Aerobic septic system

Does an aerobic septic system require sprinklers? I’m a newer inspector that hasn’t seen a lot of septic systems. I have trouble telling the difference between aerobic and anaerobic. Is an air pump an indication of the type of system? I have tried to research this topic but I haven’t been able to find a lot of info. Any feedback would be greatly appreciated.

Michael,
An aerobic system requires the introduction of air to a system via an air pump.
These systems require maintenance and if you’re seeing them in our area you will want to spend some time learning.
Some installers are a good source of information.

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Your basic class 4 residential system usually has a two chamber tank (solid side and liquid side) that gravity feeds or is pumped up to the absorption bed. Anerobic bacterial breakdown is very slow and is the kind that occurs under water in the tank. When the effluent enters the absorption bed the breakdown becomes aerobic in the oxygen rich environment and is very fast. About 10 to 15% of bacterial breakdown happens in the tank and 85 to 90% occurs in the bed. If oxygen is introduced the effluent in an oxygenation chamber about 90% of the nitrates are removed and the bed can be very small, roughly 50% of a normal bed. A system such as this requires a written maintenance and service agreement under the NBC in Canada.

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I have seen these with a sprinkler head, and a pipe with the finished product running on the ground.

Just an added data point for you in your path to knowledge: look up deep well injection septic systems. I did a resort in the Bahamas that had a small pretreatment system and a 400 foot injection well. The Bahamas are basically piles of sand on top of limestone and reef deposits, which look like Alpine lace Swiss cheese for the first 50 feet, then open up to a cave system, all full of sea water. The ocean basically breathes in and out of the island chain’s supporting reef and limestone structure. And since the island chain relies on fresh water lenses between 5 and 15 feet down (within the sand layer but on top of the salt water) for drinking water (whole other story), apparently it’s relatively safe to inject pre-treated sewage 400 feet under the ground for the ocean to carry away.

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