The ecological risk of PFOS in extended chronic and multigenerational ex-posures was quantified through survival, growth, reproduction, and vitellogenin (egg yolk protein precursor) responses as well as PFOS bioconcentration in zebrafish (Danio rerio). Fish were exposed to environmentally relevant PFOS concentrations through 180 days postfertilization (dpf) in the parental (P) and first filial (F1) generations and 16 dpf in the second filial (F2) generation. Survival decreased significantly in P and F2 generation exposures, but not F1, at the highest PFOS treatment. Significant adverse effects on body weight and length occurred predominantly at highest exposure treatment. Finally, PFOS had no significant effects on P or F1 egg production and survival or whole-body vitellogenin levels in P or F1 male fish. The present investigation indicated a threshold for ecologically relevant adverse effects in zebrafish at 119 μg/L (standard deviation [S.D.] 23 μg/L, n = 10) for survival and 87 μg/L (S.D. 48 μg/L, n = 19) for all statistically significant negative effects observed. Importantly, males had significantly increased PFOS accumulation and bioconcentration fac-tors versus females in both P and F1 generations. PFOS transfer to eggs was not a depuration pathway. Finally, a toxicokinetic model was developed to reliably predict PFOS whole-body burdens.

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that pose significant risks to ecosystems and human health. Increasing regulatory demands for PFAS management have increased the need for rapid and deployable analytical technologies for both abiotic and biotic matrices. Traditional detection methods, such as standardized chromatography, often require weeks to months for analysis due to a limited number of appropriately accredited laboratories, delaying critical decision-making. This literature review is intended to identify promising emerging PFAS analytical techniques or technologies to facilitate more rapid (near real-time) analysis and explore their relevancy in supporting human and ecological risk assessments. Recently developed optical and electrochemical sensing approaches are enabling the detection of PFASs within minutes to hours, with detection limits typically aligning within reported ambient concentrations in water, soil, and sediment. These emerging technologies could (1) support planning and prioritization of sampling efforts during the problem formulation phase of risk assessment, (2) complement traditional chromatography methods to lower time and resource demands to improve sampling frequency over space and time, and (3) aid in risk-informed characterization of PFAS exposures based on identified chemical classes or groups. This review highlights those approaches and technologies that could potentially enhance the comprehensiveness and efficiency of PFAS risk assessment across diverse environmental settings in the future.

The larval fathead minnow, Pimephales promelas, 7-day subchronic survival and growth standard toxicity test method is commonly used for research and regulatory testing of effluents and compounds, including emerging contaminants such as Perfluorooctanesulfonic Acid (PFOS). Existing feeding guidelines for testing are described in multiple methods but are open to interpretation. The current study sought to determine the impact of feeding ration on P. promelas survival and biomass during a subchronic exposure to PFOS. The study was conducted in two phases: (1) a control experiment to determine the most significant feeding ration factors that maximize biomass, with consideration to laboratory logistics, and (2) application of down-selected feeding rations in a PFOS exposure to determine toxicity reference values. The control optimization study supported that feeding ration and feeding frequency were significant factors in fish biomass. In the subsequent PFOS study, fish were fed a high or low ration of Artemia twice daily, while exposed to 0.3 to 3.4 mg/L PFOS. Fish fed a high ration of Artemia had significantly (p < 0.05) greater biomass than fish fed a low ration in all exposure concentrations except 3.4 mg/L, where survival was low in both treatments. The feeding ration was not a significant factor on the survival endpoint for either treatment, but the PFOS concentration was (p < 0.0001) (high ration LC50 = 2.44 mg/L; low ration LC50 = 2.25 mg/L). These findings contribute to a better understanding of the impact feeding ration has in toxicity assessments and downstream regulatory decisions.

Water quality monitoring data are routinely collected during dredging and placement operations to address various state and federal requirements, including water quality standards, with the intention of protecting ecosystem health. However, such efforts may be limited by the lack of a standardized national strategic focus and user-friendly streamlined interfaces to interpret the data. Inconsistencies in how and what data are collected and lack of consensus on scientifically backed biological-effects thresholds make it difficult to quantify potential dredging operations impacts (or lack thereof) both within individual projects over time and across multiple projects of differing characteristics. Summarized herein is an initial effort to define a scientifically backed path forward to improve the value of current and future water quality monitoring and management decisions based on water quality data collected. The provided turbidity data were generally below applicable state thresholds for two case studies but for a third case study did periodically exceed thresholds at depth. This includes providing rationale for strategic focus on the most relevant dredging operations and projects, based on three general site-specific data categorizations: (1) sediment type, (2) dredge type, and (3) ecosystem type.

As part of the US Army Corps of Engineers’ mission to evaluate and move dredged material (DM) to maintain navigation channels, environmental evaluation of the prospective material is required by the Code of Federal Regulations. While existing guidance manuals provide useful guidance to DM regulators, they are over 30 years old and not reflective of the latest science. However, efforts to update procedures and publish the documents individually or as a combined dredging manual have been thus far unsuccessful. These issues, coupled with a lack of consistent reporting and decision documentation, lead to delays arising from challenges addressing project-specific issues not clearly covered within the existing guidance, revisiting previously resolved issues or negotiating disputes between permitting authorities. This technical report provides a path toward modernization of the environmental compliance aspects of DM evaluation guidance in part through software executables guiding the management and decision process and through a structured, evidence-based approach. The value added is an updated approach to DM testing and evaluation decisions.

This technical note synthesizes and disseminates results of a 2020 survey of USACE dredging program and project managers to identify and prioritize needs related to the modernization and streamlining of the dredged material assessment decision guidance pursuant to Section 404 of the Clean Water Act (CWA) and Section 103 of the Marine Protection Research and Sanctuaries Act (MPRSA). Priorities identified through the survey and subsequent follow-on interviews—together with advances in science and technology—will facilitate development of an electronic decision guidance tool to enable consistent, timely, and cost-effective dredged material management decisions. This tool will also facilitate a standardized database for ready access to historical data.

A number of sites around the United States have used activated carbon (AC) amendments to remedy contaminated sediments. Variation in site-specific characteristics likely influences the long-term fate and efficacy of AC treatment. The long-term effectiveness of an AC amendment to sediment is largely unknown, as the field performance has not been monitored for more than three years. As a consequence, the focus of this research effort was to evaluate AC’s long-term (6–10 yr) performance. These assessments were performed at two pilot-scale demonstration sites, Grasse River, Massena, New York and Canal Creek, Aberdeen Proving Ground (APG), Aberdeen, Maryland, representing two distinct physical environments. Sediment core samples were collected after 6 and 10 years of remedy implementation at APG and Grasse River, respectively. Core samples were collected and sectioned to determine the current vertical distribution and persistence of AC in the field. The concentration profile of polychlorinated biphenyls (PCBs) in sediment pore water with depth was measured using passive sampling. Sediment samples from the untreated and AC-treated zones were also assessed for bioaccumulation in benthic organisms. The data collected enabled comparison of AC distribution, PCB concentrations, and bioaccumulation measured over the short- and long-term (months to years).