How to Install Septic-Tank Risers

in-ground septic tank surrounded by dirt
What You'll Need
Tape measure
Adapter rings
Riser lids and pins

A septic-tank riser extends to a septic tank to bring the tank’s lid to the surface. If you install one of these cost-effective devices, you will no longer have to dig to gain access to your septic tank’s lid for inspection or repairs. Follow these steps to install risers on your tank without having to hire a professional.

Step 1 – Choose the Material

There are three different materials used to construct risers: concrete, polyvinyl chloride, or PVC, and polyethylene. These three materials differ in price, durability, and ease of installation.

While concrete is the cheapest material, it is also the hardest to install because it’s heavy. Polyethylene risers are lighter and easier to install, and they are resistant to soil erosion. However, they can leak gases and water more easily than other options. PVC is more expensive, but it is the lightest material of the three. In addition to being easy to install, this material doesn’t leak water or gases easily.

Step 2 – Decide Where to Install the Risers

Risers replace the lid and bring access to the septic tank closer to the ground's surface. This access can be installed above ground, where the risers are easily visible, or hidden just below the surface. Above-ground installation is mainly used in areas that are neither visible nor interfere with lawn care. Installing risers above ground also allows you to access the tank easily. However, below-ground installation hides the risers right below the surface. While this method makes the risers more discreet, you will have to remove the grass on top of the risers every time you need access to the tank.

Step 3 – Determine the Height

Septic tanks can be installed up to 3 feet below the surface, but the average depth is 18 inches. Risers are sold in heights of 6 inches or 12 inches. They are stacked on top of each other until they reach the surface or stop right below the surface. Measure the distance from the tank to where you want the new lid to be installed to determine the number of risers you will need.

Step 4 – Gain Access to the Septic-Tank Lid

To install risers, you must first gain access to the lid of the septic tank by digging down to it. Expose enough space, approximately 2 feet in all directions, to allow room for the installer to move freely.

Step 5 – Install an Adapter Ring

Remove the existing lid on the septic tank. Install an adapter ring in the opening to the septic tank. The risers will attach directly to this ring. Secure the ring to the tank by using concrete.

Step 6 – Install the Risers

Install as many risers as needed to achieve the necessary height required for an above- or below-ground installation. Connect the risers to each other by screwing them together. Screwing them together makes them waterproof and airtight. If one ever gets damaged, you can easily replace a septic-tank riser.

Step 7 – Install a New Lid

Lids come in different diameters. Choose a lid based on the size of the risers you use. Install it on top of the last riser, and secure it with the two pins that it comes with.