Cesspools & Seepage Pits
Understand the signs and symptoms of common cesspool problems and failures. Learn how to diagnose your system and how a few simple steps will help avoid the headache and high costs associated with cesspool and seepage pit problems.
Before septic tanks were designed, sewage from homes was often disposed of in covered up circular pit called a cesspool. Many homeowners call a seepage pit a cesspool, or the other visa-versa. Seepage pits and cesspools are two very different designs. They are similar in structure but serve different functions. Seepage pits are used for dispersing clarified wastewater from a septic tank. Cesspools is combination tank and drainfield. The wasteflows into the cesspool and the liquid disperses into the surrounding soil.
Cesspools were an early design of the current septic system, offering a sub-grade method for disposal of residential sewage. Cesspools were easy to build and could be installed anywhere. In the early days cesspools were installed in the basements of city buildings. These methods were very different than todays standards for septic system designs that are based on soil and groundwater conditions. New systems are designed for relatively long-term use.
In most states, cesspools are now banned by health and building codes. Therefore, the construction of cesspools is unheard of today. There still remains many cesspools that remain in active service. The majority of active cesspools is in the Northeast US.
The area between the outer perimeter and outer soil filled with gravel. There may be a concrete cover that, covered with soil to grade. Raw wastewater flows into the top of the chamber of the cesspool. The chamber retains and partially treats the organic solids and the effluent seeps through porous wall to the gravel-filled outer area, and then into the surrounding soil.
There are large number of cesspools that are in active use. The highest density of these is in the Northeastern US. Homeowners with cesspools should understand that in most states, cesspools are prohibited by health and building codes. When your system fails or you apply for a building permit to build an addition or when you sell your home you may be required to replace your septic system with a modern and expensive system costing $6000 to $70,000.
A seepage pit is identical in design to a cesspool. It is essentially an upright leach or drain field made by constructing a porous walled chamber within a dug pit. An area between the walled chamber and the dug out is filled with gravel. Seepage pits are typically 4 to 8 feet in diameter and 4 to 40 feet deep. Septic tank wastewater flow inside the structure and is stored while it gradually soaks into the surrounding soil.
The cylindrical block or brick arangement surrounded by gravel provides structural support for the pit. The outside diameter of the wall structure is 2 to 3 feet smaller in diameter than the dug pit. More modern seepage pits may be made of cast concrete rings. The cast concrete rings have horizontal holes to allow seepage of the effluent into the soil. If bricks or blocks are used thay are stacked without the use of mortar so the effluent can flow through them. In some area a perforated vertical pipe or pipes may be used to create the storage chamber. Sometimes the chamber is filled with large stones to minimize any safety hazards in the event of a collapse. The bottom of the pit is may be covered with up to 12 inches of gravel.
A typical cesspool will fail similar to a drain field, leaching field trenches, seepage pits. They progressively develop the biomat growth. The biomat grows thicker near the bottom. As it seals the soil pours the effluent level increase causing the cesspool level to increase to where the biomat is permeable it flows the sidewall.
The biomat is made up of anaerobic bacteria that grow in the absence oxygen. Septic tank troubles can cause an abundance of organic waste matter to feed the biomat organisms, accelerating growth resulting in a slower rate of effluent from the septic tank to flow through the biomat into the soil. In a saturated state the soils aerobic environment is non-existant, and digestion of the biomat by the aerobic soil bacteria will cease.
To the right is a typical failing seepage pit/cesspool produced by septic tank problems. The biomat has become very thick and impermeable. The wastewater flowing to the seepage pit / cesspool will quickly and exceed the hydraulic capacity of the biomat. The result is back-ups into the septic tank and home. Eventually effluent surfacing on the ground above the seepage pit/cesspool or septic tank will occur. The damp spots will result in lush grass growth and you will be experiencing a failing septic system.
Pumping of Cesspool and Seepage Pit
Independent of if you are installing a controlled septic aerator or pumping for regular maintenance it is important to ensure that the cesspool or seepage pit iscorrectly pumped. Many timesthe pump out is not done correctly. To ensure the pump out is done correctly schedule the work when you are available to witness the workObserving the pumper is the only way to ensure the cesspool or seepage pit is pumped correctly. ALL liquids and solids should be removed from the cesspool or seepage pit. Have a garden hose available for the pumper that hasa jet nozzle attachment. During the pumping of the cesspool or seepage pit spray the hose on the sidewalls and the bottom to clean it well. Some pumpers make no effort to remove the bottom few inches of sludge. Some will tell you that they need to leave some solids in there to seed the start-up, don't believe it.
A septic system that has a septic tank and a seepage pit-cesspool as the soil absorption system provides an ideal configuration for controlled septic aeration. All other tank and soil absorption system are distinctly different as to the location of the controlled septic aerator is installed.The Aeo-Stream® controlled septic aerator should be installed in the seepage pit. You will only need a 3" opening to install our system. Installing the controlled septic aerator in the seepage pit-cesspool allows the aerobic bacteria to proliferate adjacent to the biomat and rapidly digest the biomat. The aerobic bacteria multiply rapidly with adequate biomat as the food and oxygen provided by the Aero-Stream® controlled septic aerator.
To Learn More Visit These Related Topics
- How Septic Aeration Works: Knowledge of septic system aeration functionality, how and why septic aeration works to fix septic tank problems and drain field problems.
- Septic Tank Problems: Learning septic tank functions, common septic tank problems, signs of septic tank problems and diagnosing septic tank problems.