HomeMy WebLinkAboutPIP 06-10; BRESSI RANCH INDUSTRIAL LOTS; SEWER REPORT; 2007-02-21CAA- 0
SEWER REPORT
BRESSI RANCH
Lots 19-22
February 21, 2007
Prepared For:
CITY OF CARLSBAD
Prepared By:
PROCTDESIGN CONSTANT$
PLANNING • ENVIRONMENTAL • ENGINEERING'. SuRvE/GPS
701 B Street. Suite 800, San Diego, CA 92101
619-235-6471 FAX 619-234-0349
Job No. 3370.10
L A~
Curtis J.Tume RCE 59285
Registration Expires 6/30/07
I
'No. 59285
Prepared By: KO
Checked By: NP
Pzi' O&-(
1.0 INTRODUCTION
This sanitary sewer report has been prepared to document the final design and supporting
calculations for the sewer system associated with the proposed development of Bressi Ranch
Lots 19-22 within the City of Carlsbad. The sewer system for the development will connect to
an existing sewer lateral stub from the existing 8" sewer main at the western edge of the property
in the south-west corner of Lot 19.
2.0 DESCRIPTION OF STUDY AREA
The property consists of approximately 7.7 acres of undeveloped land located in the vicinity of
Gateway Road and Innovation Way in the western portion of Carlsbad, California. The property
is bounded on the west by Lots 16 & 18 of Carsbad Tract 02-15, on the south by Gateway Road,
to the east by Innovation Way and to the north by Lot 23 of Carlsbad Tract 02-15.
3.0 PROPOSED SANITARY SEWER IMPROVEMENTS
The proposed private sewer system consists of an 8" PVC sewer main with 6 access holes and
connects to an existing 8" sewer at the western edge of the property in the south-west corner of
lot 19. Individual 4" PVC private sewer laterals will service the buildings on site and each will
be connected to the onsite 8" main. Bressi Ocean Collection, LLC proposes to develop
approximately 108,624 square feet of commercial facilities.
4.0 ESTIMATED SEWAGE FLOW (DEMAND)
According to the Carlsbad Standard Sewer System Design Criteria manual, sewage demand is
approximated as 220 gallons per dwelling unit for an average day. The Carlsbad Municipal
Water District Sewer master Plan (1993) states that every 1,800 SF of building space is
equivalent to 1 dwelling unit (EDU). Therefore, average sewage demand is determined by
P:3370\ENGRREPORTS\SWR\3370SEWER19-22.DOC
dividing the total square feet of building space by 1800 and multiplying this number by 220
gallons per day. See table 1 for these quantities.
5.0 DESIGN CRITERIA
Where D = pipe diameter, and d = flow depth:
8-inch diameter pipe:
Maximum Depth at Peak Flow = Y2 pipe diameter (0.5 feet) or d/D !~ 0.50
Minimum Pipe Slope = 0.40%, desirable 0.5%
Minimum Sewage Flow Velocity =2 feet/second
Peaking Factor = 2.50
Unit Flow Generation Factor = 1 EDU/1,800 SF of building space
Sewage Generated = 220 gallonsfEDU/day
Pipe Roughness Coefficient 'n' = 0.011 for PVC pipe
Design calculation equations were obtained from the City of Carlsbad Engineering Standards,
Volume 1, Chapter 6, 2004 Edition. Maximum sewer depth shall be 15 feet. Depths greater than
15 feet require approval from the City Engineer.
6.0 CONCLUSION
In conclusion, it was determined that 8-inch PVC pipe is suitable to carry the service flow
without exceeding the criteria depth of peak flow < Y2 pipe diameter or d/D < 0.50. The pipes'
minimum velocity and slope requirements were maintained. The sewer depth ranges from 6.00
feet minimum to 13.94 feet maximum.
P:\3370\ENGR\REPORTSSWR\3370SEWERI9.22.DOC
Project Design Consultants
701 B Street Suite 800
San Diego CA 92101
PDC job #3370.10
Date: 02121/07
TABLE I
SEWER FLOW CALCULATIONS
BRESSI RANCH INDUSTRIAL LOTS 19-22
Generation Q-gpd Q-gpd O-cfs Q-cIs
Pipe Section by Bldg. Area Factor Avg daily Peak Peak! Peak! Peak! Peak! Area-halt Hyd Red 0-cap Excess
Manhole (SF) (EDU) flow (pd) Factor Section Total Section Total Slope n 0 (ft) (sf) (ft) v (ft/sec) (cfs) Cap (cfs) d d/D
7-6 13258.67 7.37 1621 2.5 4051 4051 0.0063 0.0063 c20) 0.011 0.670 0.176 0.0169 1.4104 0.2486 0.2424 0.0259 0.04
6-5 32806.03 18.23 4010 2.5 10024 14075 0.0155 0.0218 0.0240 0.011 0.670 0.176 0.0301 0.3581 0.3363 0.0467 0.07
5-2 11040.00 6.13 1349 2.5 3373 17449 0.0052 0.0270 0.0200 0.011 0.870 0.176 0.0348 2:19 0.3599 0.3329 0.0543 0.08
4-3 21358.88 11.87 2611 2.5 6528 6526 0.0101 0.0101 -0.0i98) 0.011 0.670 0.176 0.0222 1.5055 0.2654 0.2553 0.0341 0.05
3-2 30160.00 16.76 3686 2.5 9216 15742 0.0143 0.0244 0.0210 0.011 0.670 0.176 0.0327 066 0.3537 0.3294 0.0509 0.08
2-EX 0 0.00 0 2.5 0 33191 0.0000 0.0514 0.0134 0.011 0.670 0.176 0.0507 ç3.1472 0.3785 0.3272 0.0808 0.12
IiECEWED
FEB 21 2001
ENGINEERING
DEPARTMENT