The primary purpose of the credential is to set a standard of practice and create a baseline of knowledge for onsite wastewater system installations. Iowa counties are encouraged to adopt regulations providing for the certifying of installers and to require the CIOWTS credential.  

Counties currently requiring the Basic Level CIOWTS credential:
Benton, Black Hawk, Bremer, Buchanan, Butler, Cedar, Chickasaw, Clayton, Dallas, Delaware, Floyd, Grundy, Hamilton, Hardin, Iowa, Jasper, Jones, Linn, Marion, Scott, Story, Tama, Warren, Washington, and Winneshiek.   Check with the county sanitarian for specific requirements.   A map showing the counties that require the CIOWTS credential can be found in the Documents and Files section at the bottom of this page. 

The IOWWA Certified Installer of Onsite Wastewater Treatment Systems (CIOWTS) Handbook can be viewed or downloaded in the below "Documents and Files" section.  

A pass score of 70% or higher must be achieved to receive the CIOWTS credential.    The credential runs on a two-year cycle.   During each two-year cycle, the credential holder must have a minimum of 12.0 hours of continuing education earned in the onsite wastewater industry.    IOWWA has events scheduled throughout the year that provide continuing education approved for the CIOWTS credential.   For those taking the Installation Overview course prior to a scheduled test, the 12.0 CE hours earned will be applied to the first two-year cycle.

CIOWTS Test Study GuideThis study guide, published by the Consortium of Institutes for Decentralized Wastewater Treatment, is a 464-page notebook that serves as a self-study aid for those interested in testing for the Certified Installer of Onsite Wastewater Treatment Systems (CIOWTS) credential.    The handbook is also a valuable office or field reference guide and can be purchased as a publication or PDF file.  Order through Iowa State University: Installation of Wastewater Treatment Systems ManualNOTE: You must set up an account to purchase - the password must be a MINIMUM of 12 characters.   

1. Complete the  CIOWTS Test Application (found at the bottom of this page) and submit to IOWWA.  Instructions for application submittal is found on page 3 of the application.  You can download the CIOWTS Test Application found below in the Documents and Files section at the bottom of this page (various formats).    If you are not able to download the application, email  contactus@iowwa.com and request a copy.    You cannot take the CIOWTS Test without the submittal of the CIOWTS Test Application prior to the test date.  

2. If you have less than one year of experience installing septic systems, it is mandatory that you attend the Installation Overview Course prior to taking the test.   The course and test are held in the same 2-day event.

3. The next course, testing date and location can be found on the Training and Events tab, Upcoming Trainings list page of this website.   The installation Overview Course and CIOWTS are generally planned for early spring and late fall each year.   If there is enough interest, the course and test may be held mid-summer.  

For both the Basic and Advanced Levels you must verify that you are at least 16 years old.   Proof of age must be submitted prior to taking the test at the test site registration (e.g. copy of driver’s license or birth certificate).   

Basic Level Exam - 75 questions, 2 hours to complete
Advanced Level Exam - 125 questions, 3 hours to complete

All questions are written in multiple choice format.   The CIOWTS exam is based upon the following content areas.  Next to each subject area the approximate percentage of questions in that content area on the exam.   State and local codes are not part of the test.

1. Knowledge of site plans; basic surveying; topography; site features
2. Knowledge of materials requirements; standards and specifications; soil profile descriptions; pump performance; treatment and dispersal technologies
3. Ability to conceptualize an installation activity
4. Ability to make mathematical calculations of area, volume, elevation, rates, measures and weights

1. Knowledge of installation plans; elevations; topography
2. Ability to transfer designer’s plan to site; reconcile variations; identify conflict
3. Knowledge of equipment needs and limitations; materials and supplies; soil characteristics
4. Ability to make mathematical calculation
5. Ability to identify subcontractor and homeowner needs and potential conflicts

1. Knowledge of soil characteristics; ability to recognize soil characteristics in the field
2. Knowledge of specifications and installation techniques for tanks, baffles, filters and screens, piping and fittings, aggregate and fill material, proprietary treatment components, pumps and siphons, liner materials, valves, switches and tubing
3. Knowledge of electrical requirements
4. Knowledge of gravity and pump/siphon dosed system requirements
5. Knowledge of timers and remote monitoring
6. Knowledge of bedding, testing, pipe connection methodologies
7. Knowledge of pump performance specifications; total dynamic head in pressurized systems
8. Ability to make mathematical calculations, conversions

The CIOWTS credential runs on a two-year cycle. During each two-year cycle, the credential holder must have a minimum of 12.0 hours of continuing education earned in the onsite wastewater industry.    Refer to the "Upcoming Trainings" in the drop-down on the IOWWA  "Trainings and Events" web page.   Upcoming events from multiple sources are shown.  For those taking the Installation Overview course prior to a scheduled test, the 12.5 CE hours earned will be applied to the first two-year cycle.

IOWWA will accept up to 6 CE hours of online training per credential cycle and 2 CE hours per credential cycle for county contractor meetings (even if multiple county contractor meetings are attended). 

Continuing education earned at workshops sponsored by the DMACC Onsite Wastewater Training Center are pre-approved by IOWWA.    IOWWA is provided with a list of attendees.      IOWWA also accepts the IDPH Plumbing Code and Plumbing disciplines.  You must submit the course dates, titles, instructor and location to IOWWA.

If CE hours are obtained at an event not sponsored by IOWWA, prior approval for the course will need to be made from IOWWA.  Course title, description and presenter(s) biography information will need to be submitted to IOWWA at least 30 days prior to the event.   If you receive CE hours from other sources, be sure to provide IOWWA with a copy of your certificate or record of CE hours earned.  Email to IOWWA,  contactus@iowwa.com or fax to 1-480-802-6643.  

CONTINUING EDUCATION SEARCH:   For the CE search, you can enter a full name, at least 4 letters of the first or last name, or at least 4 letters from the company name.     The results will show all records within the search criteria.  To see the data for only one person, find their name in the list and click on the name.  The listing shows IOWWA members as well as non-members.

The list will include continuing education hours as noted in the IOWWA database.    If an event is not listed, please email contactus@iowwa.com the Certificate of Attendance showing the event name, sponsoring affiliation, location, date of event and continuing education hours received.

IMPORTANT NOTE FOR CIOWTS CREDENTIAL HOLDERSYou must know your current credential cycle dates when checking your continuing education.    Events listed are for 2 years however only those that fall within your two-year CIOWTS credential cycle will count.

* Use the CIOWTS Certified Installer Search (search by zip code).   

file IOWWA - CIOWTS HANDBOOK 0.19 MB           
file CIOWTS TEST APPLICATION 0.08 MB           
file CIOWTS Required County Map.pdf 0.23 MB