After the failure
in June of a 321-foot section of 12-inch concrete sewer main below North
Calumet Road, the Chesterton Utility is having serious thoughts about the
condition of an additional 730 feet of pipe.
Dave Ryan told the Utility Service Board at its meeting Monday night, the
other three sections of pipe--514 feet on Wabash Ave., 181 feet south of the
failed section on North Calumet Road, and 35 feet north of it--are just as
old as the section which was recently replaced: 75 years or more.
And there’s no good
reason to suppose that the pipe still in the ground is in any better
condition, eaten away as it’s been over the years by sewer gas, hydrogen
sulfide in particular.
For that reason
Ryan expressed an interest in exploring the feasibility of slip-lining the
remaining sections of concrete pipe. From a cost-benefit perspective it
would probably be the smart thing to do, he said, given the fact that it
cost just under $80,000 to replace the failed section, at $242 per foot, but
could cost as little as $56,000, or $75 per foot, to slip-line all 730 feet
of the remaining sections.
also be a minimally invasive solution to the problem, Ryan added, requiring
no excavation and having a likely service lifetime of a lifetime.
Still, Ryan warned
the Service Board, there’s no guarantee, that the 730 feet of pipe are in
good enough condition to take a slip-line. That determination would have to
be made by the contractor.
unanimously to authorize Ryan to pursue the slip-lining. They also expressed
their appreciation for the expeditiousness of the repair on North Calumet
Road. “Your staff did a great job,” Member Scot McCord said at the end of
the meeting. “I don’t think any businesses were hurt. And then to get it
turned around as fast as you did.”
Member Jim Raffin
concurred. “You guys minimized the disruption,” he said.
West Morgan Ave.
In other business,
Ryan suggested that there may be call to slip-line another section of sewer
main, this one the 30-inch monster 14 feet under West Morgan Ave. between
South 15th Street and South 14th Street.
At issue: a sink
hole whose cause hasn’t been conclusively identified but is probably a
breach at the top of the 30-incher.
Since the sink hole
first appeared, late this spring, the Utility has filled it twice with
gravel, the second time after the hole re-appeared to a depth of two to
three feet. That gravel could well be disappearing through a rupture in the
pipe, Ryan said.
A crew did do a bit
of excavation and while not deep enough to expose the 30-inch main it did
indicate that there are no other utility pipes in the area which could be
the cause of the sink hole, Ryan remarked.
In any case, Ryan
told the Service Board that he will investigate the cost of slip-lining this
section of pipe and report back.
July in Review
47.66 percent of its 3,668,000 gallon per day (gpd) allotment of the
wastewater treatment plant; Porter, 47.84 percent of its 851,000 gpd
allotment; the Indian Boundary Conservancy District, 50.43 percent of its
81,000 gpd allotment; and the plant as a whole, 47.74 percent of its
There were no
bypasses in July, which saw a total of 5.84 inches of rain, the wettest
month of the year so far.
In July the Utility
ran a surplus of $302,645.79 and in the year-to-date is running a surplus of