Occurrence of pharmaceuticals and plasticizers in leachate from municipal landfills of different age

• Pharmaceuticals, plasticizers were detected in leachate from open and closed cells. • Acetaminophen was order-of-magnitude lower in leachate from closed cells. • There was no consistent significant difference in leachate from closed and open cells. • Emerging contaminants are likely to leach for many years after landfill closure. Contaminants of emerging concern (CECs), such as pharmaceuticals and plasticizers, are present in leachate due to disposal of pharmaceuticals and plastic waste. Leachate is usually released to publicly owned treatment works, but CECs could pass through and be discharged into water resources. Landfills generate leachate for many years after closure, but it is currently unknown whether CECs continue to leach over time or dissipate soon after the waste is deposited. Leachate samples from four domestic landfills with various closure status in North Carolina, United States, have been collected from summer 2019 to summer 2020 (n = 36). Samples were analyzed for 13 pharmaceuticals (7 detected), and 3 plasticizers (2 detected). Carbamazepine and ibuprofen were detected in 100% of samples at respective median concentrations of 45 and 14,867 ng/L in open cells and 100 and 3,049 ng/L in cells closed for > 13 years. 17α-ethinylestradiol, acetaminophen, bisphenol A, doxycycline, and metformin were also frequently detected at concentrations spanning over 5 orders of magnitude between the compounds. Carbamazepine was present at significantly higher concentrations in older leachate (p < 0.1), while acetaminophen, doxycycline and bisphenol S were found at significantly lower concentrations. Lower concentration of bisphenol S is likely related to its usage pattern and not to its attenuation in the landfill. This study showed that leachate could be a source of CECs many years after closure. Thus, the transport of these compounds with landfill leachate is expected to persist for as long as leachate is generated in the landfill.