Until recently, few studies have sought to understand the fate and transport of pharmaceutical compounds after they leave the human body. Numerous compounds have been detected in the environment.  While many degrade, others persist over a wide range of environmental conditions.  Data on the environmental and toxicological effects of many compounds does not exist.  Toxicology studies have shown that concentrations in the low ppb range of some pharmaceutically active compounds can sicken, alter sex or even lead to death in certain species.  It is critical to determine compounds entering the environment and to understand their fate. In Louisiana many municipalities treat wastewater using natural systems, such as lagoons and wetlands, rather than conventional mechanical means.  Most research to date has focused on the fate of pharmaceuticals in conventional treatment plants, not treatment wetlands.  A treatment wetland in the city of Mandeville, LA has been operating since the early 1990s, receives wastewater which discharges out of the treatment wetland, into bayous and into Lake Pontchartrain. Sampling was conducted to assess the loading and transport of several pharmaceutical compounds from the plant influent all the way to the lake. Water samples were analyzed for fifteen compounds.  Thirteen compounds were detected in the plant influent, while only eleven compounds were detected in the effluent. Drugs in the acidic class (Acetaminophen, Naproxen, Ibuprofen, Gemfibrozil) were reduced by ~80 to 100%.  Similar results were found for neutral drugs (Cotinine and Caffeine) which decrease between 96-100%.  However the neutral drug Carbmazepine decreased by only 36%. Sulfonamides (Sulfapyridine and Sulfamethoxazole) both decrease by ~70-75%. Compounds commonly called Beta Blockers (Atenolol, Nadolol, Metoprolol, Sotalol) also decrease between ~60-85%.  The research shows that this natural treatment system varies in removal rates for each compound, however most compounds observed decreased by over 70% during the treatment process.