By Blake Jackson
A new policy brief from the New York Soil Health Program delves into the complex issue of biosolids, the solid byproduct of municipal wastewater treatment, and their implications for soil health, sustainability, and public safety.
Biosolids, also known as sewage sludge, are organic materials remaining after wastewater treatment. In New York, approximately 16% are processed and applied to farmland as a soil amendment, providing valuable nutrients and organic matter while reducing disposal costs for municipalities.
However, concerns exist regarding potential risks from emerging contaminants like PFAS, microplastics, pharmaceuticals, and other persistent pollutants not fully addressed by current regulations.
Existing state and federal rules classify biosolids based on pathogen reduction and select heavy metals. However, these classifications don't account for many modern contaminants. While some biosolids are labeled "exceptional quality" and sold for residential use, others containing emerging pollutants may pose long-term risks to soil, water, and human health.
The policy brief advocates for a precautionary approach to biosolid land application, urging a careful balance between nutrient recycling benefits and the potential for environmental contamination.
The brief highlights pyrolysis as a promising solution. This process heats biosolids without oxygen, effectively destroying PFAS compounds and other pollutants. Pyrolysis also produces biochar, a carbon-rich material that can enhance soil health and sequester carbon.
New York field trials suggest that biochar derived from biosolids can support crop yields comparable to synthetic fertilizers, with ongoing research into its effects on soil properties.
The policy brief offers six key considerations: prioritize safety in the circular bionutrient economy beyond just pathogen concerns; invest in innovative research and pilot programs, particularly for technologies like pyrolysis; foster educational opportunities for stakeholders to ensure informed understanding; support efforts to identify contaminated soils through testing programs; update biosolids classifications to reflect current contamination science; and establish protective regulatory thresholds for emerging contaminants to aid in cleanup efforts.
These recommendations aim to ensure the safe and sustainable management of biosolids for the benefit of both agriculture and the environment.
Photo Credit: gettyimages-zoran-zeremski
Categories: New York, Education, General