By Richard L. Gaw
Staff Writer

Local residents took up a portion of the Nov. 17 New Garden Township Board of Supervisors meeting to levy verbal attacks on American Mushroom Institute President Rachel Roberts and local mushroom growers for what they deemed as negligence on the part of the agency and the industry to properly address a growing concern for the impact of composting and fertilization on the quality of air and water in the region.

Appearing at the meeting via Zoom, Roberts gave a summary update that closely aligned with a press release AMI delivered on Oct. 21 announcing that in an effort to improve air and water quality emanating from area mushroom farms, the Pennsylvania Department of Agriculture (PDA) is undergoing two pilot assessments at an undisclosed farm in New Garden Township. One is the installation of a carbon-activated geomembrane tarp that has been placed over a lagoon at the farm and is designed to capture and reduce hydrogen sulfide emissions during the composting process. 

Roberts said that the tarp – estimated at $35,000 – is designed for small farms who conduct their own composting.

The second study involves the use of a nanobubble treatment system – whose cost of purchase and installation is $2 million - that is designed to lessen odors, improve water quality and compost aeration and assists in the reduction of phorid fly populations through enhanced oxygenation. 

“This is one of the largest nanobubble technology installations ever done, so again, it’s not a question of whether science will bear the fruit of what we all want,” Roberts said. “The question is, ‘How does this work, exactly, on a mushroom farm?

‘Cautious optimism’

AMI’s recent press release said that these new tools are giving Pennsylvania mushroom operations “cautious optimism,” with promising early indicators related to odor reduction, compost uniformity, and environmental practices.

Despite the hopeful forecast, Roberts told the audience gathered at the New Garden Township Building that when it comes to the reduction of the phorid fly population at mushroom farms, the study has not yet been able to provide definitive data.

“We’re seeing real progress in terms of more tools being tested by growers, but data is still the missing link,” Roberts said. “We’ve never had baseline data in terms of fly population and there is no traceability of flies. You can’t tag flies, and you can’t know which flies are where. That slows regulatory confidence to some extent.”

Echoing the press release, Roberts said that AMI and PDA provided sufficient crop damage, crop loss, and mushroom quality data for the U.S. Environmental Protection Agency (EPA) to approve the emergency use of a specialized insecticidal fly netting product by Vestergaard, known as AgriScreen 3.0. Currently, two dozen mushroom farms (about 500 mushroom composting houses) in Pennsylvania have implemented the screens.

“Some of the farms that are using it say it is really effective in killing flies, but again we don’t know what that is doing to the overall population of flies,” Roberts said. “Sometimes, houses have flies and sometimes they don’t, so we are really attempting to get some baseline data about phorid flies. How do we discover what tools are creating an overall impact on fly populations?”

Roberts said that there has been discussion about providing this netting for local homeowners.

“We would love to see those nets in the hands of residents in ways that can help the residents,” she said. “They are only for residential use in other countries. We brought them here for the growers, but can we get those nets in use by the homeowners?”

Roberts also said that AMI is also in the final stages of receiving approval for $12 million in funding from the National Resources Conservation Service to address water quality at mushroom farms. 

West Chester University study, passage of H.B. 2034

Roberts’ presentation arrived when the results of a recent assessment of hydrogen sulfide levels at area mushroom farms is still reverberating throughout southern Chester County households. Responding to complaints by several residents, New Garden Township sponsored a one-year study in 2022 that was conducted by Lorenzo Cena, Ph.D., a professor of Occupational and Environmental Health at West Chester University, which measured the air quality near mushroom farms, specifically whether ammonia, methane and hydrogen sulfide met or exceeded acceptable levels as determined by the Pennsylvania Department of Environmental Protection (DEP). 

In September of 2024, Cena shared the study’s findings, revealing that in some areas, hydrogen sulfide levels were 33 times higher than the recommended levels established by the DEP for the general public, which specifies that concentrations of the gas over the course of one hour should not exceed 0.1 ppm and that concentrations over a 24-hour period should not exceed 0.005 ppm.

If Cena’s study results have begun to call attention to the local mushroom industry’s best practices, then the passage of Pa. House Bill 2034 – “Update to PA Agricultural Best Management Practices” – sponsored and introduced by State Rep. Christina Sappey during the Agriculture and Rural Affairs Committee and passed in the Committee by a vote of 23-3 on Nov. 17 – will force the industry to adhere to high standards for dealing with foul odors emanating from their farms and reducing phorid fly populations at their operations. 

Under its provisions, H.B. 2034 will require mushroom growers to submit their plans for phorid fly and hydrogen sulfide mitigation to the PDA; require the PDA to conduct random inspections of mushroom growing operations for compliance best management practices; and authorize the PDA to administer fines to operations who are not in compliance with their plans, or when farms are not in compliance after inspection. 

“The position we have decided to take on the bill is that we were concerned that it was sending a message that everything in the bill wasn’t already happening,” Roberts said about the mushroom industry’s stance on H.B. 2034. “We have been trying really hard to get our voice out there and say, ‘Here are the things we are working on. It is slow going. There is one entomologist who can’t work with every farm. When it comes to air quality, we’ve been trying to put out the good news for a few months that things are moving along, and that things look like they’re going to work.’”

Residents respond

During the public question and comment portion of the presentation, several residents accused the mushroom industry and the AMI of not being willing to cooperate with – or listen to – local residents who have fought to see environmental improvements fully enacted at local mushroom farms.  Pointing to a particular incident regarding Cena’s study, township resident Don Morgan questioned Roberts on whether the industry is being fully cooperative with the study, which is still on-going.

Roberts said that while the growers wanted to cooperate with Cena, they asked that he guarantee that the data he compiled – and compiles – will be in the form of a non-disclosure agreement, which would allow the growers to see the data and respond to it.

“Dr. Cena told us, ‘I can’t do that. I am a researcher. I am not doing this specifically to help you figure out your issue. I am doing this as research and I can only do what I’m doing if I know that I can publish that research publicly,’” Roberts told Morgan.

“Why would you ask something that you already knew he couldn’t comply with?” Morgan replied. “This was a grant from the Department of Agriculture. You knew that. It has to be published, and the mushroom growers were going to be informed of the data before the public. It was public money supporting that - money out of my pocket and every pocket here. You said that it shouldn’t be disclosed. What good would the study be?”

During the growers’ meeting with Dr. Cena, Roberts told Morgan that they invited Cena to place his air quality monitors alongside the industry’s monitors and work with him collaboratively.

Londonderry Township resident Tony Spadaccini, a former industrial air pollution and water treatment engineer, told Roberts that the solutions being proposed by the AMI are “unattainable.”

“The mushroom has a low work force,” he said. “By my calculations, there are seven [mushroom growing] cycles per year times 2,000 mushroom houses. That’s 14,000 changes. Now you’re going to say, ‘You now have to put the nets on and take them off and then spend three to four hours steam cleaning the nets.’ Where is the workforce going to come from?”

Brendan Nerney of New Garden Township said that since arriving in the township three years ago, he has been forced to caulk his home’s windows shut and place mesh screens in his HVAC system. He told Roberts and the board that while both the township and the AMI have been cooperative with him regarding the issue of odor and flies, he said that the data shared at Roberts’ presentation was just more of the same thing residents have heard for too long.

“The fact that people have been hearing about this for ten years is just unfathomable to me,” Nerney said. “We keep hearing that there is funding going, taxpayer dollars and subsidies, and if we look at the mushroom industry as a whole - including a board member of AMI - we have seen price-fixing settlements. We have seen migration settlements and charges and prosecutions within the industry, so to try to keep giving us lip service and keep telling us, ‘Just trust me, Bro. We’re going to do what’s right,’ I don’t see any trust.

“It’s been ten years,” Nerney told Roberts, who encouraged her to address the township in person in the future, not through a Zoom arrangement. “At what point do people come to the realization that there is a problem, and that you can’t just keep throwing money at it and keep making these empty promises with no tangible results?

“At what point do you guys just go in and shut these houses down…? There has to be some kind of accountability besides just having meeting after meeting or a Zoom call.”

To contact Staff Writer Richard L. Gaw, email [email protected].