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Information for Biosolids Managers

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Policy and Science Behind the Standards for Use or Disposal of Sewage Sludge

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Biosolids Analytical Methods

EPA publishes laboratory analytical methods, or test procedures that are used by industries and municipalities to analyze the chemical, physical and biological components of wastewater and other environmental samples that are required by regulations under the authority of the Clean Water Act (CWA). Many methods are published in the Code of Federal Regulations (i.e., 40 CFR Part 136).

Other CWA Methods of Interest are not Currently Approved for use at 40 CFR 136, but are nonetheless accepted methods.

EPA Biosolids Publications

Presented are EPA publications that may contain valuable information related to risk assessment, control of pathogens and vector attraction reduction, biosolids management, EPA research, EPA's Office of Inspector General, and the availability of other publications.

If you have trouble accessing any content in the following documents, please contact Liz Resek (

Peer Review

The Cooperative State Research Service Technical Committee W-170, with the assistance of experts from EPA, academia, environmental groups, and units of state and local government agencies, organized a Peer Review Committee which conducted a review of the Environmental Protection Agency 40 CFR Parts 257 and 503 Standards for the Disposal of Sewage Sludge Proposed Rule.

Technical Support Document

The information contained in the Technical Support Document (TSD) was used to establish general requirements, management practices, operational standards, frequency of monitoring, and recordkeeping and reporting requirements, which are essential to protect human health and the environment from pollutants in sewage sludge when sewage sludge is applied to the land.

Risk Assessment

The U.S. Environmental Protection Agency (EPA) has developed a comprehensive risk-based rule to protect the public health and the environment from reasonably anticipated adverse effects of pollutants that may be present in biosolids (sewage sludge). EPA uses risk-based assessments to screen pollutants and select those that may require regulation. The biosolids risk assessment process considers multiple exposure pathways for each regulated biosolids use or disposal scenario. EPA’s risk assessment methodologies for biosolids have received extensive scientific review and public input.

Pathogens and Vector Attraction Reduction

This document provides basic information about why pathogen control and vector attraction reduction in biosolids are essential for the protection of public health and the environment.

Biosolids Management

Effective and protective biosolids management options help support our Nation’s needs for clean water. Provided are EPA documents related to various biosolids management topics.

Emerging Technologies

The technologies in this publication can be used to help reduce the volume of residuals and produce biosolids that can be used to help improve soil fertility and tilth, while decreasing the use of inorganic fertilizers and promoting the conservation of energy. This document provides information regarding emerging biosolids management technologies organized into three categories: 1) embryonic technologies in the development stage and/or tested at laboratory or bench scale; 2) innovative  technologies that have been tested at a full-scale demonstration site in this country; and 3) established technologies that are widely used (i.e. generally more than 25 facilities throughout the U.S.). Research needs are also identified to help guide development of innovative and embryonic technologies and improve established ones.

Emerging Technologies for Biosolids Management (PDF) (135 pp, 2 MB)

EPA Research

The following publications have been produced as part of EPA's strategic long-term research plan and are published and made available by EPA’s Office of Research and Development to assist the user community and to link researchers with their clients.

EPA Office of Inspector General

The Office of Inspector General (OIG) produced a report on findings that describe the problems the OIG had identified in preventing and addressing contamination of surface water from hazardous chemicals passing through publicly owned treatment works and corrective actions the OIG recommended. Final determinations on matters in this report were made by EPA managers in accordance with established audit resolution procedures.

Biosolids Technology Fact Sheets

Stabilization of biosolids helps to minimize the potential for odor generation, destroys pathogens (disease causing organisms), and reduces the material’s vector attraction potential.

Belt filter presses are one of several methods used to remove water from liquid wastewater residuals.

Composting is one of several methods for treating biosolids to create a marketable end product that is easy to handle, store, and use.

Thickening is the process by which biosolids are condensed to produce a concentrated solids product.

Centrifugal thickening and dewatering is a high speed process that uses the force from rapid rotation of a cylindrical bowl to separate wastewater solids from liquid.

Heat drying is an effective biosolids management option for many facilities that desire to reduce biosolids volume while also producing an endproduct that can be beneficially reused.

Biosolids are primarily organic materials produced during wastewater treatment which may be put to beneficial use. Composting is the biological degradation of organic materials under controlled aerobic conditions. The process is used to stabilize wastewater solids prior to their use as a soil amendment or mulch in landscaping, horticulture, and agriculture.

Biosolids are primarily organic materials produced during wastewater treatment which may be put to beneficial use. An example of such use is the addition of biosolids to soil to supply nutrients and replenish soil organic matter. This is known as land application.

Anaerobic digestion stabilizes the organic matter in wastewater solids, reduces pathogens and odors, and reduces the total solids/sludge quantity by converting part of the volatile solids (VS) fraction to biogas.

Proper facility design, operation, management, control and careful oversight are necessary to minimize odors. Water quality professionals have a responsibility to mitigate nuisance odors.

Recessed-plate filter presses are used to remove water from liquid wastewater residuals and produce a non-liquid material referred to as “cake”.

Incineration is combustion in the presence of air. Incineration of wastewater solids involves drying the solids and combustion of the volatile fraction of the solids. Combustion can only take place after sufficient water is removed.

Non-reuse options for wastewater biosolids in the United States, including landfilling, may be needed when recycling options are practical. For example, land acquisition constraints or poor material quality may limit beneficial reuse options. In these situations, landfilling of biosolids may be a viable alternative.

External Resources

EPA continues to partner with many organizations to ensure efficient use of biosolids, advance environmentally sound recycling of biosolids, and stay abreast of continuing research. These partner organizations are but a few of the many sources for additional biosolids information and resources.

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