Well Water Problems: Symptoms, Tests and Fixes

Pick the problem that matches what you see, smell or taste, and the page for it walks from the symptom to the cause, the lookalikes that get mistaken for it, the EPA or CDC limit where one exists, the test to order and the treatment that fits the numbers on the report. Several of the serious ones, bacteria, nitrate and PFAS, have no symptom at all, so the list is not a substitute for an annual test.

Test first, then treat in order. Stages protect each other: a sediment filter keeps grit out of everything downstream, an iron filter keeps oxidized iron off softener resin, and UV disinfection goes last on clear, softened water. The problems below are listed in that treatment order, which is also the order the equipment goes in the pipe. The testing guide covers what to order and how to read the report.

Cloudy water, grit or sand
Nuisance
Sediment
Sand, silt, rust flakes and cloudiness. Fix it first: every other filter downstream depends on it.
- Cloudy, milky or tea-colored water that clears when it sits
- Grit, sand or dark flakes in aerator screens, toilet tanks and the bottom of a glass
How to test: home kit
Symptoms, test and fix →
Orange or rust stains
Nuisance
Iron
Orange-brown stains on fixtures and laundry, metallic taste. The most common well water complaint in the US.
- Orange, red or brown stains in toilets, sinks, tubs and the dishwasher
- Laundry comes out with rust-colored streaks; whites turn yellow
How to test: certified lab
Symptoms, test and fix →
Black or dark brown stains
Health concern
Manganese
Black or dark-brown stains and slime; a health concern for infants above 0.3 mg/L. Usually travels with iron.
- Black, brown or purple-black stains in toilets, dishwashers and on laundry
- Dark flakes or slime in the toilet tank and water heater
How to test: certified lab required
Symptoms, test and fix →
Rotten-egg smell
Nuisance
Sulfur (hydrogen sulfide)
Rotten-egg odor from hydrogen sulfide gas or sulfur bacteria. Find out whether it is the well or the water heater before buying anything.
- Rotten-egg or sewage smell, strongest when the tap first opens
- Smell only in hot water (water heater anode reaction) or in both hot and cold (the well)
How to test: home kit
Symptoms, test and fix →
Scale, spots and soap scum
Nuisance
Hardness
White scale on fixtures, spotted dishes, soap that will not lather and water heaters that die early. Not a health issue, but the most expensive one to ignore.
- White crust on faucets, showerheads and the inside of kettles
- Spots on dishes and glassware; cloudy film on shower doors
How to test: home kit
Symptoms, test and fix →
Failed coliform test
Health concern
Bacteria
A positive total coliform or E. coli result. Stop drinking the water, shock the well, retest, and fix the cause before you rely on a UV unit.
- A positive total coliform or E. coli lab result (there are usually no taste, odor or color clues)
- Gastrointestinal illness in the household, especially after heavy rain or flooding
How to test: certified lab required
Symptoms, test and fix →
PFAS (forever chemicals)
Health concern
PFAS
Per- and polyfluoroalkyl substances. No taste or smell; you only know from a lab test. Treat with certified carbon or reverse osmosis.
- None. PFAS have no taste, odor or color at the levels that matter.
- A well near a military base, airport, firefighting training site, landfill, industrial plant or fields spread with biosolids
How to test: certified lab required
Symptoms, test and fix →
Nitrate (farm or septic)
Health concern
Nitrates
Invisible and tasteless; a health risk for infants and pregnant women above 10 mg/L. Common near farmland and septic systems.
- None; nitrate is colorless and tasteless
- A well in or near cropland, feedlots or dense septic development
How to test: certified lab required
Symptoms, test and fix →
Yellow or tea-colored water
Nuisance
Tannins
Yellow to tea-colored water that stays colored after standing. Harmless, but it stains and it fouls other filters.
- Yellow, amber or tea-colored water straight from the tap
- Color does not settle or change after the water stands (unlike iron)
How to test: certified lab
Symptoms, test and fix →

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