Resources

Understanding your water, in plain language

A few explainers on the topics that come up most often when neighbors reach out to us.

Is the Naval Air Station PFAS site in my tap water?

No. The severe PFAS groundwater contamination at the former South Weymouth Naval Air Station (tens of thousands of ppt in 2018 on-site sampling) is under federal Superfund cleanup and sits in a different aquifer area than the Mill River wells and Great Pond reservoir the Weymouth Water Department actually uses. The town's own supply tested ND–11.4 ppt for combined PFAS6 in 2025 — well under the state's 20 ppt limit.

How to read your CCR

Every water utility publishes an annual Consumer Confidence Report listing every contaminant it tested for, the detected range, and the legal limit. Watch for the difference between a primary standard (MCL, health-based and enforceable), a secondary standard (SMCL, aesthetic and non-enforceable), and a guideline like MassDEP's ORSG (non-enforceable) — Weymouth's own report uses all three.

Private wells

If your home is on a private well rather than the Weymouth Water Department system, none of the municipal testing above applies to you directly. Massachusetts DEP recommends private well owners test independently, since well water isn't subject to Safe Drinking Water Act monitoring requirements.

Should you filter your water?

Weymouth's own supply currently tests clean on the measures that matter most, but a household-level filter can still make sense — especially if your service line's material is still listed as "unknown" in the town's 2024 inventory, or if you simply want an extra layer of certainty while the town's MWRA connection project plays out over the next several years. A few reasonable options, matched to what's actually shown up in this system's own testing data:

Activated carbon filtration

Effective against chlorine taste and odor, many disinfection byproducts, and some PFAS compounds, depending on the specific carbon media and contact time. Common in pitcher filters, faucet-mount units, and whole-house systems.

Reverse osmosis

The most thorough household option for PFAS, sodium, and a broad range of dissolved contaminants. Typically installed under a kitchen sink for drinking and cooking water specifically — a reasonable choice if you're on a sodium-restricted diet given Weymouth's elevated sodium readings.

NSF/ANSI 53 or 58 certified filters

Look for filters independently certified for PFOA/PFOS reduction specifically (NSF/ANSI Standard 53 or 58), rather than taking a manufacturer's general "removes contaminants" claim at face value. If your service line is listed as lead or unknown, look for NSF-certified lead reduction as well.

Not sure where to start? A free household water test is the easiest way to figure out whether filtration makes sense for your specific home, and if so, which approach fits.

Further reading