Compilation of Environmental Sample Data

The 20 digital datasets available in this report are listed in table 2. The datasets contain analytical data for more than 600 samples collected at the Ely Mine site. Data were received from the USEPA and other supporting agencies in various electronic and paper formats. Only data for samples collected by the USGS were quality assured with respect to quality control samples and correctness in comparison to field notes and reported laboratory results. No quality-control samples are included in the digital datasets.

The original data were formatted for consistency and compiled into 1 of the 20 datasets. Most of the original data attributes were retained, such as historic-sample-location name, sample or laboratory identifier, date and time the sample was collected, analytical result with laboratory qualifier when appropriate, significant figures, units of analytical result, aspect of the sample analyzed (e.g., for water samples, total or filtered; for fish tissue, wet weight or dry weight), method of analyses, the source of the data, and the agency that collected the data. For some samples, multiple analyses were performed for the same constituent using different analytical methods. Null data (i.e., no value) in any of the datasets indicate that this information was not included with the original data. Constituent names were standardized where appropriate; for example, results reported as "Al" were changed to "Aluminum." Analytical units were not standardized for several constituents; for example, within the "Stream_Water_Analyses" dataset, concentrations of calcium are reported in micrograms per liter and milligrams per liter.

A naming convention was developed to identify unique sampling locations. This was necessary because commonly a location had been sampled multiple times by several agencies that each assigned a different identifier to the location. The extent to which a single location was associated with multiple identifiers was determined from an evaluation of spatial data and historical site knowledge. A unique site number was assigned to each location based on an abbreviation of the stream name and distance (in meters) upstream of the mouth. For the sample locations that were not located within a stream (ponds, surface seeps, and mine-waste pile), a site number was assigned based on the description of the location or a historic location name. The site number is common among all the datasets with sample-location-specific information and can be used to associate (link) data from different datasets together.

Table 2 is available as a pdf.