HomeMy WebLinkAbout009 Tru North Center Wastewater ReportTruNorth Center
Wastewater Design Report
TruNorth Center
Wastewater Design Report
Summary
This report outlines the wastewater daily flow analysis calculations for the proposed TruNorth
Center Development. The Master Site Plan sewer report did not account for the sewer demands
for this site. The City will review the sewer demands calculated in this report and evaluate the
adjacent system’s capacity to accommodate the estimated demands.
Proposed Project Demand
The proposed TruNorth Center consists of two buildings, an office building (1340 E. Main St)
and a coffee/donut shop (1342 E. Main St). The future office building is an 11,626 SF two-story
structure with a max occupancy of 78. Based on a conservative basis the office building will use
0.273 gpd/sf, per water supply planning book by David W. Prasifka. Taking these factors into
consideration the office building contributes:
(0.273 gallons per day
square feet ∗11,626 square feet)=𝟎,𝟎𝟎𝟎 𝐠𝐩𝐝
The future Alza coffee/donut shop is a 5,148 SF three-floor structure with a max occupancy of
128. Based on a conservative basis the office building will use 41 gpd/seat, per water supply
planning book by David W. Prasifka. Taking these factors into consideration the coffee/donut
contribute:
(41 gallons per day
seat ∗128 seats)=𝟎,𝟎𝟗𝟎 𝐠𝐩𝐝
The addition of these two structures amounts to an average daily flow of 8,371 gpd or 5.8 gpm.
(𝑃𝑚𝑎𝑥
𝑃𝐴𝑣𝑒
)=18 +𝑃.5
4 +𝑃.5 =18 +.𝟎𝟎𝟎.5
4 +.𝟎𝟎𝟎.5 =𝟎.𝟎𝟎
(P = Population/thousands)
A peaking factor of 4.61 was calculated to conclude a peak hour sewer demand of 1,609.1 gph.
The population for this development was determined by combining the max occupancy of both
of the buildings, this provides a conservative estimate as it is not expected both buildings will
often be at max occupancy simultaneously.
This project will require the approval of the City of Bozeman Engineer and MDEQ.
Wastewater Daily Flow Analysis
TruNorth Center
Average Daily Flow
Building Area
TruNorth Office Building 11626 sq. ft.
Annual Water Use/sq. ft.0.273 gpd/sq. ft.
Average Daily Flow 3,174 gpd
Max. Occupancy
Alza Building 128 occupancy
Annual Water Use/seat 41 gpd/seat
Average Daily Flow 5,197 gpd
Total Annual Water Use 8,371 gpd
Peaking Factor Calculations
Max Occupancy
78.00
128.00
206.00
=Q(max)= 18 + P
0.50 P = Population/thousands = 206/1000 = 0.206
Q(ave)4 + P
0.50
Peaking Factor =
Peak Hour Sewer Demand
Average Daily Flow 8,371 gpd
348.8 gph
5.8 gpm
Peaking Factor 4.61
Peak Hour Sewer Demand 1609.1 gph
26.8 gpm
215.12 cfh
3.59 cfm
0.060 cfs
Peaking
Factor
4.61
Tru North Office Building
Alza Building
Total Population