Biosolids & Septage Management Affected by Strict PFAS Limits in New England
NEBRA has been advancing understanding of PFAS related to wastewater and biosolids for the past two years. “But, this spring, the issue of regulating PFAS in biosolids and other residuals, such as septage, has reached a critical level in northern New England,” said Ned Beecher, NEBRA’s Project Lead. The challenge is this: PFAS are the only commonly-used chemicals regulated in drinking water in parts per trillion. (A part per trillion is one second in 31,700 years.) And there are many ways that such small traces of PFAS can get into groundwater and drinking water, including through conveyance in wastewater, biosolids, and residuals, where their inevitable presence is due to PFAS used in many consumer products and in our daily living environments. If society wants to ensure no waters are impacted at levels above identified screening values – e.g. U. S. EPA’s 70 parts per trillion (ppt) for PFOA + PFOS in drinking water – then the management of wastewater and residuals may be challenged. If PFAS are regulated in waters at even lower levels, as is currently the case in several states (e.g. Vermont’s 20 ppt limit in groundwater for 5 PFAS combined), then current wastewater and biosolids/residuals management practices might not be acceptable. What that means – what the solutions are – are challenging questions now front and center for regulators and municipalities managing wastewater, septage, and biosolids.
Getting traces of PFAS out of drinking water is possible with moderately-priced granulated activated carbon systems. But keeping them out of wastewater, or removing them from wastewater and biosolids, is not economically feasible – nor will it be for the foreseeable future. The only solution is to remove the most concerning PFAS from commerce. That has worked dramatically for PFOA and PFOS, which have been reduced through voluntary phase-outs. But, because they are persistent and do not degrade in the environment, their continued presence will confound efforts to address them.
With the limitations on data and understanding of fate and transport in soils related to PFAS, state regulators – especially those focused on groundwater protection – have begun to target biosolids and septage. Two dramatic regulatory actions this spring have put laser focus on how biosolids and residuals recycling can be disrupted.
In Maine, on March 22nd, without warning, Jerry Reid, new Commissioner of the Department of Environmental Protection (ME DEP), imposed a moratorium on biosolids distribution and use, pending testing of all biosolids for PFAS. Wastewater utilities and companies managing biosolids scrambled to complete required sampling plans and tests. These Maine tests are finding PFAS in typical low levels in biosolids, similar to other data in the literature and other state investigations. Maine DEP is applying very low screening levels (which NEBRA has argued are scientifically indefensible for use related to biosolids), and all but one Maine biosolids product exceeds the screening levels (some tests are still pending).
But exceeding the screening values does not preclude possible use of the biosolids. Maine DEP regulations allow for demonstration, through loading rate calculations, that biosolids applied to soil for several decades will not raise soil levels above the screening values. Those calculations have now been applied to several Class A products, such as the compost from the Casella Organics’ Hawk Ridge Compost Facility in Unity, New England’s largest compost facility. Maine DEP has determined that that compost is safe for use and permitted resumed sales and distribution in mid-April, lessening the impacts of the moratorium.
But programs that land apply Class B biosolids are still unable to proceed, even as spring planting season begins. The Lewiston Auburn Water Pollution Control Authority (LAWPCA), which has been a model leader in progressive biosolids recycling, has suddenly had 2/3rd of its permitted land application fields shut down. Municipalities have met with the Maine DEP Commissioner, and there is discussion of collaboration on advancing the science through robust modeling of fate and transport of PFAS applied to soils in biosolids. NEBRA points to field data that indicates that PFAS in soils at even much higher levels than ME DEP’s screening values do not impact groundwater at levels approaching the state’s 70 ppt groundwater screening value.
Meanwhile, in New Hampshire, a facility that has been managing septage for 30+ years has been shut down by the NH Department of Environmental Services (NH DES) because of PFAS found in neighbors’ wells. NH DES assumes that the PFAS migrated from the septage lagoon and natural wetlands treatment system to the nearby wells, where the highest level of PFAS measured was somewhat more than twice the state’s groundwater standard of 70 ppt. Within a week of taking action, on May 2nd, NH DES and the local town selectmen held a public informational meeting attended by more than 100 residents. The septage facility owner is cooperating with NH DES on providing bottled water to neighbors and further investigation. But the business – which has been permitted by NH DES for decades and has not had any enforcement action before this – is shut down, ordered to stop receiving and processing any septage, and fiscal costs for cooperating are mounting.
“These situations are warnings to the wastewater and biosolids/residuals management profession,” said Beecher.“While the sites targeted by regulators in Maine and New Hampshire have seen more biosolids and residuals activity than average, there are likely a few similar sites in every state. Regulators need to carefully assess the costs and benefits of setting drinking water and groundwater standards, recognizing the potential impacts on important, beneficial environmental programs like wastewater treatment and biosolids recycling.”