Drinking water quality
Your water utility tests at the source, not at your tap. The last 50-200 feet between the city main and your kitchen sink is where most issues show up — lead service lines, copper pipes, old fixtures, well-water bacteria, well-water nitrate, PFAS from a hyperlocal source.
The two-sentence summary
Public water utilities meet the EPA Safe Drinking Water Act standards at the point of distribution — they have to. The analytical questions that matter to you mostly concern what happens in the plumbing and fixtures downstream of that point, plus emerging contaminants the SDWA is still catching up to (lead-and-copper rule revisions, the 2024 PFAS NPDWR).
First-draw vs flushed: why the order matters
First-draw means the first water that comes out of the tap in the morning, before anyone has run it. It's the most-sensitive sample for detecting metals leaching from interior plumbing or fixtures (lead in solder, copper in pipes, zinc).
Flushed means water collected after letting the tap run for 30+ seconds. It bypasses interior plumbing contamination and is the most-sensitive sample for detecting what's coming from the service line or the city main.
Many home tests omit the first-draw sample. Don't trust a water report that didn't take both.
What we test, line by line
Lead
EPA action level: 10 µg/L (revised 2024, previously 15 µg/L). Sources: interior plumbing solder (pre-1986), lead service lines (pre-1986), brass fittings. See the lead deep dive.
Copper
EPA action level: 1.3 mg/L. Sources: copper pipes under acidic conditions. Indicator of corrosion that may also be releasing lead from solder.
Iron + Hardness
Not health-driven thresholds (these are aesthetic / nuisance regulations: 0.3 mg/L iron, 120 mg/L hardness). We test them because they predict whether you need a water softener and whether the corrosion picture explains lead/copper findings.
Total coliform / E. coli
Coliform bacteria detected in 100 mL = failed. E. coli detected = unsafe (presumptive fecal contamination). This is the screening test that matters in private wells, and in public-water buildings with extended low-use periods (vacation rentals, second homes).
Nitrate / Nitrite
EPA MCL: nitrate 10 mg/L (as N), nitrite 1 mg/L. Sources: agricultural runoff, septic systems, fertilizers. The clinically critical case is methemoglobinemia in infants ("blue baby syndrome"). Test if you're pregnant or have an infant on formula and you're on a private well in an agricultural area.
pH
Not a regulated MCL. We test it because it predicts whether your water is corrosive enough to leach lead and copper from interior plumbing.
PFAS (per- and polyfluoroalkyl substances)
The 2024 EPA Final National Primary Drinking Water Regulation for PFAS set enforceable maximum contaminant levels:
| Compound | EPA MCL |
|---|---|
| PFOA | 4.0 ng/L |
| PFOS | 4.0 ng/L |
| PFHxS | 10 ng/L |
| HFPO-DA (GenX) | 10 ng/L |
| PFNA | 10 ng/L |
| PFBS + PFHxS + PFNA + HFPO-DA | Hazard Index ≤ 1 |
Public utilities have until 2027 (compliance monitoring) / 2029 (treatment compliance) to meet these. Until then, if you're near a known PFAS source (industrial site, military base, fire-training site) or your utility's last public report showed detectable PFAS, point-of-use treatment (carbon block filter or reverse osmosis) is the only way to be sure right now.
Our PFAS panel uses EPA Method 537.1 / 533 at a PFAS-capable ELAP-accredited lab. PFAS samples must be collected in PFAS-free containers; we supply.
Private wells
Private wells aren't regulated by the SDWA — testing is on you. At minimum, we recommend annual testing for total coliform + E. coli + nitrate. Lead, arsenic, radon-in-water, and agricultural runoff (pesticides) are worth testing periodically based on your area.
When to test
- Pre-1986 service line OR pre-1986 home plumbing.
- Private well, especially before pregnancy or with an infant in the household.
- You live near a known PFAS source (industrial site, military base, fire-training facility, landfill).
- Unexplained GI symptoms in multiple household members.
- Pre-purchase, especially for a well-water property.
- You recently changed water source (moved, well rehab, city main work in the street).
When NOT to test (yet)
- You've had a clean utility report in the last 12 months, your home is post-1986, you're on the city main, and you don't have a specific concern. The marginal value of a generic panel is low.
- You just installed a new water softener / RO filter / carbon block. Wait 30 days for the system to equilibrate before testing.
Selected references
- EPA. Final PFAS National Primary Drinking Water Regulation. April 2024.
- EPA. Lead and Copper Rule Revisions. 2021; additional 2024 amendments.
- EPA. Drinking Water Standards and Health Advisories Tables. Updated annually.
- CDC. Methemoglobinemia and infant nitrate exposure. MMWR.
- NIH. Per- and polyfluoroalkyl substances and human health. Environmental Health Perspectives 2022.