The Utah Inland Port Authority’s main environmental expert says she’s worried about cancer-causing contaminants leaking from a large old landfill in the far northwestern corner of Salt Lake City.
“When we get precipitation, rainfall, snow, water fills up those trenches full of trash, and that’s where we get the leachate, which, if you can imagine, [is] a trash soup,” said Mona Smith, environmental and sustainability director for the port. “... It’s migrating toward the Great Salt Lake and there’s a risk of it coming into contact with the groundwater.”
Leachate is water that has percolated through a trench filled with trash and then carries some contaminants from that waste.
While more study of the landfill needs to happen, Smith said the site hosts a group of chemicals known as PFAS, sometimes called “forever chemicals,” as well as metals and a dangerous compound called 1,2-Dicholorethane.
The toxic site, just north of Interstate 80 at about 7200 West, has been on the radar of state environmental officials since the mid-1980s, but cleanup efforts have never occurred. Now, the port authority has acquired the North Temple Landfill and plans to clean it up. Port officials hope to make the plot a jobs center and economic driver.
(Rick Egan | The Salt Lake Tribune) The former North Temple Landfill, on Friday, Jan 31, 2025.
What’s the problem?
Salt Lake City operated the landfill from 1959 to 1979, filling at least 620 acres of the total 770-acre parcel with municipal waste. The trash was buried in unlined shallow trenches and covered with dirt. When storms bring rain or snow to the site, the water pulls contaminants out of the trash and deposits them elsewhere, possibly into the wetlands of the Great Salt Lake or in groundwater.
Smith said her biggest worry is water contamination, but wildlife often visit the site, too. When Smith and a reporter recently visited the site, a herd of pronghorn were grazing there. It’s possible the animals ingested plants fed by contaminated water.
Since the city shuttered the landfill in 1979, it has changed hands multiple times. Most recently, the state Trust Lands Administration owned the toxic tract, after buying it from The Church of Jesus Christ of Latter-day Saints’ Suburban Land Reserve. While both previous owners participated in site assessment efforts, neither ponied up the cash to fully remediate the site.
(Christopher Cherrington | The Salt Lake Tribune)
“The real easy question is, ‘Why hasn’t this been done before?’” asked Ben Hart, UIPA’s executive director. “The obvious answer is there wasn’t money.”
The port paid $20 million to buy the parcel from the Trust Lands, and plans to spend $30 to $40 million on the first phase of cleanup. The total cost of the project remains up in the air, but could total $150 to $200 million.
Some funding for the cleanup will come from the $150 million bond that was supposed to pay for the now-scrapped transloading facility proposal.
(Rick Egan | The Salt Lake Tribune) Mona Smith, environmental and sustainability director with the Utah Inland Port Authority, talks about the former North Temple Landfill, on Friday, Jan. 31, 2025.
Cleaning up and building up
While cleanup strategies still need to be finalized, officials are considering evaporating and treating the trash soup, and then consolidating the remaining solid waste on a portion of the landfill. That waste would be covered and lined, so that it wouldn’t leach in the future and would open up the rest of the property to development.
Port officials said they were also looking into building a wall on one side of the property to prevent the trash soup from migrating toward the lake. The western portion of the landfill, where the trash trenches are dug more deeply, also needs more study.
Once cleanup is complete, Hart and others want to build a research park or lure manufacturing businesses to the site. Last year, both the Utah Legislature and the Salt Lake City Council prohibited the construction of warehouses on the old landfill.
Port officials say they believe the site, once remediated, will be attractive to businesses looking for easy access to a major metropolitan area, an airport and two interstates.
“We want this to be the centerpiece of this Northwest Quadrant,” said Joel Ferry, executive director of the Utah Department of Natural Resources and a non-voting member of the port’s board. “So, we want this to be clean, safe and usable long term.”
The acquisition of the landfill comes as Utah Sen. Jerry Stevenson, R-Layton, looks to give the port authority power to spend tax dollars on land adjacent or related to a port project area, not just within its boundaries. The bill, SB239, would also allow port officials to make grants to other government agencies, shield private business proposals to the port from public records requests and give the governor power to appoint three members of the port’s five-member board.
The legislation passed unanimously out of the Senate Economic Development and Workforce Services Committee on Wednesday, even though a handful of residents criticized the bill and the port’s continued development.
