Onsite Wastewater Treatment Systems

Onsite wastewater treatment systems, frequently called decentralized systems, refers to any system used to treat and dispose of/recycle wastewater from homes, businesses, industrial facilities, and sometimes entire communities. Septic systems usually serve up to 20 people, oftentimes individual households or small businesses, and include a septic tank and soil absorption field. The frequency of septic systems varies by region, ranging from ten to over fifty percent of homes in some states. Larger, more complex systems use advanced treatment units which treat and discharge to surface waters or the soil. When used properly, onsite systems protect public health and the environment by reducing disease transmission and removing pollution from surface and groundwater. Individual onsite systems are typically regulated by states, tribes and local governments, while large capacity septic systems are regulated by the EPA.

Environmental Health professionals play an important role in managing onsite wastewater treatment systems. Septic system professionals are involved in installing, operating, maintaining, and repairing onsite systems. Professionals with local or state health departments evaluate potential sites for onsite systems, issue permits or licenses for technicians, conduct inspections, and enforce local regulations. Additionally, environmental health professionals partner with industries involved in developing land containing buildings using onsite systems to ensure that these treatment systems continue to discharge clean and usable water.  


Septic Smart Week: September 17-21, 2018

In partnership with US Environmental Protection Agency, NEHA is raising awareness for SepticSmart Week from September 17 - 21, 2018. SepticSmart Week is focused on getting homeowners and communities to care for and maintain their septic systems. Find out more about the tools and resources that have been created - many allow for jurisdictions to add their own information to the resource.


A select group of national organizations that signed a Memorandum of Understanding (MOU) with US EPA

Recent Updates

NEHA renews the Decentralized Wastewater Management Memorandum of Understanding Partnership

NEHA is part of a select group of national organizations that signed a Memorandum of Understanding (MOU) with US EPA to improve the quality and quantity of resources and education available to professionals in the wastewater field, state and local regulatory agencies, and those whose work involves building on or buying/selling land with dwellings that will use an onsite system. This past month NEHA participated in a renewal meeting and signing ceremony to continue collaboration between the EPA and other decentralized system partners. NEHA is excited to be a part of improving decentralized wastewater management by aiding consumers and professionals in the field. 


Available Wastewater Resources & Programs


The Flooding Preparedness and Response for Private Water Systems page includes a range of resources to assist private well and septic system users before, during, and after a hurricane or mass flooding disaster.

The How Your Septic System Can Impact Nearby Water Sources tool is a newly published set of interactive diagrams which illustrate the relationship between septic systems and drinking water, septic systems and surface water, and ways to improve septic systems and better protect nearby water sources. These resources provide homeowner outreach and education to improve use and maintenance of residential septic systems. An example of the diagrams can be found to the left.   

EPA Septic Wiki

EPA Decentralized MOU Partnership




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