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sample for several parameters, includine TDS. Upon recent investigation, the laboratory <br />discovered that they actually ran that sample in duplicate for TDS, with both sample <br />results reporting an identical 910 mg/1. Due to a computer error, the laboratory did not <br />log these two TDS results into our computer database or onto the laboratory report. A <br />copy of the raw laboratory data is attached. An updated DMR for this parameter has <br />been sent to CDPHE. A copy is also attached. <br />Review of Hydrologic Data: <br />Hydrologic data was reviewed for 2001 for the subject Outfalls. In addition, five years of <br />historical hydrologic data (December 1996 through December 2001) was reviewed for <br />the three Outfalls (see attached tables). The following was determined: <br />• In the last 5 years, none of the three Outfalls have ever exceeded the current <br />required limits for TSS, Tr Zn, or Tr Fe, with the exception of Outfall 024, which <br />had a single historical TR Zn exceedence of 0.24 mg/1, as opposed to the permit <br />limit of 0.23 mg/1. <br />• In 2001 none of the Outfalls exceed the average maximum concentration limit (1 <br />mg/1) for TR Fe. In fact, available data shows TR Fe results as consistently being <br />an order of magnitude below the average maximum concentration for all Outfalls <br />in 2001. There is no maximum concentration limit for TR Fe. <br />• Only Outfall 022 flowed each week of December 2001. The other two Outfalls <br />flowed only during the first week in December. Dilution effects from the <br />Williams Fork River versus typical low flows and the lack of exceedences seen <br />from the Outfalls in 2001 (when flowing), make any significant Outfall impact on <br />the Williams Fork in December highly unlikely. <br />Based upon the information presented herein, RAGEC is of the opinion that no <br />significant environmental impact from any of the three subject Outfalls has occurred. <br />To conclude, RAGEC's abatement for this data omission began before our January 28, <br />2002 DMR submittal, and before receipt of the February 21, 2002 NOV. RAGEC <br />personnel involved in the omission were contacted on January 23, 2002 to discuss the <br />situation. On January 24, 2002, I followed up with a memorandum (attached). <br />If you have any questions, please contact me at your convenience at (970) 870-2750. <br />Sincerely, _ <br />Brian A. Watterson <br />Environmental Geologist <br />enclosures <br />File:I:\en\env\dmg\nov 2002-003response.doc <br />