A Surveillance Study: Pharmaceutical and Personal Care Products (PPCPs) in Biosolids

Enormous quantities of pharmaceutical and personal care products (PPCPs) are used worldwide every day. Significant amounts of these PPCPs reach wastewater treatment plants (WWTP) where they are primarily concentrated within biosolids in the solids treatment train and are not completely treated (McClellan et.al., 2001). Approximately 60% of the biosolids generated in the United States (US) are land applied. As a result, the US Environmental Protection Agency (EPA) has recognized the need to evaluate the occurrence, fate, and potential risk of unregulated pollutants in biosolids considering that land-applied biosolids may result in introduction of these pollutants to the environment via transport to soils, surface, and ground waters, as well as edible crops and animal products (Gerba et. Al., 2009, US EPA 1999). The 40 CFR Part 503 Sludge Rule provide us confidence and a framework on how to best manage risks from unregulated emerging pollutants in biosolids (National Academic Press, 2002). Additionally, Section 405(d) of the Clean Water Act (CWA) requires EPA to periodically review sewage sludge regulations to identify any additional pollutants that may occur in biosolids, and to set regulations if sufficient scientific evidence shows they may adversely impact human health or the environment. The emergence of analytical methods to measure increasingly lower concentrations of pollutants, combined with new data on the potential for human health and environ-mental impacts, requires the EPA to evaluate these newly detected compounds. With the universe of compounds that must be considered under this paradigm, the EPA is working to modernize, standardize, and streamline the risk assessment process for risk assessment of these constituents of emerging concern in biosolids. The EPA's Office of Water has developed a draft Biosolids Chemical Risk Assessment and Biosolids Screening Tool (BST) and a User's Guide to identify pollutants, pathways, and receptors of greatest interest and inform decisions regarding the need for refined risk assessment of land-applied biosolids, which is currently under review by a Scientific Advisory Board. Additional information can be obtained on EPA's website. In context of this issue, the EPA Recently funded nearly $6M to four institutions for research to support states, municipalities, and utilities in determining the potential risk from pollutants found in biosolids. Results from this research will be used to inform the development of standards and policies for biosolids management. One of the four funded projects, being led by Michigan State University, Colorado State University, University of Georgia Research Foundation, and the Great Lakes Water Authority is focused on PPCPs and PFAS as representative pseudo-persistent emerging contaminants (due to continuous discharge despite relatively rapid dissipation in soils). The teams aim to improve knowledge of occurrence, transport, fate, plant uptake, livestock, and human exposure to pollutants in land-based biosolids. The study will generate scientific information that will be important in risk management and in informing beneficial use management strategies. As an extension to this interdisciplinary, multi-institutional, multi-state, and university-industry collaborative partnership, including an initial 12 wastewater utility partners, the team has funded additional sampling to expand the study to 28 individual WRRF sites in North America (Figure 1). The objective of this surveillance study is to understand the range of concentrations of these compounds in biosolids, and to determine correlations of concentrations as a function of treatment processes. Participating Utilities were contacted in the summer of 2022 to complete a 102-question survey about their operations and process trains. After analyzing the survey data, samples were collected. Currently samples collected from the 24 WWTPs and remaining will be collected by end of 2022. Samples were collected as solids entered the solids treatment train (e.g., blended primary and waste activate sludge entering the anaerobic digesters) and at the compliance point of the stabilized biosolids product leaving the WWTP, regardless of end use or disposal method. WWTPs where the solids treatment trains were complex or had multiple outputs, more than two samples were collected and assessed. The samples were analyzed for 57 PPCPs (Table 1) by SGS AXYS according to method MLA-075 (EPA 1694). In addition to PPCP analyses, general characterization of the sludge was also conducted which included: pH, alkalinity, total solids, total volatile solids, and chemical oxygen demand (COD) and other parameters. To maintain anonymity, with respect to potentially sensitive data, WWTPs are not named, and data is presented to analytical laboratories and universities according to facility codes. Results from this surveillance study will be presented to provide an initial overview of the range of PPCP concentrations that enter solids treatment processes, percentage treated/removed by the various solids treatment trains, and the final concentration present in the biosolids. The data is invaluable in supporting an understanding of what utilities throughout North America could expect and can support an understanding of how PPCPs are removed through biosolids treatment processes, which can support decisions on management practices and strategies for biosolids disposal/beneficial reuse.