System Types

In general, sanitation systems can be characterized as decentralized or centralized. A decentralized system treats human waste co-located with or near the source of the waste, in contrast to a centralized system where waste is collected and transported to a centralized treatment plant. Decentralized systems can provide an effective, low-cost alternative to a centralized system and often serve rural and smaller communities, as well as communities in which centralized systems may not be feasible due to distance, terrain, or other factors.

Sanitation systems, ranging from household/business to neighborhood to city systems, are categorized according to the location of the system components and associated functions, and whether they are owned and managed by a household/business, shared by a group of households/businesses or are publicly owned and managed as with city/ community utilities.

  • Decentralized systems, supported by a variety of technologies, range from individual septic systems, to cluster systems that serve multiple properties, to advanced systems that include treatment technologies that remove pollutants such as nutrients. These systems tend to be smaller, more affordable systems treating wastewater closer to the point of generation. These systems include:
    • Individual on-lot systems serving a single property in which source, collection and treatment are on the property. These typically serve a household or business. The systems are owned and managed by the property owner. A septic system is a common example of an on-site system but there are a variety of other technologies that are suitable for on-site systems that are feasible in developed and/or developing regions.
    • Cluster systems have shared ownership and management and serve a neighborhood or cluster of up to 30 properties with aggregate wastewater flows of less than 10,000 gallons per day (Barnstable County Wastewater Cost Task Force, 2010).
    • Satellite collection systems are owned by a municipality or utility that does not own a wastewater treatment facility. These systems serve from 30 to 1,000 properties in which discharge 10,000 to 300,000 gallons per day into another municipality’s wastewater collection or treatment system (Barnstable County Wastewater Cost Task Force, 2010).
  • Centralized systems, owned by a municipality or utility, collect and transport waste to a centralized treatment plant. These systems provide for most or all of a town’s wastewater management and may provide service to neighboring areas.