Chemical Dosing of Agricultural Runoff

Low Intensity Chemical Dosing of Agricultural Runoff in the Sacramento-San Joaquin Delta, Rio Vista, CA. 2007 – 2010.
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

Link to USGS LICD Website:  

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. 

The project is a collaborative effort between Bachand & Associates, UC Davis and the USGS.  Dr. Bachand is a Lead Principal Investigator. Bachand & Associates leads the construction, implementation, O&M, and hydrologic and water quality 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.  

Manuscripts and Related Reports

Y.K. Henneberry, T.E.C. Kraus, J.A. Fleck, D.P. Krabbenhoft, P.M. Bachand and W.R. Horwath.  2011. Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts. Science of the Total Environment 409: 631–637.

Bachand, P.A.M., C.J. Richardson and P. Vaithiyanathan.  2000.  Phase II Low Intensity Chemical Dosing (LICD):  Development of Management Practices.  Final report submitted to Florida Department of Environmental Protection in fulfillment of Contract No. WM720.  December, 2000.  (Publicly available from Aquatic Commons).