TRANSPORT, FATE, AND EFFECTS OF ORGANIC WASTEWATER COMPOUNDS AND PHARMACEUTICALS ON MACROINVERTEBRATES IN AN URBAN BASIN IN KANSAS CITY METROPOLITAN AREA, USA, 1998 TO 2006

The transport, fate, and effects of organic wastewater compounds and pharmaceuticals were studied at sites in the Blue River Basin, Kansas City Metropolitan Area, Missouri and Kansas, USA. Measurements of stream discharge, concentrations of 72 wastewater and 22 pharmaceutical compounds, and benthic macroinvertebrate communities were used to study constituent effects on urban stream water quality from 1998 to 2006. Sample locations were determined based upon proximity to tributaries, wastewater inputs, and hydrologic alterations. Fourteen stream sites were sampled during base-flow conditions and 10 of those sites were sampled during storms. Bottom-sediment samples were collected in 3 impounded reaches, and benthic macroinvertebrate community indicators were described at 10 basin sites and 1 outside control site.

Sites upstream from wastewater treatment plants and/or the combined sewer system area had lower concentrations of organic wastewater compounds and pharmaceuticals, and higher diversity in aquatic communities. Sites downstream from wastewater treatment plants had the highest concentrations and loads of organic wastewater compounds and pharmaceuticals. In many lotic stream reaches, only a small part of organic wastewater and pharmaceutical compounds was typically removed by in-stream assimilation and transformation processes, an indication that such contributions frequently exceeded the ecological assimilation capacity of these reaches. However, after an extended dry period with reduced inputs, total organic wastewater (sum of all detectable compounds) concentrations measured in bottom sediments decreased to approximately one-third of the values determined 6 to 8 months earlier, indicating that many organic wastewater compounds were likely degraded in anoxic bottom sediments.

In addition to increased inputs of organic wastewater and pharmaceutical compounds, declines in macroinvertebrate community health were correlated with several, inter-related urbanization factors, including increases in nutrient enrichment and percent urbanization. Thus, the effects of organic wastewater compounds and pharmaceuticals on macroinvertebrate community health and diversity were difficult to separate from other common urban water-quality effects.