These customers were responsible for treating the water so it would be safe for their own customers. The privately-owned California Water Service Company became a buyer of CCCWD water In 1951. Later CCCWD bought all of CWSCs holdings in Contra Costa County, including its treatment, pumping, storage and distribution facilities. In 1961, CCCWD took responsibility for water service in the central part of Contra Costa County. In 1965, CCWD broke ground to construct the Contra Loma Reservoir in Antioch. It was designed with a capacity of to serve for peak storage and emergency supply for the Contra Costa Canal. In 1966, CCWD began construction of the Bollman Water Treatment Plant in Concord. It is now the largest treatment plant in the district, with a capacity to treat 75 MGD. The District Center office building constructed in Concord during 1971 consolidated many of CCWD's offices and maintenance facilities in one location. The building was subsequently named for Thomas Carlson, who led the formation of the District. In 1988, CCWD sought voter approval of the Los Vaqueros proposal that included building a reservoir inside a watershed. The voters approved the project, then estimated to cost $800 million. After completing the engineering work, ground was broken for construction in 1994, and the project completed in 1998. CCWD expanded the Los Vaqueros Reservoir to a capacity of in 2011 by extending the height of the dam. The expansion was completed in 2012. CCWD built the Randall-Bold Water Treatment Plant in Oakley in 1992 to treat water using ozone disinfection technology. The plant was expanded in 2007, and now has a design capacity of 50 MGD, and is expandable to 80 MGD. The facility includes an on-site underground storage reservoir for treated water. Governance Board of Directors CCWD is governed by five directors, each of whom is elected from a division that contains approximately 110,000 persons and serves a four-year term. Candidates for director positions must be registered voters, and must reside within the district which they represent. The elections are held in November, every two years on even-numbered years. CCWD director elections follow the same schedule as the statewide office elections. Current Directors, as of 2022, are: Patt Young, Director, Division 1 John A. Burgh, Director, Division 2 Ernesto A. Avila, P.E., President, Division 3 Antonio Martinez, Vice President, Division 4 Connstance Holdaway, Director, Division 5 Management The General Manager is responsible for the