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What’s the Difference Between Septic Tank and Cesspool?

What’s the Difference Between Septic Tank and Cesspool?

Have you ever wondered what’s the difference between a septic tank and a cesspool?

While both are designed to receive and hold waste, septic tanks and cesspools have a distinctly different filtration process.

Before installing either one to your home or business, it’s a good idea to understand the differences between the two, along with their advantages and disadvantages, first.

This post discusses everything you need to know about septic tanks and cesspools, including which onsite sewage facility is better for your family and the environment.

Septic Tank vs. Cesspool: Quick Overview

Septic tanks and cesspools both collect wastewater and sewage that aren’t connected to the main sewer.

The biggest difference between the two is the filtration process—or lack thereof.

Septic Tanks

Septic tanks usually come with two or three chambers that separate waste into solids and liquids.

The solid waste is stored in the tank’s inlet while liquid waste (effluent) is moved to a soakaway chamber known as a drainage field through a separate outlet.

The drainage field would then evenly spread the tank’s liquids into the soil surrounding it.

Pros of Septic Tanks

  • Aren’t affected by community backups, clogs, or overflows
  • Greatly reduce the risk of pollutant transmission and pathogens
  • Last a long time; steel tanks up to 20 years, concrete tanks up to 40 years
  • As they run independently on the property, they don’t carry the monthly costs related to city-operated sewage systems
  • Replenish groundwater and remove pollutants from surface water, which therefore cuts down on pollution and help local plant and wildlife
  • Achieve greater water efficiency

Cons of Septic Tanks

  • Relatively costly installation and replacements, ranging between $3,000–$10,000
  • Need semi-regular maintenance, costing anywhere between $200–$600
  • Can get clogged by a host of materials
  • May create foul odors due to ruptured pipes

Cesspools

Unlike septic tanks, cesspools don’t have a treatment process. They also lack several vital outlets. The only outlet they have is a single pipe that releases the gas that accumulates in the tank.

Pros of Cesspools

  • Cheap installation
  • Prevent homeowners from paying monthly sewer utility bills
  • Rarely require replacement as long as they’re properly maintained, cesspools

Cons of Cesspools

  • Outdated and illegal in most areas
  • Can lead to groundwater pollution
  • High operation and management cost
  • Susceptible to the development of foul odor and gas
  • May quickly overflow because they don’t treat wastewater
  • Costly replacement

What’s the Difference Between Septic Tanks and Cesspools?

Septic tanks and cesspools are widely used in American households. Let’s take a look at the differences between the two.

Design

When it comes to construction, septic tanks and cesspools have a near-identical infrastructure.

Septic tanks are semi-permanent underground filtering systems that are usually made up of concrete, plastic, or fiberglass.

They’re usually available in 1,000 and 2,000-gallon sizes and are often used in rural areas that aren’t connected to a sewage system.

On the other hand, cesspools, also known as leaching pools, cesspits, or soak pits, are underground storage tanks that only temporarily hold sewage waste.

They’re often sold in 750, 1000, 1200, and 1500 gallon options.

Traditional cesspools look like wells: deep cylindrical chambers dug about 2–3 meters into the ground. The design was reinvented after the 1936 Public Health Act was issued and now looks a lot like septic tanks.

Similar to septic tanks, cesspools are made with concrete, fiberglass, or plastic.

Safety

Septic tanks are safer than cesspools.

The term “septic” is used to describe the tank’s anaerobic bacterial environment that mineralizes or decomposes the waste discharged into the tank’s chambers.

Apart from the chambers themselves, a septic system is paired with other onsite wastewater treatment units like biofilters or aerobic systems with artificial aeration.

In comparison, cesspools don’t have an integrated waste/fluid separation system.

Organic solids float on top of the cesspool’s waste storage while inorganic solids sink to the bottom. The cesspool’s naturally occurring bacteria would then break down solids into liquid, which would flow out of the tank and into the soil that surrounds it.

Unlike septic systems that treat wastewater, cesspools merely dispose of it. As a result, sewage eventually contaminates the soil surrounding the cesspool.

For this reason, some states discourage or ban the use of cesspools and would either recommend installing septic tanks or connect to municipal sewage systems instead.

Cleaning

Both septic tanks and cesspools need to be cleaned regularly.

For septic tanks, residual solid waste, known as septage or fecal sludge, needs to be emptied or de-sludged every 12 to 24 months by a professional to prevent blockages and leakage.

This is commonly done with a vacuum truck.

Cesspools require regular pumping, too. Depending on the size and the number of occupants on the property, they may need to be emptied monthly, quarterly, or annually. A 5,000-gallon cesspool for a family of four usually requires emptying every month or so.

Most cesspools are fitted with an alarm that notifies homeowners that the tank is at 75% capacity and needs emptying.

Keep in mind that cesspools emit hazardous gases, so opening the lid is highly discouraged. Emptying should only be performed by professionals.

Maintenance

Septic tank and cesspool maintenance are relatively straightforward. They both follow the same cleaning process, except for a few vital points. Here are some tips to follow to prevent costly replacements and repairs:

Septic Tank

  • Regularly inspect the condition of your septic system
  • Properly organize your septic system’s records (diagram, system maintenance, etc)
  • Routinely perform a septic inspection every two to three years
  • Pump your septic tank every one to three years
  • Don’t use bleach or harsh household chemicals as it kills the good bacteria in the septic tank
  • Monitor and conserve your water usage
  • Don’t dispose of coffee grounds, cooking fats, facial tissues, etc into the sewage system as they don’t easily decompose
  • Try to avoid using your garbage disposal unit
  • Promptly address leaks and other plumbing issues

Cesspool

  • Don’t drive over the cesspool as it may get crushed
  • Don’t park a vehicle, boat, or mobile home near the drain field
  • Plant trees a safe distance away from the cesspool
  • Prevent clogging and overflowing by regularly emptying the cesspool
  • Prevent the risk of rupture by regularly clearing the cesspool’s baffle clogs
  • Schedule cesspool inspections at least once every three years
  • Keep all records of maintenance work performed by professionals
  • Keep a close eye on what goes down the drains and toilets

Should You Replace Your Cesspool With a Septic Tank?

Yes, replacing your cesspool with a septic tank is highly recommended. Cesspools are outdated and hazardous to the environment. In fact, they’re illegal in most states!

Moreover, cesspool maintenance tends to cost more than septic tank maintenance, as cesspools need to be drained more frequently than septic tanks.

Final Thoughts

The primary difference between a septic tank and a cesspool is its filtration process. Septic tanks are designed to filter and separate waste into solids and liquids, while cesspools merely store and later dispose of wastewater.

In the battle between septic tanks and cesspools, septic tanks win by a long margin! If given the choice, it’s always better to go for septic tanks rather than the alternative.