Public water system · PA5100049
ActiveMars Borough Water Works
At a glance
Mars Borough Water Works (PWSID PA5100049) is an active community water system in Butler County, Pennsylvania. It reports serving 1,956 people through 665 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, none is health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,956
Service connections
665
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Mars Borough Water Works compare with other water systems in Butler County?
By EPA's size categories, Mars Borough Water Works is a small system (501 to 3,300 people). Butler County has 155 active public water systems. Its population served is about twice the county average of 1,007 people per system, and accounts for 1.3% of the 156,059 people reported by systems filed under the county. Across Pennsylvania, the 7,217 active systems average 1,741 people each. Nationally, the average active community water system reports serving 6,703 people, so Mars Borough Water Works is well below 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. Pennsylvania has 1,762 active community water systems, 24% of the state's 7,217 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,632 Pennsylvania systems (92%) list groundwater as their primary source.
Who owns and regulates Mars Borough Water Works?
EPA lists Mars Borough Water Works as owned by a local government. The PA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 15 of the 155 active systems in Butler County (9.7%) are also owned by a local government.
Does Mars Borough Water Works have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2025. The violations listed here began between January 2020 and July 2025. By type: 11 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Groundwater Rule (3 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 |
|---|---|---|---|---|
| 2025-07-11 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-06-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2023-03-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2021-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Radium-226code 4020 | No | Resolved |
| 2021-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Radium-228code 4030 | No | Resolved |
| 2021-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Uraniumcode 4006 | No | Resolved |
| 2020-12-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | 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.
Mars Borough Water Works: frequently asked questions
Who runs Mars Borough Water Works?
Mars Borough Water Works (PWSID PA5100049) is a community water system owned by a local government. It is regulated by the PA state drinking water program.
How many people does Mars Borough Water Works serve?
Mars Borough Water Works reports serving 1,956 people through 665 service connections in Butler County, Pennsylvania.
Where does Mars Borough Water Works 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 Mars Borough Water Works have any drinking water violations?
Of the 12 most recent violations in EPA's records, none 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 Mars Borough Water Works' 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, none 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 PA state drinking water program.
Where can I find Mars Borough Water Works' water quality report?
As a community water system, Mars Borough Water Works 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 Butler County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Pa American Water Co Butler | Butler | 43,286 | Community | Surface water |
| Cranberry Twp WTP | Butler | 42,000 | Community | Purchased surface water |
| Slippery Rock Muni Auth | Butler | 15,778 | Community | Groundwater |
| Municipal Water Auth Adams Twp | Butler | 8,700 | Community | Purchased surface water |
| Harmony Boro Water Auth | Butler | 6,669 | Community | Surface water |
| Zelienople Boro | Butler | 4,123 | 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, “Mars Borough Water Works, PWSID PA5100049, Pennsylvania”, https://aquacensus.com/water-systems/pennsylvania/mars-borough-water-works-pa5100049 (data as of October 1, 2026).