Group A Transient Non-Community Water Systems

Information on this page is geared to the specific needs of Transient Non-Community (TNC) water system owners and operators. It is designed to make their jobs easier and help them comply with federal and state requirements.

TNC water systems provide drinking water to a population that changes day to day. They include campgrounds, hotels, rest areas, and restaurants with their own water supplies, among others.

TNC water systems serve:

Twenty-five or more different people each day for 60 or more days within a calendar year;
Twenty-five or more of the same people each day for 60 or more days, but less than 180 days within a calendar year; or
One thousand or more people for two or more consecutive days within a calendar year.

Group A Transient Non-Community water systems are regulated under Chapter 246-290 of the Washington Administrative Code.

Group A TNC Water System Design Guidelines and Workbook

Group A Transient Non-Community Water System Design Guidelines 331-676 (PDF)
These guidelines explain how to design Group A-TNC water systems to ensure safe, adequate, and reliable drinking water for those the water system will serve. They will also help you prepare a complete Group A-TNC Design Workbook 331-677, linked below.

Group A TNC Water System Design Workbook 331-677 (Word)
Completing this fillable Workbook satisfies project report, design, and source approval requirements for a new or expanding Group A-TNC water system (WAC 246-290-110, -120, and -130, respectively). Useful information for completing this workbook is found in the Group A-TNC Water System Design Guidelines 331-676, linked above.

Monitoring Requirements

Monitoring requirements vary for TNC water systems depending on the system's characteristics. You can find your monitoring requirements for your particular system online in Sentry Internet Data. View or download your system's Water Facility Inventory (WFI). Look on page 2 of your WFI in sections 33 and 34 for your system's monitoring schedule for Coliform and Nitrates.

Example Only

Coliform Bacteria. Start sampling for coliform bacteria according to the schedule on the second page of your Water Facilities Inventory (WFI) form in Section 33. The coliform schedule specifies the minimum number of coliform samples required from your water system each month per WAC 246-290-300. For questions, contact the regional office.

Nitrate Monitoring. Nitrate monitoring is required for your TNC water system per WAC 246-290-320. Please refer to the nitrate monitoring schedule in Section 34, second page of your WFI form. For questions, contact your regional office.

How to Collect and Submit Coliform and Nitrate Samples to a Certified Laboratory

Coliform Information and Public Health Advisory Packet

Coliform Information Packet. Materials to help you better understand total coliform bacteria. The packet contains information about what coliform is, how to test for it, and what to do if you find it in your water system.
Coliform Public Health Advisory Packet. Tools to help you respond to the presence of fecal contamination in your water supply. If you have fecal contamination in your system, the Department of Health will work closely with you to help resolve the situation and determine if a public health advisory is required.

Nitrate Public Health Advisory Packet

Nitrate Public Health Advisory Packet. Materials in this packet are designed to help you respond during times of high nitrate levels in your water supply. If you have nitrate contamination in your system, you will be working closely with the Department of Health to resolve the situation and make sure your customers are adequately notified.

Additional Program Requirements

Planning. The foundation of a safe, successful, and sustainable public water system. You are required to maintain a Small Water System Management Program per WAC 246-290-105. For questions, contact your regional office.

Engineering. These requirements apply to new projects, construction, treatment changes, source changes, or other engineering concerns. Each regional office has engineering staff assigned to specific counties to provide technical assistance and review of water system design. For questions, contact your regional office.

Sanitary Surveys. All Group A water systems are required to have a sanitary survey once every three or five years per WAC 246-290-416. A sanitary survey is a periodic inspection of water system facilities, operations, and records used to identify conditions that may present a sanitary or public health risk. Our staff members conduct sanitary surveys. However, in some counties, we contract with local health jurisdiction staff or an independent consultant to conduct the surveys. A fee is charged for the sanitary survey per WAC 264-290- 990(3)(c). For questions, contact your regional office.

Operating Permit and Operating Permit Fees. All Group A water system owners are required to obtain an annual operating permit and pay the appropriate fees per WAC 246-294. Operating permit fees are calculated based on information you report on your WFI form. Fees vary based on system type and size and are explained on the back of the annual fee statement/application form that we send out each year. For questions, contact your regional office or Headquarters.

Accredited Drinking Water Laboratory. All water quality samples must be analyzed at an accredited drinking water laboratory. To ensure your system receives proper credit for samples, remember to include your public water system identification number, which is a combination of the first five digits and letters on all submitted samples. Fully complete each section of the chain of custody lab analysis form. Incomplete or unreadable lab analysis forms may result in the need to re-sample. Lab personnel can provide you with instructions on how to collect samples for various tests. To find a list of accredited labs in your area visit Ecology's lab search website. For questions, contact Headquarters.

Water Facilities Inventory (WFI) Form. All owners of Group A water systems are responsible for keeping their WFI information current and accurate within 30 days of any change to WFI information WAC 246-290-480(2). Even if no changes to your WFI information have occurred, owners are still required to submit a signed and dated WFI form to this Department each year. You can download a copy of your current WFI through Sentry Internet. All you need is your Public Water System (PWS) ID number. For questions, contact your regional office or Headquarters.

Cross-Connection Control. All TNC systems shall apply the principles and provisions of WAC 246-290-490, including subsection (4)(b), as applicable to protect the public water system from contamination via cross-connections. Additionally, water systems shall comply with provisions of WAC 51-56-0600 of the Uniform Plumbing Code (UPC). The UPC addresses the installation of backflow preventers. Backflow preventers are required to be tested annually. You can find guidance on development and implantation of our cross-connection control (CCC) program in Cross-Connection Control Rules and Definitions 331-355 (PDF) and Cross-Connection Control for Small Water Systems 331-234 (PDF).

Other Requirements

Seasonal Water System. If your water system is occupied only part of the year, start-up and shut-down procedures are important to follow to ensure your water is safe to drink. Collect several coliform samples at different locations in your distribution lines two weeks prior to opening the water system to the public. These coliform samples are additional to the required coliform samples and are for water system’s information only. Please follow the procedures provided in Start-Up Procedures for Non-Community Water Systems 331-310 (PDF) and Shutdown Procedures for Non-Community Water Systems 331-311 (PDF). For questions, contact your regional office.

Satellite Management Agency (SMA). If your water system is required to have an SMA per RCW 70A.125.060 and WAC 246-290-035, one can be found on our Approved Satellite Management Agency List. An SMA can help oversee the daily operational activities of the public water system, water treatment facility, and/or distribution system. For questions, contact Headquarters.

Surface Water Systems. If your water system has surface water sources, they are subject to extensive federal and state requirements to protect public health. Group A surface water sources are subject to requirements identified in Part 6 of Chapter 246-290 WAC. This regulation complies with the federal Surface Water Treatment Rule and includes filtration, disinfection, operating, monitoring, and reporting requirements. For questions, contact your regional office.