Why October is the month to check a Tacoma sump
Western Washington's wet season ramps up in October and November, often with atmospheric rivers that drop days of heavy rain on already wet ground. Many Tacoma neighborhoods sit on glacial soils that drain slowly, and homes on hillsides or near the Puyallup River valley can see the water table rise quickly under a basement slab.
Two things go wrong at the worst moment:
- The primary pump has not run since spring. Floats stick, check valves seize, and a pump that hummed fine in April may not start in November.
- Power fails during the storm. Wind and saturated soil bring down trees and lines across Pierce County in the same events that fill sump pits. A pump with no power is a pit that overflows.
The checklist below covers both.
The one-hour sump pump checklist
- 1
Look at the pit before you touch anything
Remove the lid and check for silt, gravel or debris in the bottom of the pit, and anything that could jam the float: a cord loop, a zip tie, a sock. A pump sitting in silt overheats and clogs.
- 2
Check the power
The pump should plug straight into a GFCI-protected outlet, not an extension cord. Test the outlet with a tester. If the GFCI trips repeatedly when the pump starts, that is a sign the pump or its cord is failing.
- 3
Run the bucket test
Pour water slowly into the pit until the float rises. The pump should start, empty the pit to the shut-off level and stop on its own. Time it: a cycle that takes much longer than it did last year, or a pump that runs but does not lower the water, points to a clogged intake, a failing impeller or a stuck check valve. The full procedure is in how to test a sump pump.
- 4
Listen to the check valve
When the pump stops, you should hear the check valve close with a single thunk and the water in the discharge pipe should stay up. If water rushes back into the pit and the pump restarts on its own, the valve is leaking; replacing a check valve is a 30-minute job.
- 5
Walk the discharge line outside
Follow the discharge pipe to where it empties. It should drain at least 10 feet from the foundation onto ground that slopes away, and the end should be clear of leaves and soil. A discharge that dumps next to the house sends the same water back into the pit.
- 6
Test the backup
If you have a battery backup, unplug the primary pump and run the bucket test again to make sure the backup starts. Check the battery's age and the charger's status light; most backup batteries need replacing every few years. If you do not have a backup, read our battery backup roundup and the install guide.
- 7
Set up an alarm
A high-water alarm in the pit, or a leak sensor beside it that sends a phone alert, is the cheapest insurance you can buy. It tells you the pit is overflowing while there is still time to act.
Hillside homes and valley-floor homes need different things
Tacoma's terrain changes what a sump is up against. On the hillsides of the North End, West End and around the bluffs, the usual problem is water moving downhill through the soil after days of rain and arriving at the uphill wall of the basement. The sump runs hard during and just after storms, then quiets down. Here the biggest wins are outside: downspouts carried well away, a swale or drain that diverts surface water around the house, and a discharge that does not run back down toward the foundation.
On the flatter, lower ground toward the tideflats and the Puyallup valley, the water table itself can sit close to the slab for weeks in a wet winter. The pump may cycle steadily for days, which is exactly when a worn switch or a weak backup battery gives out. Homes like these benefit most from a cast-iron primary pump with a mechanical float, a backup that has been tested under load, and a high-water alarm, because the pump is doing real work for most of the season rather than a few hours after each storm.
Either way, write the date of each test on a strip of tape on the pit lid. It turns a vague "I think it works" into a record you can check.
Should a Tacoma home have a backup pump?
If the basement is finished, if the sump runs often during the wet season, or if your area loses power in windstorms, yes. You have two choices:
- Battery backup. Works anywhere, runs for a limited time on a charge, needs battery replacement every few years. See the best battery backup sump pumps.
- Water-powered backup. Runs on city water pressure with no battery, but needs adequate municipal pressure and uses water while it runs. It does not work on most private wells. See water-powered backups.
Size the primary pump to the lift from the pit to the discharge point; our sump pump sizing calculator does the math.
Signs it is time to replace the pump
Replace the primary pump if it runs but cannot keep up during a normal rain, if it trips the GFCI, if it is noisy or vibrates, or if it is old enough that you cannot remember when it went in. A failing pump in November is far more expensive than a planned swap in October; how to replace a sump pump covers the job and sump pump cost the budget. If the pump runs constantly even in dry weather, start with why a sump pump runs nonstop.
Frequently asked questions
How often should I test my sump pump?
At least twice a year, and always in early fall before the wet season. Pour water into the pit until the float rises and make sure the pump starts, empties the pit and shuts off. Test the backup the same day by unplugging the primary pump and repeating the test.
How long does a sump pump battery backup last during an outage?
It depends on the battery size and how often the pump has to run. A backup might last many hours with an occasional cycle, but far less when water is pouring in during a storm. Check the manufacturer's runtime figures and plan for the worst case, not the average.
Where should the sump discharge go?
At least 10 feet from the foundation onto ground that slopes away from the house, or into an approved storm connection where local rules allow it. Do not discharge into the sanitary sewer unless your utility permits it, and keep the outlet clear of leaves and soil.
My sump pump runs when it is not raining. Is that normal?
Some running after long wet periods is normal while the ground drains. Constant cycling in dry weather usually means a leaking check valve sending water back into the pit, a float set too low, or groundwater from a high water table. Start with the check valve; it is the most common cause.
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Tariq Hassan has run water damage jobs across Snohomish County for eleven years, from burst supply lines to sewage backups that need to be treated as the biohazard they are. He pulls wet insulation early because that is the difference between a drying job and a mold job.
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