High-Capacity Sump System, Truro

Truro is a different problem

Truro sits at the head of the Bay of Fundy, where the Salmon and North Rivers meet the highest tides on earth. When a high tide coincides with heavy rain or spring runoff, the rivers cannot discharge and the floodplain does what floodplains do.

That means sump systems here are not managing nuisance seepage. They need capacity sized for genuine volume, and they need to work when the power is out and the ground outside is already saturated.

What was wrong with the existing setup

Four things, and each of them is common.

An open pit. No lid. A continuously evaporating pool of groundwater inside the basement, contributing directly to the humidity the homeowners were fighting.

No check valve. Every time the pump shut off, the column of water sitting in the discharge pipe ran straight back down into the basin. The pump refilled, restarted, and lifted the same water again. That is the short-cycling they had been hearing, and it was steadily consuming the pump’s service life.

Discharge too close. The line ended about two feet from the foundation, putting the water straight back into the saturated soil the system was trying to relieve. The pump then removed it again.

No backup. The storms that flood this property are the storms that take out the power.

What was done

A sealed basin with a gasketed access lid, ending the open-pit humidity source. A cast-iron primary pump sized against total dynamic head, the actual lift and run length, rather than by horsepower on the box.

A check valve on the discharge to stop backflow. A freeze-relief fitting on the exterior line, so that if the outdoor end ices closed in winter the pump has somewhere to push rather than dead-heading against a block of ice until the motor burns out.

A battery backup pump mounted above the primary on its own float switch, wired to a deep-cycle battery on a maintainer, with an alarm.

The discharge was rerouted 9 m out onto grade falling away from the house.

Result

The pump cycles normally instead of continuously, and the system has multi-hour capacity without grid power.