20180601133320.pdfilonsla tsreske 27 Ave A, Suite 4
Snohomish, WA 98290
Telephone (360) 29 4-8941
www.donnabreske.com
& Ass*c$ates
Civil Engineering & Land Use Planning
M:ay 29,2018
City of Edmonds
Attn: Mitch Boyd, ZachRichardson, and City of Edmonds
City Hall - second Floor
Edmonds, WA 98020
Subject: Response to Plan Review Comments from Engineering Division
Donna Breske & Associates, LLC is in receipt of the City of Edmonds Plan Review Comments
Engineering Division for Project: CathcartlBllis-Additior/ADu with application #: 8LD20180315. This
letter was prepared by Alex'White, EIT of Donna Breske & Associates, LLC and reviewed and signed
by Donna L. Breske, PE. The responses to the referenced comments are as follows:
Response to Request for Additional Information:
GENERAL
l) The project is located in the downtown core per ECDC 17.50.070. Please show the haul route to be
usedfor the project.
Response: The haul route to major highways from the site is shown on the site plan.
TESC
2) Please add a note to the plans that all dísturbed soils will be compost amended per BMPT5.l3.
Response: BMP T5.13 Note is now added to TESC plan.
j) Reference City of Edmonds standard detail El.2 for construction entrance.
Response: City of Edmonds standard detail EI.2 appears to have been recently replaced with ER-901,
which is shown on the TESC plan.
4) There appears to be an extra grate around the catch basin insert detail. Please remove.
Response: The extra grate is removed.
II/ATER AND SETTER PLAN
5) A 10' sewer easement, extendingfrom the west property line to the east, will be requiredþr the
existing City of Edmonds sewer main. Please use the attached easement template.
Response: The granting of the sewer easement will be negotiated with the project owner. The template
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ilsn*a tsreske 2l Ave A, Suite 4
Snohomish, WA 98290
Telephone (360) 294-89 4l
www.donnabreske.com
& Associates
Civil Engineering &.Land Use Planning
6) Label sewer pipe material and size. The sewer lateral (from the main to the edge of easement) shall
be 6". Once on private property the sewer may reduce to 4".
Response: All sewer pipes have been labeled with size, materials, and slope. 6" pipe is shown within the
easement and reduces to 4" beyond the easement on private property.
7)Show a 6" cleanout at the edge of easement. Please add a note that the 6" cleanout at the property
line shall have a 12" cast iron lamphole cover with %" hexbolts.
Response: A 6" cleanout is shown at the edge of easement, and is called out as 12" cast iron lamphole
cover with Vz" hexblots.
8) Provide invert elevations at the main, the cleanout at the property line and at the house so that a
minimum 20Á slope and minimum 2' pípe coverage can be verified.
Response: The invert elevations are shown and indicate2o/ominimum slope, wifhz'min of pipe cover
9) If a new sewer lateral is proposed and the connection will be core drilled, show the connection at the
sewer main per City standards and with a Romac Inserta-tee. If the sewer connection will be cut in,
please show a wye to be installed.
Response: A Romac Inserta-tee is proposed per city standards for a core drilled connection.
ROAD AND DRAINAGE PLAN
l0) Please show all private utilíties outside of the I0' Sewer easement. It appears that the storm line will
be located within the easement.
Response: The storm line has been removed.
11) Please revise the title of this plan to "Drainage Plon". No roads are being installedþr this proiect.
Response: Addressed.
I) í4riilþoting drains be installed? If so, please show the discharge location of thefooting drains.
Response: Footing drains will not be installed, foundation is to be slab on grade.
l3) Please provide onsite proposed contours.
Response: Proposed point elevations have been called out.
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Ðon*a Breske 27 Ave A, Suite 4
Snohomish,IVA 98290
Telephone (3 60) 294-89 41
www.donnabreske.com
& Asscclates
Civil Engineering & Land Use Planning
I4) Include the approximate cut andfill quantities
Response: Grading quantities are shown.
SITE PLAN
l5) There is a callout for a possible walk on the archítectural site plan. Please show the walk and
provide the walk material. If the walk material is an impervious surface as defined in sectionl8.30.0l0
of the ECDC, please include the walk in the impervious totals table.
Response: The concrete walkway is now shown on the plans, and impervious area table.
16) Add a note to the plans stating existingfailing, damaged or non-ADA compliantfrontage
improvements shall be removed and replaced as determined by the City Engineering Inspector
Response: The note has been added to the site plan.
STORMWATER REVIEW COMMENTS
City of Edmonds
Reviewer: Zack Richardson, PE
City of Edmonds, Stormwater Engineer
Recommendation: I recommend that BLD20I80315 be withheld until the comments below are
adequately addressed.
Review Comments:
l. General: It appears that the topographic survey used on the civil sheets is not the same as the site-
specific survey that was included with the submittal documents. Update all civil plans to use the site
specific survey topo.
a. Topo must identify measured rim and inverts þr all existing drain structures to be altered (íe.
connected into);
b. Based on the combined informationfrom the civil topo and the site survey,it would appear the
invert of MH-8-714 would be at 99.33 (102.03 - 2.7)and thereþre notfeasiblefor connection as
proposed; update as needed.
Response: The current site plans use the site specific survey as a base map.
a. Rim and inverts of all drainage structures within the vicinity are shown.
b. Connection to the City's conveyance system is no longer proposed due to capacity issues in the City
system.
2. Drainage Report: Include soils report as appendix to this report and revise soils reported as noted.
Response: The soils report has been added to the drainage report.
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Civil Engineering &, Land Use Planning
2l Ave A, Suite 4
Snohomish, WA 98290
Telephone (3 60) 294-89 41
www.donnabreske.com
a. Revise text of report as needed to state what was encountered to establish an "impervious layer" and
state the specific location/depth of said layer.
Response: Groundwater was encountered al7" below grade, and is indicated in an email from the septic
designer that is provided in the report.
b. Revise text of report as needed to state the specific location/depth of the encountered groundwater
layer.
Response: The groundwater was encountered at T" below grade per the analysis of the septic drain field
designer that supplied the soils report.
c. Revise text of report to addresses whether the encountered groundwater was reflective of the actual
groundwater table or a perched layer, and give supporting informationþr the conclusion made
(typically requires a post-test check of excavated pit).
Response: The analysis of the soils was conducted by Conrad Ellidge, who is a licensed septic drain
field designer.
3. Drainage Report: Correct site address on cover
Response: Addressed.
4. Drainage Report: Expand Section 2.5.4 to provide more inþrmation about the revised natural
drainage pattern (piping to south rather than sheetflow to north):
Response: This section has been expanded to provide more information.
a. Explicitly state whether the revisions alter the threshold díscharge areafor the site
Response: The report indicates that changes made to the discharge area, are to protect the property from
excessive sheet flow from the overflowing ROW system.
b. Provide explanation ofwhy the revisedflow path is necessary.
Response: The currently proposed flow path will follow the existing drainage patterns.
c. Address concern or potential impacts for the localize system conveyance capacity (between discharge
point and point where drainage recombines with current site runoffcollection point)
Response: The concerns of conveyance capacity are to be addressed by the City. Runoff from the site
will continue to follow the current drainage pattern.
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Civil Engineering & Land Use Planning
2l Ave A, Suite 4
Snohomish, WA 98290
Telephone (360) 294-8941
www.donnabreske.com
d. Eliminate references to the perforated pipe connection (which is not actually proposed)
Response: The perforated pipe connection has been removed, and all references to the pipe.
5. Drainage Report: Expand sectíon 2.5.5 to address the impacts to the existing impervious surfaces on-
site and the mitigationþr those surfaces:
Response: Existing impervious surfaces disperse into the on-site vegetation.
a. It is unclear if the existing splash block shown is mitigationfor previous impervious surfaces; clarify
as needed.
Response: A note has been added to clari$z this.
i. If the block is mitigationfor previous impervious surfaces, then the 50'vegetatedflow path cannot be
altered (as curcently proposed) without compensatory mitigation.
Response: The 50' flow path will be achieved and is shown on the plans.
ii. If the block is not actually providingþrmal mitigation, then the project must apply the retrofit
requirements per ECDC I 8. 3 0.D. 5.b.i.
Response: Retrofit will not be required
6. Drainage Report: For the portion of Appendix A copied into the report, circle or identifu infeasibility
criteriafor all BMPs under 'other hard surfaces' (cunently only roof BMPs addressed).
Response: Criteria for other hard surfaces has been circled. The soils do not infiltrate feasible, the site is
constrained for flow path space. The City conveyance system is overflowing and will not allow for
feasible detention system connection.
7. Drainage Report: Revise report and plans to provide detention (pending revised of soils report to
verifu other BMPs are truly infeasible) to meet MR #5.
Response: Detention will not be provided.
a. Connection options exist within Alder St or entirely within public righrof-way (alley) out to 6th Ave
S; accordingly thefeasibility criteria selectedþr detention is not applícable.
Response: Connecting to the system in 6th Ave is not financially feasible for this scale of project, and it
is not entirely clear how far downstream the conveyance capacity issue is located.
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Dsn*a Breske 27 Ave A, Suite 4
Snohomish, WA 98290
Telephone (360) 294-89 4l
www.donnabreske.com
& Ass*ciates
Civil Engineering & Land Use Planning
b. The necessity of installing a pump is not listed in the infeasibility criteria.
Response: Addressed.
8. Plan Sheet 2: Provide enough spot elevations at corners of improvements, low points, and grade
brealrs, to show drainage is being achieved as intended.
Response: Spot elevations have been added to the drainage design, as well as a grading plan.
a. It is not clear that runoff ß going to be adequately directed to the intended collection points
Response: The collection points have been removed.
b. It appears that the dispersion strip ß roughly in the natural low point of the site and would be
proposing to directflows up hill to achieve dispersion; adjust as needed to demonstrate positiveflow
away from dispersion device.
Response: Proposed grading will allow for the required flow path for the transition zone.
9. Plan Sheet 2: Provide and call-out a downturned elbow or vertical tee on the last drain beþre
flowíng into any proposed BMP or the City's system (whichever is nearer inflow path to the PGIS)
Response: This is no longer necessary.
10. Plan Sheet 2: Add a 2' minimum sump dimension þetween invert of outlet and top of rockfloor) to
the yard droin detail.
Response: This detail has been removed. No basins or drains are proposed.
I l. Plan Sheet 2: Update plan to reflect sidewalk and curb repair work and coruected asphalt limits þr
angle of connectingfor the storm drain connection within the Alder St. ROW.
Response: This will not be required per the current design.
12. Plan Sheet 4: It appears that the construction access road is proposed at the natural low point of the
site, so that a majority of runoff during construction will likely flow out tlte access road an bypass the
permitted protection (it is øssumed that silt fence will not be installed across entrance as shown); adjust
permitted protection límits and/or provide alternative permitted protection BMP that can be installed
across the entrance of the access road and withstand construction trffic.
Response: A silt fence was not proposed to cross the construction entrance, the zig-zag line indicates
the limits of disturbance, while the line-type with spaced squares indicates the silt fence location along
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Dsn*ln Breske 2l Ave A, Suite 4
Snohomish, WA 98290
Telephone (3 60) 29 4 -89 4l
www.donnabreske.com
& Associates
Civil Engineering & Land Use Planning
the property line. These lines are no longer shown to cross the construction access. The entrance will be
cross sloped to allow runoff to disperse into the adjacent grass.
13. Plan Sheet 4: Provide soils detail (soil depth, amount of tilling in into native, etc) and/or
specifications (organics content, soil type, etc) sfficientþr tlte contractor to purchase and install soils
to meet the requírement of BMP 75.13
Response: A note for BMP T5.13 has been added.
Sincerely,
,1..4-ÁÆ;*
Alex White, EIT
42s-208-9744
Donna L. Breske, P.E.
Phone: 360-294-8941
Mobile: 206-715-9582
P** "{ #--d#d
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