Conventional Septic Systems

• The conventional septic system consists of an underground concrete tank with sand and gravel drainfields spreading out from the house. Initially expensive to install, this system is inexpensive to maintain and will last 40 years or more.
  
  

Poor Drainage

• If your soil is not permeable enough, a traditional septic system alone may not be able to adequately remove pathogens from waste. A recirculating sand filter system, a peat filtering system or an aerobic septic system might be your best option.
  
  

Limited Area

• If your residence is on a small lot where adequate drainfields will not fit, a composting toilet or incinerating toilet may work best for you. The composting toilet needs a single room (e.g., a basement), and an incinerating toilet needs only an electrical outlet and outside ventilation.
  
  

Failed System

• An aerobic septic system is often installed once a conventional septic system has failed (perhaps due to drainfield collapse.) This system treats waste in the presence of oxygen and requires mechanical and electrical facilities unlike traditional septic systems.
  
  

Groundwater Proximity

• In areas where the groundwater or fresh bodies of water (e.g., lakes, bays, or rivers) are too close to the home to allow for adequate drainfields, composting or incinerating toilets are often recommended.