Disproportionate Economic and Regulatory Challenges of Harmful Algal Blooms in Vulnerable Communities: A Multidisciplinary Analysis

Harmful algal blooms (HABs) have increased in severity and abundance over the last several decades, threatening water quality for an increasing number of water purveyors. Using Clear Lake, California as a case study, we performed three multidisciplinary analyses to evaluate the socioeconomic impact of HAB water treatment in vulnerable communities. First, a water rate analysis was conducted to determine if there is a relationship between source water quality and water rates. Second, a chemical cost analysis was performed to determine if water treatment costs change with seasonal HABs. Third, a regulatory analysis was performed to determine if adequate funding mechanisms exist to alleviate the financial strain caused by HABs in vulnerable communities. Through these analyses, we found that (1) residents served by Clear Lake water purveyors contributed an average of 3% of their gross monthly income (GMI) toward water bills during the study period, double the threshold for affordable water expenditures; residents of three Clear Lake purveyors paid more than triple the threshold; (2) the chemical cost of water treatment at the Golden State Water Company–Clearlake system (GSWC-CS) increased upward of 34% during HAB season; and (3) current funding mechanisms can be improved to address ongoing operations and maintenance (O&M) costs for contaminants of emerging concern, including cyanotoxins.