05-0091 STEP Tank Review No 2
City of Yelm
Community Development Department
105 Yelm Avenue West
P.O. Box 479
Yelm, WA 98597
May 28, 2008
Mike Beach
Pacland
606 Columbia St NW
Olympia, WA 98501
RE: Wal-Mart – COY Project Number SPR-05-0091-YL
2nd Review of STEP Tank System
Mr. Beach:
The City of Yelm and Parametrix has completed the second review of the proposed Wal-Mart Step Tank revisions. Your application included:
Construction Plans
Engineers Response Letter
Transmittal
We have reviewed the construction plans and engineers response letter for compliance with the City of Yelm Development Guidelines, the Department of Ecology Criteria or Sewage Works
Design Manual and National Electrical Code.
The following comments need to be addressed before the plans may be approved for construction. The City requires a meeting with Pacland and DR Strong to discuss the comments below.
The last submittal did not address the comments sufficiently and this issue needs to be resolved to the satisfaction of the City.
Review Comments:
Parametrix requested the water meter readings since October to check the average daily flow for the Wal Mart store. Based upon the additional data and excluding the first month of operation,
it appears that the average flows have increased by an additional 16 percent to 4,493 gpd. Additionally it appears that a maximum month average daily flow is approximately 5,670 gpd.
Using the maximum month flow and a peaking factor of 1.5, proposed by the designer, the peak day flow would then be approximately 8,500 gpd. Per this peak day flow, the total liquid
volume calculates to approximately 17,000 gallons, with the current design at 12,000 gallons.
The City is currently conducting daily water meter readings to confirm the peaking factor. We will forward the information after we have collected at least 2 weeks or information.
The peak hour calculation should be revised and resubmitted based on the information obtained and the above comment.
Additionally, the Working Volume calculation should be revised based upon Comments 1 and 2 then resubmitted.
Plan Sheet C-5.2
Given the control panel’s current location, please provide additional information on how the direct line of site will be met in accordance with the NEC and the Department of Ecology
Standards.
The invert elevation difference between the outlet of the 8,000-gallon and the inlet of the 6,000-gallon tanks could be modified to allow both tanks to be used for surge buffering.
It is our understanding that the STEP pumps and controller have not been connected to the standby power system and that electrical modifications would be necessary to make this possible.
Please submit written verification that the electrical modifications have been done or revise storage volume calculations in accordance with DOE standards.
Please clarify what “per manufacturer’s recommendations” means regarding the sewer connection between the existing tank and the proposed tank. Will a Core-n-Seal boot work at that angle
or will a fiberglass adaptor be installed with a Fernco coupler?
Please submit a copy of the manufacturer’s written recommendations regarding the structural integrity of the existing tank on the domed end with the proposed tank installation in close
proximity.
Plan Sheet C-3.0
It is our understanding that in accordance with NEC and DOE requirements, the control panel or a pump lock out must be located within direct line of sight of the pumps but according
to the site plan this does not appear to be possible. Please verify that the design will meet all provisions of NEC and DOE regulations.
Please review the above comments. We would like to schedule a meeting with you and your sub consultant as soon as possible to discuss these comments and agree upon a solution. You
may contact me with some dates that you are available for the meeting.
If you have any additional questions or comments please do not hesitate to call or contact me at jimg@ci.yelm.wa.us.
Community Development Department
Respectfully,
Jim Gibson P.E.
Development Review Engineer
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