HomeMy WebLinkAboutPN_Project_Narrative_230522_v1
Puget Sound Energy
P.O. Box 97034 Bellevue, WA 98009-9734 PSE.com
May 15, 2023
Community & Economic Development - Permits
1055 South Grady Way, 6th Floor
Renton, WA 98055
(425) 430-7200
permittech@rentonwa.gov
RE: Boring for Submarine Cable Thermal Testing – Shoreline Exemption
To Whom It May Concern:
PSE is seeking a shoreline exemption for our proposal to conduct in-water exploratory boring to test the
thermal properties of the soil at the Quendall Cable Station. Boring at Location I would be located in
Lake Washington between Mercer Island and Renton (see enclosed materials for further detail). PSE is
proposing to complete geotechnical survey activities to evaluate site conditions in order to design
replacement cable crossings that will be completed as separate projects in the future. The thermal
survey work is needed to analyze site conditions and will be conducted by completing borings along the
existing cable line.
The scope of work for this project is classified as information collection, research, site exploration and
investigation activities. The location of the bore must be in the vicinity of the existing cable to
appropriately gauge the thermal properties of the underlying soil ahead of cable replacement. Because
this activity is related to a study associated with a future proposal, this project is exempt from SEPA
review pursuant to WAC 197-11-800(17). Because the proposed activity meets the criteria listed below,
this project is also exempt from the substantial shoreline development permit requirement of Renton’s
Shoreline Master Program (RMC 4-9-190(C)(l)).
• The activity does not interfere with normal public use of surface waters.
• The activity will have no significant adverse impact on the environment, including but not
limited to fish, wildlife, fish or wildlife habitat, water quality, and aesthetic values.
• The activity does not involve the installation of any structure, and upon completion of the
activity the vegetation and land configuration of the site will be restored to conditions existing
before the activity.
• The activity is not subject to the permit requirements of RCW 90.58.550, as the project does not
relate to oil or natural gas exploration in marine waters.
Please note: PSE was recently informed by Renton officials that Location I is not in the jurisdiction of the
City of Renton. However, after receiving conflicting information from other jurisdictions and reviewing
Washington Department of Ecology Shoreline Master Program (SMP) Handbook (publication 11-06-010,
Chapter 5, page 6), it seems clear that Location I is the jurisdiction of the City of Renton. The SMP
Handbook states that “RCW 35.21.160 extends [local] jurisdiction to the middle of water bodies such as
bays, sounds, lakes, and rivers…” This application for a shoreline exemption is being submitted as a
result of that review.
All borings will be completed in PSE-owned easements and properties. Location I will be accessed from
a barge. The method of the bore will be a vertical sample collection using a hollow-stem auger. No
more than 0.7 square feet of ground disturbance will occur from the hollow-stem auger (10 inch
diameter) at each bore location. The outer casing of the hollow-stem auger will encase the rod that is
driven down to collect the sample, so turbidity will not be able to escape during the bore work. The
bore will be driven to a depth of up to 50 feet below the floor bottom at bore Location I, and drilling
fluid generated during the bore will be collected into containment drums on the barge for disposal at an
appropriate upland location once work is complete. Once cores are collected, the bore holes will be
filled with approximately 4 cubic yards of grouting material (bentonite clay) in accordance with
Washington State Department of Ecology (Ecology) requirements.
Adverse effects are not anticipated from this project due to the minimal disturbance and short-term
duration. Impact minimization measures for this project include the use of BMPs for sediment control.
During the sampling impacts to water quality are not expected due to the containment of sampling
fluids and cuttings within the casing and the minor amount of potential sediment disturbance. There is
a slight potential for minor sedimentation of the water directly beneath and immediately adjacent to
the barge due to the placement and removal of the barge anchors and the containment casing. To
reduce the potential for spills and leaks, the work crew on the barge will have an adequate supply of
tools (vacuum pump, booms, diapers, and other absorbent material) to control and contain deleterious
materials in the event of an accidental fill. Additionally, vehicles and equipment will be inspected daily
for fluid leaks prior to the start of each workday.
If you have any questions, please feel free to contact me at dylan.marcus@pse.com.
Sincerely,
Dylan Marcus (He/Him)
Associate Municipal Land Planner
6500 Ursula Place South | Seattle, WA 98108
(206) 716-2754 (office) | (206) 225-7568 (cell)
Dylan.Marcus@pse.com