Applicants for short subdivisions, long subdivisions, and subdivision alterations shall demonstrate an adequate, potable source of water for each new parcel in the proposed subdivision. For purposes of this section, new parcel shall include all parcels created except parcels containing existing residential structures served by existing water supplies. Minimum source capacity for individual and community supplies shall be 1,000 gallons per day/connection. The minimum water quality testing parameters for individual and/or community water system sources shall be a complete inorganic chemical analysis and a recent (less than six months) bacteriological sample. All water quality tests must comply with drinking water standards in Chapters
246-290 and
246-291 WAC. See Chapter
13.08 SJCC for fire flow requirements.
A. Community Water Supplies.
1. For a new community system with groundwater as the proposed source, the yield of the well(s) shall be demonstrated by a pump test as outlined in subsection
(C) of this section. In addition, the well(s) must have complete water quality tests (inorganic chemical analysis and bacteriological sample) submitted prior to preliminary approval.
2. If the applicant proposes to connect to an existing community water system, the water system must demonstrate to the department of health and community services the ability to provide water to the proposed parcels and compliance with current regulations. Prior to final approval the applicant must provide proof of authorization for service connection for the proposed lots.
3. The community water system or expansion of an existing system must be approved, constructed, and a water service installed to the property line of each lot prior to final plat approval.
B. Individual Wells.
1. If water is to be provided by private wells, in order to provide proof of adequate supply for preliminary approval, a well (or wells) with sufficient capacity to serve the proposed lots as a community system must be drilled and tested, or individual wells must be drilled and tested and approved on each lot.
2. Individual wells must comply with the community water supply standards for siting, testing, and source capacity. Said well(s) must be pump tested as outlined in subsection
(C) of this section. Any conditions of approval for the wells will be incorporated as conditions of final plat approval.
C. Seawater Treatment. Desalination of seawater must be designed by a qualified, licensed engineer and meet applicable local, state, and federal requirements. Designs shall comply with Washington State Health Department guidelines.
D. Pump Test Protocol. All new groundwater supplies shall be pump tested in accordance with DOE's WRIS Bulletin 30, Aquifer Test Procedures. The developer shall complete and submit a pump test protocol to be reviewed by the County hydrogeologist prior to testing. Minimum requirements for conducting the pump test include:
1. Pump tests shall be conducted between mid-July and mid-October or as defined by the County hydrogeologist.
2. At least one monitoring well must be used, if available.
3. The developer shall be responsible for costs associated with the aquifer test.
4. At a minimum, the following steps should apply:
a. A step-drawdown test to determine the pumping rate and recovery data,
b. A 24-hour sustained-rate pump test using an automatic recording device, and
c. If the water level does not stabilize or chloride levels increase (greater than 20mg/L on field samples), continued pumping for 72 hours.
E. Minimum Review Requirements. All new groundwater supplies shall be reviewed and include an evaluation of long-term well capacity and impact on the local aquifer. The County hydrogeologist will determine whether all or part of a hydrogeologic site evaluation (subsection
(F) of this section) will be required. The County hydrogeologist will review the initial information and other relevant data and either make a decision regarding the proposal or provide detailed additional testing and analysis requirements needed to evaluate the impacts the proposed withdrawal will have on local groundwater resources. A hydrogeologic site evaluation will be required for projects that have potential for groundwater contamination or impairment. Information required to be submitted for initial review include:
2. Water quality tests for complete inorganic chemical analysis;
3. Surveyed wellhead elevation;
F. Hydrogeologic Site Evaluation. If required, a hydrogeologic site evaluation shall be prepared and address resource availability in relationship to the scope of the project. The hydrogeologic site evaluation must address requirements as specified by the County hydrogeologist which may include but is not limited to the following:
1. Hydrogeologic Setting.
a. Description of the geologic setting of the site illustrated with geologic and soil maps.
b. Description of the occurrence and movement of groundwater in the area, including a general discussion of the aquifers present in the area.
c. General discussion of groundwater availability in the area, including a discussion of historic problems such as well failures or seawater intrusion.
d. A scaled map showing location of wells and springs within 1,000 feet of the site or as required by the County hydrogeologist.
2. Site-Specific Resource Availability.
a. An aquifer test conforming to the guidelines found in WRIS Bulletin No. 30. The test should be analyzed to determine the hydraulic properties of the aquifer (storativity and transmissivity), and to the degree possible, the spatial variability of these properties.
b. A map(s) showing static water level elevations for the aquifer(s) proposed for use for the project.
c. An evaluation of theoretical changes to water level elevations resulting from the proposed withdrawal, and the method that was used.
d. An evaluation of the potential to induce or exacerbate seawater intrusion in the aquifer.
G. Project actions that cannot mitigate potential impacts that degrade or impair the groundwater source will be denied.
(Formerly 13.06.150; Ord. 14-1996; Ord. 14-2000 § 4; Ord. 10-2001 § 9; Ord. 20-2007 § 6; Ord. 22-2013 § 9)