Environmental Health
Drinking Water & Wells
Public Water Systems
  Group B Compliance  
  Sampling Requirements   l  Reporting Requirements  l
 Recordkeeping Requirements  l  System Maintenance & Operation  l  Other Info

Group B systems have many requirements, from both the state and local jurisdictions. Systems failing to meet these requirements are subject to enforcement action. This may include notifying customers, lending institutions, or local building authorities about system inadequacies, which could affect loan approvals and building permits. Key operating requirements are listed below. To read the complete requirements, go to the Washington Administrative Code (WAC 246-291). For questions about other sources of drinking water, contact the DOH at 800-521-0323.

Sampling Requirements

  • Bacteria Collect a water sample and have it analyzed for coliform bacteria at least once every 12 months. The sample should be taken at the farthest end of the distribution system, or as directed by the Environmental Health Department.
  • Nitrate Collect a water sample and have it analyzed for nitrate every 36 months. NOTE: For new systems, this requirement begins 36 months after an initial inorganic and physical analysis.
  • Other Contaminants Additional samples are required in areas of known contamination, or if treatment is provided for any inorganic chemical or physical contaminant. Systems providing treatment must collect samples before and after treatment. The Health Dept will determine how often samples must be taken.
  • State-certified lab analyzes all samples All samples should be tested by a state-certified lab. For a list of certified laboratories, visit the WA State Dept of Ecology Certified Water Laboratories Database.
    NOTE: In order to receive monitoring credit, the water system name, identification number, and system type (Group B) must be included on the lab form submitted with the water sample.

For instructions on collecting a water sample for the County water lab, see Water Testing Instructions and Pick-up Locations.

Reporting Requirements

  • Water facilities inventory and report form (WFI) Submit an updated WFI form to the Health Dept at least once every 3 years, and within 30 days of water system changes, such as the number of homes being served, the owner or operator name, or a new address or contact phone number. Updates speed retrieval of information for your use or lending institutions requiring information for loan approval.
  • Bacteria detected Contact the Health Dept before the end of the next business day after the laboratory notifies the system that fecal coliform or E. coli has been detected in a sample, and within 10 days if coliform is detected.
  • Maximum contaminant level (MCL) violations Contact the Health Dept before the end of the next business day after the laboratory notifies the system of an MCL violation. Water system customers must be contacted within 14 days.
  • Other records Provide operational records to the Health Dept upon request.

Recordkeeping Requirements

The following information must be retained for the period specified.

  • Bacteriological and turbidity analyses keep for 5 years
  • Chemical analyses (including nitrates) keep for as long as the system is in operation
  • Other records of operation and analyses keep for 3 years
  • Records of corrective action and public notifications keep for 3 years
  • System evaluations and related material keep for 10 years

System Maintenance and Operation

  • Sanitary control area Protecting a water source from potential sources of contamination is one of the most important aspects of owning and operating a public water system. The system owner must maintain and enforce covenants to protect source water. Covenants generally cover a 100-foot radius around the well, but the size of the protected area may vary.
  • System operation and reliability You must guard against contamination from unprotected cross connections, and conduct operations and maintenance in a way to minimize failures and provide safe, reliable water to customers. If power outages, pump failures, or other problems occur, you must notify your system customers.
  • Conserve water All water systems should conserve water. The Health Dept may require newer systems to incorporate specific conservation measures. For tips on conserving water, see Water Conservation Tips (WA Dept of Ecology). NOTE: If your system-wide water use exceeds 5,000 gallons a day, or the total property being irrigated by the system exceeds one-half acre, you must get a water right permit from the Department of Ecology.
  • Budgeting All water systems should budget and establish rates to meet expenses. Contact the Health Dept for information on water system budgeting.

Other Information

  • Expansion Before a system expands beyond the existing number of approved connections, plans should be submitted to the Health Dept for approval. If more than 14 residences eventually will be served, proceed as if you have a Group A public water system. See WAC 246-290 for requirements.
  • Other resources For other useful information and links, see Other Information and Resources.
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This page last updated: 04/19/22