Full Description

The disposal of water treatment plant residuals can be problematic and increasinglyexpensive. Prior to the 1970s, most water plant residuals were returned to receiving water downstream of the water supply, in effect, returning the material removed, plus coagulant, back to the source water. The regulatory community has since elected to curtail the direct discharges of water treatment residuals. However, recognizing that the elimination of discharges lacked a scientific basis, some regulators have revisited the initial policy of banning direct discharges to surface water and will allow direct discharges to resume once specificconcerns are scientifically addressed. This paper presents two example studies concerning coagulant solids discharge to surface water (the Dan River in Virginia). Thestudy approach to direct discharge for these two water plants utilized available plant solids discharge information, laboratory analysis data, additional field work using artificial stratum placed in the river, and field investigations of in-stream benthic communities. Includes table, figures.

Product Details

Edition: Vol. - No. Published: 01/01/2000 Number of Pages: 8File Size: 1 file , 600 KB