Natick Water Hardness & Quality Report (2026)

The Natick Water Department serves approximately 37,000 residents across 21 square miles in Middlesex County, Massachusetts. The utility sources its supply primarily from local groundwater wells and surface water from Morses Pond, though the Morses Pond treatment plant is currently offline due to PFAS contamination. Daily pumping averages roughly 3.3 million gallons. Natick is actively considering joining the Massachusetts Water Resources Authority (MWRA) to supplement up to a quarter of its supply with treated surface water from the Quabbin Reservoir watershed, and treatment upgrades including granular activated carbon for PFAS removal are planned. Official water quality reports are available at natickma.gov.

The groundwater recharge areas underlying Natick sit within the Charles River Basin. Bedrock belongs to the Proterozoic Z metamorphic suite — including the Mattapan Volcanic Complex and Boston Bay Group sediments — overlain by Quaternary glacial till and outwash forming shallow aquifers. Prolonged subsurface contact with calcium and magnesium-bearing minerals in these formations, along with mineral leaching through the fractured Avalon terrane rocks, produces a hard groundwater character without the diluting effect of surface runoff.

Moderately hard water promotes scale buildup in water heaters, dishwashers, and washing machines over time, increasing energy costs. Faucet aerators and showerheads may clog, reducing flow. Monthly vinegar descaling of fixtures, annual hot-water system flushing, and drain screens help manage deposits. A water softener is recommended for households wanting to extend appliance life and improve soap efficiency. Natick's tap water has five contaminants flagged above EPA health-based guidelines — primarily PFAS detected across all local sources — driving both the Morses Pond shutdown and the planned MWRA integration; filters are recommended for vulnerable groups.