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Water problem — solved

Bacteria in Well Water

Pennsylvania is one of the few states with no statewide construction or water-quality standards for private wells — your well, your responsibility. Penn State's long-running studies find roughly half of tested PA wells fail at least one drinking-water standard, and bacteria is the most common failure. Unlike iron or hardness, you can't see, taste, or smell it. The fix starts with a test, and every path from there is well understood.

Root causes

What causes it in NEPA homes

Surface water infiltration

A cracked cap, shallow or damaged casing, or ground sloping toward the wellhead lets runoff — and everything it carries — reach your water without the soil filtration that normally protects an aquifer.

Total coliform (the indicator)

Coliform bacteria are mostly harmless themselves, but they only survive where surface contamination is getting in — so a positive test means the door is open for organisms that do cause illness.

E. coli (the serious one)

E. coli lives in the gut of warm-blooded animals, so a positive result means septic or animal waste is reaching your well. It can cause real illness and calls for immediate action: boil or use bottled water until it’s resolved.

Nearby septic systems

An aging or failing septic field uphill of a well — yours or a neighbor’s — is a classic rural NEPA contamination route, especially in fractured bedrock where water moves fast and filters little.

Your options

Ways to fix it

Test first — then every year

Penn State and the EPA both recommend testing private wells for coliform annually, plus after floods, plumbing work, or any change in taste or clarity. It’s the single most important habit for well owners, and where every fix below starts.

See the full testing schedule

Fix the wellhead

Before any treatment, close the door contamination walked through: a sanitary well cap, casing extended above grade, and ground sloped away from the well. Sometimes this alone turns a chronic positive into a clean test.

Shock chlorination

A high-dose bleach disinfection of the well, pressure tank, and plumbing — held 12–24 hours, then flushed. It’s the right response to a one-time contamination event (like flood water or well work). If tests turn positive again within months, the source is ongoing and continuous treatment is the answer.

UV disinfection

An ultraviolet lamp inactivates 99.99% of bacteria and viruses as water flows past — no chemicals, no taste change. The catch: UV needs clear water to work, so sediment, iron, and hardness must be treated upstream or shadows shield the microbes. We design the pretreatment as part of the system.

UV disinfection for wells

Continuous chlorination

For wells with persistent contamination or heavy biology (like iron bacteria alongside coliform), a feed pump maintains a low chlorine dose with a retention tank for contact time, and a carbon filter removes the residual before your taps — city-water safety on a private well.

Good to know

Frequently asked questions

My test found coliform but no E. coli — is that an emergency?
It’s a warning, not an emergency. Total coliform without E. coli means surface contamination has a path into your well, but fecal organisms haven’t been detected. Retest to rule out a sampling error, inspect the wellhead, and plan disinfection. If E. coli ever shows up, switch to bottled or boiled water immediately and treat it as urgent.
Does boiling make the water safe?
A rolling one-minute boil kills bacteria, viruses, and parasites — it’s the correct short-term response to a positive test. But it does nothing for chemical contaminants (it actually concentrates nitrate), and nobody boils shower water. It’s a bridge to a fix, not the fix.
Why does my well keep failing even after shocking it?
Shock chlorination disinfects what’s in the well today — it can’t stop what arrives tomorrow. Repeat positives mean an open pathway: a casing or cap defect, surface water reaching fractured rock, or septic influence. That calls for a wellhead fix plus continuous treatment like UV. Needing to re-shock more than about twice a year is the classic sign.
Nobody has gotten sick — do I really need to treat it?
Contamination is intermittent by nature: the well that tests clean in August can fail after the October rains. Healthy adults may shrug off low-level exposure while kids, grandparents, and guests don’t. Since the well isn’t regulated by anyone but you, an annual test and a properly designed barrier are what stand in for the water utility you don’t have.