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CITY OF BAKERSFIELD
PUBLIC WORKS DEPARTMENT
NORTHEAST BAKERSFIELD SEWER
STUDY
FOR A
NEW SEWER TRUNK LINE TO WASTE
WATER TREATMENT PLANT NO. 2
September 21, 2005
Prepared By
Meyer Civil Engineering, Inc.
City of Bakersfield - Northeast Sewer Study
INDEX
PURPOSE……………………………………………………………………..…PAGE 3
EXISTING SEWER
INFRASTRUCTURE…………………………………………………………..…PAGE 3
LOCATION MAP…………………………………………………………………PAGE 5
SEWER SERVICE AREA
CALCULATIONS……………………………………………………………...…PAGE 6
ALIGNMENT
ALTERNATIVES……………………………………………………………....…PAGE 6
RIGHT OF WAY
IMPACTS……………………………………………………………….……...…PAGE 8
CITIZEN IMPACTS…………………………………………………….……... PAGE 11
COORDINATION AND PERMITS TO CONSTRUCT
PROJECT...…………………………………………………………….…....…PAGE 12
PIPE
MATERIALS...………………………………………………………….…...….PAGE 13
COST
ESTIMATES...………………………………………………………….…….…PAGE 13
CONCLUSIONS AND
RECOMMENDATIONS……………………………………………….……..…PAGE 13
APPENDIX A COST
ESTIMATES……………………………………………….…………….....….PAGE A-1
APPENDIX B PRELIMINARY
PLANS……………………………………………….……………….….….…PAGE B-1
APPENDIX C TECHNICAL
APPENDIX………………………………………….……………….……..…..PAGE C-1
APPENDIX D PRELIMINARY SOIL
REPORT………………………………………….……………….……..….....PAGE D-1
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Meyer Civil Engineering, Inc. Page 3
PURPOSE
The City of Bakersfield plans to construct a new sewer trunk line that will help relieve
sewer lines that flow from northeast Bakersfield to Waste Water Treatment Plant No. 2
(WWTP#2). WWTP#2 is located on Mount Vernon Avenue, south of the Route 58
freeway, near Planz Road. This study consists of estimating flows generated from
anticipated land uses in the service area, reviewing existing facility capacities presently
in place, preparing conceptual sewer mains and force mains alignments, preparing
alternative alignment studies for the trunk line, identifying right of way and permitting
requirements, and making recommendations in regard to a final project. The
recommended alternate is Alternate 1. This alignment is shown on the proposed
Master Plan which is included herewith as Plates 1 and 2 in the drawing jacket. Please
refer to this plan for illustration of the existing sewer systems, service area boundaries,
and proposed conceptual and preliminary designs.
EXISTING SEWER INFRASTRUCTURE
The service area for the proposed trunk sewer contains approximately 47 square miles
of mixed use and undeveloped properties. The existing facilities within the project
boundary primarily consist of those constructed to serve a sewer assessment district
known as AD93-1. The service area boundary lies wholly within the project area and is
7236 acres in size. Developers of subdivisions have connected to these facilities for
service to their project both within and outside of the district boundary. Extension
beyond the district boundary occurs on the west side of the district at Panorama Drive.
These facilities are all small in size and provide no additional value of regional service.
The AD93-1 facilities connect to the City system through an interim connection to an
East Niles Community Services District main located in East Brundage Lane. These
flows are then conveyed to WWTP#2.
Analysis of the AD 93-1 facilities was performed utilizing planned land uses under the
2010 General Plan. Estimates of flow were prepared using the City of Bakersfield
Subdivision Design Standards. Reserved land uses were considered to be developed
as single family residential at a rate of four dwelling units per acre. The following table
outlines land use densities and flow rates used through this study.
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Land Use Sewer Loadings
Designation Land use Description
Dwelling
Units (DU)
per ACRE
GPD per
DU
Average
Load, MGD
per AC
Average
Load, CFS
per AC
Equivalent
SF DU's
Equivalent
Population
per ACRE
LR Single Family (LR) 4.0 260 0.001040 0.001608 4.00 10.40
SR Single Family (SR) 3.0 260 0.000780 0.001206 3.00 7.80
ER Single Family (ER) 1.0 260 0.000260 0.000402 1.00 2.60
RR Single Family (RR) 0.5 260 0.000130 0.000201 0.50 1.30
LMR Multi Family (LMR) 6.0 200 0.001200 0.001855 4.62 12.00
HMR Multi Family (HMR) 10 200 0.002000 0.003092 7.69 20.00
HR Multi Family (HR) 15.0 200 0.003000 0.004638 11.54 30.00
GC Commercial (Area) 0.003593 0.005556 13.82 35.93
OC Commercial (Area) 0.003593 0.005556 13.82 35.93
MUC Commercial (Area) 0.003593 0.005556 13.82 35.93
R-MP R-MP (LR Equiv) 4.0 260 0.001040 0.001608 4.00 10.40
R-EA R-EA (LR Equiv) 4.0 260 0.001040 0.001608 4.00 10.40
R-IA R-IA (LR Equiv) 4.0 260 0.001040 0.001608 4.00 10.40
Units in the above table are defined:
DU is “dwelling units”
GPD is “gallons per day”
MGD is “million gallons per day”
CFS is “cubic feet per second”
AC is “acres”
SF is “single family”
The above abbreviations will be used throughout this study. Land use designation
maps are included as Plates 3 and 4 in the drawing jacket.
Generally the AD93-1 facilities performed adequately with a few exceptions. The
following facilities are identified as inadequate:
TABLE OF AD93-1 CAPACITY DEFICITS
Location & Description Name(s) Size Design
Flow
Capacity Deficit
Gravity Sewer in Hwy 178 west
of Masterson St.
P-48, P-49 & P-50 18” 10.75cfs 8.61cfs 2.13cfs
Gravity Sewer south of Hwy
178 between Vineland and
Masterson
P-50 18” 9.65cfs 5.56cfs 4.09cfs
The above items will be addressed later in this study as to how these inadequacies are
to be corrected. The existing pumps stations should perform adequately as
constructed.
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SEWER SERVICE AREA CALCULATIONS
Sewer service area calculations were performed following the City of Bakersfield
Subdivision Design Standards. More particularly these rates are as follows:
Single Family Dwelling: 2.6 persons at 100 gallons per person per day ave.
Multiple Family Dwelling: 2.0 persons at 100 gallons per person per day ave.
Peaking Factor: Pf=2.65x(Average Discharge)-0.1 for flows in CFS
Commercial Uses: 0.00556 CFS per gross acre average
Peaking Factor: Pf=1.8
Industrial Uses: 0.00750 CFS per gross acre average
Peaking Factor: Pf=2.0
The above rates were applied to planned land uses as defined in the 2010 General
Plan. Densities were based on practical build-out densities typical for the area. Due to
relatively hilly terrain yield is lost from space taken up by side slopes between lot pads.
Typical gross densities were taken from filed maps in the area. These densities are
represented in the above table “Land Use Sewer Loadings”. The project area contains
considerable acreage under reserved land uses. Reserved land uses were considered
as developed as single family dwellings.
A detailed table of land uses and their associated area is contained in the Technical
Appendix. These values were applied to a sewer modeling program “SewerCAD” by
Haestad methods. The program is designed to analyze sewer flows on the basis of
actual gravity and pumped constraints. Results from these models are contained in the
Technical Appendix.
In addition to the estimated flows based on the General Plan, flows from the Kern
Sanitation Authority (KSA) are added at the location of Oswell Street and Redbank
Road. This is considered in anticipation of taking KSA’s waste water treatment plant
offline and accepting their flows into the City’s WWTP#2. This flow as provided by KSA
is estimated to be five million gallons per day or 7.7 CFS average.
Total discharge to the WWTP#2 is estimated to be 75.73 CFS peak or 48.98 MGD. This
can be equated to a population of 268,300 persons.
ALIGNMENT ALTERNATIVES
A master plan has been prepared within this study to conceptualize practical
alignments to collect sewage flows throughout the study area. These alignments are
provided to determine delivered flows to the planned trunk sewer line and to correct
problems within the AD93-1 system. The trunk sewer line has been studied in detail to
prepare preliminary plans for construction.
The alternate alignments are shown on Plates 5 and 6 in the drawing jacket. Two major
alignments were considered for the proposed trunk sewer line between Vineland Road
and Edison Highway to WWTP#2.
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ALTERNATE 1. This alignment runs south on Vineland Road to Redbank Road then
west on Redbank Road to Oswell Street, then south on the extension of Oswell St to
the extension of East Planz Road, then west on East Planz to the WWTP#2.
ALTERNATE 2. This alignment runs south on Vineland Road to East Wilson Road then
west on East Wilson Road to Oswell Street, then south on the extension of Oswell St to
the extension of East Planz Road, then west on East Planz to the WWTP#2.
The east-west run of Alternate 2 is located one-half mile south of Alternate 1. Primary
ground surface slope over the service area south of the freeway is to the west with
minor fall to the south. Development of the alternates was in consideration of this
topography. Line depth was set on each alternate by determining the length and slope
required for routing sub-mains to the trunk. The alternates were then developed to
include sub-mains to comparable points of service. Thus, the cost estimates for each
alternate include these sub-mains for proper comparison.
Both alignment alternates have three major crossings, Freeway 58, the Eastside Canal
and the AT&SF Rail Road. Along Alternate 1 the Eastside Canal and AT&SF Rail Road
crossing are immediately adjacent to each other while along Alternate 2 they are
separated enough that two separate bores will be required.
The Alternate 1 alignment could be considered to be more “rural” in that this alignment
does not involve developer widened roadways. As a result less pavement replacement
is required for Alternate 1 as compared to Alternate 2. Also, since the Alternate 2
alignment is more developed, more utility conflicts can occur and more homeowners
could be impacted by construction of Alternate 2.
A spin-off alternate (Alternate 1A) was prepared to identify additional costs associated
with KSA contributing flows. This is essentially the same as Alternate 1 with a
downsizing of the 72” pipe run to 66” size.
The AD93-1 facilities do not have the capacity to accept additional flows from the future
developed areas. Services area flows were adjusted to other locations in the new
facilities to resolve capacity issues in the AD93-1 system. One needed revision to the
system is to route flows from the lift station at Alfred Harrell Hwy and Highway 178 via a
new force main to the future facilities south of Highway 178. This is due to the fact that
flows need to be offset for downstream capacity for the AD93-1 facilities to accept
expanded areas from west of the district. The redirected force main is not included in
the cost estimates in this study as alignments are still conceptual.
In addition to the above alternates a parallel line is proposed to alleviate capacity
problems on the AD93-1 system. An 18” parallel line will be needed to augment
capacity of the sewer located in Vineland Road. Please refer to the Master Plan. This
line will begin at the northwest corner of Section 18 and proceed east to Vineland in
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Paladino. The line will then continue south to Hwy 178 and cross with a bore, then
south to Kern Canyon Road and back northeast to connect to the AD 93-1 sewer. This
line is called Alternate 3 – 18” Sewer Bypass (please refer to Plate 7 in the drawing
jacket).
RIGHT OF WAY IMPACTS
Both alternates studied will need procurement of permanent right of way as Section 11
has no street right of way dedications at the north line for one mile (Alternate 1) or east-
west centerline for three-quarters of a mile (Alternate 2). Alternate 1 is proposed to
cross an existing radio station antenna site in Section 11. This alignment will clear
underneath a structural guy wire adequately with special care. Temporary construction
easements are recommended for both alignments outside of City property. Most of the
alignments deal with only minor utility conflict with no need for utility relocation. The
alignments have been chosen so that power poles may be held in place by the utility
while trenching operations proceed.
Both alignments will require the removal and replacement of crops along the
approaches and departures to the Freeway 58 bored crossing.
Costs have been included in the estimates for the procurement of construction
easements and permanent right of way.
Photo 1. Radio Station Site (looking west).
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Photo 2. Typical Rural Residential Area.
Photo 3. Existing Railroad Crossing.
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Photo 4. Kern Island Canal.
Photo 5. Planned Alignment for Freeway Crossing (looking north).
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Photo 6. Planned Alignment for Freeway Crossing (looking south).
Photo 7. Sewer Pickup Point for North East Trunk Sewer.
CITIZEN IMPACTS
The proposed alignments of the trunk sewer traverse areas that are relatively
unpopulated, nonetheless, such a project will always have impacts to the public.
Following is a table that lists impacts to citizens that could occur during normal
construction procedures. Also provided in the table are methods listed to minimize
these impacts:
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TABLE OF POTENTIAL CONSTRUCTION INPACTS
Item Potential Impact Methods to Reduce Impacts
1. Traffic Delays due to Lane
Closures
Contractor to be required to file and follow
a comprehensive traffic control plan.
Minimize shutdowns during traffic peak
times.
2. Property Access Contractor to maintain alternate property
access points with plates, temporary
bridges or other devices.
3. Construction Dust Contractor to file and maintain a dust
control plan with the San Joaquin Air
Pollution Control District.
4. Construction Storm Water Contractor to file and maintain a Storm
Water Pollution Prevention Plan with the
Regional Water Quality Control Board.
5. Construction adjacent to School –
Dangers to Children
Contractor to file notice with the School
District and provide safety fencing and
warning signs. Security guard is to patrol
off hours.
6. Property Damage Specifications are to include protection of
property clauses and directives to
contractor for correction.
7. Mail Delivery Failure Specify requirement contractor to notify
Postmaster and provide temporary
mailboxes as may be required.
COORDINATION AND PERMITS TO CONSTRUCT PROJECT
The project will require initial contact by the City’s design consultant with all agencies
and utilities impacted by the project. The following table lists those agencies and
companies that will need to be contacted for permitting or licensing.
TABLE OF PERMITTING AGENCIES
Item Agency of Company Permitting or Licensing
1. Kern County Roads Department Plan review, general traffic control plan,
and encroachment permit.
2. Caltrans Plan Review and encroachment permit to
bore.
3. Cal OSHA Tunneling license to bore.
4. Pacific Gas and Electric Location of gas lines to cross.
5. AT&SF Rail Road License to bore.
6. Kern Delta Water District Encroachment Permit to cross and bore.
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The specifications are to include directive to the contractor for application to obtain
construction permits associated with the above licenses and permits.
PIPE MATERIALS
Available pipe materials for the proposed project are somewhat limited in the larger
diameters required. Following is a table that shows viable pipe materials and their
associated sizes.
TABLE OF PIPE MATERIALS
Size Range PVC-SDR35 Vitrified Clay Pipe PVC Lined RCP
6” to 21” Acceptable Acceptable Not economic
24” to 42” Not acceptable Acceptable Acceptable
48” to 72” Not available Not available Acceptable
The City of Bakersfield does not allow thin wall pipe products above the 21” size as the
City has experienced problems with thin wall pipe in the larger diameter sizes.
Manholes for sewer mains larger than 15” diameter are to be PVC lined. Manholes on
large diameter pipe junctions will need to be larger than the sewer pipe by
approximately 12” to allow for proper construction of the junction. All borings will
require steel casing in accordance with Caltrans and Kern County requirements.
COST ESTIMATES
Cost estimates have been prepared for the alternates and the first phase of
construction for the recommended alternate. The estimates can be found in Appendix
A of this study.
Alternate 1 is estimated to cost $12,900,000. This includes sub-mains for the service
area south of Freeway 58.
Alternate 2 is estimated to cost $15,100,000. This also includes sub-mains for the
service area south of Freeway 58.
Alternate 1 first phase facilities estimated cost is $11,900,000. Alternate 1A (Alternate 1
with no KSA flows) is estimated to cost $11,500,000.
The 18” Bypass line for AD93-1 (Alternate 3) augmentation estimated cost is
$2,850,000.
CONCLUSIONS AND RECOMMENDATIONS
The recommended Master Plan is included in this study as Plates 1 and 2 in the
drawing jacket. The Master Plan includes Alternate 1 as the recommended sewer trunk
line from Vineland Road at Edison Highway to WWTP#2. Alternate 1 overall will impact
less residences, utilities and roadways and will cost approximately $2.2 million dollars
less than Alternate 2.
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Preliminary construction plans for the sewer trunk line have been prepared as a part of
this study and are included as Appendix B. It is recommended that these plans be
adopted as the recommended design and that the Master Plan be followed for good
orderly development in the expanding Northeast area of Bakersfield.
Respectfully Submitted,
Richard Meyer, RCE 28104
Meyer Civil Engineering, Inc.
City of Bakersfield - Northeast Sewer Study
Meyer Civil Engineering, Inc. Page B-1
APPENDIX B
PRELIMINARY PLANS