Agricultural Runoff Chemical Dosing

Low Intensity Chemical Dosing of Agricultural Runoff in the Sacramento-San Joaquin Delta, Rio Vista, CA,  2007 – 2014. 

Collaborating Organizations: 

Bachand & Associates, UC Davis Department of Land Air and Water Resources, and USGS

Funding Organization:

Department of Water Resources and CALFED, Proposition 13 

Project Description:

The Sacramento-San Joaquin Delta is a valuable resource, with large swaths of agricultural land surrounded by a river system that provides water to approximately 22 million Californians.  However, agricultural  drainage water from the Delta Islands contributes somewhere in the range of 13 – 49%  of dissolved organic carbon (DOC) to the San Joaquin Sacramento river system depending upon the season.   When these waters are chlorinated or ozonated for use as drinking water, carcinogenic disinfection byproducts (DBPs) are formed posing a human health concern.  Furthermore, during nearly one hundred years of farming, the islands have subsided  approximately 20 feet. This subsidence has created a large hydraulic head against the levees, increasing the risk of levee failure and catastrophic flooding of farmland.  

Based on research conducted by Dr. Philip Bachand in the Florida Everglades, Bachand & Associates is working collaboratively with USGS and UCD to test the use of chemical dosing in combination with constructed wetlands to remove DOC from agricultural drainage water and to mitigate subsidence.  This project is a combination of laboratory and field scale studies.  

Dr. Bachand is the technical lead on the project and Bachand & Associates leads the construction, implementation, O&M, and data collection of the two-year constructed wetland field study.  Bachand & Associates designed and is constructing an in situ field-scale pilot study, including nine 4,000 ft2 mesocosm cells, coagulant dosing systems, water delivery structures, and data collection systems.  Work was done in conjunction with laboratory-based research conducted by the University of California at Davis.  

Project Description on USGS  


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