Spatial and Temporal Variation of Freely Dissolved Polycyclic Aromatic Hydrocarbons in an Urban River Undergoing Superfund Remediation

Abstract

Urban rivers with a history of industrial use can exhibit spatial and temporal variations in contaminant concentrations that may significantly affect risk evaluations and even the assessment of remediation efforts. Concentrations of 15 biologically available priority pollutant polycyclic aromatic hydrocarbons (PAHs) were measured over five years along 18.5 miles of the lower Willamette River using passive sampling devices and HPLC. The study area includes the Portland Harbor Superfund megasite with several PAH sources including remediation operations for coal tar at RM 6.3 west and an additional Superfund site, McCormick and Baxter, at RM 7 east consisting largely of creosote contamination. Study results show that organoclay capping at the McCormick and Baxter Superfund Site reduced PAHs from a pre-cap average of 440 ± 422 ng/L to 8 ± 3 ng/L post-capping. Results also reveal that dredging of submerged coal tar nearly tripled nearby freely dissolved PAH concentrations. For apportioning sources, fluoranthene/ pyrene and phenanthrene/anthracene diagnostic ratios from passive sampling devices were established for creosote and coal tar contamination and compared to published sediment values.

Effect of water–sediment regulation of the Xiaolangdi Reservoir on the concentrations, bioavailability, and fluxes of PAHs in the middle and lower reaches of the Yellow River

“…However, the PAH levels in the present study were much higher than those in the Pearl River Estuary , the Niagara River (Michor et al, 1996), the Danube River (Maldonado et al, 1999), the lower reach of the Mississippi River (Mitra and Bianchi, 2003), and the lower Brisbane River (Shaw et al, 2004). For the freely dissolved concentrations of P 16 PAHs, the levels in this study were much higher than those in the Danube River (Vrana et al, 2014) and the Seine River (Bourgeault and Gourlay-Francé, 2013), but were comparable to the levels in the Morava River (Prokeš et al, 2012), and were lower than the levels in the Willamette River (USA) (Sower and Anderson, 2008).…”

Improvements in pollutant monitoring: Optimizing silicone for co-deployment with polyethylene passive sampling devices

“…In total, 25 PAHs were identified among all polymers (Figure 2). Polymers were first compared using PAHs due to analytical methods available at that time, and since PAHs are still contaminants of concern in Portland Harbor (Sower and Anderson, 2008). Concentrations were normalized for each silicone by mass so differences in volume between polymers would not confound comparisons.…”

“…First, laboratory methods were employed to optimize silicone pre-deployment cleaning to reduce background chromatographic interferences, and for infusing silicone with labeled internal standards for uptake rates and water concentration estimates. Second, we compared five silicone polymers in a field application at a Portland Harbor Superfund site with a history of POP (including PAH and pesticide) contamination (Sethajintanin and Anderson, 2006; Sower and Anderson, 2008). Sequestration data and operational logistics were used to select silicone polymers best suited for co-deployment studies with LDPE.…”

Review of the fundamental geochemical and physical behaviors of organoclays in barrier applications

“…surface cap (covers) (Yin et al, 2010), vertical barriers and underwater sediment cap of an in situ remediation system (Sower and Anderson, 2008;Meric et al, 2012), and (2). waste containment liner system (Lo and Yang, 2001;Lorenzetti et al, 2005;Katsumi et al, 2008;Lake and Rowe, 2005) and even possibly the final cover of a landfill or a surface impoundment system.…”