8275-civil review122601December 26, 2001
Mike Robinson
AHR Civil Engineers and Land Surveyors
5405 15th Street East
Fife, Washington 98424
RE: Yelm Multi-Family Civil Review No. 1
City of Yelm Project No. BSP-01-8275-YL
Dear Mr. Robinson:
General Comments:
Add the Conditions of Approval to the cover sheet.
Replace the Director of Public Works title in the approval box with Development Engineer. Typical all sheets.
Grading and Storm System Comments:
The pipe schedule has 3 pipe slopes not correct. The min. pipe slope allowed is 0.5% and the min. pipe cover is 1.5’ unless ductile iron is utilized. Add callouts to the pipe schedule
for pipe type to be used.
The percolation trenches need to have monitoring ports installed in them. Show these in plan view and add a detail to the plans.
Your design uses an infiltration rate of 10 inches/hour for your calculations, based on the existing soils. This is a correct assumption but in the design a sand liner is utilized under
the percolation trench. According to Table 3.3.1 the infiltration rate for sand is 8.27 inches/hour or less and with a factor of safety of 2 it becomes 4.14 inches/hour. Please revise
your calculations or revise your design accordingly.
Basin A1 has the garage roof drainage going directly to the percolation trench. Are all the roof drainage downspouts located in the back of the garages as the plans show? If not how
are you controlling the roof runoff from the front side of the garages? If it is day lighted to the asphalt surface than it will need to be treated. This may just need to be clarified
on the plans.
All utility pipes located under rockeries need to be sleeved. This included water, sewer and storm.
All water, sewer and storm services need to be sleeved when located under sidewalks and curbs.
All sidewalks are required to be 5’ in width. This is shown on the plans. However when a car parks against the curb the car’s overhang covers up approximately 2 feet of the sidewalk.
In these areas wheel stops will be required or widen the sidewalk to seven feet to accommodate this issue.
Are the wet tanks going to “float or be buoyant” when it is pumped out for maintenance?
Add details for the trash enclosures. This should include dimensions, type of material, gate opening widths and grades.
Add the City of Yelm trench restoration detail 4-10 to the plans.
Add the City of Yelm sidewalk detail 4-11 to the plans.
Add the City of Yelm concrete curb detail 4-13 to the plans.
Add the City of Yelm rock wall detail 4-18 to the plans.
Show the location and design of the mailbox area. This area needs to be approved by the City of Yelm Postmaster. Submit a plan to the Community Development Department with the postmaster’s
signature and location shown on it.
The trash enclosures need to be reviewed by Lemay, Inc. Submit a plan to the Community Development Department with Lemay’s approval of the trash enclosures.
The grading plan needs to have additional spot elevations shown for the rockeries and elevations for the sidewalks.
Show pipe inverts for the roof drainage system and a detail for the cleanouts.
Add the required Washdot standard details for the handicapped ramps.
Add spot elevations and radii at the curb returns along existing Safeway access roadway.
The bypass structure does not appear to be able to contain the floating oils and debris. When this structure starts to “bypass” the water quality tank it will release all of the oil
and debris to the infiltration gallery. This system would be better served by using a dual tee to contain the oils and debris.
Page 7, No. 10 of the Stormwater Report states, “ No easements will be required for city access to the stormwater system. The city will need to have access to the stormwater system
to maintain it in emergencies and for lack of maintenance. Also in the stormwater and maintenance agreement, there will need to be provisions for the city to charge the owner a fee
for the maintenance if the city is forced to maintain the stormwater facilities.
The sub basin A1 wet tank volume is not adequate. Please revise the length of the wet tank.
Water System Comments:
Use current General Notes (Water Main Installation). The current notes are numbered 1 thru 16 not 15.
Use the current Water Details dated 3/2000. The details that should be shown on your plans are 6-3, 6-7, 6-10, 6-11, 6-13, 6-14 and 6-15.
Replace the phone number in general note no. 8 with (360) 458-8438. (Sheet C5)
At all water connections, bends, tees, etc. need to have call outs for thrust blocking, connection type, mechanical or flange joint and size.
Add an 8” gate valve between Building B and Building C on the 8” line in front of Building C.
Show where you are proposing to locate your irrigation meter and backflow protection device.
All 1 ½” water meters must be upgraded to 2” water meters. This is per the City of Yelm Ordnance.
All service lines need to be 2” in diameter.
All service lines need to have a gate valve located at the connection to the main. These gate valves will need to have a square nut valve.
The six-unit apartment would be better served by connecting to the watermain adjacent to the building. If you choose to keep the current design the service line will need to be upsized
to 2” and a gate valve also added at the watermain connection.
As of January 1, 2002 the water connection fees have been changed to $1,500.00 per an ERU. The previous fee was $1,000.00.
Sewer System Comments:
Add sewer details 7-3, 7-7 and 7-11 to the sewer plans.
A hose bib is required within 50 feet of each sewer step tank. Please show the locations on the plans.
The location of the tanks, side sewers and pressure mains are in conflict with the landscaping buffers. The step sewer system needs to be moved outside the landscape buffer to facilitate
maintenance.
A third riser needs to shown on the 6000-gallon capacity step tank. This is per our Development Guidelines.
All the step tanks need to have a check valve installed. Show the check valve on the plans.
Provide sewer tank sizing calculations.
Conditions of Project Approval dated May 22, 2001
Under Review
Completed
Under Review
Shown on civil plans
A: To be paid at building permit
B: Not completed
C: Not completed
In Process
Under Review
Under Review
Completed
Completed
Not completed
Under Review
Not completed
Not completed
Not completed
Preliminary plans have been submitted.
Completed
Under review
Not completed
After you have revised the plans please resubmit the plans to Community Development Department. You will need to resubmit 4 sets of plans and 2 storm drainage reports. If you have
any questions or want clarification on the review comments please call me at (360) 458-8438 and I will be glad to help you.
Respectfully:
City of Yelm Community Development
Jim Gibson
Development Engineer
Cc: Cathie Carlson
Tim Peterson