Water filter service in Greenwich, CT

What is in the water in Greenwich

Greenwich is served by Aquarion Water Company of Connecticut, Greenwich system .

Source water: A blend of surface sources inside the town and beyond it. The Putnam and Rockwood reservoirs, the Bargh and Brush reservoirs and the Mianus River lie within Greenwich, supplemented by the Laurel and North Stamford reservoirs in Stamford. Water is pumped from Bargh into Rockwood and then into Putnam. The Bridgeport, Stamford and Greenwich systems are interconnected, so the water in a Greenwich tap did not necessarily fall on Greenwich. The system dates from 1857 and serves roughly 53,000 people. Putnam Reservoir also supplies water across the state line: it provides 65 per cent of the water in one of the Westchester rate districts in New York. Reported by Connecticut Department of Public Health for 2004.

Reservoir water is coagulated, filtered through sand and chlorinated at the final stage, and the chemistry is adjusted to hold back the corrosion that would otherwise draw lead out of household plumbing. The hydraulics are the unusual part in Greenwich. Water is pumped from Bargh up into Rockwood, and Rockwood then feeds Putnam, so the town's supply moves uphill through a cascade of reservoirs rather than arriving by gravity from a single upland store. Putnam then exports: it provides 65 per cent of the water in one of the Westchester rate districts over the New York line. Greenwich is therefore a net supplier to another state while its neighbour Stamford is a net importer from one, and the two towns sit either side of that trade on the same company's network.

These figures describe the distribution system. Your own tap can differ, and for lead it very likely does.

We do not yet hold a sourced figure for every field on this page. Where something is missing it is left blank rather than estimated, because an unsourced number here would look like information.

Buildings and plumbing in Greenwich

Connecticut utilities had to submit service line inventories to the state under the federal Lead and Copper Rule Revisions, and the company's address level lookup covers Greenwich. Two things about the housing here change the arithmetic. Lots are large, so the private run from the curb stop to the house is often much longer than in a dense town, and contact time is what determines how much a lead or galvanised line contributes. And a long private line is the owner's to replace, which makes the length a cost as well as a risk. Establish the recorded material for both sides of the curb stop before deciding between a point of use filter at the kitchen tap and a whole house approach.

What this means in practice

• Chlorine and chloramine taste. Confirm with free and total chlorine test strip, plus the utility report for the disinfectant type.
• Lead in drinking water. Confirm with certified laboratory analysis of a first-draw tap sample.

What these figures mean for filter choice

Lead is a plumbing question rather than a supply question in Greenwich, as it is everywhere. What that means practically is that a filter certified under NSF/ANSI 53 for lead at the tap you drink from sits downstream of the entire problem, whereas a whole-house filter at the point of entry sits upstream of nearly all of it and costs several times more.

Filters that apply here

• Lead reduction filters. Point-of-use filters certified for lead under NSF/ANSI 53.
• Under-sink carbon filters. A carbon block cartridge on the cold line under the sink.
• Reverse osmosis, tank. A membrane system under the sink that produces treated water to a dedicated tap and stores it in a small pressure tank.
• Whole-house filtration. A filter plumbed into the main line where water enters the building, so every tap, shower, and appliance downstream is fed treated water.
• Sediment filters. A mechanical filter that captures sand, silt, rust flakes, and other particles.

Installation in Greenwich

• Free water testing. Typically 45 to 60 minutes.
• Whole-house filter installation. Typically 3 to 5 hours.
• Under-sink reverse osmosis installation. Typically 2 to 4 hours.
• Repair, any brand. Typically 1 to 3 hours.

Renters, co-ops, and businesses

• Options for renters
• Co-ops and condos
• Offices and commercial sites

Nearby areas

• Stamford, CT , Western Connecticut Planning Region
• Danbury, CT , Western Connecticut Planning Region
• Bridgeport, CT , Greater Bridgeport Planning Region

Sources

• Aquarion Water Company, 2025.
• Aquarion Water Company, 2024.
• Connecticut Department of Public Health, 2004.
• Population: US Census Bureau sub-county population estimates, Vintage 2024 (POPESTIMATE2024).