Maine DEP Disrupts Biosolids Recycling

Moratorium imposed statewide, pending testing and evaluation for PFAS.
NEBRA’s PFAS & biosolids page for details on the Maine farm concern.

Just at the beginning of the spring season, when 50% or more of some of the major biosolids soil amendment products are distributed for the upcoming growing season, Maine DEP has pulled the plug because of misrepresented concerns about PFAS - a family of chemicals of emerging concern in use since the 1950s. Worldwide, PFAS have become the focus of heightened regulatory and public attention in the past several years. Biosolids contain PFAS because PFAS are ubiquitous in our daily living environments and products.

Maine Public Radio report, March 22, 2019

Maine Public Radio report, March 22, 2019

On Friday, March 22nd, late in the afternoon, Maine DEP alerted managers of New England's largest composting facility that, in 15 minutes, the Department would be imposing an immediate moratorium on the land application of any biosolids or biosolids composts in the state. Soon after 4:00 pm, the memorandum went out to water resource recovery (WRRF) facilities and biosolids managers across the state. The action does not cover non-biosolids composts, which research indicates also contain measurable traces of PFAS, although usually at lower levels.

"Where do you want us to put the biosolids?" was the immediate question raised by Clayton (Mac) Richardson, Superintendent at the Lewiston-Auburn Water Pollution Control Association. Scores of other public wastewater treatment facilities across Maine face the same question.

Biosolids are the solids, rich in nutrients and organic matter, that are separated from wastewater in engineered treatment facilities (WRRFs). Biosolids are treated and tested to meet strict federal and state regulatory standards for use as fertilizers and soil amendments. If recycling to soils is not possible, the only other options are landfill disposal or incineration. In Maine, there is no capable incineration facility and initial indications are that the two in-state landfills are not keen on taking in dramatically-increased volumes of organic material. Landfills carefully manage organic matter and the mix of materials they accept.

Those in the biosolids profession, and many researchers and regulators, see landfilling or incinerating biosolids as a waste of the nutrients and organic matter biosolids provide to soils. Recycling to soil is widely recognized as the most sustainable option, in most cases. About 60% of biosolids produced in the U. S. are recycled to soils.

In Maine, recycling biosolids to soils has been a beneficial practice for decades, and major municipal investments in advanced treatment practices and quality controls have been steadily improving biosolids quality (e.g. at LAWPCA and Sanford). The markets for Maine’s and New England’s biosolids products have been robust; biosolids composts and other products sell for up to $40 or more per cubic yard. Biosolids recycling is one of the largest and most significant recycling programs in the state, advancing reduced greenhouse gas emissions and other sustainability metrics, while putting to use a local resource.

All that is on the line, because of DEP’s unprecedented action.

Every state in the U. S. accepts biosolids recycling to soil. And, while many states and U. S. EPA have been aware of traces of PFAS in biosolids and evaluated their implications, no others have formally curtailed biosolids use.

Ned Beecher, Executive Director of NEBRA, the regional non-profit membership group focused on biosolids management, notes that “research and data to date do not indicate that PFAS in typical biosolids are a concern for drinking water quality or human health.”

The Maine DEP action came soon after a media event led by a Maine-based environmental group and advocates from Massachusetts who highlighted an unusual case of PFAS contamination of farm soil in Arundel (Reuters’ lead coverage). Maine DEP had investigated the farm’s PFAS concerns in 2016 - 2018; its findings are summarized in a recent NEBRA Information Update.

Soon after the media event, NEBRA and several of its members in Maine had discussions with key Maine DEP staff about the situation, expressing concern that the media coverage seemed to be focused on municipal biosolids, even though DEP's own data and investigation had pointed to the main contaminant of concern being from a direct industrial source, likely from the 1980s. During those discussions, there was no indication that Maine DEP was about to impose a moratorium on land application.

“What Stoneridge Farm has experienced is terrible, with the loss of milk sales,” said Beecher. “But PFAS chemicals were not widely known to be a concern back in the 1980s and 1990s, when the Farm took in various materials to boost soil organic matter and provide nutrients. Analytical techniques did not allow for measuring such trace amounts in soils. No one at the time had any idea then that one of the materials used at the Farm apparently had very high levels of one PFAS chemical: PFOS - which remains the one concern that has affected the Farm’s business.”

According to Maine DEP, PFOS continues to be the one issue at Stoneridge Farm. PFOS and PFOA are the two most prominent PFAS chemicals - and both have been phased out over the past 15 years. What shows up at the Farm came from decades in the past. U. S. EPA established the current public health drinking water advisory level of 70 ppt for PFOA and PFOS, in May, 2016. Maine DEP utilizes that screening value. In comparison, Health Canada uses 600 ppt as the health protective screening level for PFOS.

“Perspective and context are important here,” notes Beecher, “the levels of PFOS detected in the Farm’s milk over the past year meet current Health Canada drinking water standards. And the Farm’s drinking water has never tested above Maine’s lower health screening level. These chemicals are all around, for better or worse, which is why they show up in biosolids. Scientists are still debating what the proper protective levels are for PFAS with respect to drinking water and human health.”

Speaking about DEP’s new biosolids testing requirement, Beecher said “we here at NEBRA fully support and have proactively done testing and evaluation of PFAS in biosolids. And we are glad to help DEP collect more data. But the trace levels need to be kept in context. We measure PFAS in biosolids in 1s and 10s of parts per billion. One part per billion equals a second in 31.7 years - a tiny amount. What counts is whether or not these trace levels of PFAS in biosolids present any risk. Research and various states’ investigations to date suggest they don’t. Research continues, as it should. But it makes no sense at this point to disrupt important municipal programs that have been going on for decades.”

NEBRA, the Maine Water Environment Association (MEWEA), and wastewater utility staff are now working on developing PFAS sampling plans and conducting the testing required by DEP. “We’re moving on,” said Beecher. “We object to DEP’s rushed and indefensible moratorium. But now we are looking forward, and we expect constructive discussions with DEP and other stakeholders. Biosolids will continue to be managed safely, as they have been.”

More about biosolids and PFAS.