Water: Septic (Onsite / Decentralized) Systems
Septic (Onsite/Decentralized) Systems
Nearly one in four households in the United States depends on an individual septic system (also referred to as an onsite system) or small community cluster system to treat their wastewater.
These various types of decentralized wastewater treatment, if properly executed, can protect public health, preserve valuable water resources, and maintain economic vitality in a community. EPA concluded in its 1997 Response to Congress (PDF) (101 pp, 5.8MB, About PDF) that "adequately managed decentralized wastewater systems are a cost-effective and long-term option for meeting public health and water quality goals, particularly in less densely populated areas."
Unfortunately, in far too many cases, these systems are installed and largely forgotten – until problems arise. EPA helps to ensure the success of these systems through the promotion and implementation of effective decentralized wastewater management programs.
Why is EPA concerned about onsite wastewater treatment systems?
Onsite wastewater systems include a wide range of individual and cluster treatment systems that process household and commercial sewage. These systems are used in approximately 20 percent of all homes in the United States. An estimated 10 to 20 percent of these systems malfunction each year, causing pollution to the environment and creating a risk to public health. More information on septic system usage in the United States can be found in the Septic System Fact Sheet (PDF) (2 pp, 118K, About PDF).
Who regulates onsite wastewater treatment systems?
States, tribes and local governments are responsible for regulating individual onsite systems. EPA provides guidance and technical assistance to help develop and enhance onsite programs.
- EPA regulates large capacity septic systems under the Underground Injection Well program.
- EPA regulates system discharges to surface waters under the National Pollutant Discharge Elimination System.
- EPA regulates disposal of sewage sludge (biosolids) and domestic septage under 40 CFR Part 503.
- EPA develops voluntary policies and guidance for onsite wastewater management programs.
- EPA sponsors state-of-the-art research on onsite and clustered wastewater system technologies through demonstration projects.
- EPA works with state and local officials, industry professionals, and partner organizations to support onsite wastewater management.
- EPA promotes homeowner awareness to strengthen onsite wastewater management.
- Annual Report 2013: Decentralized Wastewater Management Program Highlights (PDF) (4 pp, 983K, About PDF)
Homeowners most often are responsible for maintaining their onsite wastewater treatment systems. Proper system maintenance as well as mindful daily household use (e.g., not pouring cooking grease down the drain and water conservation efforts) will help keep a system from malfunctioning and will help to maintain their investment in their home.
To encourage homeowners to be SepticSmart, EPA has launched a national program to promote proper septic system care and maintenance by homeowners. SepticSmart provides information on how a septic system works and simple and everyday tips on how to properly use and maintain a septic system.
In addition to helping educate homeowners, SepticSmart serves as an online resource for industry practitioners and local governments, providing access to tools to help educate their clients and residents.
Learn more today!
State, tribal, and local officials are responsible for regulating onsite wastewater treatment systems. EPA offers a wide variety of resources to assist state and local governments in their efforts to manage these systems.
Model Program to Assist State Septic Programs in Managing Water Quality Impacts in the Chesapeake Bay Watershed - On June 28, 2013, EPA released a model program for onsite wastewater treatment systems in the Chesapeake Bay watershed to help states more effectively prevent nutrients from entering the Bay from onsite or septic systems, which will improve water quality. When properly designed, sited and maintained, decentralized systems like septic systems can treat wastewater effectively and protect surface water and groundwater. Inadequately treated sewage from decentralized systems can pose risks to human health and the environment. The model program is part of EPA's effort to collaborate with state and local partners in promoting nitrogen reductions from onsite systems. The model program implements an executive order signed by President Obama in 2009 recognizing the Chesapeake Bay as a national treasure and calling on the federal government to lead a renewed effort to restore and protect the nation's largest estuary and its watershed.
- A Model Program for Onsite in the Chesapeake Bay Watershed (PDF) (100 pp, 1.9MB, About PDF) - Assists states to develop and implement a model program to manage onsite systems and minimize nitrogen impacts to the Chesapeake Bay.
- A Model Program for Onsite Management in the Chesapeake Bay Watershed Response to Comments (PDF) (23 pp, 91K, About PDF) - EPA's response to comments on "A Model Program for Onsite Management in the Chesapeake Bay Watershed."
EPA's Voluntary National Guidelines for Management of Onsite and Clustered (Decentralized) Wastewater Treatment Systems (PDF) (2 pp, 55K, About PDF) are a principal resource for state and local officials. EPA has issued these guidelines to raise the quality of local management programs, suggest minimum levels of activity, and encourage institutionalizing the concept of decentralized wastewater management. Implementation of the guidelines can help communities meet water quality and public health goals, provide a greater range of options for cost-effectively meeting wastewater needs, and protect consumers' investment in home and business ownership.
The National Association of Counties has also developed a fact sheet, Planning for Septic Systems: Use of Online Decentralized Systems in Developing Areas (PDF) (2pp, 543K, About PDF) that provides information for homeowners and community officials on the realities of septic systems, the benefits of an onsite wastewater management plan, the steps in developing a plan, and resources for more information.
To learn about real world examples of communities that have implemented decentralized management programs to address their local wastewater needs, check out EPA's Case Studies of Individual and Clustered (Decentralized) Wastewater Management Programs which highlight differing communities that have taken various local approaches to better manage their decentralized wastewater systems.
The EPA's Wastewater Information Systems Tool (TWIST) is an off-the-shelf, user-friendly management tool that allows state and local health departments to effectively inventory and manage small wastewater treatment systems in their jurisdictions. It is designed to track information related to homes and facilities served, permits, site evaluations, types of systems, inspections and complaints.
The Local Government Environmental Assistance Network (LGEAN) is a "first-stop shop" providing environmental management, planning, funding, and regulatory information for local government elected and appointed officials, managers, and staff.
Professional service providers are the front line when it comes to siting, designing, servicing, and maintaining onsite wastewater systems. This site offers many resources for professionals to promote a highly trained and competent service industry.
Onsite Wastewater Treatment and Disposal Systems Manual (PDF) (365 pp, 21MB, About PDF) - This manual provides technical information about onsite wastewater treatment and disposal systems. It does not contain standards for those systems, nor does it contain pertinent rules or regulations. The intended audience for this manual includes those involved in the design, construction, operation, maintenance and regulation of wastewater systems (EPA 625-R-00-008).
Source Water Protection Practices Bulletin: Managing Septic Systems to Prevent Contamination of Drinking Water (PDF) (5 pp, 578K, About PDF) - This fact sheet discusses ways to prevent septic systems from contaminating sources of drinking water (EPA 816-F-01-021).
Utility Bill Insert (PDF) (2 pp, 150K, About PDF) - This colorful 3" x 5" bill insert is intended for use by wastewater and water supply utilities. One side has information for customers that discharge to sanitary sewer systems; the other side is for customers with septic systems (EPA 832-F-03-007).
Not in My Septic System! Magnet (PDF) (1 pp, 548K, About PDF) - This is a magnet that septic tank pumpers can distribute to customers. It lists items that homeowners should not dump down the drain and provides a reminder of the next service date (EPA 832-E-05-001). For ordering information, contact NSCEP. If you would like to print your own magnets, see Printing a Publication Using a Professional Printer for more information.
Also check out our Technical Information page for more information on:
- Alternative technologies, such as recirculating sand filters, high efficiency toilets, aerobic treatment units, and chlorine disinfection.
- EPA's Environmental Technology Verification Program.
- Links to state web pages with information on approved advanced onsite technology products.
EPA's Wastewater Information Systems Tool (TWIST) is an off-the-shelf, user-friendly management tool that allows state and local health departments to effectively inventory and manage small wastewater treatment systems in their jurisdictions. It is designed to track information related to homes and facilities served, permits, site evaluations, types of systems, inspections and complaints.
EPA and 18 partner organizations are joined by a Memorandum of Understanding (MOU) to work collaboratively at the national level to improve decentralized performance and protect our nation's public health and water resources. EPA initiated this MOU partnership in 2005 through an MOU with 8 public and private sector organizations; the MOU was then periodically expanded, reaching 18 partners in November 2014. The 2014 MOU renewed the commitment of EPA and its partner organizations to work together to encourage proper management of decentralized systems and increase collaboration among EPA, state and local governments, and decentralized system practitioners and providers.
Decentralized Partnership Products
- 2014 MOU Renewal: 2014 Decentralized Wastewater Management MOU (PDF) (5 pp, 2MB, About PDF)
- Decentralized MOU Partnership Papers - The EPA Decentralized MOU Partnership recently developed four short position papers for state, local, and tribal government officials as well as interested stakeholders. These materials include information on the uses and benefits of decentralized wastewater treatment and examples of where it has played an effective role in a community's wastewater treatment infrastructure.
- Decentralized MOU Partnership Webcasts - Since October 2010, the EPA Decentralized MOU Partnership has sponsored a series of webcasts discussing issues of interest to the decentralized community. Information on past and upcoming webcasts is available on this website.
Additional Partners to the Decentralized Program
Indian Health Service (IHS) - IHS's goal is to assure that comprehensive, culturally acceptable personal and public health services are available and accessible to American Indian and Alaska Native people.
National Association of Counties (NACo) - NACo's homepage contains information for county officials, including legislative affairs, projects and programs, and conferences and events.
National Association of County and City Officials (NACCHO) - NACCHO offers tools and programs for local health officials on various issues. It also offers an up-to-date review of public advocacy issues and a comprehensive bookstore.
National Environmental Training Center for Small Communities - NETCSC assists small communities by providing training and training-related information and referral services in the areas of wastewater, drinking water and solid waste.
U.S. Department of Agriculture, Rural Utilities Service (USDA-RUS) - The Water Program section of this site contains information on grant programs as well as informative pamphlets.