since 1972, 10 benthic surveys and 9 static fish bioassays have been conducted to assess the impact of avtex fibers, inc. effluent on the lower south fork of the shenandoah river. avtex is a rayon and polyester fibers plant located in front royal, virginia. single surveys in 1972 and 1973 indicated a severe impact on the benthic community along the right side of the river, below the plant, as a result of the channelized effluent. in early 1974 the company constructed an activated sludge treatment system to reduce bod and supplement the neutralization and chemical precipitation (zinc hydroxide and liquid-solid separation) facilities that had been used to treat waste waters since 1948. after the new equipment was placed in operation, the previously stressed area became more stable. the major improvements in the effluent were a 70 reduction in bod//5 and a 60 reduction in the amount of zinc entering the river. community conditions in 1977 indicated a partial remission of improvement, probably due to drought conditions. refs