A 2006 report by a Minnesota-based engineering firm estimated the Rapid City landfill would reach capacity in 2053.
Now, as work on a new $4.5 million cell nears completion, city officials say the landfill could be full by 2037. And as former landfill superintendent Jerry Wright noted in an Aug. 13 letter to Public Works Director Dale Tech and the Journal, the lost time equates to a loss of tens of millions of dollars.
As part of the state Department of Environment and Natural Resources landfill operating permit process, the Rapid City landfill — located since 1960 on an approximately 360-acre facility just southwest of S.D. Highway 79 and East Catron Boulevard — must renew its permit every five years.
In 2006, a report by Wenck Associates, Inc. was conducted ahead of the landfill’s application for a permit renewal, which was approved by the DENR in 2007. Assuming an annual 1.7 percent growth in collections, the report estimated the landfill would close cell 19 — the final cell expected to be constructed on the landfill’s current permitted land — by the end of 2053. The current cell under construction is cell 18. The report also estimated cell 12 would close in 2014 and cell 14 would be capped by the end of 2021. In reality, cell 12 was completely full by 2010 and cell 14 by 2013.
But in a Journal discussion with Tech, assistant Public Works Director Dan Coon and current landfill superintendent Karl Merbach, there appeared to be little concern.
“This study in 2006, it was valid up to the day it was published,” Tech said. “They have estimates in there about how much waste is going to go in a particular cell. Well those cells, if they’re not built or designed yet, you have no idea what the actual volume you’re going to be able to get in them. It’s all just based on estimates and was a snapshot in time. It was accurate the day it was published and every day beyond that things change.”
The 2006 report estimated cell 18 would be full in 2046 and cell 19 at capacity at the end of 2053. Neither of those cells was designed when the report was completed, Coon noted.
“To say a report that’s 12 years old was going to follow exactly in line, I don’t know of any plans that we do that happen exactly like we think they’re going to happen,” Coon said. “The landfill life operation is a very dynamic system. A lot of variables go into it.”
Those variables, Merbach said, include how much of the solid waste is diverted through yard waste, composting and recycling. Landfill workers can separate organic waste material and turn it into compost, which it sells for $20 per ton, but when it comes to recycling, Rapid City uses a source separation method where recycling is separated at the source, i.e. in someone’s home. If people don’t separate their waste from recycling, there’s not much the landfill can do.
“I can give you a blue bin in front of your house but that’s up to you if you want to recycle or not,” Merbach said. “Do we see tons of recycling in the regular garbage? Yes. Frustrating but not much we can do about it.”
Coon said past studies have indicated that only about 20 percent of what could be recycled ends up being recycled in Rapid City.
Grinding and compacting waste also plays a large role in maximizing the landfill’s available air space, or the space from the bottom of a cell to the maximum permitted height the DENR allows a cell to reach. In a landfill, air space is currency. Compacting and grinding ensure the currency isn’t wasted.
Then, there are factors that landfill staff and systems have absolutely no control over. Floods can lead to an inundation of carpets and people’s waterlogged basement possessions. Tornadoes and hail storms can cause the landfill to take in a lot of roofs, shingles and siding. Fires can bring in tons of burnt housing materials.
“All it takes is one flood in the city where all of a sudden we’ve got people tearing out carpets and walls and everything else, to change the whole dynamic of what could come in,” Merbach said.
Even the state of the economy can have a huge impact on waste collections. In 2008 and 2009, when the subprime mortgage crisis threw the U.S. and global economy into a tailspin, the landfill saw collections drop by more than 20 percent based on tonnage received. A downturn in construction, Merbach said, was the likely culprit.
Tech, Coon and Merbach exuded an air of confidence, not concern, in the landfill’s current operations.
“If you come back at the end of 2019 and ask these same questions, we may say, ‘Now we think we can go to 2040 because we’ve modified some of our practices,’” Coon said.
In fact, city landfill staff have seen their capacity estimates rise from 2033 in a 2013 report to the state to 2037 in the 2017 report. The purchase of a new compactor for $715,000 — approved by the Rapid City Council last week — is expected to further extend the landfill’s life.
No matter when cell 19 is capped and closed, a 106-acre lot just south of the landfill appears to be the likely site of any future landfill expansion. Purchased by the city 14 years ago, it’s estimated the area could add another 30 years of life to the landfill. The land has yet to go through the arduous permitting process to become approved for landfill use, though. And if the last 12 years following the 2006 study are any indication, the only thing constant in the landfill's life is change.