Water-quality data including mercury and methylmercury at selected sites in the Cache Creek watershed, Yolo County, California

This dataset includes water-quality and sediment data for 647 environmental samples collected at 53 surface-water sites in Cache Creek (Cache C) watershed, Yolo County, California, between December 2009 and April 2019, and data for 190 associated quality-control samples (replicates and blanks). About 90 percent of the samples were collected at the following six primary sites that were sampled most frequently, and the other 39 extra sites were sampled only 1-5 times each. In addition, continuous turbidity measurements were made at 8 sites to aid with the calibration of turbidity measurements. The sites Cache C at Rumsey (11451800), Cache C at Yolo (11452500), and CCSB Inlet at Rd 102 (11452600) are upstream of the Cache C Settling Basin (CCSB); all other sites are in the CCSB and are shown on the map included in this data release.

NWIS_Site_Number: Field_ID:
11451800 Cache C at Rumsey
11452500 Cache C at Yolo
11452600 CCSB Inlet at Rd.102
11452900 CCSB Outlet
11452800 CCSB S. Abutment Spillway
384115121402501 CCSB N. Abutment Spillway

Constituents analyzed include total mercury and methylmercury in dissolved and particulate forms, reactive divalent mercury in particulate form, suspended sediment, dissolved organic carbon, and absorption-fluorescence data for dissolved organic matter. The grain-size distribution of suspended sediment in selected samples is also reported. Six data tables and a Data Dictionary were prepared for this data release. All tables are provided as machine readable tab-delimited text (*.txt) files and as Excel formatted (*.xlsx) files. The data dictionary provides definitions and details presented in the data tables, including analytical methods citations. Two of the six data tables present and summarize quality control results collected for the study.