Zone 7 Patterson Pass Water Treatment Plant (WTP) Ammonia Facility Replacement Project

2 Documents in Project


SCH Number
Lead Agency
Zone 7 Water Agency
Document Title
Zone 7 Patterson Pass Water Treatment Plant (WTP) Ammonia Facility Replacement Project
Document Type
MND - Mitigated Negative Declaration
Present Land Use
Water Treatment Facility / Large Parcel Agricultural / Water Management
Document Description
As part of the disinfection process, Zone 7 uses chloramination to minimize formation of disinfection byproducts ad chlorinous taste and odors, and to maintain a disinfectant residual in the distribution system. The proposed project includes the removal of the existing gaseous ammonia system at the Patterson Pass Water Treatment Plant (WTP) and replacement with an aqua (or liquid) ammonia system (using a 19 percent ammonia solution). The existing gaseous ammonia delivery components are near the end of their service life and the proposed project is intended to replace the existing system in order to improve the reliability of plant operations and employee and public safety. New facilities proposed under the project include an aqua ammonia tank and storage building, a chemical fill station and underground containment structure, and two additional feed lines. No substantive changes in treatment plant capacity or operation are anticipated as part of the proposed project.

Contact Information

Jack Fong
Agency Name
Zone 7 Water Agency
Contact Types
Lead/Public Agency


Cross Streets
Greenville Road and Patterson Pass Road
State Highways
Arroyo Las Positas

Notice of Completion

State Review Period Start
State Review Period End
State Reviewing Agencies
California Department of Conservation (DOC), California Department of Fish and Wildlife, Bay Delta Region 3 (CDFW), California Department of Health Care Services (DHCS), California Department of Parks and Recreation, California Department of Transportation, District 4 (DOT), California Highway Patrol, California Native American Heritage Commission (NAHC), California Regional Water Quality Control Board, San Francisco Bay Region 2 (RWQCB), Department of Toxic Substances Control, Department of Water Resources, Office of Historic Preservation, Resources Agency, San Francisco Bay Conservation and Development Commission (BCDC), State Water Resources Control Board, Divison of Financial Assistance
Development Types
Other (Water treatment facility (storage blgd, fill stn, feed lines))
Local Actions
Water treatment facility replacement
Project Issues
Aesthetics, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Geology/Soils, Hazards & Hazardous Materials, Noise, Transportation, Vegetation, Wetland/Riparian

Disclaimer: The document was originally posted before CEQAnet had the capability to host attachments for the public. To obtain the original attachments for this document, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at or via phone at (916) 445-0613.

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