Your driller’s completion test covers bacteria. That’s the standard. It confirms that shock chlorination during construction left the well free of bacterial contamination at the time of drilling.
It tells you nothing about arsenic, nitrates, lead from new pump components, hardness, iron, manganese, PFAS from nearby sources, or VOCs from industrial activity in the area. For a new well, the initial test is the most important one you’ll ever do.
Why This Test Matters More Than Any Other
Before you connect the well to the house and start using it daily, you have one chance to establish a clean baseline. Future tests will compare against this one. An arsenic reading at 8 ppb in year 3 looks different if you know year 1 was 7 ppb (stable, likely natural geological source) versus if you have no baseline at all.
Document everything. Keep copies of all test results. Email them to yourself. They matter when you investigate any future changes, and they may be required when you sell the property.
The Minimum Initial Panel
These are the contaminants every new well should test for, regardless of location.
Bacteria (coliform and E. coli): Run this independently of the driller’s test with a certified lab. The driller’s test and your independent test should both come back negative. Two independent negatives at the start give you a reliable baseline.
Nitrates: The EPA MCL for nitrates is 10 mg/L. Nitrates in new wells can come from agricultural runoff, septic systems, or naturally occurring geological sources. Elevated nitrates are a concern for infants under 12 months. See the nitrates in well water page for health information and risks.
pH: Water’s acidity or alkalinity affects its corrosivity. Low pH (acidic) water corrodes copper pipes and brass fittings, leaching lead and copper into the water. Normal range for drinking water is 6.5-8.5.
Hardness: Determines whether a water softener is worth considering and affects appliance longevity. Hard water above 180 mg/L (10.5 gpg) causes significant scale.
Iron and manganese: Both are common in most aquifers. Iron above 0.3 mg/L causes staining and taste issues. Manganese has a health advisory at 0.3 mg/L lifetime exposure, 0.1 mg/L for infants. See the manganese page for specifics.
Arsenic: The EPA MCL for arsenic is 10 ppb (0.01 mg/L). Naturally occurring geological arsenic is a real risk in specific regions. New Hampshire, Maine, Vermont, Massachusetts, and much of the Southwest (Arizona, Nevada, New Mexico) have documented elevated arsenic in groundwater. If you’re in any of these areas, arsenic testing is not optional. The USGS arsenic mapping shows regional risk by county.
Lead: New pump components, brass fittings, and pressure tank connections can leach lead, especially when water is slightly acidic. Test lead from a first-draw sample (water that’s been sitting in the pipes for 6+ hours overnight) to catch any contributions from your plumbing components.
Extended Panel by Risk Situation
The minimum panel covers what everyone needs. These additions apply based on your specific situation.
Near agricultural land: add nitrates (already in minimum panel), pesticides, and herbicides. Farm chemicals applied to fields above your aquifer can reach groundwater. This is especially relevant in the Corn Belt, the Central Valley in California, and the Mid-Atlantic coastal plain.
Near industrial areas or known Superfund sites: add VOCs (volatile organic compounds) and PFAS. The EPA’s ECHO database and your state environmental agency can tell you about industrial permits and contamination sites near your property.
Near military bases or airports: add PFAS specifically. AFFF firefighting foam used at military installations and commercial airports has contaminated groundwater at hundreds of sites across the country. PFAS testing requires specific lab protocols and costs more than standard panels, but it’s necessary near these facilities.
Near old mining areas: add a heavy metals panel covering arsenic (already in minimum), lead, cadmium, selenium, and manganese. Mine drainage is acidic and can mobilize metals that otherwise stay locked in rock.
Timing for the Initial Test
Collect your initial samples at least 2-4 weeks after the well is drilled and after any shock chlorination by the driller. Residual chlorine from disinfection during construction will produce a false negative on bacteria tests if you test too soon.
For lead sampling, collect a first-draw sample after water has sat in the pressure tank and new plumbing connections overnight (6+ hours without use). That gives you the worst-case lead reading from new components.
How to Find a Certified Lab
Use a state-certified lab, not a home test kit, for your initial panel. Search “EPA certified drinking water lab” plus your state name. Your state health department’s website usually has a list of certified labs with contact information.
Mail-in labs are also an option. The best mail-in water tests review covers several that offer comprehensive well water panels with proper sample collection materials and certified lab analysis.
The full initial panel for a new well typically costs $150-300 depending on which extended tests you add.
What to Do With the Results
File them. Email a copy to yourself with the date, lab name, and lab accreditation number. Compare them against EPA limits for each contaminant.
Any result above an EPA MCL requires action before using the water for drinking or cooking. The well water treatment pages cover options by contaminant. For arsenic specifically, see how to remove arsenic from water.
You’re drilling a new well for $15,000-25,000. A $200 initial test is the smallest and most important investment in the whole project.