The sustainable practice of treating and turning residual materials from wastewater treatment facilities into a certified reusable fertilizer.
Sludge is a solid or semisolid material derived from the water or wastewater treatment process. Biosolids are derived from sludge that has been treated to reduce pathogens and meet federal and state pollutant regulatory limits and standards. These residuals are beneficially utilized as a fertilizer or soil conditioner to improve soil physical and chemical properties and enhance crop growth. Biosolids come in different forms from compost or manure-like cake to dried pellets. Farmers, landscapers and soil manufacturers use biosolids as an affordable alternative that reduces the use of chemical fertilizers sourced from petroleum.
Biosolids are considered safe when they meet the federal and state requirements for pathogen reduction and pollutant limits. Biosolids can be classified into two classes, class A or class B. Class B biosolids undergo a treatment “process to significantly reduce pathogens.” This material has additional regulations for distribution and use, including a requirement for state approval of a site permit for class B biosolids to be land applied. Class A biosolids undergo a more extensive treatment “process to further reduce pathogens,” and therefore are not subject to further regulations for distribution and use. The class A biosolids are treated to such an extent that they do not need a site permit but must follow federal and state regulations and guidance. Either material, when used in accordance with state and federal regulations, are equally protective of public health and the environment.
Biosolids management programs are a sustainable practice for recycling nutrients and organic matter back into the environment. Alternatively, biosolids can be disposed at a landfill or an incinerator. When biosolids are land applied, they improve the soil microbiology and health to promote nutrient cycling thereby creating plant available nutrients ready for crop uptake. Biosolids increase plant growth and enable soil carbon sequestration. Soil carbon sequestration is the act of capturing carbon dioxide from the atmosphere, and storing into the soil carbon sink through vegetative production and photosynthesis. Neither landfilling nor incineration of biosolids are effective in helping reduce carbon footprint.
Sludge Quality Certifications
A generator or authorized agent of the residual must apply for a sludge quality certificate (SQC), before they can distribute biosolids in the state of New Hampshire. The applicant must supply general information, all industrial inputs into the treatment facility, annual volume generation, a description of the treatment process with proof of federal compliance, and test reports of the 177 required compounds. Under RSA 485-A XVI-c (a), NHDES must establish an annual testing program of the residuals that hold an SQC, where the biosolids are analyzed by a third party. Sludge Quality Certificates hold a five-year term, and may be renewed upon completion of the SQC renewal form. A facility generating biosolids out of state that wants to obtain an SQC in New Hampshire, must first meet the regulatory standards of their own state.
NHDES has developed a fact sheet for applicants seeking to apply for an SQC.
Did you know?
Did you know?
Biosolids are not poop: During the wastewater treatment process, bacteria digest the organic material that we flush down the drain. These bacteria themselves die, becoming a stabilized material that can be a valuable source of fertilizer that helps improve soil quality.
Sampling Analysis Plans
Sludge Quality Certification (SQC) holders must establish a sampling and analysis plan for their biosolids. Under NHDES rules, the permittee must follow the guidance of "The Wastewater Treatment Plant Operators Guide to Biosolids Sampling Plans" as published by the New England Interstate Water Pollution Control Commission. This guidance helps the operator establish a plan to test for priority pollutants outlined in their permit. NHDES also advises the permittee to follow the Northeast Biosolids Residual Association guidance for PFAS sampling. If a test result exceeds the standards, the permittee must immediately notify NHDES and cease distribution in New Hampshire. Distribution is allowed in New Hampshire only when compliance is met.
NHDES Reporting Requirements
SQC, Sludge Site and Sludge Facility permittees must each submit an annual report to NHDES in January that provides information on the biosolids that were produced and/or applied over the course of the previous year. The report by the SQC holder must include:
- A comparison of the soil and biosolids test results to required limits.
- The volume of the material generated and where it was used.
- The biological treatment that the material received.
The report should also describe any programs the facility is implementing to monitor and reduce the concentration of emerging contaminants in their biosolids.
Annual reports are reviewed by NHDES staff for completeness and compliance requirements. The SQC holder is responsible for rectifying any misinformation and/or non-compliance issues identified through the NHDES’ review. NHDES has created a template for required SQC annual reporting.
EPA Electronic Reporting
NPDES permitted facilities must submit a biosolids annual report to EPA by February 19 of each year covering the previous year. Facilities are only required to submit the report if they are a publicly owned treatment works (POTW) with a design flow rate equal to or greater than one million gallons per day, or a POTW that serves 10,000 people or more, or is required to have an approved pretreatment program. The annual report and requirements can be found on EPA’s website.
NeT is the NPDES eReporting Tool developed to facilitate electronic submittal of data by the regulated community through the Central Data Exchange (CDX) platform, EPA’s electronic reporting site. Program services under NeT include, but are not limited to, the EPA Biosolids Annual Program Report.