An Omaha-area landfill is the destination for AltEn’s solid waste

For years, six companies, including Corteva and Bayer, sent their pesticide-coated seed corn to AltEn to turn into ethanol. The process created tons of waste, including a mountain of smelly sludge contaminated with pesticides.

Now, the companies are footing the bill to clean up that mess. They’ve hired the environmental engineering firm NewFields, which has designed a plan to deal with the 115,000 tons of solid waste piled at the site of the former ethanol plant near Mead, Nebraska.

The team will mix the waste with bentonite clay to solidify it; pack it into plastic-lined trailers; top the loads with a plastic cover; and transport it 24 miles northeast to a landfill near Bennington, an Omaha suburb.

The team aims to move 24,000 tons within the next five months before determining if the plan can work for the remaining waste, which is often referred to as wet cake.

“There are lots of things that we need to learn,” Bill Butler, a senior engineer with NewFields, said. “How well do the materials mix? How quickly can we mix it? How quickly can we load and transport it, and put it in the landfill?”

Mike Hey is a manager for Waste Management, the Texas-based company that runs the landfill. He said their analysis showed it’s typical, non-hazardous waste.

“At the end of the day, this is normal material for us,” Hey said. “Our landfills do accept wet cake, frequently. It’s a waste that’s out there and it’s a part of many processes.”

Odor

Moving the waste will likely stir up the odor that originally alerted residents to the plant’s unorthodox practice of turning pesticide-treated corn into ethanol.

Don Gunster, an environmental scientist with NewFields, said his team will take precautions like spraying an odor suppressant to minimize the smell.

“So, for example, Friday home football games, we will not be working in that pile to prevent any of that odor from disrupting community activities,” he said. “And [we’ll be] covering the pile every night. Things AltEn didn’t do.”

The team will also test air quality at and around the site, adding to the groundwater monitoring the group and Nebraska’s Department of Environment and Energy are currently conducting to ensure no nearby wells are contaminated with pesticides above Environmental Protection Agency health levels.

“What we’ve found is that none of the off-site wells contain any pesticides above those levels,” Butler said. “And on-site, we only have one well that has two pesticides above that screening level.”

Previous work

This pilot plan for the solid waste comes after more than two years of work on the site. The group formed after a February 2021 pipe burst released about four million gallons of contaminated water. Eight days later, NDEE shut down the plant with an emergency order.

The group first worked to stabilize the site to prevent more waste from trickling into Saunders County’s waterways. They reduced the amount of water in AltEn’s lagoons, constructed a new water treatment system and consolidated and covered the solid waste.

“The site is very stable now, we have taken a lot of time and care,” Gunster said. “There’s no fear of stormwater overflow at the lagoons and we’ve drained all of the piping and mechanisms, so we won’t have another valve break or tank release.”

By the end of 2022, the group reports it had treated 49 million gallons of wastewater and applied 31 million gallons to nearby farms. It plans to apply another 20 million gallons this fall. It estimates 100 million gallons still need to be treated, not including any stormwater that may accumulate.

The group has also removed 870 tons of pesticide-treated seed corn from the AltEn site. Another 6,675 tons will be disposed of at an Oklahoma facility within the next five months.

Community input

As they’ve put together the plan, the group has been meeting with Mead community leaders like Jody Weible, who originally rang the alarm bells on AltEn’s environmental impacts to the village.

Weible said she thinks the plan is thorough and safe, and hopes it can keep up the progress she’s seen.

“I haven’t had mosquitos or anything for years. Now I have mosquitos again, I have butterflies again,” she said. “So everything’s coming back to normal. And they’ve listened to us, they’ve respected our wishes and are being considerate. That means a lot.”