Miss Elaine ready; the tunnel boring machine should reach Lake Ouachita in 3 months
MOUNTAIN PINE – Pointed to the southern slope of Blakely Mountain on Monday, new Miss Elaine was ready to begin her more than half-mile journey to Lake Ouachita.
Dedicated to District 2 City Manager Elaine Jones, whose 24 years on the Hot Spring Board of Directors will end in December, the micro-tunnelling machine is expected to reach the lake in three months. Possessing 150-pound cutter teeth, its rotating head will begin cutting through the mountain today, the leading edge of a 2,600-foot, 60-inch tunnel, according to Michels Corp., will be the longest of its kind in North America.
The crusher behind the rotating head will reduce the excavated material to the size of a golf ball. A 4 inch pressure hose will pump the material to the surface.
Two hundred and forty feet of 56-inch pipe were welded to the MTBM power unit on Monday. A clamp around the outside of the pipe was attached to a thruster. Its two hydraulic rams will pull the pipe across the mountain 240 feet at a time, eventually pushing the MTBM into the lake. Cranes on a barge will recover the machine out of the water.
“This is very unique and challenging work,” said Hailey Edlebeck, Michel’s Corp engineer. who oversees the project, at Monday’s launch and inauguration ceremony. “We look forward to commencing mining (today) and hope for a successful hole on the other side.”
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Last year, the city council chose Michels to build the lake spigot and intake for the over $100 million Lake Ouachita water supply project. The $19.27 million contract included drilling the tunnel through the mountain and running the pipe through the opening.
The pipe will connect the water intake to the 17 mile long raw water main. The 48-inch and 42-inch pipe will flow lake water by gravity to a new treatment plant off Amity Road, crossing Upper Hamilton Lake, Highways 270 West and 70 West, Mazarn Creek and Little Mazarn Creek underway of road.
The $14 million contract the council awarded Michels last week to float and sink the line on Upper Hamilton Lake and dig it under Mazarn Creek has brought the price of the raw water pipe to more than 47 millions of dollars. It is one of the most expensive parts of a project that has increased in price. The low bid the city opened last month for the new factory off Amity Road was $12 million higher than the $24 million estimate.
“When we started this process, we were pre-COVID,” City Manager Bill Burrough said at Monday’s ceremony. “It was a project of around $110 million. At the end of the day, we will probably have around $150 million in this project.
“These are big numbers, but what we are solving are big challenges. I believe, deep in my heart, that when this is over, history will be very kind to this board and those who serve it. preceded and followed.”
The city has had access to an under-allocated 23 million gallons per day from Lake Ouachita for more than five years, paying the U.S. Army Corps of Engineers more than $400,000 a year to store water behind Blakely Dam Mountain. It took the city and the Mid Arkansas Water Alliance 13 years for the Corps to reallocate 50,000 acre-feet, or the amount that evaporates from the lake on a hot day, from power generation to supply municipal.
The 23 million gallons nearly doubled the supply the city has access to on Lake Hamilton and the city reservoir at Lake Ricks.
“Our planning today will see us well into the future,” Mayor Pat McCabe said at the ceremony.
It’s unclear how much of what the city has called a “generational” supply will be available to customers within the regional water system’s 145-square-mile service area. According to a report provided by the city’s finance department, more than $77 million of the $106 million construction fund was encumbered. The construction of the new treatment plant and the finished water line will exceed the fund balance.
The city said the finish line may have to wait. The 24-inch line will carry treated water from the new plant to the large distribution line that runs along the King Highway and feeds the 3 million gallon elevated storage tank behind Cornerstone Market Place.
The city can route water from the new plant into the water main that runs along Central Avenue/Highway 7 South. He enlarged an 1,800-foot segment between Long Beach and Ashley Roads from 8 inches to 12 inches, but the main one can only take a fraction of the new plant’s 15 million gallon-per-day capacity.
Burrough told the board earlier this month that he may have to consider authorizing another rate increase to complete the supply project. The higher rates that came into effect in 2018 secure the debt financing the project. Minimum monthly rates for residential meters within the city have risen from $5 to $13 over a four-year period that expired at the end of last year. They went from $7.50 to $19 for out-of-town customers. Annual increases of 3% came into effect at the beginning of the year.
The city said it hopes to have water from Lake Ouachita in the distribution system by the end of next year.