The site was originally permitted in September 1977 as a Type I municipal solid waste facility consisting of 113 acres. The original permit was issued to Mr. Bob G. Lee. The permit was amended to increase the size to 175 acres and was issued to Lee Trucking Company, Inc., in October 1981.
The permit was administratively updated in October 1986, to change the name to Lee and Son Trucking Company, Inc., which was a wholly owned subsidiary of WM of North America, Inc.
The permit was transferred to WM of Texas, Inc. in March 1991. The Hillside Landfill was upgraded to Subtitle D requirements* in the early 1990s. On June 30, 2005, TCEQ authorized a vertical expansion of the landfill.
