DANVILLE, Va. – Ever since the first report of smelly, bad-tasting drinking water in Danville was reported on March 3, 2015, in the wake of the 2014 coal ash spill, residents have wanted to know what caused the bad taste and odor.
More complaints came in periodically over the next year.
In May of 2016, researchers at Virginia Tech began a comprehensive study of the Dan and Smith rivers.
They studied 12 sites and water plants monthly for a year.
"We take a bucket out of the river. We would also take some of the water that's underneath the typical water column. So, down in the sediment. We try to get that kind of water separately. We took some samples...kind of scrapings off the rocks and things," Virginia Tech civil and environmental engineer Dan Gallagher said.
"Then, we bring those back to the lab so we can do metals analysis. That's where we could look at some of the coal ash signatures."
Gallagher presented the study's findings Friday at the Institute for Advanced Learning and Research.
He said the lab testing of the samples also included chemical analysis.
"We tested, chemically, for what we think of as typical odorants," Gallagher said. "Geosmin is worldwide, widely known (as an odorant), so we measured the concentration of geosmin and about half a dozen other chemicals."
The study was paid for by a $500,000 grant from the National Fish and Wildlife Foundation.
"We've got a massive, what we're now calling a background data set, so if something ever does happen, you've got a great data comparison: This is what shifted. This is what might have caused it," Gallagher said.
Even though the study doesn't provide a definitive answer for residents as to the cause of the occasional taste and odor issues, Danville water director Alan Johnson hopes the study will still provide some peace of mind.
"With this study, we are able to pinpoint that there is nothing harmful or any kind of issues that could be concerns," Johnson said.
He said the study could also help other localities that conduct similar studies.
"They'll be able to kind of compare their results to this and maybe see if there's some links in between the different sources that they could possibly pinpoint and see some changes in their source waters as well," Johnson said.
To view an executive summary of the study's findings, click here.