In the wastewater treatment world, biosolids are often seen as the ultimate recycling success story. Biosolids are the nutrient-rich organic byproducts resulting from wastewater treatment and over 60% of biosolids produced nationally in the U.S. are land applied. They are used in agriculture, landscaping, forestry, and even by homeowners on lawns and gardens. Although biosolids are under scrutiny once again due to the source of their composition—human and industrial waste—preliminary evidence suggests that the beneficial use of biosolids rests on solid ground.
To learn more about the future of biosolids, new Babcock staff member, Colleen Thompson, interviewed Greg Kester, Director of Renewable Resource Programs at the California Association of Sanitation Agencies (CASA). Greg is the subject matter expert when it comes to emerging issues regarding all renewable energy, recycled water, biosolids, and climate change mitigation. “Biosolids have a plethora of benefits, they assist in creating healthy soils which help crop growth, they are significant mitigators of climate change, reduce irrigation use, offset the use of inorganic fertilizers, and essentially are the best example of recycling,” said Kester. In fact, many agricultural areas depend on biosolids to help provide micronutrients such as phosphorus to help enrich their soils and produce plentiful crops. Kester went on to say that, “Phosphorus is a finite resource that will be exhausted within a hundred years and it is vital that we recycle the amounts of phosphorus that come from our wastewater treatment facilities through biosolids.” Clearly, Mr. Kester is a fan of biosolids and knows his stuff.
But Kester also recognizes that the world of biosolids land application has a new potential challenge. The man-made forever chemical compounds collectively called Per- and Polyfluoroalkyl Substances (PFAS) have caused concern over the possibility for inadvertent contamination of wastewater and treatment plant sludge. To be clear, wastewater treatment facilities are not sources of PFAS. However, as federal and state governments work to establish the occurrence and extent of PFAS in the environment, some states have temporarily discontinued biosolids use in spite of all the benefits biosolids have to offer. They want to be certain that land disposal practices do not inadvertently exacerbate the extent of PFAS spread in the environment.
Arizona is one such state that put land application of biosolids on hold to allow for study of the issue. According to PFAS in Biosolids: A Southern Arizona Case Study, “While treated wastewater and biosolids are not sources of PFAS, they do reflect the activities of our community and receive PFAS through receipt of consumer product and industrial discharges, therefore monitoring for PFAS is appropriate to understanding the transport and migration of these compounds within the environment.” The study “took a broad look at PFAS contamination, retention, and migration in farm soils where biosolids were historically land applied.” The good news is that the Arizona study concluded that although PFAS were detected in biosolids at low ppb levels, the influence and migration of PFAS through the soils was minimal. The study also noted that irrigation water with PFAS detection may also contribute to a minimal increase in PFAS in irrigated soils.
Although land application has not been halted, California is now involved in an attempt to determine the extent and severity of the PFAS problem in the Golden State. The Phase III Investigative Order recently issued in California is designed to collect data regarding the amount of PFAS entering and exiting Publicly Owned Treatment Works (POTWs), including the amount of PFAS present in biosolids. While implementation of the Board Order has just begun, there is considerable concern in the POTW world that California’s PFAS investigation could have far-reaching implications. According to a recently released analysis, should state regulators deem land disposal of biosolids unacceptable due to the presence of PFAS, there will be substantial cost impacts.
The environmental industry, POTWs, and CASA are obviously concerned about future regulation of PFAS. Before California acts and implements more PFAS regulations, Kester hopes California Water Regulators will look to Michigan’s methods regarding PFAS in wastewater and biosolids. According to the North East Biosolids & Residuals Association (NEBRA), “Michigan’s experience illuminates a cost-effective approach to addressing PFAS in wastewater and biosolids. Other states can learn from these experiences.” Michigan’s methods focus on, “industrial discharges to wastewater treatment facilities with Industrial Pretreatment Programs (IPP).” By doing this, Michigan was able to concentrate on where the greatest risk lies and where the resources and effort expended can decrease the highest amount of potential risk. They found that, “typical biosolids that are not industrially impacted do not impact groundwater at levels exceeding the U.S. Environmental Protection Agency’s (EPA) 70 ppt drinking water advisory level.” This meant they could continue the use of their wastewater treatment facilities’ biosolids that were not industrially affected and do not affect the groundwater.
In the final analysis, it is hoped that the laboratory data generated and the cost-benefit of the use of biosolids will inform appropriate decision-making regarding the future of biosolids. Macro- and micronutrients are incredibly plentiful in biosolids, it would be a shame to “waste” them and bring an end to the ultimate recycling success story.
Babcock Laboratories prioritizes the sharing of timely topics to ensure our clients have access to all the latest on PFAS research and industry developments. As a DoD, NELAP, and CA ELAP accredited lab, Babcock is an industry leader for PFAS analysis. For more information about PFAS testing, contact Babcock labs.