2014-11-20_REVISION - M1977036 (3)

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1. Water information 1.1 Introduction The Greeley 35`h Avenue Mine operation is not expected to negatively affect surface water or groundwater. The mining is relatively shallow; typically 15 -50 feet below the ground surface. Impact to groundwater will be minimal within the existing mine. Any water depletions to the Cache la Poudre River associated with mining are currently mitigated to prevent injury to vested senior water rights by having an approved Temporary Substitute Water Supply Plan in place. Estimated water requirements for the project vary depending on several factors including season, precipitation, and construction. Projected water usage estimates range from 25,000 — 3.4 million gallons per month. Larger values of makeup water usage occur during months of anticipated slurry wall construction. Monthly makeup water estimates are shown in Table 2. Table 1: Greeley 3eh Avenue Makeup Water Month Exposed Water Surface Area (acres) Estimated Water for Dust Control and Construction (gal) Actual Water for Dust Control and Construction (gal) May 2013 26.3 1,000,000 678,300 June 2013 26.3 1,000,000 1,705,000 July 2013 26.3 700,000 1,393,400 August 2013 26.3 500,000 1,172,500 September 2013 26.3 500,000 566,900 October 2013 26.3 500,000 425,100 November 2013 26.3 300,000 458,900 December 2013 26.3 125,000 150,900 January 2014 26.3 25,000 - February 2014 26.3 25,000 - March 2014 26.3 150,000 - April 2014 26.3 400,000 May 2014 26.3 700,000 June 2014 26.3 3,400,000 - July 2014 26.3 3,300,000 August 2014 26.3 1,800,000 September 2014 26.3 2,100,000 - October 2014 26.3 500,000 - November 2014 26.3 500,000 December 2014 26.3 1 175,000 - January 2015 1 26.3 1 30,000 -