After underestimating particle pollution from its dump, Eugene company seeks to double limit 

A north Eugene landfill is seeking to double parts of its pollution limit through a permit modification from the Lane Regional Air Protection Agency after underestimating its activity.

For decades, Delta Sand & Gravel Co. in the Santa Clara neighborhood has supplied materials and operated a dumpsite for construction projects. Its landfill takes asphalt, concrete, rocks and tires, some of which are demolished or shredded before they are buried.

These operations rely on heavy-duty vehicles, which federal and local agencies regulate because of their effects on human and environmental health. In addition to emissions, the vehicles create soot and dust. The Environmental Protection Agency calls particulate pollution, or particulate matter, among the most dangerous forms because it can be inhaled into the lungs.

In accordance with its existing permit, issued in 2022, Delta has filed semiannual and annual reports. When the Lane Regional Air Pollution Agency reviewed those reports, it determined the company had underestimated how many miles its vehicles could travel on the site’s unpaved roads in recent years, which in turn underestimated how much particulate pollution the company’s vehicles could create.

The agency’s discovery wasn’t based on a health concern, said spokesperson Matt Sorensen, but instead was trying to “right size” the particulate matter levels to reflect actual site activity.

The company’s permit now estimates that its vehicles could log nearly 6,800 miles on unpaved roads each year — and it wants a permit that allows more than double its current particulate-matter limit. 

Comparison of Previous and Proposed Emission Limits
(in tons per year) 

Regulators set limits to reduce risk, but there’s no threshold at which particulate pollution is considered harmless. Delta’s proposed emissions — even after doubling — are still well under thresholds for significant emissions.

The landfill also generates greenhouse gases, climate-warming pollutants that can come from vehicles or decaying waste. In the case of Delta, these gases, including carbon dioxide, largely come from decomposing organic materials such as stumps and logs, Sorensen said.

According to the Oregon Department of Environmental Quality, Delta’s landfill is the fourth-largest carbon dioxide emitter among the 27 facilities in Lane County that report emissions, releasing 11,850 metric tons in 2023 — the latest year for which data is available. It ranks behind the county’s dominant sources — large sites such as Short Mountain Landfill and International Paper — which each emit more than 100,000 metric tons. 

In an email to Lookout Eugene-Springfield, Delta President Stan Pickett said the company has worked closely with the Lane Regional Air Pollution Agency to ensure it accurately reports emissions. He said that the earlier underestimating stemmed from an unanticipated increase in traffic in and out of the landfill.

He said the company’s engineers made conservative calculations in their proposed emissions so they don’t exceed the cap in their modified permit through 2028. The proposed numbers aren’t a reflection of the site’s actual emissions, he said. 

“Delta Sand & Gravel is committed to all federal, state and local regulations when performing emission calculations, and following proper methods and procedures when reporting,” Pickett said.

The regulations require a public notice and comment period. People can submit written comments to LRAPA through Nov. 17 at 5 p.m. Feedback given in writing or in person could lead to changes in the proposed permit. If the agency receives more than 10 requests, it could hold a public hearing.