Revision History for DS 836

Stephen P. Opsahl and Cassi L. Crow

Concentrations of Selected Constituents in Surface-Water and Streambed-Sediment Samples Collected From Streams In and Near an Area of Oil and Natural-Gas Development, South-Central Texas, 2011–13

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Posted online April 29, 2014

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Revised and reposted January 28, 2015, version 1.1

Text was revised. On page 17, right column, first full paragraph, the following three statements were added after the first sentence in that paragraph: “Eight of the samples analyzed for MBAS were analyzed after the recommended holding time of 48 hours had been exceeded. Analyzing samples after holding times have been exceeded could affect measured concentration. The data for these samples were included in the report for completeness.”

Appendix 1 was revised. A footnote was added to indicate that 8 of 18 water samples exceeded the recommended 48-hour holding time for MBAS analysis and that 9 of 18 water samples exceeded the recommended 48-hour holding time for nitrate and orthophosphate analysis. 

Appendix 10 was revised. A footnote was added to indicate that 3 of 6 water samples exceeded the recommended 48-hour holding time for nitrate and orthophosphate analysis.