What's in Caroline County, MD tap water?
Caroline County sits about 69 miles from our Arlington base and is served primarily by Town of Denton, which provides water to roughly 4,500 people. It draws from the Coastal-plain aquifers. Maryland's Eastern Shore and Southern Maryland sit on coastal-plain aquifers. That groundwater commonly carries naturally occurring arsenic and radionuclides, iron and manganese, and nitrate from farming, with saltwater intrusion a growing concern near the Chesapeake Bay.
Find a local installerTown of Denton water quality report, explained
What testing of Town of Denton water shows for Caroline County, compared with EWG's health guidelines. Being above a guideline is not a legal violation.
Primary water system (EPA)
Town of Denton
Serves about 4,500 people
Contaminants EWG most often flags above its health guidelines for the Coastal-plain aquifers:
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 · Caroline County, MD
Caroline County, MD tap water is fully legal.
It is also 15× the health standard for lead.
Caroline County draws its water from the ground rather than from a river, through a small system serving about 4,500 people. Well water arrives with whatever the rock it sat in put into it, and small systems test less often than large ones.
Groundwater does not carry the chlorination byproducts that dominate river supplies, because it needs far less disinfection. What it carries instead comes out of the rock: arsenic, radium, manganese, and nitrate where there is farming above the aquifer. Boiling concentrates all of them rather than removing them.
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 3 ppb — meaning nine in ten homes tested below that, and one in ten above it. It has no violations on file.
Town of Denton, on the EPA's record
- Source
- groundwater
- Connections served
- 1,756
- People served
- 4,500
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 Town of Denton. 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.
5 contaminants above EWG's health guidelines
Everything EWG found above its guideline in Caroline County's water, from testing in 2018-2023. 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 |
|---|---|---|---|
| Arsenic | 2.72 ppb | 0.004 ppb | 679× |
| Total trihalomethanes (TTHMs) | 22.8 ppb | 0.15 ppb | 152× |
| Haloacetic acids (HAA5) | 9.37 ppb | 0.1 ppb | 94× |
| Radium, combined (-226 and -228) | 1.40 pCi/L | 0.05 pCi/L | 28× |
| Chloroform | 1.33 ppb | 0.4 ppb | 3.3× |
Source: EWG Tap Water Database, Town of Denton (MD0050001).
The fix for Caroline County water
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Reverse osmosis under your sink, for the contaminants EWG most often flags in the Coastal-plain aquifers.
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Common in U.S. tap water
Caroline County water quality FAQ
Is Caroline County, MD tap water safe to drink?
Public water in Caroline County meets federal EPA legal limits. But "legal" is not the same as "clean": across the Coastal-plain aquifers, independent testing routinely finds contaminants like arsenic (naturally occurring) and radium & radionuclides (naturally occurring) above EWG's stricter health guidelines. Enter your zip code above to see your exact utility's record.
What contaminants are common in Caroline County water?
For the Coastal-plain aquifers, the contaminants that most often exceed health guidelines are arsenic (naturally occurring), radium & radionuclides (naturally occurring), nitrates (agricultural runoff), PFAS (forever chemicals) and total trihalomethanes (where chlorinated). Your specific levels depend on your utility, which you can look up by zip code above.
Does Sanavia install reverse osmosis systems in Caroline County?
Yes. Caroline County is roughly 69 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 Caroline County tap water come from?
Caroline County's primary public water system is Town of Denton, which serves roughly 4,500 people. It sits in the Coastal-plain aquifers, 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 Caroline County tested for these contaminants?
No. Private wells are not covered by municipal testing, so the responsibility falls on the homeowner. If your Caroline 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 Coastal-plain aquifers
Each of these is a plain-English guide to a contaminant class common in Caroline County and the surrounding Coastal-plain aquifers — what it is, the health context, and what actually removes it.
Reverse osmosis in Denton & Caroline County, MD
Town of Denton treats this water to the federal standard, yet the contaminants listed above still exceed EWG’s stricter health guidelines — Arsenic (naturally occurring), Radium & radionuclides (naturally occurring), 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
$999, under the sink, with the included instructions.
We fit it for you
$1,250 installed in Caroline County.
Full testing record for Caroline 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 Caroline County tap?
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