HomeMy WebLinkAboutJ_Variance_Request_Justification_240102_v1Noise Variance Request Justification
The Hearing Examiner will base their decision on the specific variance shown below.
(RMC 8-7-8.D.1-7): WSDOT will provide a response to each variance factor. List each factor for granting
a noise variance and provide your response under the question.
1. That the applicant suffers practical difficulties and unnecessary hardship and the variance is necessary
because of special circumstances applicable to the applicant’s property or project, and that the strict
application of this Chapter will deprive the subject property owner or applicant of rights and privileges
enjoyed by others.
Applicant Response:
WSDOT is requesting this variance to work at night based on the fact that the I-405 corridor is a major
part of the Puget Sound Transportation system and carries 132,000 AADT (Average Annual Daily
Traffic.) The I-405 Renton to Bellevue widening and Express Toll Lanes project is addressing capacity
and mobility improvements to the public and users. This variance is requested to complete the following
major items of work:
a. Renton Hill area : 3rd St /Renton Ave bridge retrofit
b. I-405 and SR 169 Interchange/ramp improvements
c. I-405 and Parkway Interchange/ramp improvements
d. I-405 and 30Th St Interchange/ramp improvements
e. I-405 and 44th St Interchange/ramp improvements
f. Adding through lanes
g. Build Retaining walls and noise walls
h. Upgrade drainage, utilities relocation, detention ponds
i. Rebuild ITS systems
j. Additional safety items such as but not limited to pedestrian and trail improvements, ADA access,
and landscaping.
I-405 serves as a key connector for commercial, freight, motorist uses, and mass transit within the Puget
Sound area and it is vital for the economic growth of the city of Renton.
Daytime closures, full or partial, to perform this work would have the potential to worsen the already
congested I-405 corridor. Furthermore, if I-405 users encounter daytime closures, there is a risk that
traffic will overflow onto city arterials and local streets increasing travel time of local residents, business,
and transit and school bus drivers.
Furthermore, as shown on the list provided as well as the attached exhibits this work will impact city and
main arterials temporarily for which there will be collaboration with the City of Renton and WSDOT task
force.
FLATIRON-LANE Design Builder (DB), WSDOT’s representative on this project, will be required to
provide a safe and efficient movement of people, goods, and services through and around any closures on
the project, while minimizing negative impacts to residents, commuters, and businesses. In order to meet
these requirements, it is necessary that the work for this project be done at night. Working at night is the
best way to minimize negative effects as a result of construction which would only exacerbate the existing
traffic conditions mentioned above.
Page 2 of 5
June 30, 2020
2. That the granting of the variance will not be materially detrimental to the public health, welfare or
safety, or unduly injurious to the property or improvements in the vicinity of the location for which this
variance is sought.
Applicant Response:
Temporary nighttime construction is one of the few tools that WSDOT applies to lessen traffic congestion
and disruption to highway users while improving the roadway. This is a project that will impact local
arterials and streets for short periods of times following a construction program schedule posted with
enough notice to the public and worked in conjunction with the City of Renton and WSDOT task force.
Location of the number of nights and type of work are detailed as shown on the Site Map pages 1 thru 11.
In general, we can summarize how the sound will be perceived by residents from a source such as this
construction equipment as it propagates over distance as follows: a 6-dBA noise level decrease will occur
with every doubling of the distance from a stationary noise source. For example, a noise level of 70 dBA
measured at 50 feet would be 64 dBA at 100 feet, 58 dBA at 200 feet and 52 dBA at 400 feet. Noise also
decreases if an object interferes with the receiver’s line of sight to the noise source as well as with a
topographic interference either natural like a hill or a man-made berm or an existing noise wall as
currently exists along the I-405 corridor within the city of Renton.
Also, in general, because the residents are located west and east of I-405 staggered out at several locations
with different topographic features how residents will perceive the sounds emanating from the soil
investigation site will vary as follows:
a. Residents along I-405 that are protected by a noise wall or a natural berm that break the line of
sight.
b. Residents especially in the area within Renton Hills, Maple Valley, Kennedale and Parkway are
located behind an embankment or behind a structure that will not have a direct line of sight.
c. Residents located west and east of I-405, generally the sound attenuation will depend on the
relative elevation difference between the source and the receiver, and the height and location of
the intervening object.
d. Residents along I-405 west and east of I-405 that currently have direct line of sight to the I-405
traffic, will experience construction sounds at some instance during the addition of the general
purpose.
e. Residents located on local streets and arterials such as Renton Hill area will likely have direct line
of sight to some items of work during construction.
Noise levels projected for this project have been estimated to be between 61 and 92 dBA heard at 50 feet.
When the night work will occur along I-405 we can consider that nighttime background traffic noise
levels on I-405 average 73 dBA at 50 feet from the nearest travel lane during the day time so including a
noticeable reduction factor of 5 dBA during the night it will be 68 dBA. The decrease is that traffic
volumes are lower during night hours. When distance is incorporated into the assessment as well as
topography and the proposed mitigation measures, how much residences will perceive or not will depend
of the item of work that will take place. For instance it will be more likely that demolition will be noticed
in contrast with earth moving to add through lanes that will be masked by the existing nighttime traffic.
However, if the work will occur on side streets such as the Renton Hill, where residents are facing the
work site, they will experience the nighttime construction sounds depending on the type of activity
including demolition. All these issues will be addressed in conjunction with the listed mitigation included
in the Noise variance Project Narrative.
December 6, 2023
Page 3 of 5
June 30, 2020
The monitoring plan developed will address all the impacts to residents that will be impacted to minimize
any possibility that the public health or safety will be diminished. If any noise related complaints are
received, the contractor along with the agency will work on alternative mitigation measures to stop the
inconvenience including providing hotel vouchers or identify state of the art measures currently in the
market to minimize the impacts.
3. That the variance sought is the minimum variance which will accomplish the desired purpose.
Applicant Response:
The requested noise variance will allow the WSDOT/ Flatiron DB to accomplish this work in the
minimum number of nights required to complete all the locations shown on Site Plan pages 1 thru 11.
This request includes range of 500 to 600 non-consecutive nights in total, including contingency.
4. That the variance contains such conditions deemed to be necessary to limit the impact of the variance
on the residence or property owners impacted by the variance. The variance approval may be subject to
conditions including, but not limited to, the following:
a. Implementation of a noise monitoring program as follows;
1. Renton Hill area or any area where demolition will occur at night.
2. All the other areas, will only perform nighttime noise monitoring if a confirmed
complaint is received.
b. Maximum noise levels;
Noise levels projected for this project have been estimated to generate peak noise levels of 61 to
92 dBA heard at 50 feet. Background traffic noise levels on I-405 reach approximate average
noise levels up to 73 dBA during the daytime at 50 feet from the travel lane with a reduction to 68
dBA due to lower average traffic at night. However in this case when the night work occurs at
night a more detailed plan be approved by the city as soon as the final construction plan and
sequence is approved.
c. Limitation on types of equipment and use of particular equipment;
N/A
d. Limitation on back-up beepers for equipment;
All alarms will operate under OSHA and L&I rules and regulations and WAC and RCW.
e. Required use of noise shields or barriers;
Included in cover letter under mitigation measures if installation adjacent to I-405 or within the
work zone is feasible and they are not a safety risk to I-405 users and workers.
f. Restrictions to specific times and days;
Night work will occur Monday thru Friday night starting when the variance is approved, with an
expiration date of December 31, 2024.
g. Specific requirements for documentation of compliance with the noise variance conditions;
The requested noise variance will allow WSDOT/Flatiron DB to accomplish the work in the minimum number of nights
required to complete all the locations shown on Site Plan pages 1 thru 11. The project's current noise variance permit
covered the length of the project as it was understood at the time. The project is now projected to complete in 2026, thus
the need for an additional permit. This request includes range of 350-450 non-consecutive nights in total, including
contingency.
Sunday thru Saturday night
December 31, 2026.
December 6, 2023
Page 4 of 5
June 30, 2020
All specific documentation is included in this request. WSDOT will develop noise mitigation
plans as soon as the Design builder completes the construction sequence at locations where
residents will be impacted due to some specific items of work that cannot be avoided to be
performed at night.
h. Specific requirements for notification to nearby residents;
Included in cover letter under mitigation measures.
i. Required cash security to pay for inspection services to verify compliance;
N/A waived.
j. Required access to the project by the City to verify compliance with the noise variance
conditions;
As long as the city of Renton follows the security and safety protocol set forth by
WSDOT/Flatiron so they may access the work zone.
k. Specific program to allow for temporary hotel vouchers to effected residents;
Included in cover letter under mitigation measures.
l. Requirements for written verification that all workers understand the noise variance conditions
for the project; and
Included in cover letter under mitigation measures. WSDOT/Flatiron will provide the City with
an attendance sheet of workers that will participate in the soil investigation night work.
m. Provision allowing the City to immediately revoke the variance approval if the variance
conditions are violated.
Upon confirmation of the Complaint or Noise Code Violation, City of Renton will email WSDOT
by email or call within 24 hours of the violation occurrence.
5. The importance of the services provided by the facility creating the noise and the other impacts
caused to the public safety, health and welfare balanced against the harm to be suffered by residents or
property owners receiving the increased noise permitted under this variance.
Applicant Response:
I-405 is a major part of the transportation system Puget Sound and the night work necessary to complete
its funded improvement authorized by the State Legislature will not cause impacts to the public safety,
health and welfare nor harm will be suffered by the residences or properties due to the temporary increase
over the 47 dBA permitted under the City of Renton Code.
6. The availability of practicable alternative locations or methods for the proposed use which will
generate the noise.
Applicant Response:
December 6, 2023
Page 5 of 5
June 30, 2020
Reconstruction of existing highway structures to adapt to more current design that meets the city plan is a
challenge because construction has to occur at locations where longtime residents are. Furthermore, if the
work occurs during the day time there are additional consequences such extending the life of the project
affecting the public for longer periods of time. So, unfortunately, working during the night is the only
option that will allow us to use novel construction management to expedite the construction. To mitigate
those impacts from night work WSDOT has been working and will continue to do so with the city of
Renton staff and its community to minimize impacts with a greater return for their inconvenience as a
goal.
7. The extent by which the prescribed noise limitations will be exceeded by the variance and the extent
and duration of the variance.
Applicant Response:
Noise levels produced by construction equipment is expected to range from 61 to 92 dBA at a distance of
50 feet from the source of the noise. These sound levels are expected to diminish to a range of 51 to 66
dBA at a distance of 300 feet from the source of the noise. A total range of 500 - 600 non-consecutive
nights including some contingency, however, the maximum number of nights will be a maximum of one
or two per location. Furthermore, noise levels will not be concentrated at one location for more than 2
weeks at the time and not all unwanted sound will be as bothersome as others. However, the critical ones
have been identified as pile /sheet driving, demolition of existing structures and where the activity will
occur in areas where residences are not protected by natural or man-made barriers.
December 6, 2023
350-450