HomeMy WebLinkAboutA17_GeoResources Rebuttal Memo
Technical Memo
To: Bryan Telegin
Telegin Law
Project: TeleginLaw.DabobBayResidence
From: William J. Cedzich II, PE, PG, PEng
Senior Geotechnical Engineer
Date: September 22, 2025
Re: TeleginLaw.DabobBayResidence
STATEMENT OF PURPOSE
The purpose of this memorandum is to present our professional review of new conclusions provided by the
Applicant and their geotechnical consultant regarding Dabob Bay Residence. The role of GeoResources in this
matter is limited strictly to geotechnical engineering. Many of the broader disputes surrounding Twana Way
involve property access, neighbor relations, and land use planning, and fall outside the scope of geotechnical
practice. The following comments are confined to the technical adequacy of the Applicant’s new exhibits and their
consultant’s anticipated testimony.
REVIEW AND DISCUSSION
The Applicant and their geotechnical consultant have presented new conclusions suggesting that Twana Way is
inherently stable, well-founded in competent soils, and that prior use by construction vehicles demonstrates the
road’s adequacy. From a geotechnical perspective, these claims are incomplete and unsupported by required
analyses.
First, the reliance on a single lumber truck passage as “evidence” of roadway adequacy is anecdotal. Your
correspondence notes the Applicant is citing a Von Bargen lumber truck as proof of road stability. McShane’s
expected testimony also states that “construction vehicles have historically used Twana Way without the need to
widen it and without causing damage.” Anecdotes are not a substitute for engineering. [Jefferson County Code
§18.22.945(2)(d), the WSDOT Geotechnical Design Manual (Section 7.6.4), and AASHTO LRFD Bridge Design
Specifications (§11.6)] all require slope stability modeling with defined factors of safety under static, seismic, and
construction loading conditions. No such analysis has been performed or provided.
Second, the assertion that Twana Way is founded on “dense, well-drained sand and gravel” is unverified
(Applicant Witness List, p.6, Aug 15, 2025). No borings, test pits, or laboratory data have been provided to confirm
soil stratigraphy, strength, or groundwater conditions. Without such data, any statements about soil conditions
remain assumptions and cannot be relied upon as an engineering basis.
Third, while Twana Way may be described as a “full bench-cut road” (Applicant Witness List, p.6), the terminology
itself is immaterial. The alignment does not display the geometry, construction controls, or engineering design
required of a true bench cut as defined in standard references (e.g., NAVFAC DM-7, WSDOT Design Manual).
Field conditions suggest the feature is more accurately described as an informal track graded at some point in
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the past with no prescribed dimensions or engineered intent. From a geotechnical perspective, whether the track
is referred to as a “bench cut” or as “informally graded” has no bearing on slope stability or roadway performance.
The distinction is semantic rather than technical.
Finally, McShane’s expected testimony states that Twana Way lies 190 to 335 feet from the bluff and is therefore
outside of the 200-foot Shoreline Management Act jurisdiction (Applicant Witness List, p.6). Even if this is
accurate, it does not eliminate obligations under JCC 18.22.510 or Ecology’s SWMMWW to evaluate erosion
hazards and sediment delivery risk. No erosion hazard assessment or water quality evaluation has been
presented.
REVIEW AND COMMENT
Anecdotal truck use is not an engineering substitute for slope stability modeling (Applicant Witness List;
your correspondence, Aug 19, 2025).
No slope stability analyses have been provided, in contradiction with guidance provided by JCC, WSDOT
GDM, and AASHTO requirements.
Soil conditions remain unverified due to the absence of subsurface exploration or lab testing (Applicant
Witness List, p.6).
The “bench cut” terminology has no technical consequence; the alignment does not meet the standards
of an engineered bench cut and is best characterized as informal grading.
Cut slopes are sensitive to construction loads, drainage changes, and pore water pressure variations
(Applicant Witness List, p.6).
No erosion hazard or stormwater assessment has been presented despite code requirements.
CLOSING
In summary, the Applicant’s new submissions do not address the fundamental geotechnical deficiencies
previously identified. Without proper slope stability analyses, subsurface exploration, and erosion hazard
evaluations, the technical basis for claiming roadway adequacy remains incomplete. Anecdotal vehicle use—and
semantics over whether the alignment is a “bench cut”—cannot be relied upon as evidence of geotechnical
stability or safety.