Description
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. This report provides details not previously known on the contribution of anions to the high conductivity observed in the river. Spatial and temporal trends are identified. Correlation equations are obtained to estimate chloride, sulfate, or bicarbonate from specific conductance. The data in this report also lends insight into potentially natural occurring background levels of ions and locations of possible concentrated inputs into the river.
