2637_001.pdfrPACE
An Engineoring Sery1ces Company
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October 8, 2019
City of Edmonds
Attn: Jeanie McConnell
121 5th Avenue North
Edmonds, WA 98020
Jenkins Lane Lot I — Single Family Residence
#BLD20191013 I st Review — Response to Comments
Dear Jeanie:
Engineers I Planners I Surveyors
We are pleased to resubmit the attached Site Plan set for further review and approval. These plans
are submitted in response to the 1st Site Plan Review from both Planning and Engineering. The
following is a summary of responses to the review comments contained on the plan set and comment
letters. Review comments are shown in plain text and our responses are provided in bold italics.
Comments from Jeanie McConnell (�eanie.mcconiieliCcbedi-nondswa.gov):
General
A Stormwater Covenant is required to be recorded against the property based on the proposed
stormwater facilities for the project. Please complete the covenant, including notarization and
any required exhibits and submit to the city. Ensure the stormwater covenant meets
Snohomish County Record Drawing requirements. The document must be complete but will
not be recorded prior to permit issuance. Prior to construction final, location of facilities are to
be verified (by field inspection and asbuilt) and then the covenant will be recorded.
Attached
2. Submit Side Sewer Permit Application form.
Attached
Sheet 2 of 3 — UTILITY AND TESC PLAN
Clarify Note 1 to state that the storm tightline shall not be connected to the footing drains any
closer than 1 0-ft from the foundation.
Revised note.
RESUB
OCT 17 2019
BUILDING DEPARTMENI
CfTY OF EDMONDS
PACE Engineers, Inc I SDA
1724 W Marine View Drive I Suite 140
Everett, Washington 9820 1-2088
p 425 486 6533 1 f 425 486 6593
www paceengrs corn
October 8, 2019 Engineers I Planners I Surveyors
City of Edmonds
Page 2 of 9 www paceengrs.com
2. Clarify Note 13 so it is clear the 'Ift minimum cover does not apply to water and sewer. Sewer
shall have 2ft of cover and water shall have 18" cover, regardless of location being in paved or
landscaped area.
Revised note.
3. Orange protective barrier fencing shall be placed around the area of the drywell locations to
protect the area from compaction. Show on plans.
Added to construction sequence and shown on utility plan.
Sheet 3 of 3 — PLAN NOTES
1. Revise General Note 1 to reflect the current version of the WSDOT/APWA specs.
Revised note.
2. Remove General Note #19. It is not applicable to this project.
Removed note.
Comments from Stormwater Engineer, Zack Richardson (zacka ry rich a rdson (a-)ed mondsma. gov):
1. It appears the proposal for this lot has increased the impervious area and decreased the
drywall volume since the previous plat approval; the minimum value now used (by simplified
sizing) meets code but represents a revision from the previously approved drainage plan
which requires additional attention [Comment truncated for brevity]
(a) Simplified sizing to meet MR #5 does not ensure that a regular overflow will not
occur here; for this reason these systems require a piped overflow. If system
remains as currently designed, update plans to provide a piped overflow connection
to the city system.
(b) Alternatively, the applicant can demonstrate that the system achieves 100%
infiltration, typically requiring a WWHM model with the field measured infiltration
rate.
Design calculations have been provided as an attachment to this letter, to satisfy
alternative (b) above. The calculations demonstrate 100% inffitration of roof runoff.
CPAC�)
October 8, 2019 Engineers I Planners I Surveyors
City of Edmonds
Page 3 of 9 www.paceengrs com
2. Show protective construction fencing around the drywell areas.
(a) If fencing cannot be feasibly located during construction, add notes to over excavate and
obtain geotech approval of the subgrade prior to backfilling drywells.
C.ailed OUt in construction sequence and adripri fn Wilitv plan.
3. Provide detail or specification enough for contractor to install soils meeting the requirements of
BIVIP T5.13 (City detail SD-642).
Detail SD-642 has been added to sheet 4 of 4.
4. Update drywell details to be SD-638 or update plan details to provide more of the required and
shown elements from the City version:
(a) Update "marked center" to provide an observation pipe to the bottom of the facility with
detail as/where needed for construction.
(b) Extend distribution pipe through entire width of drywell and bring to surface with clean -out
with detail as/where needed for construction.
(c) Callout/show a push -on tee or downturned elbow in the yard drain upstream of the
drywells with detail as/where needed for construction.
(d) Identify 12" minimum cover depth, provide a bottom of rock elevation, and ensure the two
are consistent with proposed finish grade.
(e) Identify the top and bottom of rock elevation for each drywell.
The requested revisions have been made.
5. Show dimensions between the drywell and property lines (min F).
Dimensions have been added.
6. Provide a minimum footing drain elevation to ensure perforated portions of the footing drains
remain a minimum of 6" above top of rock for the infiltration facility, or revise footing drain
connection to be un effected by infiltration storage.
Minimum footing drain elevation is specified on Sheet 2 of 4. The attached drainage
calculations demonstrate that the stage depth in the infiltration galleries is not likely to
reach the top of the provided galleries.
7. There do not appear to be any collection point for pervious areas and the grading plan may
direct more runoff toward the adjacent road and wall to the west; update plans and/or provide
response to address concern as appropriate (infiltrates before it can reach edge, revise
grading to retain runoff, or add collection point and adjust drywell).
Roof drain cleanouts have been revised to area drains, and slope arrows show the yard
draining toward those yard drains. Given that outwash soils underly the site, and the
topsoil specification provided on Sheet 4 of 4, most runoff is likely to infiltrate before
reaching the yard drains.
CPJiCE�
W ON IN
October 8, 2019 Engineers I Planners I Surveyors
City of Edmonds
Page 4 of 9 www.pac.cengrs.com
This concludes our response to the previous review letter. Please feel free to call with any questions
(425) 486-6533, or if I can provide anything further.
Sincerely,
PACE Engineers, Inc.
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Kenneth J. McIntyre, PE
Project Manager
CPA�C