The modern septic system has been around for well over 100 years now, ever since the invention of the septic tank, which received a patent in England around 1900. The cesspool is a much older waste disposal technique. It is antique, dating back to ancient Rome and most likely to ancient Babylonia when the first pipes were invented.
Both systems are used for waste management when a connection to a centralized municipal sewer service isn’t practical or available. About 25% of North America relies on the septic tank for private sewage disposal, replacing the outdated cesspool in most cases, but there are still some cesspools in operation. Both methods share the primary goal of separating the three types of organic waste found in a sewage disposal system. These are:
The key word when comparing these two methods of disposal is “system”. The cesspool is simply a perforated concrete or block ring, similar to a well-liner but with holes, buried underground. There is no widespread distribution of effluent. Everything dumps to the cesspool, sludge piles up at the bottom, and effluent and scum drain through the holes directly into the immediate surrounding soil.
The cesspool sludge needs to be pumped frequently to keep lower holes open for water flow, and quite often the cesspool requires relocation when surrounding soil becomes saturated to the point that wastewater is pooling at the ground surface. Any cesspool past its prime today would most likely be replaced with a modern septic system.
The septic tank is the primary component of the septic system, part of an elaborate distribution method which sends only the effluent (water) to a distribution box which has outlets for multiple perforated pipes.
Baffles in the septic tank prevent scum from reaching the outlet, and the closed tank environment contains bacteria where it’s needed to digest the scum layer. Depending on local percolation tests (ground absorption capacity)the network of perforated pipes spread the wastewater over as wide an area as necessary for proper absorption. Sludge and scum never make it out of the septic tank, when properly maintained. The scum digested by the tank’s bacteria is converted to liquid effluent or sinks to the sludge layer as waste.
Septic systems and cesspools both require pumping of the sludge to maintain proper functioning. How often pumping is required will depend upon tank capacity and the number of persons per household.
Read original article here: https://www.wrenvironmental.com/septic-system-vs-cesspool/