Analysis of Anionic Contribution to Total Dissolved Solids in the Lower San Diego River


Janae Fried
BS Candidate
Advisor: Dr. Kathy Thorbjarnarson

Friday, December 11th, 2015
CSL 422 – 9:00am
watch Janae’s defense

The Lower San Diego River has been severely impacted by several anthropogenic sources.  Specific water quality objectives are set in the San Diego Basin Plan for this reach of the river and many of these objectives are not being met.  Research included in this report will test 17 sites in the Lower San Diego River watershed for sulfate, bicarbonate, carbonate, and chloride ion concentrations and analyze their relationship to the observed specific conductivity values over a nine-month period.  It was found that chloride is the dominant ion in the region and exceeds the water quality objectives set by the water quality control board at most sites over the study period.  Many sites display other trends of particular interest and further research to find the cause behind these trends is encouraged. This report provides details not previously known on the geochemical make-up of the Lower San Diego River while offering insight into potentially natural occurring background levels of ions from geologic materials and will help future researchers to locate sites of point source pollution.