Environmental studies of the Kaiparowits generating station: supplemental report

The purpose of the investigation described was to obtain a baseline of information on: (1) microbial soil communities; (2) aquatic macroinvertebrates; (3) water quality; (4) aquatic habitat; and (5) aquatic primary producers. Microbial studies were carried out in Southern Utah on Fourmile Bench and on Nipple Bench. Aquatic studies were carried out in the drainages into Lake Powell. In addition, available data was obtained on previous assessments of mercury concentrations found in Lake Powell fish. Each vegetation community was characterized by the unique occurrence of particular fungi and by the greater relative frequency and abundance of certain groups of fungi. Average pH values and soil carbonates were higher in soils of the benches than in counterpart soils near Page, Arizona, indicating greater buffering capacity against acid effluent gases. Seeps and springs demonstrated relatively well-developed communities of aquatic invertebrates compared to the low numbers and diversity of the bays. The high number of coliforms was probably related to grazing animals. Diatoms in the drainages were identified and several species also contribute significantly to the phytoplankton of lower Lake Powell.