Drinking water quality · 2024
· Verified
What's in Poolesville, MD tap water
2 contaminants in Poolesville, MD's water sat at or above a federal limit, led by Perfluorohexanesulfonic acid at 91.3x the limit.
- !2 contaminants at or above a federal limit — worst is Perfluorohexanesulfonic acid at 91.3x
- !1 contaminant within 20% of a limit
- !10 of 27 core regulated contaminants reported — 17 never appear in this report
- ✓No open federal violations
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −55 contaminants at or above a federal limit
- −4 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −14 core regulated contaminants never reported (10/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What to worry about
- Perfluorohexanesulfonic acid91.3× the federal limit913 ng/L · limit 10 ng/L
Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
higher than 95% of U.S. systems
- Gross Alpha1.5× the federal limit22.4 pCi/L · limit 15 pCi/L
Long-term exposure above the federal limit increases cancer risk.
higher than 95% of U.S. systems
- Nitrate81% of the federal limit8.05 mg/L · limit 10 mg/L
Levels above the federal limit can cause 'blue baby syndrome,' a serious oxygen-transport condition in infants.
higher than 95% of U.S. systems
+19 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| PFOA | 2.94 ng/L | 4 ng/L |
| PFOS | 2.653 ng/L | 4 ng/L |
| Combined Radium | 3.3 pCi/L | 5 pCi/L |
| Copper | 0.43 mg/L | 1.3 mg/L |
| TTHM | 18 ug/L | 80 ug/L |
| Dehp | 1.34 ug/L | 6 ug/L |
| Chlorine | 0.7 mg/L | 4 mg/L |
| Dichloropropane 12 | 0.53 ug/L | 5 ug/L |
| HAA5 | 1.94–2.07 ug/L | 60 ug/L |
| Lead | Not detected ug/L | 15 ug/L |
| Lithium | 23.01333 ug/L | — |
| Perfluorobutanesulfonic acid | 1.527 ng/L | — |
| Perfluoroheptanoic acid | 700 ng/L | — |
| Perfluorohexanoic acid | 2.3 ng/L | — |
| Perfluoropentanoic acid | 3.053 ng/L | — |
| PFBA | 933 ng/L | — |
| Gross Beta Particle Activity | 7.5 pCi/L | — |
| Radon | 1510 pCi/L | — |
| Uranium | 12.1 pCi/L | 20.1 pCi/L |
What this report doesn't tell you
17 of the 27 contaminants a community water system normally reports do not appear anywhere in Poolesville, MD's data. Absent is not the same as absent-from-the-water — it means nobody published a number.