Contra Costa County Water District (CCWD) was formed in 1936 (“County” was dropped from name in 1981) CCWD is a legal entity to contract, purchase, and distribute water provided by United States Bureau of Reclamation.
For its first 25 years, the District dealt with untreated water only, by 1950s, water quality and costs were of a growing concern to residents and treated water service began in 1961. The California Water Service Company was purchased in 1961, at this time the District formed its own treated water division.
Contra Loma Reservoir was built in Antioch in 1965-67 to provide peaking supply for system reliability and emergency storage.
The Ralph D. Bollman Water Treatment Plant was built in Concord 1966-68 and upgraded in 1986 & 1999. The plant uses Ozone primary disinfectant and has a capacity of 75 mgd.
Voters Approved Los Vaqueros reservoir in 1988.
CCWD has 778 miles of pipelines, 40 storage reservoirs, 31 pump stations, 59,947 connections, utilizes 336 employees, serving a population of 500,000.