What's in Washington County, MD tap water?
Washington County sits about 62 miles from our Arlington base and is served primarily by City of Hagerstown, which provides water to roughly 92,200 people. It draws from the Piedmont reservoirs, rivers & wells. Piedmont and northern-Maryland communities draw from a mix of reservoirs, rivers (including the Susquehanna and Monocacy) and groundwater wells. Chlorination byproducts plus agricultural and industrial runoff drive most of the contaminants that exceed EWG's health guidelines.
Find a local installerCity of Hagerstown water quality report, explained
What testing of City of Hagerstown water shows for Washington County, compared with EWG's health guidelines. Being above a guideline is not a legal violation.
Primary water system (EPA)
City of Hagerstown
Serves about 92,200 people
Contaminants EWG most often flags above its health guidelines for the Piedmont reservoirs, rivers & wells:
Larger areas have more than one water system. Enter your exact zip code below for your utility's own EPA record and EWG report.
Measured by the EPA · Washington County, MD
Washington County, MD tap water is fully legal.
It is also 4.7× the health standard for lead.
Washington County is served by City of Hagerstown, a surface-water system supplying roughly 92,200 people. It treats its own water rather than buying it from a regional wholesaler, so what comes out of the tap is its work end to end.
River water has to be disinfected hard enough to stay safe across the whole network, and this system uses chloramines rather than free chlorine. Chloramine is more stable in long pipe runs and produces fewer trihalomethanes — but it is more corrosive to old plumbing, which is precisely how lead gets into water that left the plant clean.
Every federal limit that applies here is met. Those limits weigh what removal costs. EWG says its health standards are “based only on protecting health and does not consider technical feasibility or the cost of water treatment”. Here is how far apart the two are.
Harm to the brain and nervous system · EPA limit 10 ppb (action level, lowered from 15 ppb, in force November 2027)
It was tested for 29 PFAS compounds in the EPA's latest round and none came back above reporting limits — genuinely good news, and a single window in time. Lead sampling put the ninetieth percentile at 0.94 ppb — meaning nine in ten homes tested below that, and one in ten above it. City of Hagerstown has 1 violation on file with the EPA, 1 of them health-based.
City of Hagerstown, on the EPA's record
- Source
- surface water
- Connections served
- 28,000
- People served
- 92,200
- Violations on file
- 1 (1 health-based)
How this water is treated before it reaches you
Treatment makes water safe to distribute. It is not designed to remove PFAS, and chlorine-based disinfection creates byproducts of its own.
Levels: EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR5, 2023–2025) for PFAS, and the Lead and Copper Rule 90th-percentile result for lead and copper — the highest reported for City of Hagerstown. Health standards: EWG's published drinking water standards, updated February 2025. Levels vary by sampling point and date, and being above a health standard is not a legal violation.
9 contaminants above EWG's health guidelines
Everything EWG found above its guideline in Washington County's water, from testing in 2013-2024. A level can be under the legal limit and still be listed here: EWG's guidelines are set to protect health, not to be easy to meet.
| Contaminant | In this water | EWG guideline | Times over |
|---|---|---|---|
| Haloacetic acids (HAA9) | 25.7 ppb | 0.06 ppb | 429× |
| Total trihalomethanes (TTHMs) | 27.5 ppb | 0.15 ppb | 183× |
| Haloacetic acids (HAA5) | 12.7 ppb | 0.1 ppb | 127× |
| Bromodichloromethane | 4.83 ppb | 0.06 ppb | 81× |
| Dibromochloromethane | 3.01 ppb | 0.1 ppb | 30× |
| Chloroform | 8.53 ppb | 0.4 ppb | 21× |
| Nitrate | 1.10 ppm | 0.14 ppm | 7.9× |
| Chromium (hexavalent) | 0.0791 ppb | 0.02 ppb | 4× |
| Nitrate and nitrite | 0.480 ppm | 0.14 ppm | 3.4× |
Source: EWG Tap Water Database, City of Hagerstown (MD0210010).
The fix for Washington County water
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Common in U.S. tap water
Washington County water quality FAQ
Is Washington County, MD tap water safe to drink?
Public water in Washington County meets federal EPA legal limits. But "legal" is not the same as "clean": across the Piedmont reservoirs, rivers & wells, independent testing routinely finds contaminants like total trihalomethanes (TTHMs) and haloacetic acids (HAA5) above EWG's stricter health guidelines. Enter your zip code above to see your exact utility's record.
What contaminants are common in Washington County water?
For the Piedmont reservoirs, rivers & wells, the contaminants that most often exceed health guidelines are total trihalomethanes (TTHMs), haloacetic acids (HAA5), nitrates (agricultural runoff), hexavalent chromium (chromium-6) and PFAS (forever chemicals). Your specific levels depend on your utility, which you can look up by zip code above.
Does Sanavia install reverse osmosis systems in Washington County?
Yes. Washington County is roughly 62 miles from our Arlington base and inside our service area. A Sanavia Hydra reverse osmosis system installs under your sink and reduces every contaminant class above, and we'll mail you a free water test kit.
Where does Washington County tap water come from?
Washington County's primary public water system is City of Hagerstown, which serves roughly 92,200 people. It sits in the Piedmont reservoirs, rivers & wells, so its water shares that region's contaminant profile. Larger areas may have more than one utility, so enter your exact zip code above for your own system's EPA record.
Is well water in Washington County tested for these contaminants?
No. Private wells are not covered by municipal testing, so the responsibility falls on the homeowner. If your Washington County home is on a well, nitrate and naturally occurring contaminants are worth testing for specifically, and a reverse osmosis system reduces them at the tap. We'll mail you a free water test kit either way.
Contaminants common in the Piedmont reservoirs, rivers & wells
Each of these is a plain-English guide to a contaminant class common in Washington County and the surrounding Piedmont reservoirs, rivers & wells — what it is, the health context, and what actually removes it.
Reverse osmosis in Hagerstown & Washington County, MD
City of Hagerstown treats this water to the federal standard, yet the contaminants listed above still exceed EWG’s stricter health guidelines — Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Nitrates (agricultural runoff) and 2 more. Most of them either pass straight through treatment or form after the plant, in the pipes between it and the tap, which is why the fix has to be at the tap as well.
PFAS is the reason a carbon pitcher is not enough here. The compounds do not break down, they are measured in parts per trillion, and the federal limit that covers them is not enforceable until 2029. A reverse osmosis membrane is one of the few things at household scale that reduces them rather than passing them through.
Fit it yourself
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Full testing record for Washington County · Find a local installer
Detailed city water reports
For the largest DC-metro utilities we publish the full measured contaminant table.
Nearby areas we serve
What's in your Washington County tap?
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