1729_001Mqo
INSIGHT ENGINEERING CO.
July 10, 2019
JoAnne Zulaf, Engineering Technician
121 5t' Ave N
Edmonds, WA 98020
(425)771-0220
Re: Cary Rd — BLD20190155
IECO No. 19-0983
Dear JoAnne,
The project referenced above is revised in response to the review comments dated July 9, 2019.
The review comments are numbered on the letter and have been addressed in italics as follows:
GENERAL
1) 7/9/19 Not found. Submit ROW Permit Application form
A ROWApplication has been submitted by the contractor.
2) 7/9/19 Not found. Submit Side Sewer Permit Application form
A Side Sewer Permit Application has been submitted by the contractor.
3) Done.
4) Done.
5) 7/9/19 Not found. Please see form attached. 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.
The Stormwater Covenant has been completed and turned in to the city separately.
6) Done.
PO Box 1478 # Everett, WA 98206 • Phone: (425) 303-9363
Fax: (425) 303-9362 • Email:info@insightengineering.net
7) 7/9/19 A haul route is required to approve the demolition permit. For this location it
would be Caspers to 9th to Puget to 196th to Hwy 99. Please add to plans. Show haul
routes.
The demolition permit was issued separately, and the work has been completed.
8) Done.
9) Done.
DEMO
1) Done. However, the sewer coming toward the property at the NE corner is labeled as
Water. Please revise. If the existing side sewer is to be re -used, the line must be cut and
capped a minimum of 20' from existing and/or proposed foundation, whichever is closest
to the property line.
The sewer line has been corrected and labeled as sanitary sewer. See sheet Cl.
2) 7/9/19 Please add the highlighted portion as a note on the plan. If the existing water
service line is to be re -used, the line must be disconnected at the meter during
construction. Please install a hose bib with an AVB at the meter during construction.
A callout has been added to install a hose bib with AVB. See sheet Cl.
3) 7/9/19 This is considered a new single family home and therefore all utilities shall be
underground. Please revise to show overhead utilities underground. Show existing
utilities on the plans
Utility lines have been revised to be placed underground. See sheet Cl.
4) Duplicate comment.
5) NEW COMMENT: Please show the gas from the main to the approximate location at the
house. Add a clearer label to alert contractor to be aware.
The gas line is now shown from the main to the house. See sheet Cl.
6) NEW COMMENT: Please show tree protection around all trees to remain that are near
construction areas. Add a tree protection detail to the plans.
Tree protection has been added. See sheet C2 and detail 2/C2.
WATER
1) Done.
2) Done.
(Please refer to stormwater engineer's comment 96 regarding utilities crossing infiltration
trenches)
PO Box 1478 • Everett, WA 98206 • Phone: (425) 303-9363
Fax: (425) 303-9362 • Email:info@insightengineering.net
See stormwater response to comment 46.
SEWER
1) Done.
2) Done.
3) Done.
4) Done.
5) Ok.
6) Done.
7) NEW COMMENT: Please revise the connection to the existing sewer main slightly to
show the new 8" clean out at the end of the run and the new private 6" making a wye
connection behind the new 8" clean out. Extend the 8" line as needed to accommodate
the wye connection.
The sewer connection has been revised as requested See sheet C1.
DRY UTILITIES
1) Se comment #3 under DEMO.
See response to DEMO comment #3.
STORM
1) Done.
2) Done.
Comments from Zack Richardson, Stormwater Engineer
March 15, 2019
Review Comments:
1. General: It appears that the geotechnical report generally stated that infiltration
capabilities of the site are below minimum values typically used for infiltration and that
groundwater was encountered in the upper 1.7'-2.0' of the site. It appears that infiltration
is not feasible at this location and it is unclear how or why pursue full infiltration was
pursued. Revise proposal to site -appropriate 13MPs and/or provide significantly more
geotechnical information to demonstrate infiltration feasibility.
See revised Geotechnical Addendum under Appendix F page 12 of the drainage report.
Infiltration is feasible in this location.
2. General: It appears that the WWHM model utilize a 0.30 in/hr. infiltration rate when the
Geotech calculated rate is only 0.23 in/hr.; if nitration is used, the modelling must be
updated to use the correct infiltration rate.
See revised Geotechnical Addendum under Appendix F page 12 of the drainage report.
The infiltration rate in this area is 0.3 in/hr.
PO Box 1478 • Everett, WA 98206 • Phone: (425) 303-9363
Fax: (425) 303-9362 • Email:info@insightengineering.net
3. Report: The project does not actually meet flow control rates but appears to qualify for
the peak flow exemption from flow control (i.e. 0.1 cfs increase at 1-hour steps/0.15 cfs
increase at 15-minute steps at 100-year); update MR #7 text to more clearly state this, or
revise flow control model to meet all flow rate & duration requirements.
MR#7 has been revised to state we are exempt from flow control as the developed site
will only increase peak discharge by 0.05 cfs using 1-hour timesteps. See MR47 on page
8 as well as the WWHM report under Appendix B on page 21 of the drainage report.
4. Report: The modelled pervious pavement section (storage depth) does not match the
standard detail on the plans; if infiltration remains, provide site specific detail or update
model as needed for consistency.
The pavement is now modeled as 1.5' in depth and the permeable paver detail (5/C4) lists
the storage depth as 1.5' min. See the WWHM under Appendix B of the drainage report
and detail 5 on sheet C4.
5. Report: Trench model uses a 0.4 void ratio for internal rock, which is slightly above
industry standard; provide specification/callout on plans for rock that can guarantee a 0.4
void ratio, or update model to 0.3 void ratio.
The Trench model has been revised to use a 0.3 void ratio. See the WWHM under
Appendix B of the drainage report.
6. Plans: If infiltration remains, provide detail or direction to contractor to protect against
infiltrated water running along any utility lines or crossings within typical setbacks of the
infiltration footprint; typically, this is accomplished by providing a impervious wrap
around utility trenches and/or installing trench damns at either end of the crossing.
Trench dams will be used at all utility crossing the infiltration areas and are now called
out on the plans. See sheet CI and detail 6/C4.
7. Plans: If infiltration remains, provide elevations for each of the perforated pipes into the
pervious pavement areas.
a. It appears that the outlet near the north-east corner of the home could be shifted
west to increase useable area within the infiltration footprint; please move as far
west as feasible.
IE's have been added to the cleanouts at the end of the perforated pipes. See sheet
C1. We have kept the outlet near the northeast corner the same, based on the
addendum from the Geotech.
8. Plans: Callout/note in plan view and push -on tee at CB #1 (as shown in SD-363).
A callout has been added to CB#1. See sheet C1.
PO Box 1478 • Everett, WA 98206 • Phone: (425) 303-9363
Fax: (425) 303-9362 # Email:info@insightengineering.net
9. Plans: Show limits/saw cut line for driveway removal at Cary Road, add notes to grade as
needed to maintain pre -construction drainage patterns.
A saw cut line is now shown as well as the grading note. See sheet C1.
10. Plans: If infiltration remains, update TESC sheet to address SWWPPP element #13,
protection of infiltration surfaces.
a. If construction fencing cannot reasonable be placed to keep construction traffic
off of all infiltration areas, project specific notes shall be added to the TESC plan
to direct the contractor to over excavate infiltration areas and obtain geotechnical
approval of subgrade condition/infiltration rate prior to placing any rock for the
infiltration system or pervious pavements.
A note has been added. See note #3 on sheet C2.
11. Plans: If infiltration remains, update the permeable pavers roof/footing drain detail to
show the end condition of such a pipe (cap, plug, cleanout, etc.).
The permeable paver detail has been revised to add a view showing the cleanout at the
end of the pipe. See detail #S on sheet C4.
Please feel free to contact me with any questions or comments you may have.
Sincerely.
Brian Kalab, P.E.
PO Box 1478 • Everett, WA 98206 • Phone: (425) 303-9363
Fax: (425) 303-9362 • Email:info@insightengineering.net