's | 1,845 | Non-transient non-community | Groundwater |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Lexington Park, PWSID MD0180007, Maryland”, https://aquacensus.com/water-systems/maryland/lexington-park-md0180007 (data as of October 1, 2026).