Depletion of E. coli in permeable pavement mineral aggregate storage and reuse systems

摘要

Permeable pavement reservoirs provide an important opportunity for the harvesting and storagenof stormwater for reuse. This research aims to determine whether storage in dolomite, calcitenand quartzite mineral aggregates in the base course of a permeable pavement impacts on thensurvival of the pathogen indicator organism Escherichia coli (E. coli) in storage. The reasons forndepletion were also investigated. Twelve model permeable pavement storage reservoirs werenfilled, in triplicate, with dolomite, calcite and quartzite. Three reservoirs contained no aggregate.nAfter filling with pathogen spiked rainwater, the concentration of E. coli was examined forn22 days in the reservoirs. The reservoirs were then agitated to determine if there was E. colinpresent which was not in aqueous suspension. The results of the experiments show that there isnno significant difference in the depletion of E. coli found in reservoirs without aggregate, andnthose filled with dolomite or calcite. The rate of depletion was found to be significantly lowernin the quartzite filled reservoirs. Agitation of the reservoirs yielded increases in the aqueousnconcentration of E. coli in all reservoir types, suggesting that the bacteria are adhering tonthe surface of the mineral aggregate and to the reservoir walls.