Water Filtration in Portsmouth, NH

What the city says about its supply

According to the Water Division's 2024 quality report, about 63 percent of the supply comes from the Bellamy Reservoir in Madbury and Dover, and the remaining 37 percent from groundwater wells in Madbury, Greenland and southern Portsmouth. Treatment includes coagulation, dissolved air flotation and filtration, followed by disinfection with sodium hypochlorite.

Fluoride, a corrosion inhibitor and pH adjustment are added too. The report lists every regulated result, and it shows lead at a 90th percentile of zero parts per billion against a federal action level of 15. Chlorine residual ranged from 0.26 to 1.7 parts per million, well beneath the 4 ppm limit.

Why some households still want a filter

Meeting a standard does not guarantee the water tastes the way you prefer. Chlorine residual keeps the distribution pipes protected between plant and tap, and some people notice it in the first sip or a morning coffee. Carbon filtration handles that well and is among the simpler upgrades.

The city also reports detecting PFAS compounds in some groundwater wells, below state limits, and it is designing treatment upgrades at three of them. If that concerns you, a kitchen-tap filter certified for PFAS reduction is a reasonable topic to raise. Look for independent certification instead of relying on packaging claims.

Hardness, scale and your plumbing

Hardness shifts with the blend of sources reaching your street. If scale builds up on fixtures, a test strip makes a quick start and a lab report is better. A softener belongs in the plan only when the numbers justify one, and water softener installation Portsmouth homeowners consider should include a drain connection, a bypass and a plan for where the brine goes, which matters in houses on septic.

Older galvanized or heavily scaled copper lines deserve a look first. Connecting new equipment to brittle pipe can start leaks that were not there before.

Choosing between filter types

Sediment filters trap sand and rust flakes. Carbon block or granular carbon reduces chlorine, taste and many organic compounds. Reverse osmosis units polish drinking water at one tap and remove a wide range of dissolved substances, though they send some water to the drain. Ultraviolet lamps address bacteria in wells but do nothing for hardness or iron.

Each type solves a narrow problem, which is why stacking equipment without a diagnosis tends to waste money. For city water, a carbon stage and a sediment stage often cover everything a household notices. For wells, the list gets longer and the lab report decides it. A plumber Portsmouth NH sets the sediment stage and carbon at the main line, sized to the household.

Private wells in Rye and the outlying towns

New Hampshire's environmental agency urges private well owners to test their water regularly, since bedrock wells in the state can carry arsenic, radon or uranium, and the Seacoast has seen PFAS in some private wells. Treatment for those problems is specialized and begins with a result from an accredited laboratory, never a guess.