Correspondence JUL- 25- 2003(FR1) 10:18 P.001/001
LEWIS &
•
VAN VLEET
In corp arntw0
principals
chris c. von vleet. p.e.
seRJJ- lew�5. p.e.
July 25, 2003
Tom Plusher
City of Tigard •
13125 SW Hall Blvd.
Tigard, OR 97223
RE: Bank of Tigard — ENG2002- 00112
Stormwater Pond Certification
Dear Mr. Plusher -
This morning I made a site visit to inspect the water quality /detention pond for this project. Per
that site visit and per information provided from the contractor, the pond and outlet structure
both appear to have been constructed per plan. The pond still needs to be vegetated and rip -rap
needs to be placed at the storm pipe outfalls (the inlet pipe into the pond and outlet pipe to the
ditch to the east). As soon as vegetation is in place and the rip -rap has been installed, the pond
and stormwater facilities should meet the design criteria.
Should you need any additional information, please feel free to contact me.
Sincerely,
Bryan Dickerson, P.E.
cc: Marsha Thomas, Phoenix Contractors
File
consulting engineers
18650 s.w. boones ferry road
tualatIn. oregon 97062
[503] 685.6605 phone
[503] 885.1205 fax
W15 &
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VAN VLEET
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Incorporated
principals
Chris c. van vleet. p.e.
gary J. lewis. p.e.
OPERATIONS & MAINTENANCE PLAN
SITE STORMWATER MANAGEMENT FACILITIES
Bank of Portland
Contact Person:
Phone:
Tax Lot 6505
SW 68 Parkway
August 28, 2002
Prepared by
LEWIS & VANVLEET, INC.
18660 SW Boones Ferry Rd
Tualatin, OR 97062
consulting engineers
18660 s.w. boones ferry road
tualatin. oregon 97062
(503) 8135.3605 phone
(503) 8135.1206 fax
EXTENDED DRY DETENTION PONDS
Inspect the facility at least quarterly in the first 2 years after construction, and semi-
annually thereafter.
Remove sediment from the pond every 5 to 7 years. However, the pond should be
inspected more frequently to monitor accumulated sediment and debris. It is
recommended that the pond be inspected in the spring and fall and all debris and
excessive sediment be removed and disposed of properly.
Maintain the ground cover and plantings. Mow the embankment and spillway area at
least twice a year (once during fall). Remove clippings and dispose of properly.
Remove dead foliage and debris during the fall season to prevent the release of nutrients.
STRUCTURAL STORM SEWER DEVICES
Inspect the facility at least quarterly. Additional inspections will be necessary after large
storms. Removed accumulated materials and dispose of properly off -site.
Inspect the devices more often if runoff is believed to have significant concentrations of
oil or to carry high sediment loads.
Remove accumulated sediment and oil at least annually from catch basins and outlets.
Schedule cleanouts before deposits reach 1 foot in depth, or exceed the design depth for
sediment storage, or the inlet or outlet is over 40 percent obstructed. Remove debris from
any trash racks or orifices.