The Coachella Valley Water District (CVWD) proposes to construct eight perched aquifer groundwater monitoring wells within the Coachella Valley’s Indio and Desert Hot Springs Sub-basin at various previously developed well site locations. The proposed monitoring wells will be used to monitor groundwater in the perched and shallow aquifers to address gaps and provide an improved overall understanding of water quality. The locations of the proposed monitoring well sites are:
1. Gap Well 17 – APN 696-180-067 (City of Indio well site; Ave. 44, Indio)
2. Gap Well 18 – APN 757-250-021 (CVWD Well Site 6807, Ave. 60, Coachella)
3. Gap Well 19 – APN 759-020-029 (CVWD Well Site 6805, Airport Ave., La Quinta)
4. Gap Well 20 – APN 737-200-023 (CVWD parcel at Ave. 83 Drain, Oasis)
5. Gap Well 21 – APN 751-340-018 (CVWD parcel at Ave. 74 and Polk St., Oasis)
6. Gap Well 22 – APN 729-120-020 (CVWD Booster/Reservoir Site 7990, Mecca)
7. Gap Well G3 – APN 654-190-036 (CVWD Reservoir Site 3501, Desert Hot Springs)
8. Gap Well G4 – APN 750-030-009 (CVWD Booster/Reservoir Site 4701, Desert Hot Springs)
Construction is anticipated for a duration of one week at each existing site and will be contained within each existing site. The wells will be installed using a hollow-stem auger, sonic drilling, direct circulation, or mud rotary methods. Initially, the drilling process will require setting a conductor casing and drilling a 4-inch borehole to a varying depth of 50- to 350 feet for each well. Samples of the drill cuttings will be obtained and logged at 10-foot intervals. Upon completion of drilling, geophysical logging of the test bores will be performed. The wells will be designed based on the information obtained from each borehole. Monitoring will occur at each site as needed and conducted by CVWD staff.
The project sites are not located within a conservation area associated with the Coachella Valley Multiple Species Habitat Conservation Plan (CVMSHCP). CVWD Reservoir/Booster Station 4701 is adjacent to the Indio Hills/Joshua Tree National Linkage Conservation Area and subject to the CVMSHCP Land Use Adjacency Guidelines for drainage, noise, toxics, lighting, and invasives. The sites are not subject to the CVMSHCP development mitigation fee because the sites are previously developed.