Whether a Westport house is on the town sewer or a private septic system affects what it costs to own and what you can build. The rule of thumb is geographic. Sewer service is available in many parts of town, but as a rule it is not available north of the Merritt Parkway, according to the town’s Engineering Department.
How to check a specific house
The town’s online map has a layer showing which properties are on sewer. The seller’s condition report and the listing should also say. If the house is on septic, ask for pumping and inspection records.
Life on the sewer
The town’s Water Pollution Control Facility at 4 Elaine Road serves the sewered part of town through 17 pump stations and 117 miles of pipe. Owners pay a sewer use charge based on water consumption from November through March, multiplied by 2.4, billed on the same quarterly schedule as property taxes.
The system was tested on Sept. 13, when pump stations flooded and inflow to the plant reached about 12 million gallons a day against a usual flow of about 1.75 million, according to 06880.
Getting sewer where there is none
Sewer lines are extended only when a majority of the owners between the existing sewer and the end of the proposed line petition for it, and the cost is assessed to the properties served. A 2023 proposal for 37 homes on Whitney Street, Roseville Road and Ledgemoor Lane projected about $50,856 per home, or $1.88 million in all, the Westport Journal reported.
Life on septic
On septic, the system sets limits. Adding a bedroom, an addition or a pool triggers review by the Aspetuck Health District, based on Bayberry Lane, under the state’s B100a rules. The owner has to show room on the lot for a complete replacement system, with at least three test pits about seven feet deep and a percolation test.
That matters most to buyers planning to expand. A house that can never add a bedroom is a different investment from one that can. Commission the testing during your contract period. Our guides to rebuilding and accessory apartments explain where septic capacity becomes the deciding factor.
Sources
- Town of Westport, Engineering Department, accessed Oct. 2026
- Town of Westport, Water Pollution Control Facility, accessed Oct. 2026
- Westport Journal, Largest fees in pipeline for Whitney, Roseville, Ledgemoor sewers, Feb. 10, 2023
- 06880, Coverage of the Sept. 13, 2026 flood, September 2026
- Aspetuck Health District, B100a information sheet, September 2025
