Cesspool Components & Background Knowledge | Murphy's Cesspool & Spetic Professional Services

A cesspool is basically just an upside down bucket with a bunch of holes drilled around the sides. Except in cesspool construction the sides of the bucket is made from steel reinforced precast concrete rings. These precast rings are engineered with specific design features and are made in a few diameters. 

The “rings” as we call them in our industry, are constructed from concrete and rebar.

A round steel frame made from rebar is put into a mold. Then the concrete is poured in from the top until the mold is filled. Air is then vibrated out. After that the ring is left to cure. Curing times vary depending on variables like weather and temperature. 

The rings usually have holes all the way around them that serve a dual purpose. The holes around the precast ring are a wedge shape. These wedge shaped holes are bigger around the outside wall of the ring. The holes taper inward and get smaller as they get closer to the inner wall of the precast ring. These holes actually help anchor the ring in place after it is installed and back filled. The holes also help some wastewater to drain. 

These precast rings are strong and designed to handle the pressure of the ground pressing in from around the outside. Also, the rings are designed to stack on top each other. This allows you to use more rings to reach good sand for proper drainage, it also helps increase capacity. The more rings that are stacked, the larger the capacity the cesspool will have. Sometimes the cesspool has to be deep because of soil composition. If the ground has clay layers like we have here on the North Shore here on Long Island. Or if sand just has a high clay content. 

These rings are available in different diameters also for capacity and installation options. They can be 4 feet diameter, 6 feet, 8 feet, 10 feet, and also 12 feet in diameter. They can stand 2 feet tall, 3 feet, 4 feet, and even 5 feet tall. 

The top of the bucket is also made of the same steel reinforced precast concrete as the ring. The top can be made flat or cone shaped and will have an access hole for maintenance. The flat top is referred to as a “slab”.  Where the cone shaped top, called a “dome”. 

The bottom of the Cesspool is laid on sand. This is where the drainage of the wastewater occurs. Sometimes a footing ring is used. This footing ring is used to stabilize the entire drainage structure. It keeps the cesspool from shifting, keeps it level, and also helps it from sinking. The footing ring is round like the ring, but is only 6 inches to 8 inches thick, but it’s wider than the width of the ring. Think of a donut that our upside down bucket sits on. The hole in the middle allows for wast water to drain into the sand. 

This is the basic design of a cesspool. 

Years ago the holes were dug by hand. The rings were constructed of brick, block, cesspool block. The old tops were made at the job site. This is how my great grandfather, and all of my great uncles built cesspools from the 1930’s all the way through to the early 1970’s. That’s around the time when steel reinforced precast concrete rings. In combination with backhoes and excavators became industry standard for installation. 

These aging cesspools called block cesspools are still functioning at some houses here on Long Island. In Nassau County and also in Suffolk County. They are dangerous because they can collapse. When they do collapse they usually give little to no warning. 

If you have an old block cesspool you should upgrade your entire system with a septic tank and a cesspool overflow. Made from precast concrete. A septic system is more modern and is more efficient than just a cesspool and safer than block cesspools.