Abstract
Municipal biosolids are commonly applied to land as soil amendment or fertilizer as a form of beneficial reuse of what could otherwise be viewed as waste. Balanced against this benefit are potential risks to groundwater and surface water quality from constituents that may be mobilized during storm events. The objective of the present study was to characterize the mobilization of selected endocrine-disrupting compounds, heavy metals, and total estrogenic activity in rainfall runoff from land-applied biosolids. Rainfall simulations were conducted on soil plots amended with biosolids. Surface runoff and leachate was collected and analyzed for the endocrine-disrupting compounds bisphenol A, 17α-ethynylestradiol, triclocarban, triclosan, octylphenol, and nonylphenol; a suite of 16 metals; and estrogenic activity via the estrogen receptor-mediated chemical activated luciferase gene expression (ER-CALUX) bioassay. Triclocarban (2.3-17.3 ng/L), triclosan (<51-309 ng/L), and octylphenol (<4.9-203 ng/L) were commonly detected. Chromium (2.0-22 µg/L), Co (2.5-10 µg/L), Ni (28-235 µg/L), Cu (14-110 µg/L), As (1.2-2.7 µg/L), and Se (0.29-12 µg/L) were quantifiable over background levels. Triclosan, Ni, and Cu were detected at levels that might pose some risk to aquatic life, though levels of metals in the biosolids were well below the maximum allowable regulatory limits. The ER-CALUX results were mostly explained by background bisphenol A contamination and octylphenol in runoff, although unknown contributors or matrix effects were also found.