Well Water in Nassau County: What to Test and Why

Moderate Risk
Testing Recommended 250 well tests on record
Top Concerns in This County
Iron Manganese

Why This Happens Here

Contaminant levels in Nassau County groundwater are low, with no health standards being exceeded. Well owners should feel confident that harmful contaminants are not a concern in this area.

The shallow groundwater here sits close to the surface in sandy and permeable soils, which naturally filters water well before it reaches wells. This area's flat terrain and sandy ground also mean rainfall soaks down quickly without picking up much contamination. The combination of good natural filtering and low population density keeps groundwater clean.

Specific mineral content data is not available for Nassau County, but the sandy surficial aquifer here typically produces water that is soft and low in minerals. Sand does not dissolve easily into water the way limestone does, so minerals do not build up as they pass through. Most wells in this county will likely have water that feels light and clean without heavy mineral character.

What This Means for You

Wells in Nassau County generally show no contaminants exceeding EPA health standards, which is good news for your family's drinking water. Testing in the county has not detected concerning levels of bacteria, nitrate, or other harmful substances that would pose a direct health risk. This means your area's groundwater quality is relatively stable from a health perspective.

Some wells in this county do show elevated iron and sediment in the water. You might notice rusty staining on sinks and fixtures, or a metallic taste in your water. Iron can also leave orange or brown marks on laundry and appliances over time.

We recommend testing your well to find out what is actually in your water. Every well is different, and your well's water quality could be higher or lower than what is common across the county. Testing is the only way to know what you're dealing with so you can decide on proper treatment if needed. A basic screening costs around fifty to one hundred dollars and can tell you if you need further testing. If iron is a concern, a water softener or iron filter can address the issue.

Not sure if your well is affected? Get certified results in 5–7 days.

Test Your Well Water with Tap Score →

Contaminant Detection Data

Contaminant Samples % Above MCL Distribution Confidence Risk
Iron 127 17%
High High
Manganese 122 12%
High Moderate
Chloride 241 8%
High Moderate
Sulfate 182 8%
High Moderate
Lead 122 1%
High Low
Arsenic 122 1%
High Low
PFOA ⓘ municipal 16 0%
Moderate Safe
PFOS ⓘ municipal 16 0%
Moderate Safe
Nitrate 6 0%
Low Low
PFHxS ⓘ municipal 16 0%
Moderate Safe
Radon 2 0%
Low Low
Uranium 4 0%
Low Safe
Fluoride 61 0%
Moderate Low
HFPO-DA (GenX) ⓘ municipal 16 0%
Moderate Safe
Nitrite 4 0%
Low Safe
PFNA ⓘ municipal 16 0%
Moderate Safe
pH 168
High Low
Sodium 167
High Low
E. coli 6* 0%
Low Low
Fecal Coliform 5* 0%
Low Low
PFBS ⓘ municipal 16
Moderate Safe
Hardness 70
Moderate Low
Total Coliform 11* 0%
Low Low

MCL = Maximum Contaminant Level (EPA limit for public water; used as benchmark for private wells). Distribution shows % of sampled wells in each concentration band. Methodology.
* Microbial contaminants (E. coli, coliform) reflect only samples from the last 10 years.

Data shows potential risk — a certified test confirms whether your water is affected.

Order a Tap Score Test →

Population Health Context

Population-level CDC data. Not individual risk prediction.

8.4%
Cancer Prevalence
(state avg: 6.8%)
3.3%
Kidney Disease Rate
(state avg: 3.4%)
7.8%
Heart Disease Rate
(state avg: 7.7%)

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