Environmental regulations in the United States lead to improvements in untreated stormwater quality over four decades

Occurrence, Concentration, and Distribution of 35 PFASs and Their Precursors Retained in 20 Stormwater Biofilters

“…17,29,30,61 There is particularly a critical knowledge gap regarding the fate of PFASs in biofiltration systems under field conditions, wherein the following numerous factors and their variations may also play a role: catchment land use and area, biofilter's design characteristics such as surface hydraulic loading rate, media depth, age, initial and accumulated OM and fine particle content in the filter material, surface chemistry of soil particles, number of inlets, existence/type of forebay (pretreatment), and stormwater chemistry (e.g., TSS, pH, OM, and competing ions and OMPs). 62 Field data on the type and concentration of PFASs and precursors accumulated in mature (around 10 years old) stormwater biofilter facilities will deepen the current knowledge about (1) the actual role of biofiltration systems in the sorption and fate of PFASs, 17 (2) the potential remobilization and transformation of PFASs in biofilters, (3) design modifications for targeted PFAS removals in the future, (4) the long-term operation of biofilters, including maintenance/disposal needs and measures throughout their lifecycle, 26 and (5) the health risk assessment associated with accumulated PFASs.…”

“…To date, PFAS studies on soil/sediments have mostly focused on agricultural soils impacted by contaminated wastewater treatment biosolids or surface soils near fluorochemical manufacturing facilities, along with a few on the stormwater sediments of sewers, ponds, and gully pots. ,− However, no study has investigated PFASs and precursors in the forebay and filter material of mature stormwater biofilters in urban areas. Although some lab-scale experiments reported unpromising PFAS adsorption by conventional soil media for highly contaminated groundwater/soil, ,− a critical review argued that PFAS sorption behaviors are more complex than can be described by a single soil/sediment property (e.g., soil organic carbon–water partitioning coefficient, K OC , the only parameter considered in most studies); instead, combination of several physio-chemical and kinetic factors (e.g., OM, pH, clay content, index cations, ionic strength, cocontaminants, contact time, and unsaturated/saturated flow conditions) may have significant increasing effects on PFAS sorption. ,,, There is particularly a critical knowledge gap regarding the fate of PFASs in biofiltration systems under field conditions, wherein the following numerous factors and their variations may also play a role: catchment land use and area, biofilter’s design characteristics such as surface hydraulic loading rate, media depth, age, initial and accumulated OM and fine particle content in the filter material, surface chemistry of soil particles, number of inlets, existence/type of forebay (pretreatment), and stormwater chemistry (e.g., TSS, pH, OM, and competing ions and OMPs) . Field data on the type and concentration of PFASs and precursors accumulated in mature (around 10 years old) stormwater biofilter facilities will deepen the current knowledge about (1) the actual role of biofiltration systems in the sorption and fate of PFASs, (2) the potential remobilization and transformation of PFASs in biofilters, (3) design modifications for targeted PFAS removals in the future, (4) the long-term operation of biofilters, including maintenance/disposal needs and measures throughout their lifecycle, and (5) the health risk assessment associated with accumulated PFASs.…”

Nutrient Loadings to Utah Lake from Precipitation-Related Atmospheric Deposition

“…Characterizing nutrient loads to water bodies is critical for informed management [1] and for making often costly decisions related to minimizing these loads. Excess nutrients cause issues such as excessive algal growth, which can cause low-oxygen (i.e., hypoxic) conditions and, depending on the species, toxic water conditions [2].…”