City and Borough of Juneau Director of Engineering Rorie Watt gave high praises to Juneau’s drinking water at a recent presentation to the Juneau Chamber of Commerce.
"About as good as it gets," Watt said. It’s abundant and "the best of the best in terms of quality."
Juneau residents and businesses pull 4 billion gallons of water from Gold Creek and Salmon Creek for potable water and cruise ships use another 1 billion gallons, Watt said.
“They are so good and reliable and water customers like them,” Watt said. “They have low operating cost. It would be unlikely that other sources are better.”
And with two sources of drinking water, Juneau is a municipality to envy.
“Many communities would like to have a backup system,” Watt said.
Should Juneau ever abandon its current drinking water sources, the city would next look to the Mendenhall Valley, he said.
“Valley water tends to be highly mineralized,” Watt said. That poses issues for taste and staining laundry and building up deposits on water fixtures.
“Valley water is not as favorable as Salmon or Gold Creek,” Watt said.
Drillers have even found brackish water in the valley.
“Not a very appealing scenario,” Watt said.
Another alternative is to boost the production of drinking water from Salmon Creek. To do so would require the addition of a $5 million or $6 million filtration plant for a stable year-round supply of water.
The city planned for its current infrastructure in the early 1960s and 1970s, Watt said. It spent the 1980s and 1990s building the infrastructure and the last decade in operation.
“We are back around to planning for infrastructure for the future,” Watt said. “Particularly in the context of the possibility of opening the AJ mine.”
“Looking out 10, 20, 30 years, we have to think about growth in the community, or growth in consumption,” Watt said.
He gave the example of cruise ship water use. It was unexpected when the city planned its current water system. Now cruise ships use 20 percent of the city’s water in summer months.
Watt said a draft resolution considered for hearing before the Assembly could spark discussions about Juneau’s planning for its drinking water within the Assembly and throughout the broader public.
“They are probably going to take that resolution up, I’d guess late May,” Watt said. “To continue to move forward and talk about the mine issue.”
“We have two excellent water supplies, very, very high quality water,” Watt said. “And as we move forward we need to think about how we plan to manage those systems."
If there is mining operation, Watt said he would recommend diversion of Gold Creek through a tunnel.
“Providing peace of mind for the public,” Watt said. “If there were a mine operator in there you'd build a pipe and divert the water for he entire time the mine is in operation.”
“We have to ask what risk, therefore pollution, could happen,” Watt said.
The AJ Mine has two sections in regards to water flow, above and below the drain tunnel.
“Below drain tunnel water can't get into it,” Watt said. Above the drain tunnel "pollution events could get in."
Pollution events above the tunnel tend to come from drilling, blasting and loading trucks. So potential hazards would be from explosives, drilling muds and diesel fuels, he said.
"Things you don’t want in your drinking water system, but not the things you worry about most in mining," Watt said. Most troubling are reagents used in the milling process and toxic leachate that can seep from mine tailings. These pollution events would most likely occur at the milling site, Watt said, which would likely be built at sea level, if at all.
Watt said the mine could bring $2 million to $3 million a year in royalties along with 200 jobs. Property taxes, Watt said, would approximate the $1 million Kensington and Greens Creek mines pay each year.
"A significant package of economic benefits," Watt said.
To the public and AJ Mine advisory committee though, water is the biggest issue when talking about AJ Mine, Watt said.
• Contact reporter Russell Stigall at 523-2276 or at firstname.lastname@example.org.