Coliform bacteria in well water

Coliform bacteria are a group of bacteria that indicate a path for surface water or contamination to reach your well. Most aren't harmful on their own, but a positive test means germs that do cause illness could get in too. E. coli is a specific type that points to human or animal waste. The EPA recommends that well owners test for total coliform bacteria every year^[1].

Testing in our area

• Delaware: the Division of Public Health recommends annual bacteria and nitrate testing and offers free test kits^[2].
• New Jersey: the Private Well Testing Act requires a certified-lab test at home sale and every five years for landlords^[3]; see our PWTA guide.
• Pennsylvania: wells aren't regulated by the state^[4]. Chester County lists certified labs^[5].

If your test is positive

1. If E. coli is found, use bottled or boiled water for drinking and cooking until the problem is fixed.
2. Inspect the well: a damaged cap, cracked casing, or poor grading can let surface water in.
3. Shock chlorinate the well and plumbing, then retest after the chlorine is flushed.
4. If bacteria come back, install continuous disinfection, usually an ultraviolet (UV) system with sediment pre-filtration.

UV kills bacteria without chemicals but needs clear water to work, so iron, manganese, and sediment are treated ahead of it. That's why we design well treatment as a system, from a full test.

Solutions that help

What drives the price? See Well water treatment cost. Every recommendation starts with your free water report.

Where this comes up in our service area