Recycling of Salt-Contaminated Storm Water Runoff for Brine Production at Virginia Department of Transportation Road-Salt Storage Facilities

Abstract

A large part of the Virginia Department of Transportation's (DOT) maintenance effort comprises the implementation of its anti-icing program. Earlier research confirmed that Virginia DOT captures a large volume of salt-laden storm water runoff at its 300-plus salt storage facilities throughout the state and that disposal options for this water are limited and costly. Although Virginia DOT is implementing recommended management options to reduce the quantity of salt water captured, this research was undertaken to determine the possibility of recycling salt-contaminated storm water runoff for brine production. Laboratory and field tests were conducted using bench-scale brine generation equipment. In the laboratory phase, brine was produced by using tap water, applying different hydraulic retention times and temperatures. Storm water runoff from a storage pond without any previous treatment was used in the field phase. Results show that the optimum conditions for brine production are low hydraulic retention time (high flow rates) and high temperatures. The total suspended solids present in the storm water runoff did not diminish the quality of brine in the field tests. Economic and environmental benefits can be obtained by applying this recycling strategy.