Mount Vernon: the owner's line runs all the way to the city sewer

Updated October 30, 2026 · 3-minute read · Old House Sewer Lines

A Mount Vernon sewer lateral is the homeowner's responsibility for its full length, from the house to where it joins the city sewer. The city's sewer management plan states: "The city has no ownership or responsibility for individual sewer services. The property owner is responsible for their service from the property to its connection to the City sewer" (City of Mount Vernon CMOM plan). The plan, dated August 31, 2021 and updated April 2023, was filed in federal court.

The same document closes off one option owners sometimes hope for. "The City does not presently have a lateral replacement program. Laterals are the responsibility of the individual homeowner(s)," it says in Section 4a. A cracked, root-filled or collapsed line is a private repair, paid for privately.

How the city handles a blockage call

The Bureau of Sewers, part of the Department of Public Works, is "responsible for all aspects of our wastewater collection system except for treatment," according to the plan. When a resident reports a backup, crews check the city manholes. If flow is normal in both, the plan tells them to "notify the property owners that the problem is in their service lateral and to contact a plumber or sewer service contractor." The step-by-step logic is in main or lateral: who fixes a backup.

Plumbing work in Westchester needs a plumber licensed by the county Board of Plumbing Examiners. Whether Mount Vernon also issues its own plumbing licence was not confirmed; check with the city's Department of Buildings. Westchester plumber and contractor licences explains the county system.

The federal case and the storm sewers

Mount Vernon runs a separate storm sewer system of about 3,200 catch basins, about 525,000 feet of pipe and about 78 outfalls. In a consent decree the city admitted that untreated sewage has reached the Bronx and Hutchinson Rivers through those storm pipes, and at times still does (Consent Decree, U.S. v. City of Mount Vernon). The court granted summary judgment on liability on September 21, 2020. The decree was lodged on September 19, 2023, with a $100,000 civil penalty to the United States and a further $100,000 penalty to New York State whose payment is suspended (Federal Register notice).

The decree gives Mount Vernon a month from finding each illicit discharge either to stop it or to file an Illicit Discharge Action Plan with EPA and the state. The city's plan also lists the goal "Identify illegal sump pump connections." For owners, that makes a sump pump or roof leader tied into the sanitary line a live issue; see roof leaders and sump pumps in the sewer.

State money and the backflow pilot

In April 2022 the state, the city and Westchester County formed a $150 million partnership to update aging water infrastructure. As of April 15, 2025, the Governor's office reported sewer backups down 90 percent after 40 miles of cleaning and 10 miles of repairs (NY Governor's Office).

Alongside it, the state housing agency (its Office of Resilient Homes and Communities) spent $3 million on a "Healthy Homes" pilot. Two dozen low-to-moderate income houses in the city's worst backflow areas got backflow preventers on the sanitary line, better drainage and other fixes. The release does not say it pays for lateral repairs, and it describes no open application process. A backwater valve on a private line remains the owner's equipment.

Background

Mount Vernon sits in two county sewer districts, listed on the 2026 county tax schedule as the Hutchinson Valley County Sewer District and the Bronx River County Sewer District. Its wastewater goes to the county-run Yonkers Joint treatment plant. The plan says sewer use rates are set by the county Department of Environmental Facilities and billed directly to homeowners. Since 2010, county policy has required new developments in the city to remove 3 gallons of inflow and infiltration for every gallon of new flow from market-rate units, and 1 for 1 for affordable units.

Key facts

Homeowners carry the whole service line, out to where it joins the city system (Mount Vernon CMOM plan).
Mount Vernon has no lateral replacement program, per Section 4a of the same plan.
The Bureau of Sewers sits under the Department of Public Works and handles collection, not treatment.
Consent decree lodged September 19, 2023: $100,000 penalty to the United States (Federal Register).
A $3 million Healthy Homes pilot fitted backflow devices in 24 homes (NY Governor's Office).