Arcata Wastewater Treatment Facility Improvements-Levee Augmentation

The City of Arcata is implementing improvements to its Wastewater Treatment Facility in Humboldt County, specifically focusing on levee augmentation. This project, identified by solicitation number 2020100483, involves a 30 percent design plan set funded by FEMA to bring the levee to a consistent height of 15 feet NAVD 88. The project was approved on October 20, 2025, and has been determined to have no significant environmental effect under CEQA, with a Negative Declaration prepared. Construction will utilize unpainted corrugated steel metal sheet piles driven vertically into the soil, with reinforced concrete used in areas where utilities prevent sheet pile installation. The scope also includes the placement of engineered fill with light rock facing and the installation of a storm gate system at the existing entrance. All work must comply with the current California Building Code and FEMA standards for the VE zone, with essential facilities classified as Flood design class 4. Environmental monitoring will be conducted by the City of Arcata Environmental Services and qualified biologists to protect avian nesting species, salt marsh plant species, and the threatened northwestern pond turtle.