Laserfiche WebLink
C leg/-O2? <br />11 <br />DOTY & ASSOCIATES <br />,, LLC <br />ENVIRONMENTAL, GROUND-WATER AND WASTE MANAGEMENT ENGINEERS <br />1440 BRICKYARD ROAD <br />SUITE 1 <br />GOLDEN, COLORADO 80403-8054 <br />RECEIVED <br />http://www.dotyeng.com <br />bpdoty@dotyeng.com <br />VOICE: (303) 279-9181 <br />FAX: (303) 279-9186 <br />JUN 0 2008 <br />UIVISlurl 01 rteclarnatlon, <br />mining and Safety <br />Mr. Douglas M. Ikenberry,, P.E. <br />Colorado Dept. of Public Health & Environment <br />Mail Code HMWMD-SWIM-B2 <br />4300 Cherry Creek Drive South <br />Denver, Colorado 80246-1530 <br />June 3, 2008 <br />302-17 <br />Subject: Request for Revised Ground-Water Monitoring Frequency <br />Keenesburg Disposal Site <br />Dear Mr. Ikenberry: <br />This letter requests that the ground-water monitoring frequency at the above <br />referenced site be changed to semi-annual. <br />Ground-water samples have been collected on a quarterly basis since March 1993 at <br />the Keenesburg site. Clearly, the regulatory requirement that background be <br />established through collection of a minimum of eight quarterly samples has been <br />satisfied. Constituent concentrations have been sufficiently stable during the period <br />of record that sampling can be conducted less frequently and still be protective of <br />human health and the environment. This is especially true given the low hydraulic <br />conductivity of the subsurface materials, the fact that the ground-water gradient is <br />inward, toward the resaturating pit backf ill, and the lack of use of the shallow ground <br />water in the general area. Therefore, as allowed at B4(B) of the solid waste <br />regulations, we request a semi-annual ground-water monitoring frequency for this <br />facility. <br />Because the Keenesburg site is also regulated under the mining rules, we will prepare <br />a technical revision to our reclamation permit and submit it to the Division of <br />Reclamation, Mining & Safety (DBMS) after receipt of your approval. We will continue <br />the currently approved quarterly monitoring program until such time as we have <br />approvals from both your Division and DBMS. In addition, we will advise both groups <br />when the approvals have been received and when we propose to implement the semi- <br />annual schedule.