C-4 Well site re-design and water treatment design

The project consists of the design and construction of a new groundwater treatment system and a well at the City’s existing C-4 Well site. The project will enable the City to treat constituents detected in groundwater produced by the C-4 Well and return the well to beneficial use while ensuring that water delivered to consumers meets applicable state and federal drinking water standards. The treatment system will address PFOS, as well as manganese and arsenic. PFOS has been detected in groundwater produced from the C-4 Well and is now subject to increasingly stringent regulatory requirements. As a result, the C-4 Well cannot be operated for potable water supply without appropriate treatment. The proposed improvements will include treatment tanks and associated filtration equipment, piping, a chlorination/disinfection facility, and related electrical, SCADA, instrumentation, and water-quality monitoring equipment. A portion of the existing block wall at the well site will also be reconfigured to accommodate and enclose the additional treatment equipment. The project will utilize the existing C-4 Well site and will not require development of a new well site. The C-4 Well is permitted by the California Division of Drinking Water (DDW) to produce approximately 3,500 gallons per minute (gpm). The project does not propose to increase the well’s permitted production capacity; rather, it will provide the treatment necessary to allow the existing well to operate in compliance with applicable drinking water requirements.The project involves improvements to an existing facility and is intended to maintain and improve the reliability and quality of an existing public water supply. The project is therefore proposed to be categorically exempt from CEQA pursuant to State CEQA Guidelines Section 15301 (Class 1), Existing Facilities, which applies to minor alteration of existing structures, facilities, mechanical equipment, or topographical features involving negligible or no expansion of existing or former use.