CIOWTS Credential

Certified Installers of Onsite Wastewater Treatment Systems (CIOWTS)  Credential

The NEHA Board of Directors’ Credentialing Committee decided to discontinue the CIOWTS examination because of the high cost of updating the exam.  As a non-profit organization, it would have taken many years to recover the cost of updating the exam. There will not be the opportunity for new applicants to take the CIOWTS examination. However, the CIOWTS designation is still recognized and maintained by NEHA through its credential maintenance program.  Many practicing credential holders have chosen to maintain their credential through ongoing education and NEHA will continue to support those individuals who hold the credential. To see a list of current active CIOWTS credential holders, please visit:

For applicants interested in taking the CIOWTS exam, credential testing is now offered through the Iowa Onsite Waste Water Association (IOWWA). Individuals interested in obtaining this credential should contact for information. Test dates and locations can be found at Testing is generally offered each spring and fall. 

If you currently hold the CIOWTS credential, please continue to enter your Continuing Education (CE) hours via your My NEHA account. You will receive a renewal notice via email 30, 60, and 90 days prior to your credential expiring. Please contact the Credentialing Department at 303-756-9090 ext. 328 or if you have any questions.