By Janie Southard
ST. MARYS -- Levels of mercury are on the rise in the city's wastewater system, but city officials say the increase is slight and not consistent in samples tested so far.
Dave Sprague, water department superintendent, told city council's water committee members Monday evening the city's mercury limit is 1.8 parts per trillion (ppt), as set by the Environmental Protection Agency (EPA). But the tests in January showed 11.1 ppt, up from 4.5 ppt last September.
One ppt compares to one inch in 16 million miles, Sprague told the committee.
"We don't actually know yet where it's coming from, but we're tracking it down ... There's literally hundreds of sources," he said.
He pointed out the EPA requires a lower ppt mercury limit in wastewater than that for drinking water. "This is because of worry about growth of microorganisms," he said. Ed Morris, water and wastewater treatment plant supervisor, said last month one raw sewage sample tested 68.9 ppt, but the treated discharge was 11.1 ppt. The treated wastewater is discharged into the St. Marys River.
"That was a big reduction but not enough to prevent the exceedance of our ppt limit," Morris said.
He added there's not "a whole lot of concern" because not every sample is high. "Most of the time they're non-detectable. Another sample was 0.69, well below our limit," he said.
Tracking is tough due to so many sources, but the department is currently collecting samples from the four major pump stations to determine where the readings may be consistent.
"We're not pointing fingers in any direction at this time, because we don't yet have enough data," Morris said.
"I'll bet it turns out to be someone who doesn't know they're doing anything wrong," Sprague said.
The water committee also discussed an increase in sewer rates beginning as early as April if council approves the ordinance, whose first of three readings is scheduled for next Monday's meeting.
Plans for the new $11 million wastewater plant will get underway this year with the design study, which will be largely financed through a $500,000 federal appropriation. Construction of the new facility will begin in the summer of 2007 with completion expected in 2008.
There have been no major expansions of the wastewater plant in nearly 40 years.
After several months of meetings with engineers and consultants, Sprague announced the increase to be recommended is 65 percent phased in during a three-year period. There will be a 25 percent increase this year, 20 percent in 2007 and another 20 in 2008.
"It's going to let us pay cash for some of the smaller improvements instead of borrowing and will spread the impact to residents over three years instead of the whole 65 percent at one time," Sprague said.
Connection fees was another area reviewed. The current fee of $200 per tap-in has been in effect as "long as anyone can remember," Sprague said, likely a dozen years.
State average is $1,201 per connection, but a mini-survey of like population towns prompted the department's suggested $800 one-time connection fee.
"I think everyone knows we haven't raised our rates at all in years," Mayor Greg Freewalt commented at the meeting.
The tap-in fee increase will be presented before council at the next meeting.