Twitchell and Mandeville Island Dredged Material Placement Sites (this section is for the Twitchell sites)

2 Documents in Project


SCH Number
Lead Agency
Port of Stockton
Document Title
Twitchell and Mandeville Island Dredged Material Placement Sites (this section is for the Twitchell sites)
Document Type
MND - Mitigated Negative Declaration
Document Description
The Port of Stockton proposes to construct two new placement sites on Twitchell Island (35 and 18 acres) and one new placement site on Mandeville Island (17 acres) for accepting maintenance dredged sediment from the Stockton Deep Water Ship Channel. The proposed project involves construction activities to prepare the new site for use, placing dredge slurry in the sites as part of federal operations and maintenance activities, and maintaining the sites between dredging episodes in the future as needed. Containment berms would be constructed around the perimeter of each proposed placement area using existing on-site soil, and there would be no impacts to wetlands or jurisdictional waters. Berm construction activities would occur over 6 weeks for each site and are expected to begin in August 2015 and be complete by summer of 2016.

Contact Information

Jason Cashman
Agency Name
Port of Stockton
Contact Types
Lead/Public Agency


Cross Streets
West Twitchell Island Road and Twitchell Island Ferry Road
Total Acres
Parcel #
05701400210000, 15701400090000
State Highways
SR 160, 12
San Joaquin River
Other Location Info
Rio Vista

Notice of Completion

State Review Period Start
State Review Period End
State Reviewing Agencies
California Air Resources Board (ARB), California Department of Fish and Wildlife, North Central Region 2 (CDFW), California Department of Parks and Recreation, California Department of State Parks, Division of Boating and Waterways, California Native American Heritage Commission (NAHC), California Regional Water Quality Control Board, Central Valley Sacramento Region 5 (RWQCB), Central Valley Flood Protection Board, Delta Protection Commission, Department of Toxic Substances Control, Department of Water Resources, Office of Historic Preservation, Resources Agency, Resources, Recycling and Recovery, California State Lands Commission (SLC)
State Reviewing Agency Comments
California State Lands Commission (SLC)
Development Types
Other (Dredged material management)
Project Issues
Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Flood Plain/Flooding, Geology/Soils, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Schools/Universities, Septic System, Sewer Capacity, Solid Waste, Transportation, Vegetation, Wetland/Riparian, Wildfire

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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