Damaged Central Ave Sewer Line Update

In April I was appointed to be Commissioner of the Department of Public Works. I have more than 40 years of construction experience and aware that there are accepted engineering methods available to repair sewer infrastructure located beneath or adjacent to existing structures. As the Commissioner of Public Works and as a taxpayer, I believe the Town must fully evaluate these repair options before proceeding with what is now estimated to be a $24 million public sewer project with an additional cost to the 100 East Hartsdale Avenue Building owners of approximately $600,000.

Yesterday I received what could be very good news regarding the ongoing sewer emergency at 100 East Hartsdale Avenue. Recent high-resolution sewer inspections have produced important new information about the location and condition of the damaged sewer line, which may change the scope, cost, and overall approach to the project.

In May 2024, the Town received a report that sewage was entering the garage at 100 East Hartsdale Avenue and the Water Department responded. The Town attempted to clear the sewer but was unable to clear the blockage. An investigation determined that a brick manhole located in front of the building had collapsed. The manhole is connected to a 16-inch sanitary sewer line that runs beneath the building and parking garage. The collapse occurred shortly after Con Edison performed gas work and excavation activities in the immediate area.

Following the collapse, the Town attempted to clean and inspect the sewer line with CCTV equipment. However, due to heavy blockages and debris, the Town was unable to confirm the exact location or extent of the failure. To maintain sewer service, the Town installed emergency temporary bypass pumps, which remain in operation today. These pumps have required continuous maintenance and repeated emergency repairs due to pump failures at a monthly cost of approximately $240,000 - $260,000. To date, the Town has spent approximately $5.5 million on bypass pumping operations.

Because the original camera footage was unclear, the Town’s consulting engineer assumed the sewer failure was located beneath or immediately next to the building foundation. Based on that assumption, a sewer reroute project around the structure was proposed. That plan involves difficult excavation between buildings, limited site access, easements, and the reconnection of private sewer laterals in the 100 East Hartsdale Avenue building to a new public sewer main. The reroute project, originally estimated to cost $7-12 million, is currently estimated to cost between $24 million and $29 million, while also requiring the building owner to spend approximately $600,000 to extend and connect the private sewer connections to the public main.

In order to determine where the break was, I had a specialized sewer inspection contractor clean and inspect the line. Last week, the contractor successfully cleared the sewer and recorded new high-resolution CCTV footage. The footage we received Friday confirms that the sewer pipe beneath the building remains in generally good condition and that the damaged section is located beneath the front sidewalk approximately 7-9 feet from the collapsed manhole. The sewer line beneath the building and parking garage has not failed.

Yesterday, Town staff met with the Town’s emergency contractor and a secant pile specialist after they reviewed the footage. During that meeting, they confirmed that a secant pile system appears capable of allowing the damaged section of pipe to be safely exposed and repaired in place while minimizing impacts to adjacent structures, groundwater conditions, and neighboring properties.

A secant pile system is a specialized construction method that creates a reinforced underground retaining wall using overlapping concrete piles drilled into the ground with minimal vibration. This approach allows excavation work to occur safely in tight urban areas and near existing structures while controlling soil movement and groundwater infiltration.

Based upon this new information, I have directed DPW staff to pause additional sewer reroute design work until the repair-in-place option is fully evaluated.

An in-place repair offers major advantages. It would be millions less, faster to complete, and far less disruptive to residents, businesses, and surrounding properties. And because the existing private sewer laterals (the pipes that connect the building’s internal plumbing system to the public sewer main) would remain undisturbed, the building owner would avoid the estimated $600,000 cost for extending those connections. Board of Health approval would also not be required.

Additional high-resolution CCTV inspections are scheduled for this week to inspect the sewer line between 120 and 100 East Hartsdale Avenue to further evaluate the overall condition of the line.

Many of the questions submitted for tonight’s meeting were based on the previously proposed sewer reroute plan, which is on hold while the Town completes additional camera inspections and evaluates the newly identified repair-in-place option. We understand the community’s interest and concerns regarding the reroute, and if, after a full evaluation, the Town determines that a reroute remains the appropriate course of action, we will address those questions in detail at that time and provide the necessary information to residents.

DPW will continue to provide updates following receipt and review of the additional inspection footage.

Respectively,
Frank Morabito
DPW Commissioner/ Building Inspector