Municipal wastewater treatment plants have traditionally been designed to treat conventional pollutants found in sanitary wastewaters. However, many synthetic pollutants, such as pharmaceuticals and personal care products (PPCPs), also enter the wastewater stream. Some of these nontraditional contaminants are not efficiently removed by the treatment process at the wastewater treatment plant. Emerging contaminants (ECs) have been identified in surface waters receiving wastewater effluents and have been found to potentially cause adverse effects on aquatic wildlife. These materials are produced by industry in very large quantities and are disposed of in toilets and in industrial effluent where partial treatment occurs before their discharge. Some of the pharmaceuticals excreted from the human user's body are metabolized and are more toxic and untreatable than their parent compound. Emerging contaminants have been referred to by EPA as "contaminants of emerging concern (CECs) because the risk to human health and the environment associated with their presence, frequency of occurrence, or source may not be known." In this EPA funded research, pharmaceuticals, PAHs and pesticides at the treatment plants were examined. The study focuses on the effects of stormwater infiltration, the inflow into sanitary systems and the amounts and treatability of targeted pharmaceuticals. Stormwater is a known source of many contaminants and could mix with wastewater through stormwater infiltration and inflow (I & I). Several dry and wet weather series of samples were obtained from the city of Tuscaloosa's wastewater treatment plant. Samples were examined from four locations within the treatment plant in order to determine if there are significant differences between influent quantities and removal characteristics during periods of increased flows associated with wet weather compared to normal flow periods. The data generally show treatability appears to remain similar during both wet and dry weather conditions under a wide range of flow conditions. Changes in hydraulic retention times and hourly flow variations were also observed to determine treatment plant performance. Emphasis was placed on the following pesticides: aldrin, chlordane, dieldrin, endrin, gamma-BHC, heptachlor, heptachlor epoxide, hexachlorobenzene, hexachlorocyclopentadiene, methoxychlor, and toxaphene. As expected, not all compounds were quantified in the samples, with many being below the detection limits.