Water report · not indexed
What is in the water at 20837
2 public water systems serve this ZIP code in the federal records. Everything below comes from EPA monitoring data, and everything missing is named.
TOWN OF POOLESVILLE
PWSID MD0150002 · MD · serves 5,400 people
PFAS and lithium
9 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 61 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| lithium | 41 µg/L | 19 | 9/22/2025 |
| PFPeA | 0.015 µg/L | 6 | 8/8/2023 |
| PFHxA | 0.0098 µg/L | 6 | 8/8/2023 |
| PFBA | 0.0089 µg/L | 4 | 8/8/2023 |
| PFHxS | 0.0069 µg/L | 2 | 8/8/2023 |
| PFOS | 0.0065 µg/L | 7 | 8/8/2023 |
| PFOA | 0.0054 µg/L | 9 | 8/8/2023 |
| PFHpA | 0.0054 µg/L | 2 | 8/8/2023 |
| PFBS | 0.0048 µg/L | 6 | 8/8/2023 |
A detection is a measurement, not a violation and not a health finding. EPA states that UCMR 5 results do not indicate compliance or non-compliance with any limit.
Health-based violations
No open health-based violation on record. This covers MCL, treatment technique and MRDL violations in SDWIS that have not been returned to compliance. It excludes monitoring and reporting violations, which are the large majority nationally, so this is not “no violations”, and SDWIS completeness varies by state.
Hardness
No hardness measurement. Hardness is measured at environmental monitoring stations, and none fell inside this system’s service area. That is a gap in where monitoring happens, not a finding about the water.
WASHINGTON SUBURBAN SANITARY COMMISSION
PWSID MD0150005 · MD · serves 1,900,000 people
PFAS and lithium
2 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 8 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| PFPeA | 0.0067 µg/L | 4 | 7/26/2023 |
| PFHxA | 0.0048 µg/L | 4 | 7/26/2023 |
A detection is a measurement, not a violation and not a health finding. EPA states that UCMR 5 results do not indicate compliance or non-compliance with any limit.
Health-based violations
No open health-based violation on record. This covers MCL, treatment technique and MRDL violations in SDWIS that have not been returned to compliance. It excludes monitoring and reporting violations, which are the large majority nationally, so this is not “no violations”, and SDWIS completeness varies by state.
Hardness
Median hardness 155 mg/L as CaCO₃, measured at 16 stations serving this system across 18 results, 2015-06-30 to 2022-08-04. Measured in the water source and distribution area, not at a tap, and not in your home.
What this report cannot tell you
Every figure describes water at a sampling point: a treatment plant, an entry point to the distribution system, or a monitoring station. None of it describes water arriving at your tap. Plumbing between the two can add lead and copper, and if your home was built before 1986 a test kit tells you something no federal dataset can.
Sources: EPA UCMR 5 occurrence (final release, frozen July 2026) · EPA SDWIS health-based violations · USGS and state monitoring via the Water Quality Portal · EPA Public Water System Service Area Boundaries v3. Compiled 2026-09-01.