The district also oversees small portions of Newport Beach and unincorporated Orange County.

[3] The first Board of Directors included Charles TeWinkle, who was elected as the first president, and Claire M. Nelson, who both would later go on to serve on the inaugural Costa Mesa City Council.

[1][3] Jim Fitzpatrick was a board member elected in November 2010 who also began service on the Costa Mesa Planning Commission in December of that year.

[12] The Costa Mesa Sanitary District is governed by a five-member Board of Directors, each elected to a four-year term.

[13] Beginning in 2020, the Directors were elected by geographic district, rather than at-large, after being threatened by a lawsuit from attorney Kevin Shenkman.