Pelletized Biosolids Fertilizer Products
Some of these products are sold in bags at hardware stores and garden centers. Many are sold in bulk from the water resource recovery (WRRF) where they are produced.
These slow-release heat-dried fertilizer pellets provide nitrogen and phosphorus and trace nutrients. Excellent for lawn and turf care, general fertilizing.
Available from local and regional compost facilities and distributors. May be available from your local wastewater treatment facility or lawn & garden center, or contact NEBRA for referrals.
Biosolids compost provides slow-release nitrogen and phosphorus and abundant organic matter. Excellent for building lawns and turf, mulching flower beds and shrubs, establishing vegetation on barren sites, and general gardening.
Bulk Products Requiring Site Permits
Class B biosolids products
These products are available only through contract with biosolids management companies or wastewater treatment facilities and require site permits from the state or provincial regulatory agency prior to use. A farm nutrient management plan is encouraged and required in some states (e.g. to comply with Maine’s nutrient management law). Class B biosolids must be applied at the agronomic rate, except in special land reclamation circumstances. Follow all regulations and agricultural best management practices, including buffer zones. In sensitive watersheds where phosphorus is a concern, application should be according to phosphorus needs (the same is true for manures and other fertilizers).
Ensure careful management of odors, if odors are possible. Some biosolids have minimal odor, others more. The purveyor of the biosolids or the manager of the biosolids program should know what potential for odors exist and how best to manage them. Odor concerns can be addressed by:
- immediate incorporation or injection of biosolids into soil when used for growing annual crops such as corn;
- application of biosolids during cool, less humid weather;
- maintaining setbacks from neighbors;
- communication with neighbors, ensuring them of the temporary nature of any odors.
It is important for workers to remember that these materials may contain viable pathogens (disease-causing organisms), just as manures do, and that personal hygiene is important - washing hands is a good idea! In addition, individuals with compromised immune systems or other special vulnerabilities to infection should use extra caution around biosolids, manures, and farm environments.
(generally >80% calcium carbonate equivalence)
Such biosolids are often applied as a liming agent, according to recommendations for lime or calcium carbonate equivalence. Repeated applications of lime-rich biosolids according to standard agronomic rates based on nitrogen (N) could result in an excess of calcium and high pH levels in the soil, resulting in a reduction in availability of plant nutrients. As when using any soil amendment or fertilizer, monitoring soil chemistry with annual soil tests is recommended.
Also contains abundant lime, but not as much as above. Such biosolids are generally applied to both boost soil pH and provide organic nitrogen (4 - 12%), phosphorus (2 - 4%), and trace plant nutrients. Excellent for corn and grass hay production.
Anaerobically digested biosolids
Provide organic nitrogen, phosphorus, and trace plant nutrients. Neutral pH.
Excellent for corn and grass hay production.
Pulp & Paper Mill Residuals (also known as short paper fiber or SPF)
These byproducts of the treatment of process wastewater at pulp and paper mills are rich in organic matter – mostly wood fibers – as well as clay and lime. The nutrient value can be low to moderate, depending on the wastewater treatment process from which they come. These residuals are available only through contract with a pulp or paper mill or their independent contractor. Excellent for use in landfill caps and land reclamation projects where an abundance of organic matter is needed to build a topsoil layer. See Pulp & Paper Mill Residuals.
Guide to Field Storage of Biosolids (U. S. EPA, 2000)
Septage from home septic tanks is used as a soil amendment and fertilizer for hay and corn crops by some farmers – and has been for decades. Pathogen treatment, usually using lime to raise the pH, must be done prior to land application of septage. Federal, state, and provincial regulatory programs govern the land application of septage; contact your environmental agency’s water or wastewater division for further information.
Best Management Practices
Contact your local Cooperative Extension office, or the Natural Resource Conservation Service.
Guide to Field Storage of Biosolids (EPA/USDA, 2000) is an excellent resource, providing advice on managing bulk biosolids. Chapters address odors, water quality protection, pathogen questions, and best agricultural management practices for siting and providing buffers around biosolids stockpiles.
Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables. A useful 1998 guidance document for safely using manures and biosolids is available from the U. S. Food and Drug Administration, U.S. Department of Agriculture, and Centers for Disease Control and Prevention.
States & provinces have different requirements for agronomic rate calculations; contact your environmental agency for details.