The Water Facility Inventory (WFI) form provides us with information about your water system, including:
- Current names, addresses, and telephone numbers of system owner and primary contact.
- Your systems' source of supply and water treatment.
- Type and number of connections and population served.
We use WFI information to calculate your system's annual operating permit and monitoring requirements.
Your WFI can be downloaded by accessing the WFI page on Sentry Internet. Click the link and follow the instructions below.
- Read the Disclaimer, select "I Accept," then click "Submit."
- Enter your Water System ID number in the “Water System Id” field, then click "Submit."
Note: You can download multiple WFIs by separating each PWS ID# with a comma, but no extra spaces. (Example, "ab999,ac394,98765")
- The WFI will display in a moment. You can print or download the WFI to be updated and returned.
Currently, we do not have an online option to update your WFI. You must download a copy and return it to us.
- Annually—Purveyors of community, NTNC, and TNC systems are required to submit an annual WFI update to the department.
- Within 30 days of any change in name, category, ownership, or responsibility for management of the water system, or addition of source or storage facilities
Updates are required based on a quarterly schedule determined by the type and size of the water system.
- Group A Community systems having more than 500 services and all SMA owned systems (regardless of system type). Reminder sent: October. Submit by December 15.
- Group A Community systems having less than 500 services. Reminder sent: January. Submit by March 15.
- Group A-TNC and NTNC Systems. Reminder sent: April. Submit by June 15.
- Special Groups, including state and federally managed water systems, and Group B systems with 10 or more connections. Reminder sent: July. Submit by September 15.
- Review each field to ensure your information is correct.
- To make corrections or update information, use red ink or a red font. Cross out the wrong information on the WFI, then write or type the correct information next to it.
- If all the information is correct and there are no changes to make, mark box 35, “Update—No Change.”
- Add your Signature, Printed Name, Title, and the Date.
Detailed instructions for updating each field on the WFI can be found in Instructions for Completing the WFI 331-621 (PDF).
This information is critical because it allows us to contact the right person during an emergency. Please ensure ALL contact information in fields 6, 7, 9, and 10 is accurate. Fields 6 & 9 are only for the Primary Contact information. Fields 7 & 10 are only for the legal Owner information.
Please include the following.
- Full name including middle initials—no nicknames or initials.
- Mailing address—if mailing address is a PO Box, the street address is also required.
- Daytime, evening, and cell numbers.
- Email address.
There are two options for returning your updated WFI.
Mail—send a paper copy to:
Office of Drinking Water
Central Services – WFI
PO BOX 47822
Olympia WA 98504
One year prior to any ownership changes, the current owner must notify the Office of Drinking Water and the water system customers. They must also provide ODW with all ownership change documents and final sale records before the transfer can be processed by the Office of Drinking Water, including:
- An updated WFI, plus the water system Name and ID # on each document submitted to this office.
- A recorded copy of the current document showing the present legal owner of the water system. Any one of these documents is acceptable.
- Bill of Sale.
- Statutory Warranty Deed.
- Deed of Trust.
- Quitclaim Deed.
- The new owners name and contact information.
- If the new Owner is a Legal Entity (Inc., LLC, etc.), you must also provide the name and contact information for the Legal Entity, and two governing members. Feel free to use a separate piece of paper.
If an SMA is being added, changed, or renewed on the WFI, a signed copy of the contract is required within 30 days of the effective date of the contract. Please email a copy to firstname.lastname@example.org and DWOpCert@doh.wa.gov along with your updated WFI.
Additional information about SMA's can be found at Satellite Management Agencies (SMA).
What is the difference between a Community (COMM), Nontransient Noncommunity (NTNC), and Transient Noncommunity (TNC) systems?
Water system types are distinguished by the number of people served as well as the frequency. (Click to enlarge.)
The following links will help explain the WFI in more detail and contains key information you will need if you own or manage a public water system:
- Instructions for Completing the WFI 331-621 (PDF). Detailed instructions for each field on the WFI Form.
- Recommended reading for all system operators and owners (PDF)
- Group A Transient Noncommunity (TNC) Water Systems
- Group B Public Water Systems
- Satellite Management Agencies (SMA)
WFI and Operating Permit Program Coordinator