Surface Water - Fecal Indicator Bacteria Monitoring Results

This dataset contains fecal indicator bacteria (FIB) monitoring results collected from surface waters across California. It includes results for _Escherichia coli_ (E. coli), enterococci, fecal coliforms, and total coliforms - key indicators used to assess microbial water quality and potential health risks associated with recreational water use.

The data has been cleaned and standardized to ensure consistency and usability. For each valid data point, the dataset also includes calculated 6-week and 30-day geometric means, which are commonly used to evaluate long-term water quality trends and compliance with bacteria water quality objectives. Some records are excluded from the final dataset during processing. These typically include duplicate or replicate results, records with missing or invalid result values, or any data that cannot be used to calculate a geometric mean. These records are saved to the "Excluded Records" data resource.

This dataset serves as the primary data source for the Water Boards My Water Quality Portal [Safe to Swim Map](https://mywaterquality.ca.gov/safe-to-swim/content/interactive_map/index.html), which provides the public with timely information about potential health risks associated with water contact recreation at monitored sites.

Data is sourced from the [California Environmental Data Exchange Network](https://ceden.org/) (CEDEN) database, BeachWatch database, and the Central Valley Water Board [Lower American River Recreational Water Quality Map](https://experience.arcgis.com/experience/47e27f245e044ac2a8e15083307e75f6/?draft=true&org=waterboards). There is some overlap with the [CEDEN Water Chemistry dataset](https://data.ca.gov/dataset/surface-water-chemistry-results). Both portal datasets draw from the same source, but the resources here are updated more frequently to support the Safe to Swim map.