Shortcut Pipeline Improvement Project - Phase 3

The Shortcut Pipeline Phase 3 Improvement Project Amendment, identified by Lake or Streambed Alteration Agreement number EPIMS-CCA-44206-R3, is an agreement executed by the California Department of Fish and Wildlife (CDFW) for the Contra Costa Water District. Pursuant to Fish and Game Code section 1602, the amendment focuses on environmental mitigation measures to prevent the introduction of golden mussels into Walnut Creek and Pacheco Creek. These measures are required to address the discharge of untreated water and include methods such as percolation or desiccation, discharging into the Contra Costa Water Sanitation Sewer system, chlorination, and the filtration of all discharged water to capture the species. Additionally, the agreement mandates a golden mussel monitoring plan to track species presence at specific locations along the affected waterways. The project is located in Martinez, California, within Contra Costa County, specifically situated at Walnut Creek between the western side of the Marathon refinery and the Conco Industrial site development. The CDFW, acting as the Responsible Agency, approved the amendment on November 10, 2025, following a Mitigated Negative Declaration which determined the project would not have significant environmental effects within its jurisdiction, provided that the specified mitigation measures are met as conditions of approval. The Contra Costa Water District serves as the Lead Agency for this project, with administrative oversight provided by Mark Seedall.