HomeMy WebLinkAbout17 - Design Report - J & D Family MaSub Ph 2 - Water, Wastewater ENGINEERING
- -g _ _____ NESIS CONSULTING
PLANNING
NGINEERING, INC DESIGN
7 204 NORTH 11th AVENUE,BOZEMAN,MT 59715 204 N.11'"Ave. BOZEMAN,MT 59715 406-581-3319 www.g-a-i.net
Water and Wastewater Design Report
J & D Family Major Subdivision— Phase 2
NE%SE%Sec 9T25R5E
Bozeman, Montana
January 2017
Prepared By:
Genesis Engineering, Inc.
GEI Project#: 1134.002
Prepared For:
1 & D Family Limited Partnership
270 Automotive Drive
Bozeman, MT 59718
a 204 N. 11'h Ave., Bozeman,MT 59715 Cell:(406)581-3319 www.o-a-i.net Page 1 of 8
&A��
oJa;tiwS4nslnlg/(b��i(.n4
Water and Wastewater Design Report
Table of Contents
I. Project Background............................................................................................................. 4
1. Introduction.............................................................................................................................. 4
2. Soil and Groundwater............................................................................................................. 4
3. Land Use.................................................................................................................................... 4
4. Design Standards..................................................................................................................... 4
II. Sanitary Sewer System................................................................................................. 5
1. Projected Flows........................................................................................................................ 5
2. Collection System.......................................................................................I............................ 5
3. Service Connections................................................................................................................ 5
III. Water System.................................................................................................................... 6
1. Projected Usage....................................................................................................................... 6
2. Hydraulic Analysis.................................................................................................................... 6
3. Water Distribution System..................................................................................................... 6
4. Service Connections................................................................................................................ 7
IV. Conclusion......................................................................................................................... 7
List of Tables
Table 1. Projected Sewer Peak Flow......................................................................................................... 5
Table 2. Projected Water Demands.......................................................................................................... 5
Appendix A—Drawings
Existing Water and Sewer Systems......................................................................................................... W&S-1
Appendix B—Calculations
Demand Calcs
Hydrant Flow Test
List of References
City of Bozeman Design Standards and Specifications Policy, March 2004,and all addenda.
Montana Public Works Standard Specifications(MPWSS),611 Edition
City of Bozeman Modifications to the MPWSS,61h Edition, March 31,2011&all addenda
Montana Department of Environmental Quality(MDEQ) Design Circulars DEQ-1 and DEQ-2
Design Report for the Valley West Sewer Trunk Line, Morrison-Maierle, Inc., 1998.
t* 204 N. 11'h Ave., Bozeman, MT 59715 Cell:(406)581-3319 www.q-a-i.net Page 2 of 8
y>I
� __ ; I\II~�I�
NGfNEERING,INC
,.. uz�„�y/+x..WsW..a.r�e+..��...,
I. Project Background
1-1. Introduction
Phase 2 of the J &D Family Major Subdivision is a proposed 1-lot commercial development of approximately
4.7 acres located in Section 9,T2S, RSE, PMM in Bozeman,Gallatin County, Montana. The property lies
immediately west of Cottonwood Road, and south of West Babcock Street.
This report describes the water and wastewater systems that will be required to service Phase 2 of the J &D
Family Major Subdivision. The proposed water and wastewater infrastructure will be connected to the public
water and sewer systems owned and maintained by the City of Bozeman.
1-2. Soil and Groundwater
The NRCS Soil Survey identifies two major soil types on the proposed subdivision: Lamoose silt loam(537A)
and Enbar loam (509B). These soils belong to hydrologic soil group B&C as they are comprised primarily of
loams and silt loams with slow to moderate infiltration rates.
A geotechnical investigation by Rimrock Engineering in March and April, 2007 found static water levels
between three(3)and five(5)feet below existing grade in test pits and bore holes. Rimrock's investigation
was conducted on the Norton East Ranch property immediately west of the proposed J &D Family Major
Subdivision.
1-3. Land Use
The pre-development land use on the proposed subdivision is pasture and open space,though the land is not
currently being used for grazing or other agricultural production. Upon development,the Owners anticipate
that the subdivision will consist of a business park with multiple businesses.
1-4. Design Standards
All sanitary sewer mains,water mains,service connections, and appurtenances will be designed and
constructed in accordance with the Montana Public Works Standard Specifications(MPWSS),61h Edition; City
of Bozeman Design Standards and Specifications Policy(including all Addenda), March 2004;City of Bozeman
Modifications to the MPWSS, March 2011;the Montana Department of Environmental Quality(MDEQ) Design
Circulars DEQ-1 and DEQ-2,and any additional addenda thereof. The City of Bozeman will assume operation
and maintenance of the wastewater and water systems and appurtenances upon construction and acceptance
of the installation.
i� 204 N. 11`h Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.a-a-i.net Page 3 of 8
I\IE�I�
I NGINEERING,INC
--� ,ie Z;fi..vd o/.:vow sw..!feJc..�nnrn,
II. Sanitary Sewer System
11-1. Proposed Design Flow
Since the site plan for the Lot 1 is not know at this time,Table V-1 from the Design Standards and
Specifications Policy was used to estimate its generated sewage flows for the existing B-1 zoning.
Table 1 shows the average daily demand and equivalent population calculation using Table V-1..
Table 1. Wastewater Flow and Equivalent Population:
Parcel Use Lot Area ADF/Acre ADF Equivalent Pop
(acres) (Rpd/acre) (gpd) (people)
Lot 1 B-1 Zoning 4.7 1,000 4,700 53
Infiltration 4.7 150g/ac/day 705
Total 5,405 gpd
The City of Bozeman standard of 89 gallons per capita per day was applied to the 4,700 gallons per day to
determine an equivalent population for the subdivision of 53 people,yielding a peaking factor of 4.31.The
peaking factor, PF,was calculated by the following formula,where P=population(thousands):
PF=18+po.5
4+Po.5
Multiplying the pre-infiltration average daily flow of 4700 by the peaking factor of 4.31 results in a calculated
peak flow of 20,257 gallons per day. Infiltration into the sanitary sewer system from the subdivision was
calculated to be 705 gallons per day using the City's rate of 150 gallons per day per acre over the 4.7 acre area.
Therefore,the combined estimated peak hour design flow is: Peak Hour Flow: 20,962 gallons per day
Using Manning's Equation and a minimum slope of 0.004 ft/ft for an 8-inch diameter pipe,the full-flow
capacity of the pipe is 0.76 cfs or 497,629 gallons per day. The empirically-based peak design flow occupies
4.10%of the proposed pipe. The full flow velocity of the 8-inch diameter SDR-35 main is 2.2 ft/sec exceeding
the minimum of 2.0 ft/sec required.
II-2. Collection System
No new manholes or sewer main is proposed as part of this subdivision as Lot 1 and the east portion of the
remainder tract already have water and sewer extended into the lot.
The wastewater from Lot 1 will be conveyed north by gravity sewer services within the lot to an existing
manhole in Babcock Street,then east via an 8-inch SDR-35 sewer main to Cottonwood Road where it will join
the Valley West Sewer Trunk Line and flow north.
According to the Morrison-Maierle Design Report for Valley West Sewer Trunk Line (1998),the existing Trunk
Line is designed presuming development of the subject property and has adequate capacity to convey the
peak design flow.
II-3. Service Connections
No new service connections are proposed as part of this subdivision as Lot 1 and the east portion of the
remainder tract already have water and sewer extended within the lot.Any future connections to the sanitary
;� 204 N. 11"Ave., Bozeman,MT 59715 Cell:(406)581-3319 www.a-a-i.net i_� Page 4 of 8
I\II~�I�
� NGINEERING,INC
&,L2yr.n.,,J,yw Sw.Gd..fC.•�,.r.,
sewer mains will be designed in accordance with the City's Design Standards and Specifications Policy.
Connections to the sewer main will be made with in-line gasketed wyes.
III. Water System
III-1. Projected Usage
Phase 2 of the J &D Family Major Subdivision consists of one proposed commercial lot and a remainder tract.
Using Table V-1 from the Design Standards and Specifications Policy,Genesis estimated the development's
generated water demands. Lot 1 has a total average daily demand(ADD)of 3.3 gallons per minute,a
maximum day demand of 7.5 gallons per minute,and a peak hour demand of 9.8 gallons per minute. The
average daily demands are exclusive of the suggested fire flow requirement of 2250 gallons per minute. When
modeled,the system design satisfies the fire flow occurring simultaneously with the maximum day demands
inclusive of the proposed Norton Ranch subdivision. Table 2 below summarizes the projected usage.
Table 2. Proiected Water Demand:
(1.0) (2.3) (3.0)
Parcel Use Lot Area ADF/Acre ADF ADD Max Day Peak Hr
(acres) (Rpd/acre) (epd) (Rpm) (Rpm) (epm)
Lot 1 B-1 Zoning 4.7 1,000 4,700 3.3 7.5 9.8
The Owner plans to use existing water rights and/or new irrigation wells on the property to water the larger
landscaped areas of the proposed subdivision. Smaller local landscape watering is included in the demands
above.
III-2. Hydraulic Analysis
The hydraulic modeling program WaterCAD was used to model domestic and fire protection demands for the
proposed major subdivision in Phase 1. The results of the Phase 1 model were as follows:
Available Fire Flow - 2780-3000 gpm at 20 psi near the proposed service connection in Babcock
Maximum System Pressure—132 psi upstream of existing PRV
Minimum System Pressure—20 psi near the proposed service connection in Babcock
It is noted that additional development has occurred in the area since the completion of Phase 1 and
therefore,a more recent hydrant flow test has been requested from the City near the service connection in
Babcock between Automotive Way Avenue and Cottonwood Road. The empirical test results can be found in
the appendix.
III-3. Water Distribution System
No new water main is anticipated for the proposed subdivision. Any future buildings within Lot 1 will connect
to the existing 8"stubs from Automotive Avenue or West Babcock Street.
III-4. Service Connections '
Future service connections to the water mains will be designed in accordance with the City's Design Standards
and Specifications Policy and sized based on the projected usage for each service line. Service lines less than 4
inches in diameter will be type"V copper pipe,while those larger than 4 inches will be ductile iron. Water
services will meet all applicable design standards and flow requirements.
�� 204 N. 11"Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.a-a-i.net Page 5 of 8
NGINEERING,INC
IV. Conclusion
The analysis and calculations included in this report demonstrate that the proposed designs for water
provision, including fire flow,and wastewater disposal satisfy state and local design requirements.
�� 204 N. 11"Ave., Bozeman,MT 59715 Cell:(406)581-3319 www.q-a-i.net `a� Page 6 of 8
NE�I�
NGINEERING,lNC
Appendix A
Drawings
�' 204 N. 11"'Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-a-i.net a�i Page 7 of 8
—
���
—EX W EX W EX W / 'EX W SEX W/ EX W—
\ END SEWER MAIN
J--LL-I I I I I I I I I I LLLLLLEL-11K_u I er�-j I allirl
EXI:
SEW1
y E)OSYING
/SEWER
MANH TYP
EXISTING REGIONAL
STORM POND
///� ---------4-7Q4--
� r /
1 A ---
i
0
PC
_ Xw
EXISTING 8' /
WATER STUB
EXISTING
HYDRANT N
/
EXISTING SEWER MAIN
K / EXISTI G i. F
7 / WATFVMAIN
i————————————————
�._
r—— -———— — 4-7
T DARY
EXISTING 9'
/ WATER MAIN
VERIFY SCALE REVISIONS
TNESERwNTsnwY eE NO. DESCRIPTION DATE BY
REOUCEO.U.E RELOW
MEASURES ONE INCH ON
owGiNU OMwING. _ - - Conwltmg
CNESISE',.,,gng
Design
MODIFY STYE ACCORDINGLY NGINEERING, INC Planning
HAI 13C001WCAOlEXHIBITS\EXISTING WTRSWR.dwg Plotted by chdstopher waste on 1/11/20175:16 PM 76e� �nnin o aMew Srandardo ommifinent COPYRIGHT DG
c'"�y
}
NGINEERING,INC
—1 •1Fr2yi..ryef.;14r S1a.LrleJCn..++.nP
Appendix B
Calculations
�' 204 N. 111'Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-a-i.net Page 8 of 8
&RAn
J&D Phase 2
Sewer Demand Calcs
204 N.11th Avenue,Bozeman,MT 59715
These calculations are used to determine the average sanitary sewer flow and
required sewer pipe diameters forth e Subdivision.
Using Mannings Equation,the full flow capacity of the proposed PVC sewer line is:
Qfull=(1.486/n)*A*RA(2/3)*SA(1/2) where:
Diameter= 8 inches
n= 0.0130 for PVC
A=Pi*rA2= 0.35 ftA2
P=2*Pi*r= 2.09 ft
R=A/P= 0.1667 ft
S= 0.0040 ft/ft
Qfull= 0.76 CFS
Estimate Proposed Peak Sewage Flow Rate for Pipe Design only
Parcel Parcel Area Number of Units Rate/Unit ADF
(Acres) (gallons per acre per day gal/day
Lot 1 4.7 1000 4,700
Total Area= 4.7 Total 4,700 gal/day
Equivalent Population Average Daily Flow/ 89 gal/capita/day= 53 people
Peaking Factor Qmax= 18+PA(1/2) = 4.31
Qave 4+PA(1/2)
Peak Hourly Flow Rate
PHF = Average Daily Flow*Peaking Factor= 20,256 gal/day
Infiltration gpd/acre= 0 0 gal/day
Total PHF= 20,256 gal/day
or 0.031 cfs
Using the above values,velocity at peak hourly flow is:
V=(1.486/n)*RA(2/3)*SA.5= 0.09 ft/sec
and Qmax = 4.10
Qfu II
r ,► FIRE HYDRANT FLOW TEST
L
rrsmitment
On Babcock Street,West of Intersection with Cottonwood Road
2415&2398 respectively
1/20/2017 By Erin Shane of the COB Water Department
1134.002 Water Main Pressure vs. Flow Capacity Nl
NGINEERING,IAIC
16'Dyaiaf ff i try SkfLd if C+�IR<•nI
#2415 70
62
44 60
1110
#2398 50
62 a
---- — -- a
56 ar 40
N
N
d
IL` 30
0.9
--- —— — — -2.5 20 20
29.8
10
:k for the reliability of Qt
F 54.3 0
0 500 1,000 1,500 2,000 2,500 3,000
I/(Ps Pt))o.54
— --- Flow,Q(gpm)
20
-----��2,779
ie distribution system new
Note: Rearrange the Hazen-Williams formula to provide a rough
estimate of residual pressure at a flow data point near the average
flowed hydrant: of 0 gpm and flow at 20 psi and enter that data point into the graph
Head(ft) Q(gpm) above for water modeling purposes.
143 0
116 1,390 P = PS(PS Pt)(QWQX-'Jb
46 2,779
EMHydrant Flow Test Printed:1/26/2017