Wash. Admin. Code § 246-291-125

Current through Register Vol. 24-21, November 1, 2024

Section 246-291-125 - Groundwater source approval

(1) Groundwater sources submitted to the department or health officer for design approval under WAC 246-291-120 must comply with the following requirements:

(a) Drinking water shall be obtained from the highest quality source feasible.

(b) All permanent groundwater sources must:

(i) Be designed to be physically connected to the distribution system;

(ii) Be a drilled well constructed in accordance with chapter 173-160 WAC; and

(iii) Meet water quality requirements under WAC 246-291-170.

(c) The department or health officer shall not approve a design for a new or expanding Group B system using a GWI source.

(d) The department or health officer shall not approve a design for a new or expanding Group B system using a potential GWI source until a hydrogeologic evaluation is completed by a licensed hydrogeologist or engineer that determines the source is not GWI. The GWI evaluation and determination must be completed before the department or health officer will review the Group B design report.

(2) Before pursuing groundwater source approval under this section, a purveyor shall contact the department or local health jurisdiction to identify any additional requirements.

(3) A purveyor shall provide a copy of the following to the department or health officer to obtain groundwater source approval:

(a) The water right permit, if required, for the source, quantity, type, and place of use;

(b) The water well report, as required under WAC 173-160-141;

(c) The well site inspection report form completed by the department or local health jurisdiction, or designee;

(d) A map showing:

(i) The project location;

(ii) A six hundred foot radius around the well site designating the preliminary short-term groundwater contribution area; and

(iii) The perimeter of a one hundred foot SCA, meeting the requirements in subsection (5) of this section.

(e) A map showing topography, distances to the well from existing property lines, buildings, potential sources of contamination within the six hundred foot radius around the well, and any other natural or man-made features that could affect the quality or quantity of water;

(f) The recorded legal documents for the SCA;

(g) Results from an initial analysis of raw source water quality from a certified lab, including, at a minimum:

(i) Coliform bacteria;

(ii) Inorganic chemical and physical parameters under WAC 246-291-170, Tables 2, 3, and 4; and

(iii) Other contaminants, as directed by the department or health officer in areas where it determines that other contamination may be present.

(h) Pump test data establishing groundwater source capacity including, but not limited to:

(i) Static water level;

(ii) Sustainable yield;

(iii) Drawdown;

(iv) Recovery rate; and

(v) Duration of pumping.

(i) Additional pump testing in locations where water resource limitations or known seasonal groundwater fluctuations may affect future reliability as directed by the department or health officer.

(4) Groundwater source capacity.

(a) A groundwater source for a Group B system with residential connections must be pump tested to determine if the well(s) and aquifer are capable of reliably supplying water that meets the minimum requirements under Table 1 of this section.

(b) A groundwater source must be pump tested to determine if the well(s) and aquifer are capable of supplying water at the rate required to provide the water volume as determined under WAC 246-291-200 for a source supplying a Group B system with:

(i) Nonresidential service connections; or

(ii) Both residential and nonresidential service connections.

(c) Where a locally adopted watershed plan or ecology watershed rule under Title 173 WAC establishes a higher water supply requirement, the purveyor shall use the higher value to assess the adequacy of the source of supply.

(d) A purveyor shall design the Group B system to meet the requirements under Table 1, even if a locally adopted watershed plan or watershed rule under Title 173 WAC limits water use below the values in Table 1.

Table 1 Minimum Source Capacity and Water Supply for Residential Service Connections

County	Gallons per day per dwelling unit
Clallam, Clark, Cowlitz, Grays Harbor, Island, Jefferson, King, Kitsap, Lewis, Mason, Pacific, Pierce, San Juan, Skamania, Skagit, Snohomish, Thurston, Wahkiakum, and Whatcom	750
Adams, Asotin, Benton, Chelan, Columbia, Douglas, Ferry, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Okanogan, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman, and Yakima	1,250

(5) SCA.

(a) A purveyor shall establish the SCA around each groundwater source to protect it from contamination.

(b) The SCA must have a minimum radius of one hundred feet, unless technical justification submitted by a licensed hydrogeologist or engineer to the department or health officer supports a smaller area. The justification must address geological and hydrogeological data, well construction details, and other relevant factors necessary to provide adequate sanitary control.

(c) The department or health officer may require a larger SCA if geological and hydrological data support such a decision.

(d) A purveyor shall own the SCA, or the purveyor shall have the right to exercise complete sanitary control of the land through other legal provisions.

(e) A purveyor shall record a restrictive covenant to the title of each property that is sited partially or completely within the SCA to protect the SCA in perpetuity.

Wash. Admin. Code § 246-291-125

Statutory Authority: RCW 43.20.050 and chapter 70.119A RCW. 12-24-070, § 246-291-125, filed 12/4/12, effective 1/1/14.