Eagle PlazaIPM.Note
Eagle Plaza
Steve Harrington
Jim Doty
Steve Harrington
EX
/O=CITYOFYELM/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=JIMD
Eagle Plaza
EX
/O=CITYOFYELM/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=STEVEH
EX
/O=CITYOFYELM/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=STEVEH
Jim Doty
EX
/O=CITYOFYELM/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=JIMD
Karen Bennett; Steve Harrington; Tim Peterson
Eagle Plaza
Here is the Sewer Dept. review of the Eagle Plaza STEP System Sizing
Report.
Jim Doty
Plant Manager
City of Yelm Water Reclamation Facility
931 N.P. Road
Mail:
105 Yelm Ave. W.
Yelm, WA 98597
Ph. (360)458-8411
Fax (360)458-8166
<DC90029353CCCD468AA2A2858FFCD8F58C40D5@server1.ci.yelm.wa.us>
Eagle Plaza-2.EML
Steve Harrington
11.0
Eagle Plaza STEP System Sizing Review 2-19-09
Eagle Plaza STEP System Sizing Review 2-19-09
Karen Bennett
EX
/O=CITYOFYELM/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=KarenB
KarenB@ci.yelm.wa.us
458-3835
Community Development
Karen Bennett
Karen Bennett
KarenB
Steve Harrington
EX
/O=CITYOFYELM/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=Steveh
steveh@ci.yelm.wa.us
458-8423
Community Development
Steve Harrington
Steve Harrington
steveh
Tim Peterson
EX
/O=CITYOFYELM/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=Tim
tim@ci.yelm.wa.us
458-8499
Public Works
Tim Peterson
Tim Peterson
tim
Eagle Plaza STEP System Sizing Review 2-19-09.doc
I have reviewed the STEP sizing report and came up with the following comments:
The existing Yelm Medical Facility used an Average of 678 gallons per day for the year 2008 based on City Water Department billing records submitted with the report. This figure was
based on a facility of 9000 SF. The new facility is sized at 36,000 SF and so existing water use figures have been multiplied by a factor of 4.
STEP tank size is the combination of Detention Volume, Working Volume, and Storage Volume. These terms are clearly defined in the Dept. of Ecology’s Criteria for Sewage Works Design
more commonly known as the Orange book.
Page C1-32 of the Dept. of Ecology Orange book defines Detention Volume by the equation V=2.0Q Where: V=Liquid Volume and Q=Peak day flow for the structure being served. The tank was
sized using Average daily flow for the year 2008 of the current medical building adjusted as outlined above. Since Daily meter readings are not taken, it is the position of the Sewer
Department that the Average daily flow of the highest month be used in the calculations to arrive at a Peak Day flow. The highest month for the current facility was November, 2008.
This month was during the rainy season and so it is assumed that irrigation played no part in the high flow for the month.
The Sewer department has no issue with the working volume calculation; however, the value for the working volume will change dependent on the final size and configuration of the tank.
The tank will need to be supplied with 24 hours of Storage Volume. Paragraph E-2 on page C1-32 of the August 2008 edition of the orange book states: “For vessels without 24 hours of
storage, provide a power transfer switch with an emergency generator plug. Limit the number of tanks installed with power transfer switches to the number of tanks or vessels that can
be serviced by the local agency during a power outage.” The November 2007 edition provided with the report contains similar language stating the same purpose. It became very clear following
the last big windstorm that the number of tanks installed that the sewer department can service with a portable generator has been exceeded. Therefore, we have amended the development
guidelines to require both a transfer switch in case of localized power outages. We are also requiring 24 hours of storage in the system in case of larger and longer power outages.
If the building is provided with a dedicated back-up power system (Generator) and it is wired to run the STEP System, we would be willing to entertain the idea of waiving the requirement
for 24 hours of Storage Volume.
The Sewer Dept. would like to see tanks no larger than 6000 gallons per tank to facilitate pumping of those tanks. A 6000 gallon tank can be pumped by two trucks but anything larger
requires use of two trucks and a trailer which can be logistically difficult. This position is also backed up by paragraph a, bullet #4 on page C1-31 of the Orange Book.
Eagle Plaza STEP system sizing Review
1st review Feb. 19, 2009
James Doty
1
.doc
EAGLEP~2.DOC
Eagle Plaza STEP System Sizing Review 2-19-09.doc