2005-11-16_REVISION - M2004078 - Laserfiche WebLink

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1.0 INTRODUCTION The Site is comprised of several properties (Wiant, Gurule, Villano, Sasaki, Adams, Watada, and Yokooji) located within parts of Sections 18 and 19 of Township 1 North, Range 66 West of the 6th Principal Meridian. The project is located approximately 600 to 2000 feet east of the South Platte River and is generally bounded by U.S. Highway 85 on the west, by Weld County Road (WCR) 6 on the south, and by WCR 27 to the east in Weld County, Colorado, as shown on Figure 1. SW TKO Joint Venture, LLC (the Owner) has applied for and received a 112 Reclamation Permit to mine gravel on the Site. However, prior to start of activities that impact alluvial groundwater, the Colorado Division of Minerals and Geology (DMG) has required that a groundwater Sampling and Analysis Plan (SAP) be established. The goal of the proposed SAP is to document the mechanism by which groundwater quality in the local alluvial aquifer will be monitored and evaluated as to whether impacts occur as a result of mining. 2.0 SITE CONDITIONS The average land slope is 0.1 percent and the groundwater is typically 25 feet below the surface during most of the year. The Site is surrounded by primarily agricultural land with domestic wells and irrigation wells to the north, south and east. The Site slopes north, northwest toward the South Platte River and is underlain by the Broadway Alluvium and the DenvedArapahoe Formation claystone (Colton, 1978). The alluvial deposit underlying the Site is primarily composed of the Broadway Alluvium. The alluvium is classified as sand and gravel deposited by the South Platte River and its tributaries. The deposit ranges in thickness between approximately 30 to 50 feet, but averages approximately 40 feet. The deposits extend well above the groundwater table to typically within three feet of the ground surface, creating an unconfined aquifer of relatively homogeneous material (Colton, 1978). The Broadway Alluvium is underlain by Denver and Arapahoe bedrock with outcropping of these formations located a couple of'miles east of the Site on the ridge (located near the Fulton Ditch and Brighton Ditch Lateral). Refer to the Site Map shown on the attached Figure 2. The site groundwater is directly connected to the South Platte River and is therefore generally associated with water quality that does not currently meet drinking water standards for several parameters, including nitrates and fecal coliform due to the extensive use of septic systems in the area. Degrading sources to the local groundwater other than the relatively low water quality in the river include: 1) feedlots; 2) local septic systems; 3) pesticidesmerbicides associated with the current agricultural use; 4) petroleum hydrocarbons associated with the existing oil and gas facilities; and 5) other potential sources as identified in the project Environmental Site Assessments including a former county landfill that is located southwest of Pond 2. 3.0 PROPOSED PROJECT The proposed project includes open surface mining of the shallow alluvial aggregate for direct sale or for use in concrete and asphalt hatching. The sand and gravel processing area and a batch plant will be installed in the southern portion of what will be Pond 2 (Figure 2). The southern and northern portions of the site will be used for silt storage and will be mined in the first two years of the project. Water quality data will be collected from the area near the northem silt storage area to establish baseline water quality for this area where domestic wells are nearest the proposed mining activities. Following is an estimated schedule of operation for each respective Recharge Site (RS-A through RS-D): Groundwater Sampling and Analysis Plan November 2005 Lupton Lakes Project -1-