Short answer: in New Jersey a sump pump may not discharge into the sanitary sewer or a floor drain that goes to it. The standard first choice is an absorbent surface such as grass, mulch, rock or soil, placed far enough out that the water disperses rather than running back to the foundation. Anything beyond that is set by your town, and a discharge onto a neighbor's property is prohibited.
A discharge line is one of the most overlooked parts of a sump system. When it freezes or ends in the wrong place, the pump keeps running and the basement it was meant to protect floods anyway.
Where it can never go
The sanitary sewer answer is settled statewide. New Jersey's capacity assurance rules name disconnecting sump pumps and roof leaders from sanitary sewer lines as a required strategy for systems under pressure. Clean groundwater is not sewage, and the sewer system is not sized to treat it.
The floor drain is the nearest hole and the one that gets people in trouble. A floor drain usually goes to the sanitary sewer, so putting clean groundwater down it is prohibited. It is also how a basement takes on sewage during the same heavy storm the pump exists for.
Where it can go
- An absorbent surface. Grass, mulch, rock or soil, far enough from the house that the water soaks in instead of running back toward the foundation or off the property.
- A storm sewer. Usually allowed, usually by permit, and usually only where an absorbent surface is genuinely not feasible.
- Never onto a neighbor's property. Discharge directed onto adjacent land so as to damage it or create a nuisance is prohibited, and it is one of the most common reasons these end up in front of a town official.
Municipal rules decide the details, including who approves the discharge point, so confirm yours before you bury anything. The town can also require a discharge to stop icing the sidewalk or street, even if it has run the same way for years.
Why discharge lines freeze
- The line is too shallow or has no fall. Standing water after each cycle is what freezes. A line with real fall drains itself.
- It ends at grade. An outlet flush with the ground silts in, ponds, and caps itself with ice.
- It runs too long above frost depth. Every foot above frost is a foot that can freeze.
- It discharges where the water comes back. Water put out on ground that slopes toward the house is water you will pump again.
A pump that cycles every few seconds with the pit still full is usually pushing against a plug of ice in the discharge line. Check the outside end of the line before replacing anything, because a pump running against a closed pipe can burn out.
We do not replace sump pumps. The pump, pit and check valve are a plumber's work. We do everything outside the house: re-routing and burying the discharge at proper depth and fall, drywells and rock pits, regrading so the water does not come back, and a storm connection where the town permits one. Our sump pump discharge page has the details.
Common questions
Can a sump pump discharge into the sanitary sewer? No. This is settled statewide. The sanitary sewer is not meant for clean groundwater, and state capacity rules name disconnecting sump pumps as a required strategy.
Can it run across the sidewalk or into the street? Generally not without permission. A discharge that creates icing, standing water or algae on a sidewalk, street or right-of-way is a violation in its own right.
My discharge has run the same way for twenty years. Is it grandfathered? Conditionally. An existing discharge can usually stay only while it causes no public nuisance and no icing, standing water, algae or erosion on the street, sidewalk or right-of-way. The first winter it ices the sidewalk, the owner has to bring it into compliance.
The town sent me a notice about my discharge. What now? Read which part it cites. One problem is the connection, meaning where the pipe goes. The other is the effect, meaning icing, ponding or erosion on public land. Both need an answer.
How deep should a discharge line be buried? Deep enough to have fall the whole way and to keep standing water out of the freeze zone. It depends on the run, the outlet and the ground, so it is worth having the outside end walked before anything is dug.
Still not sure how this applies to your property? That is what a free on-site estimate is for. Call 862-268-2510 or tell us what is going on, and we will give you a straight answer, including when the answer is that you do not need us.
