Posted February 13, 2018
It was always a two-intake solution.
That’s what Laurel officials said about the town's continued reliance on its old water intake in addition to the newly-installed unit three miles upstream.
The old intake, often called the 2003 intake for its construction date, is a redundancy measure, said Laurel Public Works Director Kurt Markegard.
“Leaving it in place allowed us to make sure our new intake is working, dealing with the ice better and also have the options to go back to the 2003 intake if needed," he said.
Construction on the new intake finished last year, costing more than $10 million.
The city relied on the old intake for months in 2017, as a few startup issues hampered the new unit. Officials say things are operating more smoothly now, and the new intake is the main source of water for Laurel residents and the CHS refinery.
Now Laurel, financially tapped, is gearing up for another big water system project. At the same time, that dual-intake redundancy is under threat.
Floods in 2011 caused the Yellowstone River bed to shift, lowering water levels around the old intake unit near the Highway 212 bridge. The intake needs to be fully underwater to properly work.
With the intake closer to the surface, ice jams in the winter and exposure during low-water months affected its ability to serve the city's treatment plant.
The new intake went in three miles upstream, where engineers agreed that the river topography should remain relatively stable. Construction finished in 2017, and startup setbacks followed.
“It's been a very rocky start as far as I'm concerned," said Laurel City Councilwoman Emelie Eaton. "I'm hugely disappointed that there just seem to still be continuing problems."
Markegard said that having the old intake around allows the city to deal with anything the river does, which was always the plan.
“There was nothing implied that the new intake would be the primary source (of water),” he said.
Indeed, a 2014 draft environmental assessment for the project said that having both intakes ready for use is an "immense advantage" and thus became part of the plan. If one intake is down for repairs or for another reason, the study said, there's another source of water for the city.
It didn't specify how often either intake would be relied upon.
Eaton said it was her understanding that the older intake was left in place as emergency backup. During meetings in 2017, council members received various assurances about the new intake's operation.
On July 11, Markegard told the council that the new intake was in use. That turned out to be untrue — a valve issue had kept the new intake offline, and the old intake kept water flowing to ratepayers. Markegard later said there was a miscommunication with water plant staff.
By the July 25 council meeting, Utility Plants Superintendent Tim Reiter assured the council that the new intake was 100-percent functional.
Markegard now says that the new intake job was "substantially complete" by the fall of 2017, and that's when things went online.
“Coming into the fall, we switched over into the new intake,” he said.
Chad Hanson, the Great West Engineering vice president who led the intake project, said the job was substantially complete on April 25, 2017, and has been ready for use since then.
Either way, both Markegard and Hanson said that it was an operational decision to use the old intake during the summer.
There was another problem in early January, when a mis-wired pump needed to be fixed. After that repair, Markegard said the new intake is sending water to Laurel and will be particularly useful when low water levels render the old unit useless.
“The main item for that new intake was to get us through low water events," he said. "That was the purpose to build the new intake.”
It was a temporary adjustment that allowed the old intake to be a reliable backup.
Prior to construction of the new intake, crews extended rock weirs from either shore of the Yellowstone, just upstream from the old intake. That raised the water level enough so that the city could make do with the old until the new one went online.
Now the U.S. Army Corps of Engineers is demanding that Laurel remove the weirs. The deadline is this fall, when the water is at its lowest.
Without the weirs in place, the old intake will suffer the same problems that required construction of the new unit. The old intake would have ice problems and again be exposed above the water line, eliminating the redundancy that showed its usefulness in 2017.
Though the new intake wasn't supposed to be counted on as the sole supplier of Laurel's water, it might end up being just that.
The intake project always included a plan to lower the old intake so that it's not exposed to ice and air and can continue as a backup. But that's not the city's first priority, and Markegard said they're not yet sure how that project will be completed.
“With the sed basin project potentially going out to bid again, (we're) seeing where those funds are at,” he said.
The sed basin, or sedimentation basin, is a water plant project that's been in the works for a decade. The city augmented its water fees in 2010 to begin saving money for construction.
But the floods changed everything. The city needed water, and the new intake became the priority. Laurel spent those saved reserves — and took out a loan — for the new intake amid a funding standoff with the state.
Now the intake is finished. The sedimentation basin project, estimated at around $7 million, is once again the city's priority. Partial funding comes from a $1.8 million contribution from CHS, which will gain a more stable raw water supply from the project.
The refinery has used up to half of the water that flows through Laurel's water plant.
Time is also a factor. The city must begin construction on the sedimentation basin by the end of 2018 to claim the CHS contribution, according to a Jan. 30 city council workshop.
So the job of lowering the old intake sits on the back burner. After a couple grant applications fell through, Markegard said that funding still isn't a sure thing. That's roughly estimated to cost up to $1 million.
Jumping into the sedimentation basin project feels like a quick turnaround for Eaton, who voiced concern about the new intake project in the past. She cautioned against the push for another expensive water system project.
“The fact that it's up and not 100 percent and using the old one as a backup," she said. "In my mind, I'm not willing to go forward with the next step, which is the sed basin.”
Source: Citizen Tribune