Parley?s Canyon Aggregate Pit is an aggregate production facility or sand and gravel pit located at mile post exit 131 on Interstate 80, Salt Lake City, Utah (the Facility). It is owned and operated by Kilgore Companies, LLC. Operations at the Facility involve drilling, blasting, and loading the rock with a front-end loader into a haul truck, and transporting the rock to a crushing area. Sand and gravel are stored at the Facility.
On March 7, 2012, inspectors from the EPA and the UDEQ, Division of Water Quality conducted several site visits at various industrial facilities within Salt Lake County, Utah as part of a municipal separate storm sewer system (MS4) inspection of Salt Lake County?s MS4 program. One of the industrial sites visited was the Facility covered under Utah?s Multi-Sector General Permit for Storm Water Discharges Associated with Industrial Discharges (the Permit) (UTR001024), which expired December 31, 2012. On March 4 and March 8, 2013, the UDEQ inspectors conducted additional site visits at the Facility from the public right of way and documented observations of discharge of pollutants. On June 18, 2012, and July 23, 2013, the EPA sent Respondent requests for information pursuant to section 308 of the Act, 33 U.S.C. ?1318. On July 29, 2012, and September 13, 2013, Respondent submitted its responses to the EPA information requests. Based on visual observations of discharges on March 7, 2012, by EPA and UDEQ; March 4, 2013, and March 8, 2013, by UDEQ, and