What is a Foundation Drain? 

Foundation drains are pipes that are installed under your foundation or basement floor to collect water and move it off-site to prevent your basement from filling with water.

If your home was built after 1920 it likely has a network of pipes under the basement floor called foundation drains that are supposed to pick up groundwater before it can seep into your basement. If your house was built before 1954 (approximate date), your foundation drain is likely directly connected to the sanitary sewer near your floor drain through a fixture called a palmer valve.

Foundation drains that are directly connected to the sanitary sewer work well and require no maintenance, but they also add a lot of clear water to the sewer which greatly increases the chances of a basement backup for you and your neighbors. Houses built after 1954 are required to have the foundation drains directed to a sump pump that sends the water to your lawn or to the storm sewer. MMSD's Pipe Check program offers homeowners financial incentives to disconnect foundation drains from the sanitary sewer.

If you do have a sump pump, there are a few things that you can do to minimize the chance of water in your basement and keep your pump functioning efficiently and reliably. 


If you have standing water in your basement or pooled water around your sump pump and / or electrical fixtures, do not try to do anything!  CALL A PROFESSIONAL PLUMBER!

How a Foundation Drain Connected to a Lateral Operates
How a Foundation Drain Connected to a Sump Pump Operates

Sump Pumps

It is ILLEGAL to Drain Your Sump Pump Into the Floor Drain or Wash Tub in Your Basement!

Doing so can significantly increase the risk of basement backups for you and your neighbors during heavy rain by slamming a lot of excess water into the sanitary sewer system when it's at or near capacity.

Always make sure the discharge pipe from your sump pump is at least six to ten feet away from your house. Your discharge pipe may go into another pipe underground that usually drains into a storm sewer. If you are not sure if the discharge pipe from your home is connected properly, call the plumbing inspector for your city or village.


Sump Pump Installation

Here's an overview of how a sump pump is installed in your basement.

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    The electrical contractor verifies the electrical panel meets electrical code and has room to install a new circuit for the sump pump.   

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    The electrician installs an electrical outlet dedicated to the new sump pump.

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    The plumbing contractor locates and excavates where the foundation drain tile connects to the sewer. This is typically at the floor drain at the “palmer valve”. All digging is usually done by hand and buckets.

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    The plumbing contractor disconnects the foundation drain tile from the sanitary sewer by removing the palmer valve and installing new pipe to direct the foundation drain to the new sump pump.  A new floor drain is installed and the sanitary sewer lateral reconnected.

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    The plumbing contractor installs a new sump pump basin and connects the foundation tile to the sump pump basin. 

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    With the new sump pump basin installed, a new sump pump is installed with a new discharge pipe to direct the clear water to the exterior of the home away from the foundation walls.

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    Floor is restored.

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    The new sump pump installation includes the installation of a new discharge pipe.  This new pipe directs the clear water entering the sump pump basin to the exterior of the home.  When contractor verifies that the sump pump and discharge pipe is working properly, the plumbing contractor restores the excavated hole with stone and concrete to match the existing basement concrete floor.

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    Finally, the contractor adds a flexible hose to the exterior discharge directing the water away from the house foundation wall preventing the water from recirculating along the wall back to the foundation drain.  When a stormwater lateral exists on the property, the sump discharge may also be directly connected to the stormwater lateral.

Palmer Valves 

A palmer valve is a type of check valve that was designed to allow the groundwater collected by a building’s drain tile to be directed into the sanitary sewer system through a flap that would open as water flow or pressure increases behind it. Releasing ground water into a sanitary sewer is no longer allowed, therefore the palmer valve needs to be removed and a sump pump needs to be installed to direct the water outside of the building.

Palmer valves often cause maintenance issues because they were made of metal.  Over time the ‘flap’ tended to rust or become frozen and inoperable.  Once the flap is inoperable, the foundation drainage cannot discharge freely into the sanitary sewer. The foundation drain tile system has nowhere for the ground water to drain to.  In many cases, this can lead to increased hydraulic pressure on the basement floor and foundation wall, causing common basement issues such as cracks in the floor and walls, basement seepage, etc.

MMSD has financial incentives available to homeowners to remove palmer valves and install a sump pump. Visit the Pipe Check page to learn more.


Common Sump Pump Problems

  • Remove the cover
    • If the basin is empty and the pump is still running, unplug the sump pump. The pump switch is activated by a float. Be sure there is nothing that is jamming the float.
  • Move the float up and down to be sure it is moving freely. Plug the sump pump back in.
    • The pump is now off, test the pump as described previously.
    • If the pump still runs constantly, the pump will need repair or replacement.
    • Reinstall the cover.
    • Call a plumber.
  • If the basin has water in it and the pump is running but the water level doesn’t seem to change, unplug the pump.
    • If the water level remains the same, the discharge pipe is likely blocked. Check for ice (winter) or other obstruction at the discharge.
    • If the water level starts rising slowly, the discharge piping may be partially blocked, or the pump needs to be replaced.
    • If the water level starts rising quickly, plug the pump back in immediately. The pump is likely working fine but is struggling to keep up. Try to determine the source of the water and reduce if possible or contact a contractor to evaluate the source of water and the pump capacity.
    • Plug the pump in and replace the cover.

Test the sump pump as described in the section below "How to Test Your Sump Pump". Good quality sump pumps installed properly run very quietly. The sump pump may be working fine.

  • Remove the cover and watch the water level when the pump shuts off. If the water raises immediately with a rush of water, the check valve is likely faulty or there is no check valve. (All of the water in the discharge piping runs back into the basin). Contact a plumber.
  • If the water raises quickly but calmly, try to identify the source of the water.
  • Check the discharge location. If the water is discharging immediately next to the foundation or if the ground is sloped towards the foundation, the water is seeping back into the ground and recirculating through the foundation drain. Extend the discharge pipe so the water runs away from the house.
  • Check the general grading around the house perimeter and the gutters/downspouts to identify the source of the water.
  • Test the sump pump as described below.
  • If the sump pump is working fine, try to determine if the pump itself is noisy or if the noise is coming from the piping. While a pump replacement may be necessary, often loose piping or piping that is contact with other pipes or HVAC ducts can transmit noise that can be easily fixed with added support or putting just a bit of distance between the two objects.

How to Test Your Sump Pump

Test your sump regularly, spring is a good time to test this before the snow melts. 

Remove the cover of the sump pump. While most styles of covers lift right off, some have screws that need to be removed before the cover can be lifted

  • If the basin is dry and you have no problems with basement water seepage, congratulations! You have a dry location and not much to worry about. (You should still finish the sump pump test)
  • If the basin is dry and you have basement seepage, your foundation drains may be clogged. Contact a plumber to inspect.
  • The basin typically will have some water in it and you will likely see water trickling in through the connected foundation drains.

The pump should turn on by the time the water covers the pump completely and before the basin is completely full.

  • If the pump does not turn on, skip to “Sump pump doesn’t turn on”.
  • If the pump runs, the water level should drop quickly, and the pump should turn off automatically.
  • Replace the cover

*NOTE: If you have standing water in your basement or pooled water around your sump pump and / or electrical fixturesDO NOT TRY TO DO ANYTHING! CALL A PROFESSIONAL PLUMBER!

  • Test the outlet by unplugging the sump pump and plugging in a small appliance that you know works such as a lamp.
  • If the lamp lights, the sump pump is faulty. Contact a plumber.
  • If the lamp does not light:
    • If the outlet is a ground fault circuit interrupter (GFCI) check for a fault indicator light and reset. Recheck the outlet.
    • If the outlet still does not work or the outlet is not a GFCI, check your electrical panel for a tripped circuit breaker or a circuit breaker that is turned off.

If you can’t determine why the pump is not working, call a professional (plumber or electrician).


wet sump pump basin

Should I Get a Backup System for My Sump Pump?

If you already have a sump pump, it's a good idea to have some type of backup system installed in case you lose power during a storm. There are several to chose from with a wide range in price.

Most battery backup systems are equipped with alarms to notify you if the main power goes out and the backup system is operating. Battery backup systems are not designed to run for long periods of time, but they may buy you enough time to borrow a portable generator or for the electric company to restore power to your home.

When you lose power at home, your sump pump will not run without a backup system. Unfortunately, the water will keep flowing into the basin and the most likely time for a power outage is during a storm. You have three options for providing backup for your sump pump.  

  • Battery backup systems are the most common and most widely available.
  • A water pressure backup is a pump that runs off your municipal water supply pressure during a power outage.
  • You can also just plug the sump pump into a portable gas-powered generator.
  • Battery: Automatically operates including when you are not home. Most easy of the three to install. Commonly available.
  • Water: Automatically operates including when you are not home. Virtually maintenance-free. Nearly limitless run time (assumes municipal water pressure is available)
  • Generator: Will run for an extended period of time with fuel refills, no extra cost if you already have a generator, can be used to operate other items (if sized appropriately) during an outage or anytime needed.
  • Battery: run time-limited by battery life (not a good option of your pump runs extensively during rain events), requires regular battery maintenance and checks, the battery has limited life regardless if the pump runs or not.
  • Water: Typically will require professional installation, limited capacity depending on your water system pressure, will not work if you have a private well.
  • Generator: Not efficient or economical if only using to power the sump pump, must be operated outdoors.