2. Methods
2.1. Sample collection
Samples were collected from five landfill sites across the U.S.
that release landfill leachate to wastewater treatment facilities
using previously described protocols (Anumol et al., 2013)
(Table 2). Sample kits were shipped to participating landfill sites
and the on-site personal collected samples. Grab samples (1 L)
were collected in silanized amber glass bottles, preserved with
1 g of sodium azide and returned via overnight courier to the
laboratory in coolers containing ice-blocks. Samples were filtered
through a 0.7 lm glass fiber filters (Whatman, England) before
storage at 4 C until extraction.