A sump pump is a simple machine with one job, and it fails at the worst possible time because the worst possible time is when it’s working hardest. The storms that raise the groundwater are the same storms that knock down DTE lines. In Oakland County, with a lot of mature trees over a lot of overhead wire, that happens more often than people expect.
This page is about the pump, the pit and the pipe, the backup that keeps going when the power doesn’t, and how a sump fits with the other thing that floods south Oakland basements, the sewer.
Pits, pumps and the parts that actually fail
The pit is a plastic liner set in the floor at the low point, with the footing drain feeding into it. We use a sealed lid on every pit we set. It keeps radon and the damp smell down, keeps kids and pets out, and keeps junk from falling in and jamming the float.
For the pump itself we use a cast iron submersible with a vertical float switch. Cast iron sheds heat better than plastic when the pump runs a lot, and a vertical float doesn’t hang up on the side of the pit the way a tethered float can. Pump size depends on how much water comes in and how high it has to lift it, and a basement in Waterford next to a lake needs a different pump than one in Troy that runs twice a year.
What fails, in our experience, is rarely the motor first. It’s the float, stuck or worn. It’s the check valve, the one-way valve on the discharge pipe that keeps the water in the pipe from falling back into the pit; when it fails the pump short-cycles and wears out. It’s a pipe glued in without a union so nobody can pull the pump to service it. And it’s the discharge freezing.
Discharge lines and January
The discharge pipe leaves the house, usually through the rim joist, and runs out to the yard. In a Michigan winter, water left in that pipe outside freezes, the pump keeps pushing against a plug of ice, and either the motor burns out or the water backs up into the basement.
We slope the outside line so it drains between cycles, and we put a freeze guard on it near the house, a fitting with an opening that lets water spill out at the wall if the line beyond it is frozen. That’s not a perfect answer, since water at the wall isn’t where you want it, but it’s a lot better than water on the basement floor. Where the yard allows, a buried line below frost to a pop-up emitter is cleaner.
The sump that runs all spring
Around the lakes in the northwest part of the county, Union Lake, Walled Lake, the Waterford chain, Orion, the water table rides close to lake level. When the lakes come up in April, so does the water under the basement floor, and a sump there can cycle every few minutes for weeks. That doesn’t mean it’s broken. It means it’s the only thing between the groundwater and your floor.
For those houses we use a heavier pump, set the float so it doesn’t short-cycle, and check that the discharge isn’t landing somewhere that just soaks back to the footing. On a sandy lot that’s an easy mistake, and the pump ends up circulating the same water all day.
Backups for when DTE goes down
On February 22, 2023, an ice storm knocked out power to more than 600,000 DTE customers, and some Oakland County homes went four days or more before the lights stayed on. Summer thunderstorms do the same on a smaller scale, and they bring rain with them. Ice storms at least come when the ground is frozen; a July storm cuts the power just as the water arrives.
There are two kinds of backup we install, and they’re good at different things.
Battery backup. A second pump in the same pit, run off a deep-cycle battery with a charger. It kicks in if the main pump fails or the power goes out, and most units sound an alarm. The limit is the battery. A battery backup can carry a moderate pit through a night or two, but on a lake lot pumping hard it may run down before DTE gets to your street.
Water-powered backup. It uses city water pressure to pull water out of the pit, no electricity needed, and it runs as long as the city water is on. It’s the best backup for long outages. It doesn’t work on a private well, because a well pump needs power too, and that rules it out for a lot of houses up north in Independence and the rural townships.
Some houses get both. A backup of some kind on every system we install is our default, and we’d push back if someone wanted to skip it.
When the water is coming from the sewer instead
A sump pump handles groundwater. It does nothing about sewage coming up through a floor drain, and in south Oakland that’s often what floods a basement. In August 2014, Royal Oak officials figured about 8,000 of the city’s houses took on water and that most of it was sewer backup. In June 2024, residents on Templar, Maryland and Harden in Southfield had basements fill during a storm, and the city’s own review was still trying to work out why.
For that kind of water, a backwater valve on the main line is the fix, and on houses in the combined-sewer towns we’ll usually recommend one alongside the sump. If your basement does flood from the sewer, Michigan law gives you 45 days from when you found the damage to file a written claim with the city or the agency that runs the sewer. Take photos before you clean up.
What you can check yourself
Lift the float, or pour a bucket of water into the pit, and make sure the pump starts and stops. Listen for a thump when it shuts off, which can be a bad check valve. Look at where the discharge ends outside. Test the backup alarm once a season. If your pump is more than ten years old and you’ve never replaced it, we’d plan on it.
We take emergency calls for dead pumps around the clock, and a regular install is usually a few hours.
Questions we get about this in Oakland County
We lost power for days in the February 2023 ice storm. What backup keeps working that long?
A water-powered backup, if you’re on city water. It runs off municipal water pressure, so it keeps going as long as the water does. A battery backup can carry you for a night or two depending on how hard the pump is working, which may not be enough for an outage like that one. Some people get both.
Our sump in Walled Lake runs every few minutes from March to May. Is something wrong?
Probably not. Near the lakes the groundwater rises with lake level in spring, and a pump that cycles constantly is doing its job. We’d check that the discharge isn’t soaking back to the footing, that the check valve is holding, and that the pump is heavy enough for that duty. A backup matters more here than almost anywhere.
We’re on a well in Independence Township. Can we get a water-powered backup?
No, it needs city water pressure, and your well pump stops when the power goes out. We’d put in a battery backup and size the battery for your pit. A generator hookup for the main pump is also worth thinking about if outages on your road tend to last.
Does a new sump pump stop sewage from coming up our floor drain in Royal Oak?
No. A sump pump moves groundwater from the footing drain out of the house. Sewage coming up a floor drain is the sewer surcharging, and a backwater valve on the main line is what stops it. In south Oakland a lot of houses need both.
Our discharge line freezes every winter in Rochester Hills. What can be done?
First, make sure the outside line is sloped so it empties between cycles. Then add a freeze guard near the house so water has a way out if the line is blocked. If the yard allows, a buried line below frost depth to an emitter fixes it for good. We can usually sort it out in one visit.
Our Southfield basement flooded from the sewer. Is there a deadline to file a claim?
Yes. Under Michigan’s Public Act 222 of 2001, you have to give the city or the agency that runs the sewer written notice within 45 days of discovering the damage. Southfield and the Oakland County Water Resources Commissioner both post this. Photograph everything before cleanup and keep receipts.
How long does a sump pump install take?
Replacing a pump in an existing pit is usually an hour or two. Setting a new pit, cutting the floor, running the discharge outside and adding a backup takes most of a day. If you need it because the old one died during a storm, call; we answer emergency calls around the clock.
How often should a sump pump be replaced?
There’s no fixed date, but a pump that’s past ten years old has had a long life, especially one that runs a lot. A lake-lot pump in Oakland County may wear out sooner. We’d rather replace it on a dry Tuesday than at midnight in a storm.
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