Biosolids Program
Regulation and Beneficial Use of Biosolids
We are all responsible for generation of biosolids. Pennsylvanians produce an estimated 2.2 million tons of wastewater solids, or sewage sludge and residential septage, each year, nearly a quarter of a ton per household.
This material has proven to be a valuable resource, when controlled and safely applied, as a fertilizer to help rejuvenate farmland, forests and minelands.
In order to ensure safe use of biosolids, Pennsylvania has updated its regulatory program. The regulations focus on setting strict standards for biosolids quality before land application and requiring generators to be more responsible.
This new approach was developed after extensive studies by the U.S. Environmental Protection Agency (EPA) and public review in Pennsylvania found land application is environmentally safe and beneficial to the soil. The regulations have been endorsed by the Solid Waste Advisory Committee, the Pennsylvania Water Environment Association and the Pennsylvania Septage Management Association.
Biosolids that do not meet the new environmental standards must either be incinerated or taken to a landfill for disposal.
What are Biosolids?
Biosolids are nutrient-rich organic material produced from the stabilization of sewage sludge and residential septage that meet specific quality criteria and are suitable for land application. The term comes from the most common method of their production – the biological processing of wastewater solids.
Residential septage is human or household waste in a liquid or solid form removed from septic tanks or cesspools. The nutrient content of residential septage is similar to sewage sludge and, when treated and processed, can also be beneficially land applied as biosolids.
Biosolids meet specific quality criteria and are suitable for land application. Some are land applied as a liquid, while others have water removed from them and are the consistency of wet soil. Other biosolids are in the form of compost material and pellets.
Biosolids are created through the treatment of domestic wastewater generated from public and private treatment facilities. Biosolids treatment can begin before the wastewater reaches the treatment plant.
Regulations require that industrial facilities, in many larger systems, pretreat wastewater to remove many hazardous contaminants before it is sent to a wastewater treatment plant. Wastewater treatment facilities then monitor incoming wastewater streams to ensure the quality of biosolids meet the pretreatment standards.
Federal and state standards for pollution discharge have helped wastewater treatment plants institute effective pre-treatment programs. As a result, the quality of wastewater discharges has been improved, as has biosolids production.
Once wastewater reaches the treatment plant, it goes through physical, chemical and biological processes which clean it and remove the solids. The collected wastewater solids then undergo extensive stabilization treatment. This treatment reduces odors, pathogens, or disease-causing organisms, and vector attraction, or a characteristic of the wastewater that attracts rodents, flies, mosquitoes, etc.
Stabilization treatment includes such processes as digestion, lime stabilization, pasteurization and composting. The treatment changes the temperature, organic matter, moisture content or pH of the sewage sludge solids.
Solids processing equipment at a wastewater treatment plant or other facility is used to change the chemical and physical characteristics of the wastewater solids to a biosolids product that may safely be applied to the land.
There are many examples of biosolids being safely applied in communities. For instance, the Carlisle Water Pollution Control Facility in Carlisle Borough, Cumberland County, is an advanced wastewater treatment facili
