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Mr. Joe Kraig <br />August 24, 2009 <br />Page 2 <br />the water removed with the mined product. Since the lining of the Heit Sand and Gravel Mine <br />was recently approved for the purpose of the SWSP you have conservatively still assumed <br />depletions resulting from the water lost with the mined product. If an SWSP is requested for <br />2010 the Applicant is hereby notified that replacement of water removed with the mined product <br />is not required as long as the mining of the site occurs with the lined area. <br />Total depletions for the Heit Sand and Gravel Mine during the period of this SWSP will <br />be replaced by fully consumable water leased from the City of Broomfield. <br />Depletions <br />The anticipated net annual depletions for this plan are 30.7 acre-feet for operation at a <br />site with up to 4.8 acres of exposed water surface. Table 1 provides a monthly breakdown of the <br />annual depletions at this site. Annually, these are made up of 14.2 acre-feet of evaporative loss <br />from 4.8 acres of exposed water surface, 14.7 acre-feet of water lost with 500,000 tons of mined <br />product, and 1.9 acre-feet used for dust suppression. <br />Water for dust suppression will be pumped from the settling ponds on the site. In the <br />event that the settling ponds are not available for operational use an existing well, permit no. <br />62972-F, will be used for dust suppression. Should the well be used, the monthly volumes <br />pumped will not exceed the monthly volumes specified in attached Table 2. <br />Depletions resulting from mining operations were lagged to the stream system using the <br />Glover method, a distance from the well to the stream of 2,750 feet for evaporation losses and <br />3,000 feet for operational losses, aquifer transmissivity of 140,000 gallons per day per foot, <br />specific yield of 0.2, and no flow boundary of 10,000 feet. <br />Replacements <br />The proposed source of replacement water for this pit is 42.48 acre-feet of fully <br />consumable effluent leased from the City of Broomfield. The Broomfield water will be released <br />from the City's wastewater treatment plant (WDID: 0201021), which is located on Dry Creek <br />approximately 29.75 miles upstream from the operation. Of the 42.48 acre-feet of leased water <br />from the City of Broomfield, approximately 15% will be lost during transit, based on 0.5% per <br />mile for the 29.75 miles from the Broomfield wastewater treatment plant to the Heit Sand and <br />Gravel Mine. The amount of City of Broomfield replacement water that reaches the Heit Sand <br />and Gravel Mine is 36 acre-feet. The monthly depletions and replacement requirements are <br />found on the attached Table 1. <br />Conditions of Approval <br />I hereby approve the proposed substitute water supply plan in accordance with §37-90- <br />137(11), C.R.S., subject to the following conditions: <br />1. This plan approval shall be valid between September 1, 2009 through August 31, 2010 <br />(period of effluent lease with the City of Broomfield), unless otherwise revoked or <br />modified. If this plan will not be made absolute by a water court action by the plan's <br />expiration date, a renewal request must be submitted to this office with the statutory fee <br />(currently $257) by July 15, 2009.