SU0015801 - Laserfiche WebLink

Home Browse Search

4 Environmental Analysis 4.10 Hydrology/Water Quality Construction and Decommissioning The BESS facility requires a small amount of water for construction and decommissioning, and a negligible amount for operational use (estimated at close to zero AFY). Therefore, most if not all of the water demand will occur during construction and decommissioning, when water will be used for dust control during both construction and decommissioning and to help condition the soil for compaction during construction (adequate moisture levels are required for proper compaction under any foundations). During the construction phase, it is estimated the Project will require approximately 30.7 of of non-potable water over a construction period of 15 months, including 3 months of commissioning. Project decommissioning would also require approximately 30.7 of of non-potable water, similar to construction. Additionally, some of the natural vegetation will be cleared for the PV solar facility, which actually may result in a higher water retention during construction than under the current vegetation and its associated evapotranspiration. Operations To operate the facility, no measurable amounts of water will be used. The onsite, building-type facilities will be the BESS enclosures. These will be monitored remotely, allow limited human access, and do not provide interior human workspace for long-duration activities (simply for maintenance and repair work). Thus, there will be no need for an onsite water system to supply water on demand. Workers will access the facility for only periodic inspection and maintenance, and will bring their own drinking water. Portable toilets will not be permanently deployed onsite, but only used if needed for specific operations. Installation of the BESS units, access roads, switchyard, and parking areas would create new areas of impervious (or nearly impervious) surfaces on the 106-acre property of which the Project will be built (all of which are currently considered to be pervious lands). The exact value of new impervious surface area has not yet been estimated, but for the purpose of this evaluation will be conservatively assumed to be 18.8 acres. In that case, the change in impervious area represents a loss of about 18 percent of the area available for groundwater recharge on the Project property. However, compared to the surface area of the Tracy Subbasin, the loss of 18.8 acres represents a change of only 0.01 percent of the total basin area. How much of that subbasin area is currently impervious is not known. However, the impervious acreage of this Project is expected to represent a trivial percentage of the currently impervious area within the entire subbasin. As noted above, the water required for the construction period (approximately 30.7 af) is lower than an estimate of the amount of water currently transpired by the existing vegetation (approximately 147 AFY). After construction, Project water consumption would be reduced even further (close to zero AFY), as the operational water use is dramatically lower than the construction water use and evapotranspiration would be less than under current conditions. The reduction in water consumption at the Project site through conversion of land use will provide a benefit to the subbasin. Therefore, the Tracy Subbasin will not be negatively impacted with the construction and operation of the PV solar facility. Mitigation: None required. IMPACT 4.10-3: Would the project substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river or through the addition of impervious surfaces in a manner which would: Griffith Energy Storage Project 4.10-14 Tetra Tech/SCH 2022120675 Draft Environmental Impact Report August 2023