IMPACT OF NONCHLORINATED SECONDARY AND TERTIARY EFFLUENTS ON WARM WATER FISH COMMUNITIES¹

Abstract

The fish communities in three sewage receiving Illinois streams were monitored by electrofishing as treatment changed from secondary with chlorination to secondary without chlorination to tertiary without chlorination over a 40‐month period. Degradation of the fish communities was severe during the secondary treatment/chlorination period. When treatment was changed to secondary without chlorination, strong improvements occurred in the fish communities of all streams, and degradation could no longer be demonstrated on the basis of species number. The onset of tertiary treatment resulted in few additional changes in the fish communities, with the possible exception of increased abundance of several species of minnows. Tertiary treatment consisted of nitrification, sand filtration, and, in two streams, phosphorus removal.

Fishes of Champaign County, Illinois: as affected by 120 years of stream changes

“…There is little doubt that legislation passed between the Larimore and Smith (1963) and Larimore and Bayley (1996) Karr et al 1985;Paller et al 1988). This discovery led to regulations that limited the amount of each chemical in the effluent of wastewater treatment facilities.…”

“…Impervious surfaces associated with urban land cover have been shown to negatively affect stream fish communities (Lenat and Crawford 1994;Wang et al 1997Wang et al , 2000Wang et al , 2001. Additionally, the extended period of chronic pollution that occurred in the Kaskaskia basin has likely diminished populations of these largely intolerant fish species (Karr et al 1985;Paller et al 1988;Barbour et al 1999). Although still present during our survey, Hornyhead Chub decreased over the span of the project.…”