General DescriptionSeptic systems treat and disperse relatively small volumes of wastewater from individual or small numbers of homes and commercial buildings. Cesspools are an onsite waste disposal system used to dispose of sanitary wastewater from kitchens, bathrooms, and clothes washers.
Summary of Federal Requirements
Septic system regulation is usually a state, tribal, and local responsibility but the U.S. EPA does provide guidance on their operation and maintenance.
Some septic systems are regulated by EPA as Class V underground injection wells (UIC) if they receive industrial or commercial wastes and/or they have the capacity to serve 20 or more people.
On 12 January 2005 the U.S. EPA entered into a Memorandum of Understanding (MOU with the National Association of Towns and Townships (NATaT); National Association of Wastewater Transporters, Inc. (NAWT); National Environmental Health Association (NEHA); National Environmental Services Center (NESC); National Onsite Wastewater Recycling Association, Inc. (NOWRA); Rural Community Assistance Partnership, Inc. (RCAP); Water Environment Federation (WEF); and Consortium of Institutes for Decentralized Wastewater Treatment (CIDWT)). This memorandum focuses on better planning, septic system design, and long-term operation and maintenance of septic systems.
Existing large-capacity cesspools must have been closed by April 5, 2005. The EPA considers a cesspool large capacity when used by:
- A multiple dwelling, community or regional system for the injection of waste (e.g., a townhouse complex or apartment building), or
- Any non-residential cesspool that is used solely for the disposal of sanitary waste and has the capacity to serve 20 or more people per day (e.g., a rest stop or church).
For more details on Class V wells/ large capacity septic systems see the EPA Guidance.
EPA has updated its guidance document concerning cesspools and septic systems in 2010. The updated document Handbook for Managing Onsite and Clustered (Decentralized) Wastewater Treatment Systems is a "how-to guide" for implementing EPA's Voluntary National Guidelines for Management of Onsite and Clustered (Decentralized) Wastewater Treatment Systems. The guide describes a step-by-step approach for the development of a community management program for decentralized wastewater systems. It includes specific community examples, gives an overview of the elements essential for sound management of these systems, and provides links to extensive resources.
Summary of State Requirements
The definition for large capacity may vary from State to State, but should be comparable to the Federal definition. Some examples of alternative definitions include use waste flow rates or cesspool volume capacity to classify a cesspool as large-capacity. Check with the appropriate State UIC Program for more information.
Laws and Statutes
Clean Water Act