Alert: Please correct the errors!
Orange, Riverside, and San Bernardino Counties, representing stormwater dischargers throughout the Santa Ana Basin, through a task force managed by the Santa Ana Watershed Project Authority, are assisting the Regional Water Quality Control Board review beneficial uses and water quality objectives for inland surface waterbodies. This study required compilation of 30 years of bacteria data and development of queries to determine the relative frequency of exceedences of REC-1 use objectives. Results were joined to a layer of bacteria stations and multi-attribute symbology was developed. Stratification of the data record at each bacteria station tested several factors hypothesized to be responsible for exceedences, including wet weather and seasonality. The ArcGIS Spatial Analyst extension was used to allocate rainfall stations for each bacteria monitoring station facilitating the stratification. Exceedences of objectives based on bacteria samples collected during dry weather were compared between seasons. In this paper, results of this analysis will be presented and discussed.