Trace amounts of pesticides commonly used in seed treatments have been discovered in two groundwater wells near AltEn, including a private well 6 miles downstream.
The biofuel plant south of Mead turned discarded, treated seeds into ethanol, producing wastewater and distiller's grains heavily laced with pesticides in the process.
The byproducts were released into streams and spread in fields across Saunders County before the Nebraska Department of Environment and Energy ordered the plant to shut down earlier this year.
On Sept. 1, environmental regulators notified Stan and Evelyn Keiser that their drinking water well contained three compounds, including insecticides like clothianidin (1.3 parts per billion) and thiamethoxam (less than 1 ppb) and the fungicide mefenoxam (less than 1 ppb).
Commonly used as seed treatments, clothianidin and thiamethoxam have been found at levels as high as 427,000 ppb and 85,100 ppb, respectively, in byproducts that came from AltEn.
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Evelyn and Stan Keiser had hoped to build a cabin on their property near a pond created by Stan Keiser's grandfather. The pond, once teeming with wildlife, is now a dead zone after pesticide-contaminated wastewater from the AltEn ethanol plant near Mead flowed downstream. The Keisers were also recently notified that their private well, which provides their drinking water, contains contaminants.
The levels detected in the Keisers' well, dug 40 feet below ground, were well below the levels deemed unsafe by the Environmental Protection Agency, according to state regulators.
The drinking water benchmark established by the EPA for clothianidin is 630 ppb -- the Minnesota Department of Health places the level at 200 ppb -- while the level for thiamethoxam is 77 ppb. The EPA does not have a safety benchmark for mefenoxam.
The state also pulled samples from the Keisers' pond, which is the collection point for a 6,000-acre watershed including the AltEn property and was the site of a 2016 fish kill event. Those samples turned up nearly a dozen different fungicides and insecticides, all at low concentrations.
Among the compounds detected in the samples taken from the pond on Aug. 16 were those also found in the well: clothianidin, thiamethoxam and mefenoxam.
The state environment department also notified the University of Nebraska-Lincoln of an Aug. 6 test showing clothianidin at concentrations of less than 1 ppb in groundwater at its research farm directly south of the AltEn property.
The No. 9 well where the neonicotinoid was discovered at the Eastern Nebraska Research and Extension Center is used for drinking water, according to Ron Yoder, UNL’s senior associate vice chancellor who oversees the research farm.
Other wells at the research site showed no detectable amounts of pesticides.
In an Aug. 20 email to Yoder, Tom Buell, administrator for the Department of Environment and Energy’s Monitoring and Remediation Division, said further testing of the well was being done. Those results have not yet been made public.
Although the concentrations are minuscule -- equal to roughly one drop in a 14,000-gallon pool -- the results show how quickly the compounds can move through the environment, said Shannon Bartelt-Hunt, chair of UNL’s Department of Civil and Environmental Engineering in the College of Engineering.
“These are compounds that are fairly mobile in water, they don’t stick to soil as much as some other types of compounds, and the soils there are more transmissible,” Bartelt-Hunt said, referring to the sandy soils in the Todd Valley, the ancient channel of the Platte River that cuts across Saunders County.
“It’s a sign things from the surface are moving vertically,” she added.
But whether vertical movement is happening on AltEn’s property or is occurring where pesticide-contaminated stormwater is running away from the site toward the Platte River is unknown and in need of further study, Bartelt-Hunt said.
Samples taken from a monitoring well southeast of AltEn’s damaged lagoon system -- what hydrologists call downgradient, or downstream, from millions of gallons of highly contaminated wastewater -- measured levels of thiamethoxam at 22.6 ppb in October 2020.
In March 2021 the same well showed increased concentrations of 37.6 ppb of thiamethoxam. But by June, the level of thiamethoxam in the monitoring well near the lagoon had dropped to 19.2 ppb, while the level of clothianidin was recorded at 34 ppb.
Thiamethoxam has been observed to break down into clothianidin in the environment.
Bartelt-Hunt, who is part of a collaborative between UNL, the University of Nebraska Medical Center and Creighton University researching the environmental and health impacts stemming from pesticide contamination at AltEn, said the groundwater results show further testing is needed.
Specifically, researchers need to begin examining where the pesticides from AltEn are leaching into the groundwater, whether it’s from the ethanol plant itself, or from various points along the water's path to the Platte River.
“We need to collect more monitoring data to understand how these compounds are migrating offsite,” she said. “Unfortunately, we don’t have much information on groundwater within the region at this time.”
Rain events, such as the Aug. 31 thunderstorm that dropped 4 inches in the Mead area, have pushed pesticide-laden stormwater downstream from AltEn for years despite the state’s insistence AltEn take measures to prevent it.
Last week, heavy rains saturated a dirt berm built around a pile of highly contaminated wet distiller’s grains on the east side of AltEn’s property, quickly filling a drainage area that runs southeast from the facility.
An environmental contractor hired by a group of seed industry giants to help with cleanup at AltEn was unable to completely stop the flow of water away from the site, the Department of Environment and Energy said.
Clean Harbors was able to recover an estimated 1.75 million gallons of water, it said in a report to the state, which was pumped into an emergency lagoon on the property.
The state granted the companies -- six companies that formerly sent discarded treated seed to the plant now known collectively as the AltEn Facility Response Group -- an extension in submitting a plan for cleaning up the site.
The group was initially scheduled to submit its remedial action plan on Sept. 30, but was granted a four-week extension while it seeks to “stabilize” the facility for winter, according to an email from an environmental contractor to state regulators.
NewFields, an environmental engineering firm from Atlanta hired by the response group, said work is being performed to improve the treatment of wastewater, consolidate wet cake piles and repair the damaged lagoon system at AltEn.
Plans are also being drawn up to land-apply treated wastewater, a NewFields representative told the state, as well as drain the remaining 4-million gallon digester tank, and temporary storage tanks now at the facility.
Communications between the response group and the state do not indicate what actions, if any, may be taken to address locations away from AltEn’s property.
The remedial action plan being formed by the response group, which will go through a public comment period once submitted, is now due to the Department of Environment and Energy on Nov. 1.
Meanwhile, the Lincoln Water System said it is continuing to watch the situation unfold near the wellfields where it sources the Capital City's water.
A spokeswoman for the utility said more than 100,000 quality checks are performed annually on Lincoln’s drinking water, including for 25 herbicides and pesticides, to ensure it is safe and meets regulatory requirements.
The list of pesticides screened by Lincoln Water System doesn’t currently include neonicotinoids like those found in high concentrations at AltEn, but the utility said it is working with the U.S. Geological Survey on a method to test for those compounds upgradient from its wellfields.
Seed companies to start cleanup of wet cake, but final fate of contaminated material remains unknown
Photos: Mead ethanol plant
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
Mead AltEn Ethanol plant

Mead AltEn Ethanol plant. COURTESY PHOTO
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million-gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
Mead AltEn Ethanol plant

A burst pipe late last week in a 4 million-gallon digester tank at the AltEn Ethanol plant near Mead sent liquid manure and thin stillage, a byproduct of the ethanol manufacturing process, into waterways and culverts up to 4 miles from the plant.
AltEn Ethanol, 2.4

The Department of Environment and Energy ordered AltEn Ethanol near Mead to shut down in early February, dispose of millions of gallons of contaminated wastewater on the site and repair lagoons in violation of state regulations.
AltEn Ethanol, 2.4

Unlike other ethanol plants, AltEn used treated seed instead of harvested grain for its fuel production. The byproduct from that process and wastewater near the plant have been found to carry levels of pesticides and fungicides above limits set by the Environmental Protection Agency.
AltEn Ethanol, 2.4

AltEn Ethanol has been the subject of dozens of complaints since it reopened near Mead in 2015 related to an odor coming from the byproduct of its ethanol process, seen here at the beginning of the month. The byproduct has been found to carry levels of pesticides and fungicides above limits set by the Environmental Protection Agency.
AltEn Ethanol, 2.4

AltEn ethanol plant is seen in this photo, Thursday, Feb. 4, 2021.
AltEn Ethanol, 2.4

AltEn shut down its operations on Feb. 8 after an order by the Nebraska Department of Environment and Energy. The state found three lagoons on the site were contaminated, badly damaged and holding more wastewater than permitted.
AltEn Ethanol, 2.4

AltEn is unique among ethanol plants in that it uses seeds pre-treated with pesticides to produce ethanol instead of harvested grain. It ceased operation on Feb. 8 after a state order.
Mead, 2.4

MEAD, NEB. - 02/04/2021 - A view of Mead, including the grain elevators with Frontier Cooperative, Thursday, Feb. 4, 2021. JUSTIN WAN, Journal Star
AltEn Ethanol

Emptied treated seed bags are stacked at the AltEn company in this photo taken in April 2019 during a Nebraska Department of Environment and Energy inspection. The ethanol plant near Mead used the seed to produce ethanol and the byproduct from the process to create soil conditioner sold to area farmers.
AltEn Ethanol, 2.4

AltEn Ethanol has been the subject of dozens of complaints since it reopened near Mead in 2015 related to an odor coming from the byproduct of its ethanol process. The byproduct has been found to carry levels of pesticides and fungicides above limits set by the Environmental Protection Agency.
Mead AltEn Ethanol plant leak

A pipe burst on a 4 million-gallon digester tank at the AltEn Ethanol plant near Mead late last week, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
Mead AltEn Ethanol plant leak

A notification of environmental concern inspection report from Feb. 12, 2021, noted "flow, dark water and odor," in water pictured on University of Nebraska-Lincoln property. A pipe burst on a 4 million-gallon digester tank at the AltEn Ethanol plant near Mead late last week, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy,
Mead AltEn Ethanol plant leak

University of Nebraska-Lincoln personnel using a backhoe to place bales and plastic to dam the culvert on UNL property near Mead after a pipe burst on a 4 million-gallon digester tank at the AltEn Ethanol plant late last week, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
Mead AltEn Ethanol plant leak

A notification of environmental concern inspection report from Feb. 12 noted "flow, dark water and odor," in water pictured on UNL property after a pipe burst on a 4 million-gallon digester tank at AltEn Ethanol near Mead, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
Mead AltEn Ethanol plant leak

Water pools west of the leaking digester at Mead AltEn Ethanol on Feb. 12 after a pipe burst on a 4 million-gallon digester tank late last week, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
Mead AltEn Ethanol plant leak

A depth finder measures flow from a leak on Feb. 12 after a pipe burst on a 4 million-gallon digester tank at AltEn Ethanol near Mead late last week, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
Mead AltEn Ethanol plant leak

Mead AltEn Ethanol employees use trash pumps to transport water into an emergency lagoon on Feb. 12. A pipe burst on a 4 million-gallon digester tank at the plant late last week, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
Mead AltEn Ethanol plant leak

Mead AltEn Ethanol employees work to install a trash pump to transport water into an emergency lagoon on Feb. 12. A pipe burst on a 4 million-gallon digester tank at the plant late last week, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
Mead AltEn Ethanol plant leak

Water exits the damaged area (blue arrow) of a 4 million-gallon digester tank at AltEn Ethanol near Mead on Feb. 12, releasing waste material into the waterways and culverts more than 4 miles from the plant, according to the Nebraska Department of Environment and Energy.
AltEn Ethanol cleanup

A crew works to remove waste material from a culvert southeast of AltEn Ethanol on Tuesday in Saunders County.
Saunders County Board of Supervisors

Saunders County Supervisors David Lutton (from left), Doris Karloff and Craig Breunig listen to Saunders County Attorney Joe Dobesh (not seen) speak about communications with state officials about AltEn Ethanol in February in Wahoo.
AltEn Ethanol cleanup

An earthen dam blocks the flow of waste material in a waterway southeast of AltEn Ethanol last week in Saunders County.
Saunders County Board of Supervisors

Saunders County Attorney Joe Dobesh talks about his communication with state officials about AltEn Ethanol at a Saunders County Board of Supervisors meeting in late February in Wahoo.
AltEn Ethanol cleanup

A crew works to remove waste material from a culvert southeast of AltEn Ethanol on Tuesday in Saunders County.
Saunders County Board of Supervisors

The Saunders County Board of Supervisors listens to Saunders County Attorney Joe Dobesh (not pictured) speak about communications with state officials about AltEn Ethanol on Tuesday during the board's meeting in Wahoo.
AltEn Ethanol cleanup

A crew works to remove waste material from a culvert southeast of AltEn Ethanol on Tuesday in Saunders County.
Saunders County Board of Supervisors

Saunders County Supervisors David Lutton, Doris Karloff and Craig Breunig listen to Saunders County Attorney Joe Dobesh speaks about communications with state officials about AltEn Ethanol on Tuesday during the board's meeting in Wahoo.
AltEn aerial

The AltEn plant near Mead, which the state shut down earlier this year, is shown on Aug. 25. Along with the toxic solids spread on land surrounding the site, the environmental cleanup is also focused on removing pesticides from wastewater on the site.
Wet cake in field

This 2021 Google Maps image shows a location north of Mead where AltEn's distiller's grains were stockpiled in a cornfield.
Stan and Evelyn Keiser, 6.30

Evelyn and Stan Keiser had hoped to build a cabin on their property near a pond created by Stan Keiser's grandfather. The pond, once teeming with wildlife, is now a dead zone after pesticide-contaminated wastewater from the AltEn ethanol plant near Mead flowed downstream. The Keisers were also recently notified that their private well, which provides their drinking water, contains contaminants.
Keiser pond

Pesticide contaminated water that has run off from the AltEn ethanol plant near Mead has been responsible for rendering Stan and Evelyn Keiser's farm pond a dead zone.
Mead Tour, 7.8

Curtis Pearson of Mead talks Thursday during a meeting at Mead Covenant Church about the troubled AltEn ethanol plant near the town.
Mead Tour, 7.8

Stan Keiser talks Thursday during a meeting at Mead Covenant Church about the troubled AltEn ethanol plant near the town.