Environmental Benefits of Biosolids
Less Contribution to Nutrient Pollution of Waters
When Nitrogen and Phosphorus from farm fields find their way to bodies of water it can cause excessive growth of algae, producing harmful toxins and degrading water quality. Any type of crop fertilizer containing these nutrients can potentially contribute to this problem. However, the nutrients in biosolids are typically less water soluble than those in chemical fertilizers which means they are less likely to end up in a waterway following field application. Additionally, the organic matter in biosolids can improve soil structure and reduce erosion which can prevent the unwanted movement of nutrients that are bonded to the soil particles.
Conservation of Limited Natural Resources
The phosphorus in chemical fertilizers is obtained by mining phosphate rock. Phosphate rock is a finite natural resource and the mining process has negative environmental impacts. By reusing the phosphorus in biosolids, we are encouraging the natural cycle of this nutrient and reducing the need to mine phosphate rock.
Conservation of Landfill Space
A significant portion of municipal sludge that is not reused as biosolids is disposed of via landfills. This practice not only neglects the value of biosoilds, but consumes vast amounts of limited landfill space. The land application of biosolids conserves landfill capacity for use by other materials that have no residual value.