The Laurie Board of Aldermen has a contract pending for a project to extend steel casing in its main water well in hopes of stopping sediment infiltration that has caused cloudy water for customers in the past.
Midwest Side Drill's bid to extend steel casing 150 feet further down into the city's water well #3 was accepted by the board at its November meeting pending approval of references.
If all goes smoothly, the project will likely get underway in December. After the notice to proceed is issued, the contractor will have 45 days to finish.
The company offered a base bid of $93,365, according to Public Works Director Ed Young.
In addition to the steel casing, the bid includes a new pump to fit inside the smaller diameter well hole as well as new check valves and other new parts.
With the tank capable of storing two-three days of water, Young said it is unlikely that the city will ever notice the smaller pump.
Alternative bids were also taken to include the cost to also entirely rewire the well. In an earlier attempt to stop the infiltration issues, the pump was lowered from a depth of 400 to 695 feet, requiring a connection midway down the well.
Any connection is a spot with the potential to have future electrical problems. The board chose to have Midwest go forward with the additional work with the bid cost at $5,446.
Flynn Drilling was the only other bidder. Its base bid was $97,755 with the alternative bid for rewiring at $5,600.
Located off of Route O, the well is largest of two working wells used in the city's drinking water system, but it has had intermittent problems with cloudy water from sediment since it went online in 2001. The episodes have been increasing in frequency since late 2009.
In May, the Laurie Board of Aldermen approved $15,000 for Bartlett & West Engineering to oversee a project extending steel casing 150 feet further down into the well to hopefully block out the space where engineers believe the silt is entering the water.
A diagnostic video of the well has shown an area of broken rock and silt material at this depth. Most of the water comes from deep within the well where the cut appears to be smoother, so extension would potentially seal the rough section out without affecting the water supply.
Bartlett & West had originally estimated the cost of the project at $50,000.
The board has previously attempted to fix the issue by having the pump lowered, but the sediment issues continued.
A turbidity sensor now shuts off the well from the system when cloudiness is detected, allowing the city to keep the water from coming out at users' taps.
Page 2 of 2 - In the master plan for the water system, the rehabilitation of well #3 received the highest priority on a list of potential projects. Bartlett & West Engineering recommended the city install a lining in the well below the current casing.
The city's other water source, well #2, is smaller with less pump capacity. Well #1 is no longer operational and has been capped.
Well #2 is capable of meeting the capacity of an average day, according to engineers, but at peak flow would not be enough to meet the needs of the city. DNR also recommends redundancy in the source of water for greater reliability.
In the planning process on the issue, other solutions were considered including included filtering, interconnecting to another system, surface water treatment, section control, enlarging well #2 and drilling a new well. The alternatives to the selected project were considered prohibitively expensive or not feasible.