bld20140189_Coleman_ENG2.pdf
City of EdmondsBLD20140189
TH
121 5AVENUE NORTHEDMONDS, WA 98020 • (425) 771-0220 FAX (425) 771-0221
Website: www.ci.edmonds.wa.us
PUBLIC WORK DEPARTMENT
Planning • Building • Engineering
Engineering Plan Review Comments
PermitApplication:Date:
#BLD20140189September 24, 2014
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Project Name/Address:
Coleman -902–9Ave S
Contact Person/Address, Fax or E-mail:
RANDY.MUNSON@COMCAST.NET
Reviewer: JENNIFERLAMBERTDivision:
ENGINEERING
During review of the subject submittal, it was found that the following information, corrections, or
clarifications would need to be addressed. All Handouts referred to in these comments can be accessed at
our website: www.edmondswa.govunder City Government / Development Services Department /
Engineering Division then scroll down to Handouts:
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4/24/14 –1Review -Incomplete submittal comments
nd
8/29/14 –2Review
rd
9/24/14 –3Review
COVER SHEET(pg.1 of 4)
GENERAL NOTES
1)OK
GENERAL
1)OK
2)OK
3)OK
New Comment –9/24/14
1)It appears that the plans do not scale at 1”=20’. Please check the plans and revise as needed.
DATE E-MAILED9/24/2014PAGE (1)
City of EdmondsBLD20140189
TH
121 5AVENUE NORTHEDMONDS, WA 98020 • (425) 771-0220 FAX (425) 771-0221
Website: www.ci.edmonds.wa.us
PUBLIC WORK DEPARTMENT
Planning • Building • Engineering
Engineering Plan Review Comments
SWPPP & GRADING PLAN (pg.2 of 4)
GENERAL NOTES
1)OK
DRAINAGE AND UTILITY PLAN (pg.3 of 4)
GENERAL
1)OK
WATER
1)OK
SEWER
OK
1)
STORM
1)9/24/14 –Comment was partially addressed. It appears that when scaling theplans the
impervious surface amount is closer to 6300 not 5900. Please check the impervioussurface
amounts/scalingand revise the impervious surface calculations and plans as needed.
8/29/14 Comment: If the site has more than 5000 sq ft of impervious surfaces, all stormwater
management systems must be designed by a licensed engineer. The pre-sizing chart in Handout #E72A
cannot be used regardless if less than 5000 is proposed to discharge to the detention system. Please see
comments below by Jerry Shuster.
2)9/24/14 –Comment was not addressed. The plans do not show what areas of the shared
driveway/access road will discharge to the onsite stormwater management.
a.Please clearly show what areas will discharge to the onsite stormwater management system
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for 902 9Ave S.
b.Include the amount of impervious area from the shared driveway/access road in the
stormwater calculations and revise accordingly.
DATE E-MAILED9/24/2014PAGE (2)
City of EdmondsBLD20140189
TH
121 5AVENUE NORTHEDMONDS, WA 98020 • (425) 771-0220 FAX (425) 771-0221
Website: www.ci.edmonds.wa.us
PUBLIC WORK DEPARTMENT
Planning • Building • Engineering
Engineering Plan Review Comments
c.If no areas will discharge to the onsite system,please clearlyshow how no surface water
runoff from the shared driveway/access road will discharge into the stormwater
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management system for 902 –9Ave S.
8/29/14 Comment: If there are portions of surface water runoff not located on the subject site that will
discharge to the onsite stormwater management system, the system will need to be sized to account for
the additional surface water runoff. Please show what areas of the driveway/shared access road will
discharge to the onsitestormwater management system.
3)9/24/14 –Comment was addressed; however, footing drains should not discharge to the onsite
stormwater system unless approved otherwise. Please see stormwater #3 commentbelow.
8/29/14 Comment: Pleaseshow where the footing drains will discharge to.
STORMWATER
The following comments are provided from Jerry Shuster, Stormwater Engineer. Please contact Jerry
directly at 425-771-0220 or by email at jerry.shuster@edmondswa.govwith any specific questions you
may have regarding these comments.
New comments are written in bold.
1.A “Level Spreader” is proposed for approximately 1,000 square feet of runoff.This is actually
“Dispersal Trench with notched grade board” and should be referred to as such.The cited minimum 25
foot flow path does not apply to this site since the area downstream of the proposed dispersal trench is a
steep slope (defined as 15% or greater).Steep slopes require a 50 foot flow path.There does appear to
be 50 feet between the proposed spreader and the west property line,however, the flow will not be
dispersed and therefore a flow credit cannot be granted.First the geotechnical report basically says that
no water will infiltrate and second, there is a cutoff trench designed to intercept the flow and convey it to
the yard drain thatconnects to the detention system via pump.Flow dispersion is discouraged in highly
–9/24/14 Comment: Swale and yard drain that were in previous version need
urban environments.
to be restored.
The site classifies as a Category 2 Small Site Project, therefore the detention sizing in handout E72A are
not applicable.The introduction of the handout says:
“If your site is a Category 2 Small Site Project or a Large Site Project that will have stormwater
9/24/14
detention system, this handout cannot be used. See the Supplement for more details.”
Comment: Addressed
The detention system must be designed per Section 5.7 of the Edmonds stormwater code supplement for
–9/24/14 Comment: Partially addressed. Please state in the
a Category 2 small site project.
DATE E-MAILED9/24/2014PAGE (3)
City of EdmondsBLD20140189
TH
121 5AVENUE NORTHEDMONDS, WA 98020 • (425) 771-0220 FAX (425) 771-0221
Website: www.ci.edmonds.wa.us
PUBLIC WORK DEPARTMENT
Planning • Building • Engineering
Engineering Plan Review Comments
drainage report that site is required to meet the flowing peak flow control standards since it is in a
creek drainage basin:2-yr =0.07 cfs/acre impervious; 10-yr =0.14 cfs/acre impervious; 100-yr
=0.33cfs/acre impervious. Also,thatbased on these standards the allowable discharge rates for
the site based on 0.14 acres impervious are: 2-yr =0.01cfs; 10-yr =0.02 cfs; 100-yr =0.05 cfs.
A detail of the detention system control structure with the proper elevations of the riser pipe
orifice(s) and all pope sizes must be included in the plans so it can be constructed properly per the
modeling.See detail E5.4
(http://www.edmondswa.gov/services/permits-development/handouts-
forms/services-permits-std-details-main-page-menu/services-std-details-storm-drainage-section-5-
menu.html)
2.9/24/14–Comment was partially addressed.Itappears that the “Developed Flow Conditions
Used for Pump Sizing” provided in the Appendix to the Drainage Plan used the entire 0.14 acres
instead of what will flow to the proposed pump well.Also, drawing 3 has a note specified the
maximum flow rate at a maximum dynamic head for a 2.5 in diameter discharge line with fittings.
The drainage report does not show the calculations that lead to these values for the pump system
or an overlay of the pump and system curve as required in item 4 of the pumping policy.
Item 6 (dual pump and backup power) of the pumping policy can be waived since the amount of
flow handled by the pump is small compared to the overall site.Item 7 (overflow path) however,
needs to be discussed in the drainage report and shown on drawing 3.
8/29/14 Comment: Pump calculations (not just cut sheets) need to be included per pumping policy
(http://www.edmondswa.gov/images/COE/Government/Departments/Public_Works/Policies/ENGR-
DEVSTM-2001-02.Pumping.Private_Property.pdf).See enclosed example.
9/24/14 –Additional Comment:Footing drains should not be plumbed to the detention system.
3.
Use a properly sized drywell per recommendation of a geotechnical engineer (groundwater should
remain groundwater).
8/29/14 Comment: Once the comments above have been addressed there may be additional comments.
SOIL MANAGEMENT PLAN (pg.4 of 4)
GENERAL
No comments
DATE E-MAILED9/24/2014PAGE (4)
City of EdmondsBLD20140189
TH
121 5AVENUE NORTHEDMONDS, WA 98020 • (425) 771-0220 FAX (425) 771-0221
Website: www.ci.edmonds.wa.us
PUBLIC WORK DEPARTMENT
Planning • Building • Engineering
Engineering Plan Review Comments
Please resubmit 3 copies of the revised plansand associated documents with a written response toeach
item to a Permit Coordinator. Please contact me at 425-771-0220ext 1321or by e-mail at
jennifer.lambert@ci.edmonds.wa.usif you have specific questions regarding these plan corrections.
DATE E-MAILED9/24/2014PAGE (5)