Onsite sewage treatment is necessary when you operate outside the P.O.T.W. or Publicly
Operated Treatment Works.
This means that you need to treat your own sewage. There are basically two types of septic systems,
conventional and unconventional.
Conventional systems are the usual gravity operated systems that are found in most homes today.
Unconventional or Alternative septic systems are used when conventional gravity fed systems will not work
due to any of several reasons.