SEASONAL CHANGES IN FATE AND TRANSPORT OF PHARMACEUTICALS AND PERSONAL CARE PRODUCTS DUE TO THE EFFICACY OF ONSITE WASTEWATER TREATMENT SYSTEMS IN A SINKHOLE LAKE ENVIRONMENT

Pharmaceuticals and personal care products (PPCPs) are considered contaminants of emerging concern due to their widespread presence in surface- and ground-water, and they may be released into the environment through on-site wastewater treatment systems (OSWTSs). Water samples from a residential and natural lake were collected in March 2021 for PPCP analyses, and weekly from late spring to early summer for dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), pH, and temperature. The presence of PPCPs was determined using solid phase extraction (SPE) followed by Liquid Chromatography Triple Quadrupole Mass Spectrometry (LC-MS/MS) analysis. We found that DEET, caffeine, and cotinine were detected in both lakes, with DEET and caffeine levels more elevated in the natural lake. Meanwhile, the residential lake displayed poorer water quality containing amoxicillin and acetaminophen. We suggest that differences in the local topography and human settlement (OSWTSs) contributed to these differences in water quality. As the presence of PPCPs can lead to potential bioaccumulation and detrimental impacts for the local ecosystem, addressing the current lack of monitoring and ensuring strong enforcement of OSWTS regulations is essential for highlighting the extent of the issue and reducing negative impacts on the natural environment.