An official website of the United States government.

Due to a lapse in appropriations, EPA websites will not be regularly updated. In the event of an environmental emergency imminently threatening the safety of human life or where necessary to protect certain property, the EPA website will be updated with appropriate information. Please note that all information on the EPA website may not be up to date, and transactions and inquiries submitted to the EPA website may not be processed or responded to until appropriations are enacted.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

EPA's Study of Hydraulic Fracturing and Its Potential Impact on Drinking Water Resources

Guide to retrospective case study data reports

Section 1 – What is being analyzed

For each case study site, EPA researchers took samples from a variety of sources and tested them for a broad range of substances and chemicals, including components of hydraulic fracturing fluids. Water conditions, such as temperature and dissolved oxygen referred to as  “parameters” were also monitored and recorded. These are listed in the first table labeled, “Analytes and Parameters.” (Analytes tab)

Although each case study site has different geology and hydrology, EPA generally uses the same water quality test methods for all the sites to assess conditions in the area.

Analytes and Parameters

Section 2 – Understanding the Data

Many of the data have notes and labels that represent important descriptions for understanding what the values listed mean. All of the possible data notes and abbreviations are listed  in the following reference tables:

Quality Assurance/Quality Control Definitions, Data Qualifiers and Data DescriptorsQuality Assurance/Quality Control DefinitionsData QualifiersData DescriptorsClick on the individual picture to view larger image

Section 3 – Key for Sample ID Numbers

Each sample taken has a unique identification number. The Key explains the numbering system for the samples.

NEPA=Northeastern PA, SWPA=Southwestern PA, RB=Raton Basin, WISETX= Wise Co., TX

Section 4 – Data Tables

Data for the samples are grouped together in tables for Parameters, Metals, Volatile Organic Compounds, etc. The sample ID’s will appear in more than one table depending on the analytes included in each table.

Data for the samples is grouped together in tables for Parameters, Metals, Volatile Organic Compounds, etc.Data Table 1Data Table 2Data Table 3Data Table 4
Click on the individual picture to view larger image