These data describe microbiological analyses performed on groundwater samples from domestic drinking water supply collected from 42 groundwater wells in the Central Valley of California. Samples were collected between January 2014 and April 2014 for the Groundwater Ambient Monitoring and Assessment (GAMA) program priority basin assessment of the Madera, Chowchilla, and Kings (MACK) groundwater sub-basins’ shallow aquifers. A total of 75 wells were sampled for the MACK study unit between August 2013 and April 2014. Samples for this dataset were vacuum filtered and plated on MI and mEI agars prior to incubation to promote colony growth. Colonies were tallied by their species into columns for various fecal indicator bacteria (FIBs): total coliforms (TCs), Escherichia coli (E. coli), enterococci. Non-target growths were also counted and tallied. Six additional replicate samples were collected for quality assurance. Of the 579 total FIB colonies detected, 106 were selected for polymerase chain reaction (PCR) analysis with the goal of sequencing their DNA. Selected colonies consisted of both target and non-target growths and were taken from 14 samples collected at 13 different wells. DNA sequencing was successful for 34 of the sampled colonies out of a total of 59 submitted. Results for these analyses were reported in FASTA format with the number of bases and their starting position indicated for each batch. These data support the following publication: Burton, C.A., and Lawrence, C.J., 2021, Identification of bacteria in groundwater used for domestic supply in the southeast San Joaquin Valley, California, 2014: U.S. Geological Survey Scientific Investigations Report 2021–5030, 20 p., https://doi.org/ 10.3133/ sir20215030.

These data describe microbiological analyses performed on groundwater samples from domestic drinking water supply collected from 42 groundwater wells in the Central Valley of California. Samples were collected between January 2014 and April 2014 for the Groundwater Ambient Monitoring and Assessment (GAMA) program priority basin assessment of the Madera, Chowchilla, and Kings (MACK) groundwater sub-basins’ shallow aquifers. A total of 75 wells were sampled for the MACK study unit between August 2013 and April 2014. Samples for this dataset were vacuum filtered and plated on MI and mEI agars prior to incubation to promote colony growth. Colonies were tallied by their species into columns for various fecal indicator bacteria (FIBs): total coliforms (TCs), Escherichia coli (E. coli), enterococci. Non-target growths were also counted and tallied. Six additional replicate samples were collected for quality assurance. Of the 579 total FIB colonies detected, 106 were selected for polymerase chain reaction (PCR) analysis with the goal of sequencing their DNA. Selected colonies consisted of both target and non-target growths and were taken from 14 samples collected at 13 different wells. DNA sequencing was successful for 34 of the sampled colonies out of a total of 59 submitted. Results for these analyses were reported in FASTA format with the number of bases and their starting position indicated for each batch. These data support the following publication: Burton, C.A., and Lawrence, C.J., 2021, Identification of bacteria in groundwater used for domestic supply in the southeast San Joaquin Valley, California, 2014: U.S. Geological Survey Scientific Investigations Report 2021–5030, 20 p., https://doi.org/ 10.3133/ sir20215030.

These data describe microbiological analyses performed on groundwater samples from domestic drinking water supply collected from 42 groundwater wells in the Central Valley of California. Samples were collected between January 2014 and April 2014 for the Groundwater Ambient Monitoring and Assessment (GAMA) program priority basin assessment of the Madera, Chowchilla, and Kings (MACK) groundwater sub-basins’ shallow aquifers. A total of 75 wells were sampled for the MACK study unit between August 2013 and April 2014. Samples for this dataset were vacuum filtered and plated on MI and mEI agars prior to incubation to promote colony growth. Colonies were tallied by their species into columns for various fecal indicator bacteria (FIBs): total coliforms (TCs), Escherichia coli (E. coli), enterococci. Non-target growths were also counted and tallied. Six additional replicate samples were collected for quality assurance. Of the 579 total FIB colonies detected, 106 were selected for polymerase chain reaction (PCR) analysis with the goal of sequencing their DNA. Selected colonies consisted of both target and non-target growths and were taken from 14 samples collected at 13 different wells. DNA sequencing was successful for 34 of the sampled colonies out of a total of 59 submitted. Results for these analyses were reported in FASTA format with the number of bases and their starting position indicated for each batch.

This is a point feature class of environmental monitoring stations maintained in the California Department of Water Resources’ (hereafter the Department) Water Data Library Database (WDL) for discrete “grab” water quality sampling stations. The WDL database contains DWR-collected, current and historical, chemical and physical parameters found in drinking water, groundwater, and surface waters throughout the state. This dataset is comprised of a Stations point feature class and a related “Period of Record by Station and Parameter” table. The Stations point feature class contains basic information about each station including station name, station type, latitude, longitude, and the dates of the first and last sample collection events on record. The related Period of Record Table contains the list of parameters (i.e. chemical analyte or physical parameter) collected at each station along with the start date and end date (period of record) for each parameter and the number of data points collected. The Lab and Field results data associated with this discrete grab water quality stations dataset can be accessed from the California Natural Resources Agencies Open Data Platform at https://data.cnra.ca.gov/dataset/water-quality-data or from DWR’s Water Data Library web application at https://wdl.water.ca.gov/waterdatalibrary/index.cfm.

The dataset includes Escherichia coli concentrations collected by Isleta Pueblo in the Middle Rio Grande in Albuquerque, NM, from 2017 to 2020. These data were pulled from National Water Quality Monitoring Council, 2021, Water Quality Portal, accessed December 5, 2021, at https://www.waterqualitydata.us.

The dataset includes Escherichia coli concentrations collected by Isleta Pueblo in the Middle Rio Grande in Albuquerque, NM, from 2017 to 2020. These data were pulled from National Water Quality Monitoring Council, 2021, Water Quality Portal, accessed December 5, 2021, at https://www.waterqualitydata.us.

The dataset includes Escherichia coli concentrations collected by Isleta Pueblo in the Middle Rio Grande in Albuquerque, NM, from 2017 to 2020. These data were pulled from National Water Quality Monitoring Council, 2021, Water Quality Portal, accessed December 5, 2021, at https://www.waterqualitydata.us.

Low biomass waters provide a unique challenge in the field of microbial ecology. It is difficult to determine, when biomass concentrations are extremely low, whether or not the sequencing data received are of good quality and representative of the waters sampled. Fifty-nine samples including 8 blanks were collected from a low biomass hydraulically fractured well producing from the Niobrara Shale in Colorado. At least 4 samples were collected by filtering the exact volume for each listed here: 1000 mL, 900 mL, 800 mL, 700 mL, 600 mL, 500 mL, 400 mL, 300 mL, 200 mL, 100 mL, 0 mL (blanks).

Low biomass waters provide a unique challenge in the field of microbial ecology. It is difficult to determine, when biomass concentrations are extremely low, whether or not the sequencing data received are of good quality and representative of the waters sampled. Fifty-nine samples including 8 blanks were collected from a low biomass hydraulically fractured well producing from the Niobrara Shale in Colorado. At least 4 samples were collected by filtering the exact volume for each listed here: 1000 mL, 900 mL, 800 mL, 700 mL, 600 mL, 500 mL, 400 mL, 300 mL, 200 mL, 100 mL, 0 mL (blanks).

This data release codifies and attributes values for potential explanatory factors to groundwater well locations and to groundwater basins in California. The groundwater sites are 282,000 wells that have water-quality data and are listed in the California State Water Resources Control Boards' Groundwater Ambient Monitoring and Assessment Program Groundwater Information System (GAMA GIS). The groundwater basins are 515 subbasins defined by the California Department of Water Resources. The potential explanatory factors were selected because they represent factors that may affect groundwater quality. Potential explanatory factors are attributed to groundwater sites relating to: aquifer lithology, land use (percent agricultural, urban, and natural land use), pesticide use, septic tank and underground storage densities, average number of domestic supply users, aridity index, climate (minimum and maximum temperature, and average precipitation), and distance to faults, oil and gas sites, perchlorate, and known and suspected per- and polyfluoroalkyl substances (PFAS) sources. Potential explanatory factors attributed to groundwater basins relating to: climate (minimum and maximum temperature, and average precipitation), land use (percent agricultural, urban, and natural land use), population density and number of domestic well users, septic tank and underground storage densities, and pesticide use. This data release contains a tab-delimited text file containing locations and potential explanatory factors for domestic groundwater sites (Table 1), a tab-delimited text file containing pesticide use in the 500 meter area surrounding domestic groundwater sites (Table 2), a tab-delimited text file containing distances to PFAS sources (Table 3), a tab-delimited text file containing potential explanatory factors within groundwater basins (Table 4), and a tab-delimited text file containing pesticide use within groundwater basins (Table 5).