We will run water from the home to observe the flow of wastewater and check for any leaks that show a sign of a cracked pipe. It is normal for tanks to fill up due to solid waste and you will need to have the tank pumped. We use a "sludge judge" to determine the amount of sludge. When it comes to your septic tank, InterNACHI suggests to have the tank inspected on an annual basis. Why? To avoid costly repairs by checking for hairline cracks in the tank prior to deeper and wider cracks forming from neglect, as well as checking for broken PVC plastic pipes. This inspection is recommended for potential home buyers to avoid any future problems.
"A septic system receives, treats and disposes of unwanted wastewater and solids from a building’s plumbing system. Solids are partially broken down into sludge within a septic tank and are separated from effluent (water) and scum (fat, oil and grease). Effluent regularly exits the tank into a drainfield where it is naturally filtered by bacteria and reentered into the groundwater. Scum and sludge must be pumped periodically and should never enter the drainfield." (https://www.nachi.org/inspecting-septic-systems.htm)
Both systems breakdown the sewage and are treated. Conventional septic systems (also called Anaerobic) carries liquid and solid waste into a treatment tank prior to the drain field. Whereas, the Aerobic septic systems consist of a trash tank, treatment plant, and pump tank. All liquid and solid waste travels from the trash tank to the treatment plant, and then in to the pump tank to be treated again. This is environmentally safe to water your lawn, use on surface vegetation. For further detail, visit texaswasteco.com