Alkalinity of Concrete Washout Water: A Pilot to Determine Jobsite Conditions for Potential Neutralization

Abstract

The threat of stormwater contamination by concrete washout water from mixers, pumps, and other equipment has been identified through U.S. environmental policy for some time, primarily through the NPDES Permit Program. That said, enforcement of regulations prohibiting construction site release and spillage of this water has been sparse, at best. Recently, several urban areas and municipalities have begun levying fines upon general contractors for not taking proper measures to contain the washout water, and/or to properly dispose of it off of the construction site. This is prompting contractors, manufacturers, researchers, and other stakeholders to take notice, and to seek ways to mitigate the problem. This research continued the work of a recent project in which new containment product prototypes were developed, as part of a successful collaboration between construction management faculty and students, and their counterparts in industrial design. As the next phase of the study, this paper enumerates the findings of chemical analyses of washout water to develop a baseline level of contaminants. Primary contaminants measured include pH/alkalinity, total suspended solids, chlorides, oil and grease, and others. The authors’ hope is that these findings will present a future opportunity to leverage textile, absorbents, and/or flocculants such as naturally occurring tree cellulose as potential neutralization strategies. © 2019 The Authors. Published by Budapest University of Technology and Economics & Diamond Congress Ltd. Peer-review under responsibility of the scientific committee of the Creative Construction Conference 2019.