2014-07-07_REVISION - M1980110

• Permit No: M1980110
• IBM Index Class Name: Revision
• Doc Date: 7/7/2014
• Doc Name: Responses
• From: E470 Public Highway Authority
• To: DRMS
• Type & Sequence: AM6
• Media Type: D
• Archive: No

June 26,2014
DRAFT
Sandy Acres Environmental Permit—Wetlands Report
INTRODUCTION
URS Corporation(URS) completed a desktop review and field assessment to identify wetlands and Section 404
permit requirements at Sandy Acres gravel pit pond,located between Nome Street,E-470,and U.S. Highway 85
(US 85) near Brighton, Adams County, Colorado (Figure 1). The E470 Public Highway Authority (E470
Authority) is currently engaged in the permitting process with the Division of Reclamation, Mining, and Safety
(DRMS)to allow for the filling of the gravel pit pond-(Project). This report describes wetland information and
findings as required for the permitting process.
Project Location
The Project is located approximately 3.75 miles south of the City of Brighton in Adams County, Colorado. The
Project can be found on the U.S. Geological Survey (USGS) 7.5-minute topographic quadrangle map for
Brighton, Colorado(USGS 2012)within Township 1 South, Range 67 West, and Section 26 of the 6"'Principal
Meridian. The Project is located at approximate latitude 39.9327° N, longitude 104.8487° W. Sandy Acres
gravel pit pond is bounded to the east by US 85 and E-470 to the northeast. Nome Street is located to the west
of the pond (Figure 1). The South Platte River is located approximately 0.5 miles to the west of the Project.
Fulton Ditch is located approximately 0.31 miles to the east of the Project east of US 85. Brannon Pit is located
west of the Project area, and several other gravel pit ponds are located south of the area. Gravel pit mine
operations are located to the west and south of the Project, while agricultural fields are located to the north and
east.
Sandy Acres gravel pit pond is approximately 31.6 acres. There is a 7.5 foot tall security fence surrounding the
pond and an upland buffer;the area inside of the fence is approximately 50 acres.
Site History
The site has historically been used as a gravel pit. Based on information from E470 Authority personnel, the
property was purchased by the E470 Authority in 1999 after mining operations had ceased. The history of the
site is not known. It is not shown on the 1965 USGS Henderson, Colorado 7.5-minute topographic quadrangle
map, photo revised in 1979 (USGS 1979). Gravel mining was initiated sometime between 1979 and 1993. The
Project area is bordered by roads as it is today; however, road names and topography (based on mining
operations) has changed. Based on the 1979 aerial imagery, there were no water features in or near the site
(USGS 1979). Fulton Ditch is located approximately 0.31 miles to the east of the pit pond. The South Platte
River is located approximately 0.5 miles to the west of the Project. The following observations are based on
Google Earth imagery(Google Earth 2014):
• June 1993 —the south half of what is now Sandy Acres gravel pit pond was a distinct pond. About a
quarter of the northern half was covered in water, while the remainder of the northern half was a
functioning gravel mine. At the time,the source of water in the northern half appears to be a ditch from
the southern pond. The southern half was mined and allowed to fill with water between 1979 and 1993;
mining was ongoing in the northern half in 1993.
• October 1999—the northern half of the mine has filled with water. A berm separates the northern and
southern ponds. There does not appear to have been any significant change since 1993.
• December 2002—The northeast corner of the north pond was filled during construction of E470.
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