TMDL Projects
San Joaquin River Dissolved Oxygen TMDL
Implementation Activities

Port of Stockton Dock 20 Aeration Facility

The Port of Stockton owns the aeration device that was constructed at Dock 20 on the Port's West End Complex. The Dock 20 Aeration Facility is funded under a voluntary aeration agreement among participating San Joaquin River DO TMDL stakeholders. The facility injects dissolved oxygen into the San Joaquin River when dissolved oxygen concentrations are less than the Central Valley Water Board's Basin Plan dissolved oxygen water quality objectives. Below are the following documents - the current aeration agreement and the annual operations, maintenance and cost summaries for the Dock 20 facility.

The Aeration Facility was constructed by the Department of Water Resources in 2006-2007 and was demonstrated during a multi-year study of the effectiveness of elevating dissolved oxygen concentrations in the channel through the use of an in-channel aerator. More information on DWR's Stockton Deep Water Ship Channel Demonstration Dissolved Oxygen Project can be found on their website below.

Continuous dissolved oxygen readings in the DWSC can be obtained from the California Data Exchange Center (CDEC).

Port of Stockton - Dredging and Mitigation Aeration Requirements

The Port of Stockton performs maintenance dredging of the berths at the Port, and is required to provide aeration as a mitigation measure.

Source Control – Point and Nonpoint Sources

The primary point source of oxygen demanding substances contributing to the DO impairment is from the City of Stockton Regional Wastewater Control Facility. Other municipal wastewater treatment plants in the SJR watershed may also have the potential to contribute oxygen demanding substances or their precursors. These may include, but are not limited to, the City of Manteca, City of Tracy, City of Modesto and the City of Turlock.

For the purpose of the Control Program, nonpoint source discharges are discharges from irrigated lands – lands where water is applied for producing crops, and includes, but is not limited to, land planted to row, field and tree crops, as well as commercial nurseries, nursery stock production, managed wetlands and rice production.

U.S. Army Corps of Engineers

The U.S. Army Corps of Engineers is responsible for any channel deepening or maintenance dredging in the Stockton Deep Water Ship Channel. The TMDL's Control Program required the Army Corps to submit a technical report identifying and quantifying the various mechanisms by which oxygen demanding substances are converted to oxygen demand and the impact that the Stockton DWSC has on re-aeration and other mechanisms that affect DO concentration in the water column.