Septic Systems

Ensuring proper design and installation to ensure adequate protection of public health and the environment.

In order to prevent pollution of all the water supplies in the state, both public and private, septic systems must be designed, installed, operated and maintained properly to ensure the protection of public health and the environment. To ensure the water sources of New Hampshire are protected to the greatest extent possible, NHDES must review design plans and specifications for proposed septic systems to ensure the proper siting, construction and operation of these systems. 

Once the designed plans have been approved by NHDES and, if required, the municipality, NHDES will issue an Approval for Septic System Construction. Prior to using a septic system, both an Approval for Construction and an Approval for Operation must be obtained. Plans for proposed septic systems must be designed, prepared and submitted by an individual authorized by NHDES, unless an individual homeowner does the work for his/her own domicile.

The electronic files of septic system applications can be found on the Subsurface Systems Bureau’s OneStop website.

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Can't find what you're looking for?

Can't find what you're looking for?

Use our website search by typing in keywords like “site assessment,” “well release” or “local approval.”

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Did you know?

Did you know?

Septic systems installed within the protected shoreland of waterbodies are subject to setbacks from the water.  Read more about regulations on the location of septic systems within the protected shoreland.

Designer and Installer Training and Certifications

NHDES issues permits to septic system designers and installers to ensure that effluent disposal systems are properly designed and installed, and the Subsurface Systems Bureau holds certification exams, including the required continuing education. For details, check out the Septic Designer and Installer Certification page.

For Continuing Education Seminars, check out the Approved Seminar List.

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Many changes to systems require Approval for Construction 

An approval for construction must be obtained prior to converting a structure from seasonal to full-time occupancy, prior to increasing the load on an existing septic system and/or commencing any additions to a structure; replacement, expansion or relocation of a structure, subject to the requirements of RSA 485-A:38, II-a. 

Approval status  

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An inspector will determine whether the system meets requirements 

A NHDES inspector will inspect the newly-constructed septic system and evaluate the system to ensure that it has been installed in accordance with the intent of the approved plan. Once the inspector has determined that the system meets all applicable requirements, an electronic Approval for Septic System Operation will be completed with a digital copy maintained by NHDES.  

Regional Inspectors  

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Guidance and permit applications for septic systems 

A septic system is required for any structure from which wastewater will be discharged on site and to which a water supply is or will be connected. Properly designed, installed and maintained, your septic system should give you many years of trouble-free service. NHDES provides guidance for submitting applications, which can also be submitted online through e-permitting.    

Find the applications  

Archive Records

The Subsurface Systems law was enacted in 1967, so records do not exist if the structure was constructed prior to 1967. From 1967 to 1971, state records mainly consist of those septic systems installed within 1,000 feet of a surface water. The catalog of these records is not always complete. From 1967 to 1986, state records consist only of paper records. The municipality where the structure is located may have either paper or electronic records. From 1986 to present, state records consist of paper and some electronic.   

Submit an Archive Request
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Did you know?

Did you know?

If you suspect a violation of NHDES septic regulations, you can submit an official complaint form to NHDES Land Resource Management (LRM) for investigation into the alleged violation. File a complaint  


For general septic system questions and Reviewer of the Day