The City of Laurie has received a construction permit from the Missouri Department of Natural Resources for a project to intended to stop sediment infiltration issues in its main water well.
Located off of Route O, Water Well #3 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.
With the permit from DNR, the board approved going out for sealed bids for the project at its Sept. 11 meeting.
Bartlett & West has estimated the cost of the project at approximately $50,000.
Public Works Director Ed Young has cautioned that the project it not a guaranteed fix, but a new well could not be guaranteed not to have problems as well.
The board has previously attempted to fix the issue by having the pump lowered from 400 feet to 695 feet, 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.
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 Well #3 below the current casing.
The city's only other well is smaller with less pump capacity than Well #3.
Well #1 is no longer operational and has been capped. Well #2 is capable of meeting the capacity of an average day, according to the 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, other solutions that were considered for Well #3 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.