Computer testing at a Pearson VUE Testing CenterApplications to take the CIOWTS test at a Pearson VUE Testing Center must be submitted to IOWWA by December 11, 2017.   The test must be taken at a Pearson Vue Testing Center PRIOR to December 31, 2017.   The CIOWTS Test will not be available after December 31, 3017.

The primary purpose of the certification 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 licensing of installers and to require CIOWTS certification.  Counties currently requiring the CIOWTS credential are Benton, Black Hawk, Bremer, Buchanan, Butler, Chickasaw, Dallas, Delaware, Floyd, Grundy, Jasper, Linn, Marion, Scott, Story, Warren, Washington, and Winneshiek. On January 1, 2018, Jones County will also require the CIOWTS credential for installations.  Please check with your county for specific requirements.

Through a contract with the National Environment Health Association (NEHA), IOWWA will process all IOWWA CIOWTS test applications and manage all renewals.  

To review members and non-members who have the CIOWTS credential, please refer to the "CIOWTS List as of November 1, 2017, Members and Non-Members" PDF file in the Documents & Files section below.

If you are interested in obtaining the CIOWTS credential, please review the IOWWA CIOWTS Quick Facts sheet found in the "Documents and Files" section below. The CIOWTS Test Application can also be downloaded and printed from this section.

  1. Print out the CIOWTS Test Application found below and submit to IOWWA with appropriate payment.
  2. Two options for testing:
    Option 1: Paper/pencil test - this option is no longer available.   
    Option 2
    Computer testing at a Pearson VUE Testing Center.  A valid email address is required for this option so that you will be able to receive the test code required for you to schedule the test.  Applications to take the CIOWTS test at a Pearson VUE Testing Center must be submitted to IOWWA by December 11, 2017.   The test must be taken at a Pearson Vue Testing Center PRIOR to December 31, 2017.
  3. You must receive a score of 70% or higher to pass.  There are three sections to the test: Plan Assessment; Job Staging; and Site Development/Installation.

Sponsored by IOWWA, the one and a half day Installation Overview course is available for the benefit of those taking the CIOWTS exam.  You are not required to take the Installation Overview prior to the test.    The next Installation Overview course is scheduled for Thursday, Nov. 30 and Friday, Dec. 1, 2017 in Anamosa IA.  Continuing education earned from the Installation Overview will be credited to the first two-year credential cycle.   IOWWA member fee: $200.00 / non-member fee: $290.00

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 (i.e. copy of driver’s license or birth certificate) or a readable copy of the applicant’s driver’s license or birth certificate is required with the test application submittal when using a Pearson VUE testing center.

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 conflicts
  3. Knowledge of equipment needs and limitations; materials and supplies; soil characteristics
  4. Ability to make mathematical calculations
  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

There are several options available to verify credential status:

  1. In the Documents & Files section, open the "CIOWTS Listing (member and non-member) as of June 1, 2017.   This is an alphabetical listing of those who currently hold the CIOWTS credential.
  2. Use the CIOWTS Certified Installer Search (search by zip code).   This will result in a list of IOWWA members who currently hold the CIOWTS credential.
  3. Another option is to select "Continuing Education Search" on the left side.   This search will show IOWWA members and non-members and allows you to search by name or company name.   The information lists the credential level (B-Basic or A-Advanced) as well as the credential expiration date.
  4. In the member search, you are able to search by zip code and the logo will show if the person holds the CIOWTS credential.
Important notice concerning a change to the CIOWTS "grace period".  If an individual falls short of meeting the minimum CE hour requirement for the credential and/or does not submit the appropriate renewal fees, he/she will be entered into a one-time grace period that can last for a period of up to 60 days from their credential expiration date.  At the end of the grace period all appropriate fees and continuing education hours must be submitted in order to receive the "active" status.  If a candidate fails to submit the appropriate fees and continuing education hours prior to the end of the grace period, his/her credential is revoked.  In order to re-obtain the credential, the individual must reapply and retake the examination.