| Primary Treatment | Appropriate Use | Relative Cost | Operations and Maintenance | Effectiveness |
 |
Residential or commercial sources with a population loading of less than 25 people |
Low - Can be constructed using local materials and labor |
Needs to be de-sludged every 3 to 5 years |
Moderate - Can reduce 40% to 60% of pollution loading |
 |
Small community or institutional sources, such as hospitals. Must be located well away from residential communities due to potential for odors and nuisances |
Low for areas where available land is plentiful and low value |
Low - Systems still require routine operation and maintenance tasks such as monitoring, weed and trash removal, scum and biosolids management |
Can be very effective as primary treatment devices. May also be designed for secondary treatment |
 Anaerobic Baffled |
Residential or commercial facilities with a population loading of between 25 and 200 people |
Low - May be constructed with local materials and labor |
Low - Periodic desludging is required |
Good - Generally better performance than septic tanks. Can remove 75% of the pollution load |
 |
For animal manure or other high strength waste. Can be used for small community systems that combine waste from fish and animal operations, people and commercial activities |
Moderate - Some systems require tight specifications on construction |
Moderate - Take care to ensure the source wastewater is free of chemicals or disinfectants which can kill microbes that produce biogas |
Ineffective for human waste only. When waste includes animal manure, may produce enough biogas to meet cooking fuel demands |