LACOSAN Full Circle Effluent Pipeline Project, Update to the 2004 Preliminary Design Report

The County of Lake is inviting sealed proposals for an update of the Full Circle Effluent Pipeline Preliminary Design Report which was initially issued in November of 2004.  Lake County has a long history of beneficial wastewater recycling and reuse. In 1997 the first phase of a project between the Lake County Sanitation District (LACOSAN), Northern California Power Agency (NCPA), and Calpine Corporation saw the completion of a treated effluent pipeline between the Southeast Regional Wastewater Treatment Plant, the Middletown Treatment Plant and the two geothermal power producing partners operating in a known geothermal resource area referred to as the Geysers.  This first phase was followed closely by a second phase of construction which gathered treated effluent from the Northwest Regional Wastewater Treatment Plant and the Clearlake Oaks County Waterworks District Treatment Plant and conveyed it to the SETP and ultimately on to the Geysers. This project known as the Basin 2000 project collected treated effluent from ten communities along the northern and eastern shores of Clear Lake. At the time of construction, the Basin 2000 project conveyed 85% of the countywide effluent to the Geysers providing a many faceted benefit to the County. The project utilizes wastewater recycling to enhance and protect the water quality of Clear Lake and generate power with a low carbon footprint.  In 2004 a Preliminary Design Report was completed for a project which would provide the same collection of treated effluent from wastewater treatment plants located on the western and southern shores of Clear Lake. This work has been given the name “Full Circle” because it continues and completes the reuse of treated wastewater from wastewater treatment plants encircling Clear Lake. The goal of the Full Circle Effluent Pipeline is to convey treated wastewater from existing wastewater treatment plants (WWTPs) at Lakeport and Kelseyville around the south side of Clear Lake and to inject this flow into the existing Southeast Geysers Effluent Pipeline (SEGEP) near Lower Lake for Geysers injection. To maximize flexibility for effluent reuse and improve injection quality, as well as reduce pipeline-fouling potential, the effluent from both Lakeport and Kelseyville WWTPs may be treated to tertiary (California Title 22) standards. Additionally, for reliability and redundancy reasons as well as implementability consideration, water may be drawn from Clear Lake and injected in the system, and water in the system may be used for agricultural irrigation along the pipeline alignment. There is renewed interest in the Full Circle project and preliminary discussions with the multiple partners previously involved indicates support for the project. There is a need to review and revise the former Preliminary Design Report, which was completed in November 2004 to account for changes. New technologies have emerged, new pipeline alignments may need to be considered as the highway has shifted, and new partners may want to participate in the potential for beneficial reuse of the treated effluent. Proposals should be submitted in accordance with the requirements of this solicitation, which are contained herein.