Final Public Notice: St. Helena Hospital Water Main Hardening Project Napa County, California HMGP 4558-750-070R

The U.S. Department of Homeland Security’s Federal Emergency Management Agency (FEMA) proposes to provide federal financial assistance under the Hazard Mitigation Grant Program to Adventist Health St. Helena (Subapplicant) in Napa County, California, to mitigate impacts from multiple hazard types by replacing an existing, aboveground potable water main along Deer Park Road in the City of St. Helena (the City) with a 4- to 6-feet deep underground pipe (Proposed Action). Pursuant to Executive Order 11990 (Protection of Wetlands) and FEMA’s implementing regulations at Title 44 of the Code of Federal Regulations Part 9, FEMA hereby provides interested parties with a notice of its final decision and an explanation of alternatives that were considered.

The purpose of the Proposed Action is to reduce water supply vulnerability, as the existing water main is susceptible to various hazards (i.e., seismic, cold, flood, and wildfire). The Proposed Action consists of the following: site mobilization activities; trenching under the existing pavement where the new underground water main would be located (30-inch-wide, 4-foot-deep trench; 25 linear feet would be 6 feet deep to avoid an existing utility); installing approximately 0.67 miles (3,540 feet) of 6-inch-diameter pipe and, as needed, 4-inch lateral piping with fittings, thrust blocks, and tie-ins; conducting leak testing; backfilling the trench with dirt; covering the trench with Class II aggregate base concrete; decommissioning the existing water main; and project demobilization and cleanup. The existing water main would remain in service while the new water main is installed under the road. After leak testing is conducted and the new piping is connected to the water service, service to the existing water main would be shut off. The majority of the existing water main would be retained in place, apart from two small segments (totaling approximately 5 feet in length) at the upstream and downstream water main connection points, where portions of the existing main would be cut, capped in place, and removed. 

The U.S. Fish and Wildlife Service National Wetlands Inventory map shows a 13.66-acre R4SBC (Riverine, Intermittent, Streambed, Seasonally Flooded) habitat in close proximity to the project area (approximately 150 feet west of the northern end of the project area, and 50 feet east of the southern portion of the project area). 

A map of the project area and its location in proximity to wetlands is available for public inspection. Parties interested in reviewing a copy of the map should contact the FEMA Region 9 Environmental Officer using the contact information provided in this notice. 

Two alternatives to the Proposed Action were considered: the No Action Alternative; and Alternative 1: Covering the Existing Aboveground Pipe. The No Action Alternative would result in no action being taken to protect the water main. This Alternative is not recommended because it would leave the main susceptible to hazards, and it would be at risk for complete loss of service as a result of being crushed, punctured, or otherwise damaged. Alternative 1 included covering the existing aboveground water main with gravel or soil. This Alternative is not recommended due to the potential for erosion of soil and gravel from storm drainage, along with the reduction in protection compared to the Proposed Action and the alteration of existing drainage patterns. FEMA has determined that the proposed project is the only practicable alternative available, meaning the Proposed Action must be implemented in close proximity to identified wetlands. The Proposed Action would have no long-term, significant adverse impacts on the riverine habitat and would benefit the area by reducing the risk of water service loss. In addition, various Best management practices (BMPs) would be implemented during construction, including but not limited to covering and securing open pits outside of active working hours and implementing an erosion control plan’s BMPs, including utilizing silt fences and fiber rolls along project boundaries. Based on the distance between identified wetlands and the project area, construction activities have limited potential to cause any hydrology, wetland, or water quality impacts. The City has declared that the Proposed Action conforms to local floodplain standards, and would be responsible for the management, construction, and maintenance of the Proposed Action. 

Additional information about the Proposed Action may be requested by writing the FEMA Region 9 Environmental Officer at FEMA, 1111 Broadway, Suite 1200, Oakland, California 94607, or fema-rix-ehp-documents@fema.dhs.gov. All requests should be received no later than 15 days after publication of this notice. No action will be taken before this date.