Archival data for regression models developed to estimate fecal coliform concentrations at five stream sites, Chester County, Pennsylvania (2017)

This data release supports the following publication: Senior, Lisa A., 2017, Estimated Fecal Coliform Bacteria Concentrations Using Near Real-Time Water-Quality and Streamflow Data From Five Stream Sites in Chester County, Pennsylvania, 2007–16: U.S. Geological Survey Scientific-Investigations Report 2017–5075 (https://doi.org/10.3133/sir20175075) The U.S. Geological Survey (USGS), in cooperation with the Chester County Health Department (CCHD) and the Chester County Water Resources Authority (CCWRA), has collected discrete stream samples for analysis of fecal coliform concentrations during March– October annually at or near five gaging stations where near real-time continuous data on stream discharge, turbidity, and water temperature have been collected since 2007 (or since 2012 at 2 of the 5 stations). In 2014, the USGS, in cooperation with the CCWRA and CCHD, began to develop regression equations to estimate fecal coliform concentrations using available near real-time continuous data . Regression equations included possible explanatory variables of stream discharge, turbidity, water temperature, and seasonal factors calculated using Julian Day with base-10 logarithmic (log) transformations of selected variables. Data files in CSV format include datetime, stream discharge, in cubic feet per second, water temperature, in degrees Celsius, fecal coliform bacteria concentrations, in colonies per 100 milliliters, turbidity, in FNU, Julian Day, and calculated or transformed variables of log fecal coliform concentrations, log turbidity, sin(Julian Day/365), and cos(Julian Day/365)]. Data were collected at 5 stream sites, French Creek at Phoenixville Pa., White Clay Creek near Strickersville, Pa., East Branch Brandywine Creek below Downingtown Pa., West Branch Brandywine Creek at Modena Pa., and Brandywine Creek at Chadds Ford, Pa.

本数据集配套支持以下出版物：Lisa A. Senior于2017年发表的《基于宾夕法尼亚州切斯特县5个溪流站点的近实时水质与径流数据估算粪大肠菌群浓度（2007–2016年）》，对应美国地质调查局科学调查报告2017–5075（https://doi.org/10.3133/sir20175075）。
美国地质调查局（U.S. Geological Survey, USGS）与切斯特县卫生部门（Chester County Health Department, CCHD）、切斯特县水资源管理局（Chester County Water Resources Authority, CCWRA）合作，自2007年起（其中2个站点自2012年起），在5个监测站点及其周边区域开展年度3月至10月的离散溪流采样，以分析粪大肠菌群浓度；上述站点自对应起始年份起，持续采集径流、浊度与水温的近实时连续监测数据。
2014年起，USGS联合CCWRA与CCHD，开始基于现有近实时连续监测数据构建回归方程，用于估算粪大肠菌群浓度。该回归方程的可选解释变量包括溪流径流、浊度、水温，以及基于儒略日计算的季节因子，并对部分变量实施以10为底的对数变换。
数据集采用CSV格式存储，包含以下字段：采样日期时间、以立方英尺每秒为单位的溪流径流量、以摄氏度为单位的水温、以每100毫升菌落数为单位的粪大肠菌群浓度、以FNU（散射浊度单位）为单位的浊度、儒略日，以及经计算或变换的变量：对数转换后的粪大肠菌群浓度、对数转换后的浊度、sin(儒略日/365)与cos(儒略日/365)。
本次采样覆盖5个溪流站点：宾夕法尼亚州菲尼克斯维尔的法国溪、宾夕法尼亚州斯特里克斯维尔附近的白粘土溪、宾夕法尼亚州唐宁敦下游的布兰迪万溪东支流、宾夕法尼亚州莫迪纳的布兰迪万溪西支流，以及宾夕法尼亚州查兹福德的布兰迪万溪。