Sump pumps remove unwanted water, such as surface or ground water that leak into a building. A sump pump is normally installed in a pit at the low end of a basement or crawl space floor or in another location where water needs to be removed such as in a boiler pit or an outdoor well pit.
Sump pumps on newly constructed buildings are often connected to the building foundation drain. We consider this a bad practice. It is a rare home more than 20 years old whose footing drains are intact.
If a footing drain discharge itself becomes clogged or damaged, sending the sump pump discharge into that system will not work: you'll simply flood another section of the building foundation, basement, or crawl space, or you may overload the existing foundation drain causing building water entry.
Connecting a sump pump to a municipal sewer drain is bad practice and illegal in some communities. You're adding to the municipal sewer plant's water overload during wet weather and you may thus be contributing to the discharge of raw sewage from the overloaded municipal treatment facility right into the environment.
Where permitted, we prefer to route a sump pump to a storm drain, or where soil conditions permit it might be discharged to a drywell.
Sump pump inspection list
GFCI protection: Is the sump pump connected to a GFCI-protected electrical circuit or outlet? According to some writers a sump pump should be connected to a GFCI circuit.
But we find that wet locations sometimes keep tripping off the GFCI - a safe condition, but it means the building is likely to become flooded because the circuit powering it has shut down. Some writers and electrical inspectors make an exception to the more general GFCI-requirement rules for sump pumps.
Water or Sump Pump Alarm protection: where a sump pump is relied-upon to keep water out of a building, good practice includes an alarm to inform someone when the pump is not operating. Various systems use a detector which senses water on a building floor near the sump pump.
Water alarms can sound an alarm to building occupants, turn on a light in a window for a neighbor to see, notify a security service, or even place a telephone call to report this condition. We recommend this protection for any building which is left unattended for long periods.
Battery backup sump pump systems: in areas prone to power failures the sump pump may be a battery-backup installation. The batteries are connected to a charging system and are available to operate the pump when area electrical power has been lost.
Turn off the electrical power to the charger and confirm that the pump is running on battery power. Review the specifications for the system to determine whether or not the pump may be able to continue to operate on battery power for the typical length of time that electrical power is lost.
Mechanical security: If a pedestal sump pump is installed, is it secured against tipping over? A tipped pump will jam its float and stop working.
Motor switch & Electric Motor: Does the pump's electric motor turn on in response to the float?
Pump impeller assembly: does the pump actually move water when the motor runs? Impellers can and should be cleaned of dirt, pebbles, and mineral deposits to keep the pump operating efficiently.
Check valve: is a check valve installed on the sump pump discharge line? If not water will run back into the sump pit each time the pump shuts off.
This defect causes extra cycles of pump operation and may reduce pump or switch life; in odd circumstances such as a sump pump discharge line into a stream, it can even back-siphon outdoor water into the sump pit and into the building.
Discharge line security: sump pumps cause a sudden surge in water through the discharge pipe when the pump comes on.
Many sump pump installations use a flexible discharge pipe which is not adequately secured. As a result, each time the pump cycles on and off the flexible discharge pipe jerks and moves across various contact surfaces. We've seen this result in holes worn into the discharge pipe so that each time the sump pump cycled on it sprayed water across the basement.
Trip hazards: Is the sump pit protected against someone tripping or falling into it?
If radon is a problem in the area, is a radon-cover installed over the sump pit?
Sump Pump pit openings: Is the sump well or bucket properly opened to permit ground water to enter the pit directly? Our first home had a basement sump pump installed in a water tight steel bucket the builder had pushed through the basement floor.
Water had to rise under the basement floor, leak into the basement, run across the floor, and then be pumped away. Making holes in that bucket allowed the pump to draw water from below the basement slab. It lowered the water table and stopped water from entering the basement through the foundation walls.
Sump pump water destination: is the pump delivering water to a legal destination and one which will not send water flowing back towards the building? Water should be discharged no less than 20 ft. from the building and to a spot which drains away from the building.
We discuss sump pump discharge routing at Sump Pump Discharge
In a bad building water entry situation water runs across the basement/crawl space floor into the sump pit where it is pumped away (after already wetting the building and inviting a mold contamination problem).
This condition pertains when water is entering a building through foundation walls, often because the roof drainage or surface runoff are directed right against the building foundation itself. Keeping gutters and leaders working and correcting outside drainage errors are critical in keeping water out of a building. Doesn't it make more sense to prevent water from coming into a building than to let it in and then pump it out?
In a good situation, openings in the sides and bottom of the sump pit, or an under-floor drainage system direct subsurface water into the sump pit before the ground water level rises enough to send water into the building. Over several years of operation, and partly by pumping a little soil silt as it operates, a sump pump may actually improve the flow of under-floor water into the sump pit, thus reducing building water entry.
Continue reading at SUMP PUMP TYPES or select a topic from the More Reading links shown below.
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