What Should I Test My Well Water For

Build the panel in layers

There is no single laboratory panel that detects every possible problem in every private well. The practical approach is to begin with a routine baseline, then add analyses supported by a plausible risk. Nearby land use, local geology, household plumbing, a change in the water, and vulnerable household members can all change what belongs on the order. [1][2]

Start by telling a state-certified laboratory why you are testing. Confirm that it is certified for the analyses being ordered, not simply that it performs water testing. Ask for the correct bottles, preservation requirements, collection instructions, holding times, and shipping plan before collecting. [2] An independent result should come before a treatment purchase or a sales demonstration.

Layer 1: the annual baseline

CDC recommends testing private well water at least once a year for total coliform bacteria, nitrate, total dissolved solids, and pH. [1] Each item answers a different question:

• Total coliform bacteria is mainly an indicator that a pathway may exist for harmful organisms. It is not a complete inventory of every microorganism. [1]
• Nitrate is a health-related contaminant, so it belongs in the routine baseline rather than only in symptom-driven testing. [1]
• Total dissolved solids is an indicator or operational measurement. It does not establish that water is free from health hazards. [2]
• pH helps describe water chemistry and possible operational concerns. By itself, it does not prove safety. [2]

A baseline is valuable because it gives the household a repeated set of results to compare over time. It is not an all-clear for contaminants that were never analyzed.

Layer 2: add tests that match a credible risk

Organic and radiological testing can be costly and still miss the relevant contaminant if the order is not targeted. Ask local health, environmental, and Extension offices what is associated with regional geology and land use, then ask the laboratory which exact analytical method fits that concern. [1][2]

Layer 3: account for people and trigger events

Review the panel after flooding, well repair, land disturbance, or a change in taste, color, or odor. Pregnancy or an infant beginning to use the water should also prompt a review of current results and locally important additions. [1] Household health needs matter too. Include infants, pregnant people, and people whose medical conditions may be affected by sodium or manganese when discussing the panel with the health department or clinician. [1][2]

After a flood, suspected sewage entry, or a positive fecal indicator result, use state or local instructions for timing, sampling, and immediate precautions. [1] A consumer test strip is not a substitute for the official response or a certified laboratory result.

Specify where each sample comes from

Location changes the meaning of the result. A wellhead or before-treatment sample characterizes source water and provides data used to size treatment. A kitchen-tap sample includes the effects of plumbing and any existing treatment, and lead testing generally needs a tap sample. Paired samples collected before and after an installed device can evaluate that device's performance. [2]

Do not mix those purposes. If the goal is to investigate lead from plumbing, a raw sample at the pressure tank may miss the question. If the goal is to choose whole-house treatment, a kitchen sample taken after existing equipment may hide the incoming load. Tell the laboratory about the plumbing and treatment layout and label each sample point precisely.

Keep health and nuisance questions separate

Health-related analyses can include E. coli or fecal coliform, arsenic, lead, nitrate and nitrite, radionuclides, volatile organic compounds, pesticides, mercury, and locally important contaminants. [2][3] Aesthetic or operational analyses can include hardness, iron, sulfate, hydrogen sulfide, turbidity, alkalinity, chloride, sodium, and corrosivity indicators. Manganese needs both aesthetic and health interpretation. [2]

Iron and hardness are usually nuisance concerns, while pH, total dissolved solids, color, odor, and turbidity are indicators or operational parameters. None of those results alone establishes that the water is free from health hazards. [2] Prioritize credible health risks, then gather the chemistry needed to diagnose nuisance problems and design treatment.

Turn that distinction into a written order. List the annual baseline first. Under it, add each extra analyte beside the reason for including it, such as plumbing materials, agriculture, a fuel release, or regional geology. Then mark the intended sample point for each bottle. Ask the laboratory to identify overlapping tests, missing method requirements, and analyses that need their own bottle or timing. This short worksheet makes it easier to see whether the panel answers the household's actual questions instead of merely carrying a reassuring name.

Finally, ask what the panel does not cover. A “complete,” “premium,” or “well” package is still a defined list of analytes, not a test for everything. [1][2] Save the final list with the report so future annual results can be compared on the same basis and new local risks can be added deliberately.