HomeMy WebLinkAboutWater and Sewer Report
Water and Sewer Memo:
for
145 Simmental Way
Gallatin County, Montana
September, 2021
Prepared For:
915 Building Partners, LLC
Prepared By:
Hyalite Engineers, PLLC
Brett Megaard, PE
Page 1
145 Simmental Way
ENGINEER’S WATER AND SEWER MEMO
Owner: 915 Building Partners, LLC
1891 Boot Hill Court
Bozeman, MT 59715-7245
Introduction
This report provides an estimate of the peak-hour sanitary sewer demand as well as the
average and max day demands of domestic water usage for the proposed site development.
The City of Bozeman Design Standards and Specifications (March 2004) was used as the
primary guideline for this stormwater drainage design.
General Design
The proposed development of the site will contain three multifamily units, above commercial
space. The three residential units, as well as the bathrooms serving the commercial
warehouse space, will share a new 2” copper water service and 4” SDR 26 PVC sewer
service. The sewer service will be connected to the 8” main that runs down Boot Hill Court.
The sewer services will be installed at a minimum slope of ¼-inch per foot. Cleanouts will be
provided at each bend as well as at the exterior of the building. The water service will be ran
off of the 8” water main that runs down Boot Hill Court as well. Water services are to be 2”
diameter to allow for the potential use of domestic supply for a fire sprinkler system, on top of
the fixture count demand as shown in the included Fixture Count chart.
Sewer Demands
Assuming an average daily flow of 2.17 people per dwelling with 64.4-gallons per capita per
day:
(2.17 people per dwelling) X (3 dwellings) = 6.51 people
(6.51 people) X (64.4 gallons per person per day) = 419.2 gallons per day
Using a peaking factor of 4.43 calculated from equation 10-1 from DEQ Circular 2:
(419.2 gpd) X 4.43 = 1,857 gpd (1.29 gallons per minute)
Water Demands
Assuming 2.17 people per dwelling with an average daily usage of 170-gallons per person:
(2.17 people per dwelling) X (3 dwellings) = 6.51 people
(6.51 people) X (170 gallons per day) = 1,107 gallons per day
Using a maximum day to average day ratio of 2.3:1 from City of Bozeman Design Standards:
(1,107 gpd) X 2.3 = 2,546 gallons per day (1.8 gallons per minute)
Appendix A – Residential Water Service
1 4 5 S I M M E N T A L W A Y
S E P T E M B E R 2 0 2 1
A P P E N D I X
APPENDIX A
RESIDENTIAL WATER SERVICE
Residential (2018 IRC)
City of Bozeman Water Service Calculation Worksheet
Project Address: ___________________________________ Property Owner: ________________________________
General Contractor: _______________________________________________________________________________
Permit Number: _______________ Proposed Water Meter Size: ______________
UPC Table 610.3 Standard Design Water Supply Fixture Units
Appliances and Fixtures Fixture Units # of Fixtures Total
Bathtub or combo tub/shower (1/2” fill valve) 4.0 X ________ = ________
Bath Tub (3/4” fill valve) 10.0 X ________ = ________
Shower (per head) 2.0 X ________ = ________
Clothes washer 4.0 X ________ = ________
Dishwasher 1.5 X ________ = ________
Hose Bibb 2.5 X ________ = ________
Additional Hose Bibb (each) 1.0 X _______ = ________
Lavatory Sink 1.0 X ________ = ________
Kitchen Sink 1.5 X ________ = ________
Laundry Sink 1.5 X ________ = ________
Water closet [toilet] (1.6 GPF) 2.5 X ________ = ________
Bidet 1.0 X ________ = ________
Urinal (flushometer valve) Table Values* ________ = ________
Total Number of Fixture Units ________
Fixture Unit Tables for Determining Water Pipe & Meter Size Pressure Range – 46-60 PSI
Circle the length in feet to the farthest fixture & applicable service, meter & branch sizes below based on the total number of fixture
units detailed above.
Maximum Allowable Length in feet
Meter & Supply & 60’ 80’ 100’ 150’ 200’
Service Branches
¾” ¾” 20 19 17 14 11
¾” 1” 39 36 33 28 23
1” 1” 39 39 36 30 25
¾” 1¼” 39 39 39 39 39
1” 1¼” 78 76 67 52 44
1½” 1¼” 78 78 78 66 52
1” 1½”/2” 85 85 85 85 85
1½” 1½” 151 151 151 128 105
2” 1½” 151 151 151 150 117
1½” 2” 370 340 318 272 240
2” 2” 370 370 370 368 318
If count is over 370 fixtures, water demand does not meet table 610.4 and must be engineered by a registered Montana
mechanical engineers design, signed and stamped. 04.29.20
5
5
3
3
3
3
3
12
6
12
4.5
5
4.5
12.5
56.5