What was found in ZIP 20837
The level at this ZIP's main supplier, the highest level anywhere in it, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate-Nitrite | 2355 µg/L 24% of the EPA limit 10000 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019
Highest in the ZIP: 6800 µg/L — TOWN OF POOLESVILLE · 6,005 people · 2017 | 2/2 | SYR4 |
| Nitrate | 2350 µg/L 24% of the EPA limit 10000 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019
Highest in the ZIP: 6500 µg/L — TOWN OF POOLESVILLE · 6,005 people · 2019 | 2/2 | SYR4 |
| Barium | 41.625 µg/L 2.1% of the EPA limit 2000 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019
Highest in the ZIP: 1042 µg/L — TOWN OF POOLESVILLE · 6,005 people · 2019 | 2/2 | SYR4 |
| Fluoride | 785.2 µg/L 20% of the EPA limit 4000 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 2/2 | SYR4 |
| TTHM | 86.245 µg/L 108% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 2/2 | SYR4 |
| Chloroform | 60 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 58.211 µg/L 97% of the EPA limit 60 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 2/2 | SYR4 |
| Lithium | 41.1 µg/L No EPA limit set Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2025 | 1/2 | UCMR-5 |
| Trichloroacetic Acid | 33.05 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2015 | 2/2 | SYR4 |
| Combined Uranium | 21.8051 µg/L 73% of the EPA limit 30 µg/L Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2019 | 1/2 | SYR4 |
| Dichloroacetic Acid | 20.5 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2015 | 2/2 | SYR4 |
| Bromodichloromethane | 20.1 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 2/2 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.24 pCi/L 15% of the EPA limit 15 pCi/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2018
Highest in the ZIP: 17.08 pCi/L — TOWN OF POOLESVILLE · 6,005 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 7.661 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 2/2 | SYR4 |
| Gross Beta Particle Activity | 6.505 pCi/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2018
Highest in the ZIP: 6.75 pCi/L — TOWN OF POOLESVILLE · 6,005 people · 2019 | 2/2 | SYR4 |
| Monobromoacetic Acid | 4.932 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2015 | 1/2 | SYR4 |
| Dibromoacetic Acid | 3.54 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2015 | 2/2 | SYR4 |
| Monochloroacetic Acid | 2.651 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2015
Highest in the ZIP: 3.51 µg/L — TOWN OF POOLESVILLE · 6,005 people · 2015 | 2/2 | SYR4 |
| Combined Radium (-226 And -228) | 2.36 pCi/L 47% of the EPA limit 5 pCi/L Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2019 | 1/2 | SYR4 |
| Arsenic | 2.295 µg/L 23% of the EPA limit 10 µg/L Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2018 | 1/2 | SYR4 |
| Bromoform | 2.1115 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 2/2 | SYR4 |
| Chromium | 2.1 µg/L 2.1% of the EPA limit 100 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 1/2 | SYR4 |
| Selenium | 1.836 µg/L 3.7% of the EPA limit 50 µg/L Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2018 | 1/2 | SYR4 |
| Thallium, Total | 1 µg/L 50% of the EPA limit 2 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 1/2 | SYR4 |
| Atrazine | 0.1590 µg/L 5.3% of the EPA limit 3 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 1/2 | SYR4 |
| Simazine | 0.0846 µg/L 2.1% of the EPA limit 4 µg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2019 | 1/2 | SYR4 |
| Pfpea | 0.0067 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2024
Highest in the ZIP: 0.0151 µg/L — TOWN OF POOLESVILLE · 6,005 people · 2025 | 2/2 | UCMR-5 |
| Pfhxa | 0.0048 µg/L No EPA limit set Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2024
Highest in the ZIP: 0.0098 µg/L — TOWN OF POOLESVILLE · 6,005 people · 2025 | 2/2 | UCMR-5 |
| Pfba | 0.0089 µg/L No EPA limit set Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2025 | 1/2 | UCMR-5 |
| PFHXS | 0.0069 µg/L No EPA limit set Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2025 | 1/2 | UCMR-5 |
| PFOS | 0.0065 µg/L No EPA limit set Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2025 | 1/2 | UCMR-5 |
| Pfhpa | 0.0054 µg/L No EPA limit set Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2025 | 1/2 | UCMR-5 |
| PFOA | 0.0054 µg/L No EPA limit set Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2025 | 1/2 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: WASHINGTON SUBURBAN SANITARY COMMISSION · 1,900,000 people · 2020
Highest in the ZIP: 0.0050 mg/L — TOWN OF POOLESVILLE · 6,005 people · 2018 | 2/2 | LCR |
| PFBS | 0.0048 µg/L No EPA limit set Highest in the ZIP: TOWN OF POOLESVILLE · 6,005 people · 2025 | 1/2 | UCMR-5 |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
Water suppliers serving ZIP 20837
| Supplier | State | Population served |
|---|---|---|
| WASHINGTON SUBURBAN SANITARY COMMISSION | MD | 1,900,000 |
| TOWN OF POOLESVILLE | MD | 6,005 |
Frequently asked questions about ZIP 20837 tap water
Is the tap water in ZIP 20837 safe to drink?
EPA testing detected 35 contaminants across the water suppliers serving ZIP 20837. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.
Which water suppliers serve ZIP 20837?
2 public water suppliers report EPA drinking-water monitoring for ZIP 20837. Each is listed above with its population served.
What contaminants are in ZIP 20837's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Barium, Fluoride, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.