Fish Slough Groundwater Monitoring Project, Fish Slough Site

Fish Slough Groundwater Monitoring Project, Fish Slough Site

The California Department of Fish and Wildlife (“CDFW”) proposes to construct one new groundwater monitoring site in northern Fish Slough for the purposes of obtaining subsurface geology information, conducting groundwater elevation monitoring, and water quality sampling and analysis. Work included in the project consists of borehole drilling, monitoring well construction, development and testing, and instrumentation. The proposed project is estimated to take a total of 30 days to complete once work begins. Well drilling and construction will require the installation of a temporary well pad at the proposed well site of approximately 180 feet by 180 feet per well, where total projected impacts will occur. The temporary well pad will be located adjacent to existing roads. Temporary impacts may include extension of temporary access roads to the site, and temporary above-ground piping and tanks to direct discharge water. The well pad will accommodate the drill rig, material staging, equipment, and parking. A truck mounted Direct-Mud rotary drilling rig would be used to drill and construct the monitoring well. Target borehole depth in the deep aquifer is 1,200 feet. Temporary equipment needed for the project includes a backhoe, crane, main and backup drill rigs, and vehicles to transport personnel, materials, mobilize and demobilize equipment, and transport waste. All equipment will be cleaned prior to being brought to the project site to prevent transportation of non-native plant material. Upon completion of construction and well development activities, the site will be cleaned up and all material and equipment will be removed from the site. Final well site completion will consist of the installation of a small concrete well pedestal and a steel well monument to house the monitoring well. Mud-rotary drilling requires the use of a water/bentonite clay mixture. During drilling operations, the Contractor will temporarily stockpile residual drilling fluid and drill cuttings at the project site. During well development and testing, initial development water will be directed to settling tanks so that any drilling fluid and/or sediment may settle out within the tank prior to discharging at the project location. If heavy equipment is used during the bird breeding season (May 15th-July 30th), a nesting bird survey will be conducted within 100 feet of the project area one week prior to scheduled activities to determine possible effects that the project will have on nesting birds. If nesting birds are discovered, sound barriers or buffers may be established as needed around nests to minimize impact from the proposed action.

Mono

Northern California