Reports
Traveltime and concentration attenuation of a soluble dye in the Monocacy River, Maryland
1970, Taylor, K.R.
Information Circular 9
Abstract
Three time-of-travel studies using a fluorescent dye were made on the Monocacy River in Maryland during 1967 and 1968 at flow-duration points of approximately 95, 70, and 35 percent. Time-distance relations are defined by these studies for a range of d1scharges from 100 cfs to 1,000 cfs at the index gage. These relationsh1ps will enable water users to predict the traveltimes of the leading edge, peak concentration, and trailing edge of a soluble contaminant spilled into the river.
Graphs in this report can be used to predict the maximum concentration expected from a contaminant introduced at any point and at any discharge. Examples given to demonstrate the use of the graphs show that the maximum concentration expected at the Frederick filtration plant resulting from a contaminant spill at Keysville Road bridge at an index flow of 100 cfs is only 20 percent greater than that expected for a similar spill at an index flow of 400 cfs. At 100 cfs flow, the time required for the contaminant cloud to pass the filtration plant intakes is over four times as long as that for a flow of 400 cfs. At an index flow of 100 cfs over 30 days would be required to flush the river of a contaminant spilled at the Maryland-Pennsylvania State line.
