Sewage Backup Cleanup in Brooklyn

Local conditions

Why Brooklyn cellars take the sewage backup

Brooklyn is party-wall territory — attached brownstones and row houses — and that changes the job. Water in one brownstone does not stay in one brownstone, so the first thing we do on a row-house loss is meter the neighbors before anyone starts drying. Red Hook, Gowanus, and the Columbia Street waterfront sit at or near the surge line and flooded severely in Sandy. Cellar-level commercial space along the avenues carries the same below-grade exposure as residential, usually with far more inventory sitting directly on the slab.

The combined sewer, and what surcharge means in your cellar

Most of Brooklyn sits on a combined sewer system: a single pipe carrying household wastewater and street stormwater together. On a dry day it handles the sanitary flow with room to spare. In a heavy downpour, run-off pouring in through every catch basin on the block arrives faster than the pipe can move it, and the main surcharges — it fills completely and goes under pressure instead of flowing.

Pressurised sewage looks for the lowest opening connected to that line, and in a row house that is not the street. It is the cellar floor drain, the basement toilet, the laundry sink or the shower pan in the below-grade apartment. Nothing in your building has failed. The street is simply fuller than the pipe, and your cellar is the relief valve. That is also why so many of these calls arrive in the same hour across a whole neighbourhood.

Some of that overflow is designed to discharge to the waterways rather than into buildings — the combined sewer overflow outfalls along the Gowanus Canal and Newtown Creek exist for exactly that reason. What reaches a cellar is the part the system could not relieve fast enough, and it is the same untreated mix.

House traps, backwater valves and cellar floor drains

• The house trap

  A U-bend on the building drain, usually at the front wall of the cellar, fitted as standard in older New York buildings. It catches grease, wipes and root debris, and a blocked one backs the whole building up on a dry day with no rain involved at all. Plumbers find it first for a reason.

• No backwater valve

  A backwater valve is a one-way flap on the building drain that closes when the main tries to push back. A large share of pre-war Brooklyn stock does not have one, and on a fixture below street level it is the single most effective thing that can be fitted after the fact. We do not install them, but it is the conversation to have with your plumber once this is cleaned up.

• The cellar floor drain

  The lowest opening in the building, and the first place a surcharge shows. It often gives warning: a gurgle when a toilet upstairs is flushed, or a sewer smell in the cellar days before any water appears. Both are worth acting on.

• Roots and old laterals

  Street trees on a Brooklyn block are older than most of the plumbing they grow next to. Root intrusion into a clay lateral is a slow blockage that behaves like a capacity problem until someone puts a camera down it.

Sewer backup on your line, or on the city main?

The practical test on arrival is simple. One fixture backing up in one building is almost always a blockage on that building drain. Several fixtures at once, or the whole block at once, points at the sewer main in the street. That distinction decides who fixes the cause, who is likely to pay, and whether it is going to happen again the next time it rains.

It matters for a second reason too. Sewage spills that come off the public main are a different conversation with your insurer and with the City than a sewage problem that starts at your own house trap, and property owners who establish which one it was on day one have a far easier time later.