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Paula Crocker - Odor at 270 Liberty Circle (Project SS99 -01 C)
From: Ken Griffin
To: weswhite @wt.net
Date: 9/28/2006 12 06 PM
Subject: Odor at 270 Liberty Circle (Project SS99 -01 )
CC: Glenn Hollowell, Jim Witt
Mr White
This email is a follow up to our phone call this morning concerning the odor at 270 Liberty Circle My
Utility Division spent some time at the referenced location yesterday trying to determine the source of
the odor Initially, it was thought that there was something in the storm drain line that was creating the
odor, such as a small animal or stagnate water At times, small animals gain entry to the drainage
system and become trapped. Over time they decay and create an odor We placed our video camera in
the storm drain line to see if we could determine the source of the odor The video did not reveal
anything that would create an odor
After eliminating the storm drain as the source of the odor, the focus was placed on the 30 inch
diameter sanitary sewer force main behind your property that runs from our lift station near Sandy
Lake to a gravity main line near Belt Line. A force main is used when there is not adequate fall to
provide for gravity flow in a sewer line The sewerage is forced up through the force main by using
pumps at the lift station. When the force main is installed, it has highs and lows in it that somewhat
follow the lay of the land. Whenever there is a high in the line, air (sewer gasses) tends to collect. The
air is released from the force main through air relief valves. If the air is not released from the force
main it corrodes the pipe over time which creates maintenance problems. To help prevent the
deterioration of this force main from sewer gasses, we used an epoxy lined ductile iron force main.
In reviewing the force main behind your property, it was noted that an air relief valve was installed on
the force main near your property As previously stated, the air relief valve periodically releases sewer
gasses into the atmosphere Because the sewer line behind your property was epoxy lined, we closed
the air relief valve so that it could no longer release sewer gasses
The closing of the air relief valve should eliminate the odor that has been present on your property
Also, because the force main was epoxy lined, closing the air relief valve should not have a negative
impact on the life of the force main.
I'm sorry that we had to make three visits to your property to determine and eliminate the source of the
odor My Utility Division is confident that they have eliminated the source of the odor However, if
you still detect an odor, please let me know at your earliest convenience so that I make arrangements
for my Utility Division to revisit the problem.
Ken Griffin, P E
Director of Engmeermg /Public Works
972 - 304 -3686
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file. //C \ Documents %20and %20Settmgs\PCROCKER \Local %20Settmgs \Temp \GW }0000 9/28/2006