GAINESVILLE – “I feel like I have to start by saying, ‘The water is safe to drink’,” Water Resources Director Linda MacGregor told the Gainesville City Council Thursday morning at their work session. “We’re meeting all the EPA drinking water requirements.”
Nevertheless, her department was very aware that something was not as customers wanted. For weeks MacGregor’s office had been receiving calls that the tap water they were receiving from the city tasted and smelled different than what they had been receiving.
City Manager Bryan Lackey told council members, “The smell and taste issues of our water the last few months is mainly associated with…the lake turnover issue.”
Lake turnover happens every autumn when chillier temperatures at night cool the surface water on Lake Lanier. Cool water is denser (remember that from middle school science class?) and because it is denser it falls down through the water column. Warmer water then rises to take its place on the surface.
The turnover process is slow and subtle – usually taking a couple of weeks - as this “stirring” action causes microscopic debris and un-oxygenated water on the lake bottom to mix with the cleaner water that had been above it.
This year the process has taken much longer than usual and the microscopic debris is still being picked up as the city pulls water from the reservoir. “It has never been this long-lasting or this severe,” MacGregor said.
MacGregor says the city withdraws water from the lake at two locations. One withdrawal point is in Orr Creek on the lower end of the lake, between Flowery Branch and Buford. The other withdrawal point is on the lake’s upper end, near Riverside Military Academy.
According to Lackey the Riverside location appears to be where the “taste and smell issue water” is originating.
Lackey said he and MacGregor discussed the issue at length and determined, “We’ve got to do something; we have to address this.”
After seeking advice and help from experts in the field of water supply the city started a procedure MacGregor believes will significantly reduce the smell and taste issues.
MacGregor said, “We’ve added…‘powdered activated carbon’ into the raw water. It absorbs the odor-causing things and is 80-percent effective.” That mixture then continues through the remaining usual filtration processes.
“We believe powdered activated carbon is the right approach to supplement the processes that we already have,” MacGregor added.
“The human nose is very sensitive…some people more than others,” MacGregor added as she cited numerous telephone calls where some members of a family could not detect the smell but others in the family could.
MacGregor said, “We started last week feeding the powdered activated carbon in at Riverside and it will take a little while for that newly treated water to get out to all the customers. So we hope we’ll that start seeing marked improvement and we also hope that whatever is going on in the lake will settle down.”
“And we have now started a (taste) sampling protocol,” she said, something that has not been a part of the city’s routine but will be until the issue is resolved. “It’s expensive; not many laboratories do it.”
“It takes two weeks to get the lab results. The first results won’t be in until next week.”