How To Install a Sump Pump Dry Well

A sump pump keeps basements dry, but if the discharged water has nowhere to go, it may compromise the unit’s efficiency. Installing a dry well provides an efficient solution for managing sump pump discharge, preventing water from pooling near your foundation or creating unsightly puddles in your yard. In the above video, This Old House landscape contractor Roger Cook explains the process of installing a sump pump dry well to manage basement water issues effectively. Learn more in our guide below.

Preparing for Dry Well Installation

Before beginning the installation process, prepare and gather the necessary materials.

Selecting the Right Location

Selecting the appropriate location creates maximum efficiency and reduces the risk of complications. Positioning the dry well downhill from the discharge point allows gravity to assist in water flow, improving the overall performance of the system. Keeping it away from septic systems prevents contamination and avoids potential damage to infrastructure.

Pro Tip: According to This Old House Magazine, the dry well should be positioned at least 10 feet from the foundation and 3 feet from any property line. The hole should be dug about 4 feet deep and wide, with a trench that slopes gradually toward the hole to ensure proper water flow.

The connecting pipe should maintain a minimum slope of ¼ inch per foot to ensure water drains reliably into the dry well. Use a level placed on the pipe to confirm sufficient pitch before backfilling the trench.

Gathering Materials and Tools

Having all materials and tools ready before beginning the installation saves time and achieves a smoother workflow. Safety gear, such as gloves and goggles, protects you during digging and pipe installation. Measuring tape and silicone sealant are useful for checking for precise measurements and creating watertight connections, respectively. Here’s everything you need:

• A dry well container
• Crushed stone
• Drill with a 1 1/2-inch hole saw bit
• Landscape fabric
• Level
• Measuring tape
• Polyvinyl chloride (PVC) pipe (1 1/2-inch diameter)
• Safety gloves and goggles
• Shovel
• Silicone sealant
• Wheelbarrow

Step-by-Step Installation Process for Installing a Sump Pump Dry Well

Installing a sump pump dry well involves several key steps. Follow the steps below for a successful installation.

Digging the Trench and Hole

Take care to dispose of the excavated soil properly. Use a wheelbarrow to transport the dirt away from the site. Make sure that the trench maintains a slight downward slope to facilitate proper water flow toward the dry well. Use a level to check the slope as you dig.

Follow these steps:

1. Mark the path for your discharge pipe and the location of the dry well.
2. Dig a trench about 8 inches deep from the sump pump discharge to the dry well location.
3. At the dry well location, dig a hole approximately 4 feet deep and 2 feet wider than the dry well container.

Preparing the Dry Well

Using landscape fabric helps prevent soil from clogging the crushed stone, which can impede water flow. Adequately spreading the stones on the fabric adds a layer of filtration, allowing water to percolate through the stone and into the surrounding soil efficiently.

Use the following steps:

1. Fill the bottom of the hole with a layer of crushed stone.
2. Line the sides and bottom of the hole with landscape fabric, leaving enough excess to fold over the top later.
3. Add more crushed stone on top of the fabric.

Pro Tip: As This Old House landscape contractor Roger Cook explains, the landscape fabric is there “to protect the voids in the stone from the fines, all this little material, which would quickly fill all the holes in the stone.” He recommends wrapping the fabric around the stone and pipe to ensure the drainage system stays clean and functional long-term.

Installing the Discharge Pipe

Properly sealing the connection between the PVC pipe and the dry well container with silicone sealant creates a watertight connection, preventing leaks that could undermine the system’s effectiveness. Check that all sections of the pipe are connected and secure before proceeding.

Here are the steps:

1. Lay the 1 1/2-inch PVC pipe in the trench, creating a slight downward slope toward the dry well.
2. Use the hole saw to cut an opening in the side of the dry well container.
3. Insert the PVC pipe into the hole you’ve cut in the dry well.

Pro Tip: When cutting the opening in the dry well container, use a hole saw sized exactly to the inch-and-a-half pipe diameter rather than using any pre-made knockouts on the container. As the This Old House team noted during installation, using a larger pre-made knockout would leave “a big hole with space around it and it would allow debris” to enter the dry well—defeating the purpose of a sealed system.

Placing and Connecting the Dry Well

Make sure that the dry well sits level in the hole to promote even water distribution. Carefully backfill around it to avoid shifting or tilting. Double-check the tightness of the hose clamps to prevent disconnections during operation.

Make sure you follow these steps:

1. Lower the dry well into the prepared hole.
2. Backfill around the dry well with crushed stone.
3. Connect the discharge pipe from your sump pump to the PVC pipe using a rubber connector and hose clamps.

Finishing Touches

Regular tamping makes the soil settle properly, reducing the risk of future dips or sinkholes. Laying grass seed or sod restores the yard’s appearance, helping it blend seamlessly with the surrounding landscape.

Here are the final steps:

1. Install a pop-up emitter on top of the dry well to allow for overflow during heavy rains.
2. Fold the excess landscape fabric over the top of the crushed stone.
3. Backfill the trench and hole with soil, tamping it down as you go.
4. Plant grass seed or lay sod over the disturbed area.

Pro Tip: Roger Cook, This Old House landscape contractor, explains how the pop-up emitter works as a safety valve for the dry well: “If so much water goes into the dry well that it can’t leach out the sides or the bottom, we have to give it a way to come out of the top of the tank, and that’s where this pop-up comes in. It has a little spring in the bottom, and when the water pressure pushes on it, it lifts up.

Maintenance and Troubleshooting for a Sump Pump Dry Well

Regular maintenance helps your dry well continue to function properly.

Regular Maintenance Tasks

Here are some tips to help identify potential problems before they become serious. 

• Check the pop-up emitter to check that it’s not clogged with debris.
• Clean out any silt or debris that might accumulate inside the dry well periodically.
• Inspect the discharge pipe and connections annually for leaks or damage.
• Monitor the area around the dry well for signs of oversaturation.

Troubleshooting Common Issues

If you notice water pooling near the dry well or your sump pump running more frequently than usual, check for these potential issues:

• Clogged discharge pipe
• Faulty sump pump or backup pump systems
• Improperly sized dry well for your water volume
• Saturated soil around the dry well

Improving Your Sump Pump System

While a dry well significantly improves sump pump efficiency, think about these additional enhancements for optimal performance.

• Adding a French drain: Install a French drain system to complement the dry well. This drain works by collecting water from around your home’s foundation and directing it to the dry well more efficiently. A French drain can be particularly effective in areas prone to high water levels or frequent heavy rainfall. By redirecting surface and groundwater away from the foundation, it adds an extra layer of protection against water damage.
• Implementing a water alarm: A water alarm can alert you to rising water levels in your sump pit, giving you time to address issues before they become serious problems. Water alarms are an inexpensive and effective way to safeguard your basement against unexpected water levels. These alarms provide early warnings, allowing you to take timely action before flooding occurs.
• Installing a backup pump: A battery-powered backup pump can provide peace of mind during power outages. Install it alongside your primary pump to achieve continuous protection against flooding. Battery-operated backup pumps are especially useful during heavy storms when power outages are common. These pumps automatically activate when the main pump fails, meaning that your basement remains dry even in adverse conditions.