Well Water in Collin County: What to Test and Why

Moderate Risk
Testing Recommended 367 well tests on record
Top Concerns in This County
Iron

Why This Happens Here

Collin County groundwater contains iron, manganese, nitrate, arsenic, and fluoride in amounts that exceed EPA health standards. These contaminants are present at levels serious enough that well owners need to know about them and consider testing and treatment.

The bedrock and soils in this county naturally contain iron and manganese minerals that dissolve into groundwater as water moves through the rock layers. Nitrate comes from fertilizers used on farms and urban yards, as well as from septic systems and animal waste. Arsenic and fluoride occur naturally in the local rocks and become part of the groundwater as it flows through them.

Groundwater in this county is moderately high in iron, which comes from the natural iron content in the bedrock and soil layers here. The iron dissolves as water passes through these materials underground. Many wells across Collin County show this elevated iron character.

What This Means for You

Wells in Collin County sometimes contain arsenic, fluoride, iron, manganese, nitrate, and PFOS at levels that exceed EPA health standards. Arsenic can damage your kidneys and increase cancer risk with long-term exposure. Fluoride at high levels can cause dental and skeletal problems. Nitrate is especially dangerous for infants and can interfere with how blood carries oxygen. Manganese can affect brain development in children. PFOS is a chemical that builds up in your body and may weaken your immune system.

Iron and manganese in county well water create staining on sinks, toilets, and laundry that is hard to remove. These minerals can also make water taste metallic and look discolored or cloudy. Iron buildup can shorten the lifespan of water heaters and other appliances over time.

We recommend testing your well water with a comprehensive panel since multiple contaminants exceed health standards in this county. Every well is different--your water could have higher or lower levels than what is common here. Testing is the only way to know exactly what is in your well so you can treat it properly. A comprehensive metals and minerals panel typically costs between two hundred and four hundred dollars. Treatment options like reverse osmosis or activated carbon filters can address many of these contaminants.

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

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Contaminant Detection Data

Contaminant Samples % Above MCL Distribution Confidence Risk
Iron 197 20%
High High
Nitrate 27 7%
Moderate Moderate
Manganese 123 2%
High Low
Arsenic 69 1%
Moderate Low
PFOS ⓘ municipal 116 1%
High Low
Fluoride 278 1%
High Low
HFPO-DA (GenX) ⓘ municipal 116 0%
High Safe
Lead 63 0%
Moderate Low
PFHxS ⓘ municipal 116 0%
High Low
PFNA ⓘ municipal 116 0%
High Safe
PFOA ⓘ municipal 116 0%
High Safe
Uranium 7 0%
Low Safe
PFBS ⓘ municipal 116
High 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.

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Population Health Context

Population-level CDC data. Not individual risk prediction.

5.4%
Cancer Prevalence
(state avg: 6.1%)
2.3%
Kidney Disease Rate
(state avg: 3.3%)

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