A buildup of methane and hydrogen sulfide has been detected at Cornejo & Sons’ construction and demolition landfill at 31st Street South and K-15, and plans are under way to vent the gases.
State officials will hold an informational meeting Wednesday about corrective actions to deal with the buildup. The meeting will be held in a come-and-go format from 6 to 8 p.m. in the auditorium of Jardine Technology Magnet Middle School, 3550 Ross Parkway in Wichita.
The landfill hasn’t accepted any waste since the end of last year, and a report on its closure is expected to be submitted to the Kansas Department of Health and Environment soon.
Residents near the landfill have long complained about garbage blowing from the landfill and into their neighborhood. The landfill drew significant attention when The Eagle reported the company had piled waste about 60 feet beyond the permitted height and had been cited multiple times for contaminated water and burying unauthorized trash at the landfill, which is next to the Arkansas River.
The landfill closure construction quality assurance report and professional engineer’s certification of closure are expected to be submitted soon to KDHE for review from the consulting firm, Allied Environmental Consultants Inc.
Kelly Warren, permit engineer for the facility for KDHE, said methane above the permitted 5 percent-per-volume level has been detected at gas-monitoring probes on the south side of the property, and hydrogen sulfide has been detected at one of those probes.
Ron Cornejo, CEO of Cornejo & Sons, said the buildup is not abnormal.
“All landfills generate methane,” he said. “We’re just figuring out how we should deal with it.”
Cornejo said none of the gases have come out of the ground or migrated from the property to pose a danger to the surrounding area.
Warren said KDHE and the company have agreed to a corrective action plan that involves installing five vents in the landfill next week or the following week. Pipes would be inserted to allow the gases to vent.
The primarily concern is that methane could migrate through the soil and infiltrate basements of homes, he said.
“Once it’s in the air, it’s not as much of an issue,” Warren said.
Hydrogen sulfide is mainly produced by decaying drywall, a material commonly disposed of in the landfill, Cornejo said.
The gas-monitoring probes were installed at the landfill in October 2010. No methane was detected at that time, Warren said.
Methane was first detected in June in one of two probes on the south side, he said. But no gas was detected in a new test 10 minutes later, so it was labeled a “transient” event.
A test on Sept. 15 found high levels of methane, and the probes have been monitored daily since then, with gas levels remaining high.
Cornejo said his landfill is the only construction and demolition landfill in the state that has the probes.
“Our landfill is probably the most highly regulated landfill in the state of Kansas,” he said. “We are monitored very, very heavily.”
Cornejo said he and KDHE have since determined that the probes were installed too close to the waste stream, guaranteeing high gas readings. Cornejo and Warren said probes installed by Cornejo about 150 feet off the property on the south end have not detected any gas.
“We’re not getting any migration of that gas. None whatsoever,” Cornejo said. “We’re not alarmed about it. We think it’s a pretty routine situation.”
Maps showing locations of the gases will be available at next week’s meeting, as well as information on the corrective measures.