HomeMy WebLinkAboutJustification for the Noise Variance RequestJustification for the Noise Variance Request
The variance is necessary because of special circumstances
Renton is not specifically scheduling to do night work for the sanitary sewer relocation. However, when doing horizontal directional drilling (HDD) as needed for a portion of this project,
“momentum” is everything. Once you have begun a specific task in the process (ie. pulling the pipe), you cannot effectively stop the task and restart. To stop the task would create
difficulties and hardship as it would be highly likely that we could not overcome the inertia and friction to restart the task.
The plan is and every effort will be made to do the work between the hours of 7:00 am to 10:00 pm. However, during specific tasks related to the HDD (ie. pulling the pipe), if they
run into problems or the work is proceeding slower than anticipated they will have to continue the work until the task is completed, even if that means continuing past 10:00 pm. For
this project, we are having about 800 feet of 12” sewer main installed by HDD. That 800 feet of pipe needs to be pulled into place as one continuous task. It could go in easily and
the task would be completed in a normal working day or they could run into difficulties and the task will continue into the night.
Most of the noise will be confined to the two entry / exit points on either end of the HDD. There will be the need to continually move the “mud” (the material used to lubricate and
cool the drill head, casing and pipe during the process and stabilize the borehole) from the receiving pit back to the entry pit so the area between the pits would be subject to truck
noise as they haul this material from the receiving point back to the entry point.
The granting of the variance will not be materially detrimental to the public health or injurious to the property or improvements in the vicinity and zone in which subject property is
situated.
The noise would occur during a maximum 10 non-consecutive nights over the course of 17 months. The relocation of the sanitary sewers would allow for the continued provision of a public
health service to the residents of Talbot Hill as the State performs the needed transportation improvements to the highway system.
When distance is incorporated into the assessment as well as topography and the proposed mitigation measures, we estimate that the nearest residences would still notice the nighttime
work but not as severe as without all the listed mitigation. Citizens will be impacted to the minimum extent and there is no possibility that the public health or safety will be diminished.
If any noise related complaints are received, the contractor along with the City will work with the complainant to attempt to resolve the issue(s).
The approval of this variances shall not constitute a grant of special privilege consistent with the limitation upon uses of other properties in the vicinity and zone in which the property
is situated.
The City sanitary sewer facilities need to be moved to make room for the transportation project. The State is contracting with the City to have them relocated. To maintain grade, the
primary run of sewer needs to be between 40’ and 50’ deep. To use open excavation
construction at those depths would cause major disruption to the neighborhood. Using horizontal directional drilling will, most likely, shorten the time it takes to install the new
sewer and provide less continuous disruption to the area. The potential downside to choosing this method in order to minimize the overall disruption is to possibly have some nights
where they cannot stop work and have to continue past 10:00 PM.
As stated above, we are not scheduling to do night work and we would be happy to not have to use any of the requested nights. Our planned scenario is that work starts in May 2016, we
use 0 to 4 nights in June or July 2016, and the majority of our work is completed by January 2017. However, as with any major construction project we are planning for contingencies.
The approval is the minimum variance that will accomplish the desire purpose.
The requested non-consecutive days are the minimum number of nights required to complete this work including planning for potential construction contingencies.