Public Water Supply
At the meeting of the Public Water Supply Committee September 7, there were scientific presentations to members addressing urgent current issues.
Dr. Daryl Dwyer and his student Ryan Jackwood presented their research on predicting microcystin levels. Early warning of rising levels of dangerous microcystin would be valuable for public advisories, for triggering additional sampling, and for preparing public water treatment plants to take action. With several years of data, other researchers have created a model that predicts levels of E. coli in real time. This predictive model is about 75 percent accurate while the traditional model (sampling and testing that can result in 24-hour delay of information) is about 50 percent accurate. Dr. Dwyer’s lab is using the same approach to predict levels of microcystin. The models will be validated at the end of 2017 and tested next year.
The Dwyer and Jackwood study involved a broad science team from the USGS Ohio Water Science Center and the University of Toledo with collaborators from several government agencies and data from many locations in Ohio. See the presentation here.
The team of Dwyer and Jackwood also presented research on the use of phosphorus sorbing materials in removing phosphorus from surface waters and agricultural drainage waters. The research looked at several materials that could be valuable including zebra mussel shells, residual material from the Toledo water treatment plant, and limestone. They propose “nutrient interceptors” that could filter excess phosphorus at treatment systems, at reservoirs, and in agricultural drainage. That presentation starts on slide 13 here.
Ed Pfau, a senior scientist with Hull & Associates, provided information on perfluoroalkyl substances and drinking water advisories. 3M voluntarily phased-out use of PFAs in 2000-2002. DuPont/Chemours settled lawsuits regarding PFAs at a Parkersburg, West Virginia plant. His presentation is here.