Nearly 60% of all biosolids are used as a fertilizer on farmland. The relationship between Per- and polyfluoroalkyl substances (PFAS) and biosolids have emerged as a growing health concern. Water is interconnected, putting wastewater treatment plant (WWTPs) under further scrutiny.
WWTP operators would benefit from considering regulatory, technical, cost and risk management factors when evaluating the potential presence and impacts of PFAS in both WWTPs as well as land-applied biosolids, which are primary waste associated with water treatment. Effectively managing the impact of PFAS on municipal WWTPs can pose significant challenges because naturally, WWTPs are ‘receivers’ of waste streams for treatment and continue to accept domestic sewage, septage, and industrial and commercial waste streams which may contain PFAS. Because treated water is discharged to surface water, and PFAS in surface water may pose risks to human health and the environment, it is imperative to demonstrate levels of acceptable risk (e.g., Michigan MWRA Study) by taking actions to limit exposure.
The potential presence of PFAS throughout a wastewater treatment process raises a few critical questions:
- Should WWTPs accept wastewater that contains PFAS? If so, what types and levels are determined to be acceptable?
- What are the potential risks in these media and receptors? Are there unacceptable impacts to air, soil, water, livestock, crops, and human health from the application of biosolids to land?
- Should biosolids be applied to land with sensitive receptors such as down gradient surface water streams or near drinking water wells?
We deliver global, leading-edge treatments and plant design solutions that meet complex containment, compliance and process issues. Based on this experience, we leverage the treatment of land-applied biosolids as follows:
1. Importance of understanding regulations and local policies
Regulations are dynamic and need to be understood to evaluate overall risks. Minimal regulations are in place that address the levels of PFAS in biosolids. Studies in progress or recently completed will continue to provide data to regulators and interested parties about the treatment of PFAS in wastewater and the potential of contamination of WWTPs. Risk assessments for biosolids continue to be updated with new information to evaluate whether there are unacceptable risks related to human health and the environment.
2. Collaboration with all stakeholders – authorities and public
Wastewater treatment continues to get further attention as it relates to PFAS. The long history of agricultural use of biosolids in crop and livestock production raises health concerns at the end-consumer level. Focal points include the potential for leaching of PFAS into groundwater and uptake by crops and animals. The US Food and Drug Administration (FDA) and other parties globally conducted testing on crops and livestock in known PFAS-impacted areas with varying results in terms of the suitability of continued land application under specific conditions. With ongoing research, it is imperative to collaborate with all stakeholders, including authorities and public groups. The world is still learning. Further technical information, policies and regulations continue to emerge.
3. Investigation of impacts and development of tailored, risked based solutions.
Understanding the risks and impacts identified from various studies is key when addressing the needs for wastewater treatment and the future of PFAS contaminated wastewater acceptance, treatment, and discharge. In cases where there is an unacceptable risk of continued use of biosolids containing PFAS in certain land applications, recycling and disposal of biosolids may require alternative management. The potential for additional biosolids storage and treatment increases WWTP capital and operating costs. If WWTPs must test for PFAS before accepting wastewater and for the management of biosolids, who pays for that cost and what happens to wastewater and biosolids that are not suitable? These questions illustrate the depth of the impacts that the wastewater industry faces and the need for a proactive risk evaluation.
4. Understanding of PFAS impact on biosolids and treatment processes
Due to the ubiquitous nature of PFAS compounds, many biosolids contain some level of PFAS. It is important to note that pure domestic sewage generally has low levels, and the application of biosolids from this source generally does not pose an unacceptable risk to human health or the environment. Additionally, each WWTP receives different sources of wastewater and sewage, and therefore the impact of PFAS on treatment processes and resulting biosolids varies from one WWTP to the next. That dynamic difference is a risk, especially as technical information, policies and regulations further develop. It is critical to match your risk with your operational needs, as PFAS characterization impacts the extent of related wastewater and biosolids management requirements.
5. Finding Leadership and Assistance
PFAS treatment technologies and solutions are constantly evolving. Finding and selecting the right specialists and partners in PFAS science and treatment methods is critical to success. When selecting a PFAS specialist consider their understanding of the entire water treatment process chain – including influents, effluents and land application. Given the complex nature of PFAS, it is important to have a partner that provides a holistic approach from treatment process understanding to stakeholder engagement to risk management to provide practical, regulatory compliant and economic management of biosolids.
Resources and Education
[1] Michigan Waste & Recycling Association (MWRA), Technical Study (March 2019)
[2] PFAS in Biosolids ("sludge") and Residuals
[2] Relating PFAS Leaching from Sewage Sludge and Biosolids to Water and Sludge Quality
[4] US Food & Drug Administration: Per and Polyfluoroalkyl Substances (PFAS)
Meet Fred
Fred Taylor is a Professional Engineer, licensed environmental professional and Principal at GHD. He has over 35 years of experience in the environmental compliance, engineering, remediation, and construction field across North America on chemical and industrial manufacturing facilities, hazardous and non‑hazardous waste landfills, redevelopment projects, commercial, and residential sites. Fred also provides senior support for GHD’s North America Emerging Contaminants Working Group, through project management, facilitating global collaboration, developing and implementing R&D projects, and establishing partnerships with a wide variety of industrial, academic, laboratory, and vendor partners. Contact Fred at Fred.Taylor@ghd.com.
Meet Étienne
Étienne Bordeleau, GHD Waste Management Business Group Leader, is a Chemical Engineer with 10 years' experience. He delivers bilingual waste management, leachate and process, resource recovery, and environmental technical services in North America and Australia. Étienne collaborates with public and private sector clients to set the standard of client service experience for value in their projects and their communities. This includes strategic study and planning through to design and commissioning, approvals/licensing, and regulatory compliance. He is assisting clients with PFAS containment, and assessing co‑digestion feasibility, biogas utilization, and digestate management including PFAS-related risk management considerations. Contact Étienne at Etienne.Bordeleau@ghd.com.
Meet Chris
Chris Hertle, GHD Water Market Leader, is a Chemical Engineer with 35 years’ experience. He provides specialist advice for water, wastewater and solid waste management for municipalities and industries. He has a passion for incorporating innovative approaches that maximize water, energy and nutrient recovery. He has also been involved with implementation of a number of new technologies in the water and waste sectors. Chris has recently been involved in a number of projects that have involved the assessment and implementation of treatment schemes for PFAS removal. He is also investigating alternative approaches to PFAS destruction using thermal and electrochemical processes. Contact Chris at Chris.Hertle@ghd.com.
