City of Calistoga
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Water / Wastewater Treatment
Kimball Water Reservoir
The City of Calistoga owns and operates a water reservoir and a conventional surface water treatment facility four miles northwest of the city. This water resource produces approximately one half of the total annual water demand for the community.
Kimball Surface Water Treatment Plant
The treatment processes at the Kimball Surface Water Treatment Plant include chemical coagulation, flocculation and sedimentation in a circular clarifier, chlorination, filtration and storage in a 100,000 gallon clearwell.
Dunaweal Wastewater Treatment Plant
The City of Calistoga’s Dunaweal Wastewater Treatment Plant (WWTP) is a 0.84 million gallon per day (mgd) average dry weather flow activated sludge tertiary treatment plant. The treatment processes consist of the following; primary treatment by coarse bar screening at the headworks structure, secondary treatment by aeration and clarification, tertiary treatment by coagulation, filtration and disinfection. After tertiary treatment, effluent may be discharged to the Napa River from October 1st through May 15th (as per NPDES Permit No. CA0037966, Order 00-1312). During the remainder of the year, effluent is distributed for recycled water use or stored for future use in effluent storage ponds. The following sections include detailed descriptions of the treatment processes and the equipment used.
The City of Calistoga owns and operates a water reservoir and a conventional surface water treatment facility four miles northwest of the city. This water resource produces approximately one half of the total annual water demand for the community.
Kimball Surface Water Treatment Plant
The treatment processes at the Kimball Surface Water Treatment Plant include chemical coagulation, flocculation and sedimentation in a circular clarifier, chlorination, filtration and storage in a 100,000 gallon clearwell.
Dunaweal Wastewater Treatment Plant
The City of Calistoga’s Dunaweal Wastewater Treatment Plant (WWTP) is a 0.84 million gallon per day (mgd) average dry weather flow activated sludge tertiary treatment plant. The treatment processes consist of the following; primary treatment by coarse bar screening at the headworks structure, secondary treatment by aeration and clarification, tertiary treatment by coagulation, filtration and disinfection. After tertiary treatment, effluent may be discharged to the Napa River from October 1st through May 15th (as per NPDES Permit No. CA0037966, Order 00-1312). During the remainder of the year, effluent is distributed for recycled water use or stored for future use in effluent storage ponds. The following sections include detailed descriptions of the treatment processes and the equipment used.