HomeMy WebLinkAbout005 Water Systems Memo
cushingterrell.com
March 23, 2023
Suzanne Ryan, PE
City of Bozeman
20 E. Olive Street
Bozeman, MT 59715
RE: Berkshire Heights Bozeman Parcel Distribution Water/Wastewater System Requirements
Mrs. Ryan,
The purpose of this memo is to address city code Section 38.410.070 – Municipal water, sanitary sewer and
storm sewer systems. The proposed project includes a domestic water and fire suppression service line as
well as a sanitary sewer line.
Domestic Water Usage
Utilizing guidance from Montana DEQ Circular 4, a typical flow rate of 13 gallons per employee per day can
be used to estimate wastewater flow. The same was used in this estimate for domestic water use. With 60
anticipated employees, the daily peak demand for domestic water use is 780 gallons per day. There exists a
2” water main stub from the underlying subdivision. This size main will be suitable to provide the daily peak
demand for this proposed building, The proposed service line from this main is approximately 22 feet in
length, lower than the maximum 150 feet specified in 38.410.070.
Wastewater Usage
Using the same guidelines from Montana DEQ Circular 4 mentioned above, the estimated wastewater flow is
780 gallons per day. When using a peak hour factor of 4.30 and a wastewater flowrate from Table V-1 in
Bozeman’s design standards, the peak hour flow is 2.97 gpm. There exists a 4” sanitary sewer stub from the
underlying subdivision. This main will be suitable to discharge demanded wastewater flow. The proposed
service line from is approximately 22.5 feet in length, lower than the maximum 150 feet specified in
38.410.70.
Fire Suppression Water Usage
The proposed fire suppression system is to be designed for the IFC minimum flow of 1,000 gpm for 2 hours.
The fire suppression system will connect to an existing 4” diameter stub into the property from the city’s
municipal water supply system.
It is expected that a hydrant flow test will be conducted prior to finalizing the buildings fire sprinkler design
to confirm that the available pressure and flow will meet the demand for the proposed system.
Sincerely,
Adam Schlegel, PE