# How often should well water be tested? > When to test well water in Suffolk: yearly for bacteria, after pump work and disinfection, at a sale, and a full panel for fluoride and sodium. Plan your tests. URL: https://wellbornesuffolkwellpumprepair.com/guide/testing-well-water-after-pump-work/ Learn Once a year for bacteria, after anything that opens the well, and a fuller panel when something changes. Test a private well for bacteria at least once a year and after any work that opens the well, such as a pump replacement, once the disinfecting chlorine has been flushed out. Test a fuller panel when you buy the house, when taste, smell or color changes, or when someone is pregnant or has an infant. For deep Suffolk wells, include fluoride and sodium. Key points - Bacteria: every year and after any work that opens the well. - Full panel: at purchase and whenever something changes. - Deep Suffolk wells: add fluoride and sodium. - Sample only after the disinfecting chlorine has been flushed out. [Wellborne](https://wellbornesuffolkwellpumprepair.com/) disinfects every well we open and tells owners when to sample. Private wells are not covered by the testing that public water systems must do, so the schedule is up to the owner. These are the moments that matter. ## Every year: bacteria A total coliform test once a year is the baseline. Coliform bacteria are not usually harmful themselves, but their presence means surface water or something from the surface is reaching the well, and more harmful organisms can follow the same route. If coliform is found, an E. coli test shows whether the source is fecal. In the Virginia Cooperative Extension clinic of 204 Suffolk households, 21% of samples tested positive for total coliform and 2% for E. coli. A later extension program in Isle of Wight County found coliform in 62% of its samples. Bacteria in a well almost always point to a problem at the top of the well: a loose or cracked cap, a casing that ends below grade, or failed grout. ## After pump work or any opening of the well Pulling a pump, replacing a check valve or any work through the top of the casing exposes the well to surface bacteria. Virginia’s private well rules require a well to be disinfected before it is placed in service: 100 mg/L of chlorine held for 24 hours, or an equivalent of at least 1,000 contact units. After disinfection, the chlorine has to be flushed out before sampling, or the result will be falsely clear. Once the taps no longer smell of chlorine, a bacteria sample from a cold-water tap confirms the work. ## At purchase: a fuller panel The Virginia Department of Health does not require well testing when a house sells, but lenders usually ask for bacteria, nitrate and [lead](https://wellbornesuffolkwellpumprepair.com/well-inspection/). That is a minimum. For Suffolk’s deep wells, the clinic results argue for more: - **Fluoride:** 60% of samples were at or above 2 mg/L and 19% above the federal 4 mg/L limit. It is natural in parts of the deep [aquifers](https://wellbornesuffolkwellpumprepair.com/guide/suffolk-well-systems/). - **Sodium:** 78% of samples were above 20 mg/L, a level relevant to people on low-sodium diets. - **[Iron](https://wellbornesuffolkwellpumprepair.com/guide/iron-in-well-water/), manganese and hardness:** for staining, taste and scale. - **pH and corrosivity:** aggressive water can pick up metals from household plumbing. ## When something changes Test again when the water’s taste, smell or color changes, after a flood or after any nearby event such as a septic failure, a fuel spill or new construction close to the well. Test for nitrate when someone in the household is pregnant or there is an infant under six months, and especially if the well is near fields or a septic system. In the Suffolk clinic, 62% of participants reported field crops within half a mile of their well. ## How to sample properly Use the bottles and instructions from the lab. Sample from a cold-water tap that is used often, without an aerator, and not from a hose or a tap after a filter or softener unless you are testing the treatment. Run the water for a few minutes first. Keep bacteria samples cold and deliver them within the lab’s time limit. A careless sample tests the faucet, not the well. ## Where to test Certified private laboratories test year-round. Virginia Tech’s Virginia Household Water Quality Program runs low-cost testing clinics through local Extension offices across the state. Either way, keep the results with the [well records](https://wellbornesuffolkwellpumprepair.com/guide/buying-a-home-with-a-well-suffolk/); a run of results over years shows whether anything is changing. ## Reading the results Results come back as numbers against EPA drinking water standards. Some are health limits (bacteria, nitrate, fluoride, lead, arsenic); others are taste and staining guidelines (iron, manganese, sulfate). If something is above a health limit, the next step is finding and fixing the source where possible and choosing treatment from the result. The [well water treatment](https://wellbornesuffolkwellpumprepair.com/well-water-treatment/) page explains the options. For help interpreting a result, call [(757) 919-1972](tel:+17579191972). Related service [Well pump replacement](https://wellbornesuffolkwellpumprepair.com/well-pump-replacement/) More guides - [Rotten-egg smell in well water](https://wellbornesuffolkwellpumprepair.com/guide/well-water-smells-like-rotten-eggs/) - [Iron in well water](https://wellbornesuffolkwellpumprepair.com/guide/iron-in-well-water/) - [Buying a home with a well](https://wellbornesuffolkwellpumprepair.com/guide/buying-a-home-with-a-well-suffolk/) - [After a well floods](https://wellbornesuffolkwellpumprepair.com/guide/flooded-well/) - [How Suffolk well systems work](https://wellbornesuffolkwellpumprepair.com/guide/suffolk-well-systems/) ## Questions people ask ### How long after chlorinating should I wait to test? Until the chlorine has been flushed out of the system and a chlorine smell is gone at the taps. Sampling while chlorine is still present can give a false clear result. A few days after flushing is common practice; follow the lab's instructions. ### Where can I get my well water tested? Certified private laboratories test year-round, and Virginia Tech's Virginia Household Water Quality Program runs low-cost testing clinics through local Extension offices. ### Does Virginia require well water testing? Not for an existing well at a home sale. New wells are sampled as part of construction, and lenders or local ordinances may require tests. Routine testing of an existing well is the owner's responsibility.