Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) was used to measure the concentrations of 14 pharmaceuticals, 6 hormones, 2 antibiotics, 3 personal care products (PCPs), and 1 flame retardant in surface waters and wastewater treatment plant effluents in South Korea. Tris (2-chloroethyl) phosphate (TCEP), iopromide, naproxen, carbamazepine, and caffeine were quite frequently observed (>80%) in both surface waters and effluents. The analytes of greatest concentration were iopromide, TCEP, sulfamethoxazole, and carbamazepine. However, the primary estrogen hormones, 17alpha-ethynylestradiol and 17beta-estradiol, were rarely detected, while estrone was detected in both surface water and wastewater effluent. The elimination of these chemicals during drinking water and wastewater treatment processes at full- and pilot-scale also was investigated. Conventional drinking water treatment methods were relatively inefficient for contaminant removal, while efficient removal (approximately equal to 99%) was achieved by granular activated carbon (GAC). In wastewater treatment processes, membrane bioreactors (MBR) showed limited target compound removal, but were effective at eliminating hormones and some pharmaceuticals (e.g., acetaminophen, ibuprofen, and caffeine). Membrane filtration processes using reverse osmosis (RO) and nanofiltration (NF) showed excellent removal (>95%) for all target analytes.