TO: Napa County Housing Commission
FROM: Jennifer Palmer, Executive Director of Housing Authority
REPORT BY: Alex Carrasco, Project Manager
SUBJECT: Calistoga Farmworker Center Public Water System updates and possible recommendation to Housing Authority for purchase of a related capital asset.
RECOMMENDATION
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Discussion of Calistoga Farmworker Center public water system and possible recommendation to the Housing Authority to authorize purchase of capital asset for large volume lead/lag system (arsenic treatment).
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EXECUTIVE SUMMARY
The Calistoga Farmworker Center’s public water system includes eight (8) arsenic absorption columns that contain media to reduce the amount of arsenic in the water to the lodgers and staff. The water operator, Environmental Aqua, monitors the test results of arsenic levels and performs the necessary adjustments when the media has broken down and is no longer working effectively. At this time, Environmental Aqua recommends updating the configuration of this system due to higher concentrations of arsenic and the age of the equipment (installed 2006). The update will provide for better absorption of arsenic and potential long-term cost savings due to greater efficiency (increase media longevity, reduce need to purchase media).
Staff seek a recommendation from the Housing Commission to the Housing Authority to authorize purchase of capital asset in the amount of $17,654 for the purchase of large volume lead/lag system offset by decrease of $17,654 in Water Treatment Services.
ENVIRONMENTAL IMPACT
ENVIRONMENTAL DETERMINATION: The proposed action is not a project as defined by 14 California Code of Regulations 15378 (State CEQA Guidelines) and therefore CEQA is not applicable.
BACKGROUND AND DISCUSSION
The Napa County Housing Authority’s (Authority) farmworker centers each have a Public Water System (PWS) as defined by the State Water Resources Control Board. These PWS must provide affordable, safe drinking water to customers 27/7. Environmental Aqua is Authority’s water treatment operator and is certified by the State of California for Distribution (D2) and Treatment (T2). Environmental Aqua has over thirty-eight (38) years of experience in the water improvement industry.
At the end of fiscal year 2024, water lab results detected higher concentration of arsenic in the raw water at the Calistoga Farmworker Center. Environmental Aqua acted hastily to reduce such levels and began investigation to analyze cause. After thorough evaluation of the arsenic absorption columns, Environmental Aqua identified three factors contributing to higher concentration of arsenic. First, failure of the equipment due to its age (installed in 2006). Second, wear of the absorption column valves and seals. Finally, high concentration of arsenic in the raw water. At this time, Environmental Aqua recommends updating the configuration of the system to a large-volume lead/lag system, which will provide better absorption of arsenic (longer contact between water and media) and potential cost savings due to greater efficiency (increase media longevity, reduced need to purchase media). Updating the configuration is estimated at $17,654, while replacing the existing system is estimated at $16,965.