Environmental Health
Drinking Water & Wells
Public Water Systems
  Group B Water System Approval Process  
  Review Process/Final Approval  l  Well Site Application/Inspection  l  Preliminary Engineering Report  l 

Final Engineering Report  l  Satellite Management Agencies  l  Well Isolation Covenants

All Group B systems are regulated by the Thurston County Environmental Health Division (Environmental Health Division). These systems must comply with Article III [PDF] of the Thurston County Sanitary Code, WA State DOH requirements of Chapter 246-291 WAC Group B Public Water Systems, and associated Design Workbook [Word Document on this Web Page] and Design Guidelines [PDF] (help you complete the workbook) for Group B Public Water System Approval.

For projects located within a city jurisdiction or Thurston County Coordinated Water System Plan Urban Service Area [PDF], additional standards may apply.

One well serving two residences is a separate classification than those with 3 or more connections. These water systems are classified as 2 Single-Family Residential water supply and are regulated by the Environmental Health Division.

NOTE: Expansion of a 2 Single-Family Residential water supply to provide additional connections will require the supply to meet all the requirements of Article III that apply to public water systems. This includes a design of the proposed system expansion by a qualified professional engineer and subsequent approval by the Health Department.

Review Process / Final Approval

  1. Submit copy of an approved Well Site Supplemental Application [PDF]. See Well Site Application/Inspection for requirements.
    NOTE: An approved Well Site Application is required prior to drilling and before the Water System Design Application can be submitted.
  2. Submit a completed Group B Public Water System Design Application [PDF]. Also submit with the application:
  3. Staff will review the water system design and Preliminary Engineering Report and send a letter granting preliminary water system approval, if all the requirements are met.
  4. After the water system design has received preliminary approval and construction is completed, the engineer shall inspect the water system to assure compliance with the approved construction documents.
  5. Within sixty (60) days of the inspection, the professional engineer shall submit a completed Certificate of Inspection and Installation of Public Water System Projects form along with the Final Engineering Report.
  6. Staff will review the documents and grant final water system approval and the required sampling frequency, if the requirements are satisfied.
  7. Staff will recommend approval of the Certificate of Water Availability (COWA) after the water system has been granted final approval.

NOTE: If the water system is within a city jurisdiction or Thurston County Coordinated Water System Plan Urban Service Area [PDF], the Environmental Health Division will mail the application to the applicable jurisdictional authority and will hold permit issuance until their review and comment is completed.

Complete application package requirements are outlined on the Well Site Supplemental Application [PDF], Group B Public Water System Design Supplemental Application [PDF], and Water System Design Guidelines [PDF].

Well Site Application/Inspection

Prior to drilling a new well or obtaining approval for an existing well, the location of the well must first be approved by the Health Dept. Submit a completed Master Application [PDF] and Well Site Supplemental Application [PDF] package to the Permit Assistance Center with the applicable fee (see Fee Schedule [PDF]). Also submit with the application:

  • Project site plan include the proposed well site, 100-foot sanitary control area around the well, any structures, all septic system components, drainage ditches, stormwater infiltration ponds, and public roads within 200 feet.
  • Proposed well site location flagged on the property

NOTE: Complete application package requirements are outlined on the Well Site Supplemental Application [PDF] and Well Site Application Guidelines [PDF]).

Health Dept staff will review the well site application and issue approval if all requirements are met. (This includes an on-site evaluation of topography, potential contaminant sources, and hydrologic suitability of the well location.) Once the well site has received approval, contact a licensed well driller to have the well drilled and tested for capacity and water quality.

NOTE: Prior to drilling, a Start Notification should be sent to both the Washington State Department of Ecology and Thurston County Environmental Health Division, by the well driller. For additional information and application form, see For Well Drillers Only.

Preliminary Engineering Report (Design Report)

A Preliminary Engineering Report, including detailed plans and specifications for the proposed water system, shall be prepared and submitted by a Washington State licensed professional engineer for review and approval.

The preliminary report shall follow the guidelines in the Group B Workbook, including Satellite Management Agency (SMA) information (see below), draft documents (covenants, easements, operations and management agreements), well driller's report, water quantity and quality reports, and construction documents.

Final Engineering Report

Upon completion of the water system construction, the professional engineer shall inspect the system to assure compliance with the approved construction documents. Within sixty (60) days, the professional engineer shall submit a completed Certification of Construction and Inspection form, along with the Final Engineering Report, to the Environmental Health Division.

It is important that all items listed in the plan approval letter are submitted in the report in order to avoid delaying the final review and approval of the project.

The final engineering report will be reviewed by Environmental Health Division staff and a letter will be sent to the system owner (and a copy to the professional engineer) upon approval. The letter will indicate the required sampling frequency. The system is now ready for use.

NOTE: Projects having staged construction shall submit certification document for each separate stage prior to approval and use of any segment.

Satellite Management Agencies

All new water systems shall be owned or professionally managed by an approved Satellite Management Agency (SMA). For the names of SMAs serving Thurston County, see List of Approved Satellite Management Agencies [DOH].

It is important to contact the SMA prior to system design so that the agency's design and operating requirements are incorporated into the design. A draft contract with the proposed SMA should be submitted with the Preliminary Engineering Report. If an SMA is unavailable, contact Thurston County Environmental Health.

Well Isolation Covenants

The owner of a public water supply is required to have physical control over the well isolation area (normally a 100-foot radius). Generally, this is accomplished through the filing of protective covenants (either a Declaration of Covenant [PDF] or Restrictive Covenant [PDF], or both) for the well isolation area.

  • Declaration of Covenant filed when the water supplier owns all or part of the area in the sanitary control area
  • Restrictive Covenant filed when someone other than the water supplier owns portions of the sanitary control area

It is important that the covenants are obtained prior to drilling a well or completing the water system design (see Covenant Fact Sheet [PDF] for instructions and examples).

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This page last updated: 03/31/22