2009-08-05_PERMIT FILE - M2009035

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RARE EARTh SCIENCE nn • aoo9-a35 www.rareearthscience.com August 3, 2009 Martin Azcarraga MA Concrete Construction 2323 River Road Grand Junction, Colorado 81505 Re: Wetland Opinion " 32.5 Road Property Mesa County, Colorado Dear Mr. Azcarraga: IMID ? w 0 5 2009 plVj$y®n of Recla+'ngiofl, Mining and Safety At the request of Eric Trinklein at Austin Civil Group, Inc., Rare Earth Science, LLC (Rare Earth) evaluated the 32.5 Road Clifton Sanitation District property in Mesa County, Colorado (County Parcels 2943-231-00-944, 2943-231-00-948, 2943-144-00-948, and 2943-144-00-946) for the presence of wetlands potentially under the jurisdiction of Section 404 of the Clean Water Act. The property is currently the proposed site of a future MA Concrete Gravel Pit, and the 112 Reclamation Permit application process with the Colorado Division of Reclamation, Mining and Safety (DRMS) is in progress. I personally inspected the parcels on July 14, 2009, and concluded that no wetlands under the iurisdiction of Section 404 of the Clean Water Act currently exist on the aroaerty within areas proposed for gravel mining activities. The Proposed Mining Plan is enclosed with this letter. The parcels consist of approximately 80 acres north of the Colorado River and east of Colorado Highway 141, near the community of Clifton. The north part of the property (approximately 43 acres) is occupied by the basins of seven decommissioned sewage treatment lagoons, bare ground, and a large wildlife pond in a former gravel pit which spans the boundary with a neighboring property to the east. The lagoon basins and the bare ground areas are encompassed by the Proposed Mining Plan, but the wildlife pond is not involved. The bare ground consists of disturbed upland soils (gravelly loam) and access ways. The lagoon basins, according to Brian Woods of Clifton Sanitation District, are lined with a thick layer of bentonite clay. Since decommissioning, portions of the lagoon basins have developed stands of herbaceous hydrophytic (wetland) vegetation. The lagoons basins were constructed and bermed at or near the natural or original grade on the property, rather than excavated below grade, and sources of surface water discharge or input (other than precipitation) no longer exist at the decommissioned lagoon basins. The Colorado Department of Public Health and the Environment approved the decommissioning of the lagoon basins in 2006. On July 20, 2009, 1 spoke with Carrie Rinderle of the U.S. Army Corps of Engineers (Corps) about the jurisdictional status of the decommissioned lagoons. According to Ms. Rinderle, the Corps considers the lagoons PO BOX 1245 * NOMA, ColoRAdo 81428 * 970.527.8445 * dAWN@RAREEARThSCiENCE.COM