Treatment Requirements - In California, our water is treated under the State Department of Health Services requirements as specified in Title 17 and Title 22 of the California Health and Safety Code and Chapter 7 of the California Safe Drinking Water Act. The State requires the District to periodically test the water and report the results to its customers.

Our water is taken from the Cosumnes River at Granlee’s Dam and pumped into Lakes Calero, Chesbro and Clementia from November 1 until May 31 of each year. The stored water is used throughout the year for the needs of the community. These lakes work as large settlement basins before the water is transferred to the Water Treatment Plant at the foot of the Lake Chesbro Dam.

Treatment Process - The location and type of Water Treatment Plant was dictated by physical constraints, location of the lakes, available land, and quality of the stored water. The first treatment facilities in the early 1970’s consisted only of chlorination. In 1978, 1.5 MGD capacity was constructed to meet the increased demands of development and upgraded treatment requirements. In 1987, a duplicate plant with 2.0 MGD capacity was constructed. The treatment process is comprised of coagulation, sedimentation, followed by filtration and finally disinfection. Both of these plants were retrofitted in 1995 to meet the new Surface Water Treatment Rules.

The very high quality water you receive is due to the eight stage process used by the filters to meet water quality and quantity to meet the needs of the community. The filters are designed with sand and coal beds that remove any solids and most taste and odors from the water as well as microscopic bacteria and organisms.

Storage Capacity - Water is processed through the treatment plants through chlorine contact chambers and pumped to storage in the 1.2 MG storage tank on Rio Oso Drive and the 3.0 MG storage tank on Van Vleck Ranch east of Rancho Murieta. The two storage tanks hold a two day supply of water for the District as well as a four hour supply at 4,000 gpm for fire protection.

System Operations - The system is divided into two separate systems; a pressure system and a gravity feed system. The area north of Guadalupe Drive is the pressure system and its water comes from the booster system at the Rio Oso Drive storage tank. The rest of the system is gravity flow and the water comes from the Van Vleck Tank through the south area across the yellow bridge to the area south of the second Guadalupe Drive.