Also at the meeting, the council unanimously voted to enter into a memorandum of understanding with Northshore Mining for a trial program allow the plant to send its high fluoride water to the city. The plant is treating the high fluoride water as much as it is able, but now will mix the water with the lower fluoride city water to create a more acceptable blend for both entities.
City engineer John Groutman said there was a concern about the plan affecting mercury levels in the water and that is the reason for the 90 day trial period. John Thomas of the Minnesota Pollution Control Agency approved the plan and required that the water be tested for mercury three times weekly.
“It’s basically a trial period,” utilities department manager Mike Miller said. “If anything doesn’t work out it’s 24 hours to tell them it’s done and they have the same option, they can shut it off at any time.”
*See original article titled Silver Bay police proposal gets hairy online at http://www.duluthnewstribune.com/news/4346403-silver-bay-police-proposal-gets-hairy
Notes from FAN:
• Levels of fluoride at Northshore Mining from 1992 EPA report.
• A 2006 Draft Report on titled, Evaluation of Minnesota Taconite Wet Scrubbers at Minntac, Keewatin Taconite, Hibbing Taconite, and United Taconite. One excerpt:
… Two taconite facilities, Northshore Mining and LTV Mining used soda ash (sodium carbonate) water treatment to “soften” (precipitate calcium carbonate) process water. The tailing basins at these two facilities contain water that has the highest fluoride concentrations of all the Minnesota taconite facilities. Precipitation of calcium carbonate decreased the calcium concentration of the water, which decreased calcium fluoride precipitation; thus resulting in high fluoride concentration in the tailing water.