Wastewater Treatment Plant

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History and Description


The existing site for the City’s wastewater treatment plant (WWTP) at 10059 Twin Cities Road was initially brought on-line in 1983, and provided treatment for approximately 0.83 million gallons per day (mgd). This WWTP provided for secondary treatment utilizing a comminutor, an aeration basin, oxidation ponds, and chlorine injection for bacteriological disinfection. In the winter (November-April), the WWTP was permitted to discharge to Laguna Creek, a tributary to the Consumnes River. In the summer (May-October), the WWTP reclaimed all water on City owned land for irrigation.


In 1991, the WWTP was upgraded as mandated by Federal law to full secondary treatment. The WWTP was expanded to a capacity of 3.0 mgd of wastewater. The upgrades included a headworks, oxidation ditches, secondary clarifiers, chlorine contact chamber for disinfection, and sulfur dioxide used for dechlorination. Solids removed from treatment are stored in lagoons and injected subsurface in adjacent city owned and leased farm land. A bond in the amount of $9.77 million was used to pay for these improvements.

At this time the City has a treatment capacity 3.0 mgd and is currently operating at a daily average flow of 2.0 mgd. The City owns approximately 380 acres at this site. The city also leases about 170 acres which is utilized in water reclamation for agriculture. 


The California Regional Water Quality Control Board Central Valley Region (RWQCB, a division of the California Environmental Protection Agency) issued a new National Pollutant Discharge Elimination System (NPDES) permit in December 2015 which classifies the City of Galt as a major discharger. The NPDES permit is a document that allows the City of Galt to discharge treated wastewater within the compliance requirements outlined within the permit. The RWQCB utilizes criteria for the permit from the adopted Water Quality Control Plan for the Sacramento and San Joaquin River Basins known as the Basin Plan. The Basin Plan designates beneficial uses, water quality objectives, and implementation policies for the purpose of achieving water quality objectives within all waters of the Basin. The City seasonally discharges to Laguna Creek which is a tributary to Consumnes River and both are within the Basin Plan.

The Basin Plan water quality objectives were established to protect surface and ground water from contamination. The maximum contaminant levels are specified in Title 22, California Code of Regulations (CCR). The Basin Plan contains stringent requirements to ensure that surface and groundwater do not contain chemical or toxic substances in concentrations that adversely affect drinking water supply, agriculture supply, and other beneficial uses. The Laguna Creek is within the Basin Plan and therefore is required to meet these water quality objectives. Since 2011, the WWTP has undergone two major construction projects which meet the mandates and objectives of the Basin Plan.