Section 9
Capital Improvement Program
The City of Richland maintains a Capital Improvement Program (CIP) to ensure and/or
improve the level of service for the City's sewer system customers over the next 20 years
while accommodating future growth. Funding associated with this CIP is discussed in
Section 10.
Richland's CIP has several objectives: categonzmg sewer utility needs, evaluating
alternatives that are cost-effective and operationally sound, and prioritizing the
recommended improvements.
The CIP includes major improvements for the overall sewer system as well as some
specific areas but does not include all site-specific improvements that may be necessary
to serve individual developments. Specific CIP projects and their associated costs are
summarized in Table 9-1, located at the end of this section.
Estimating Costs of Improvements
Order-of-magnitude cost estimates have been developed for each of the recommended
improvements based on 2003 dollars. The accuracy of these cost estimates can be
expected to vary from 30 percent less to 50 percent more than the actual costs. Because
all costs (including those shown in Table 9-1) are provided in 2003 dollars, future cost
budgets must be adjusted to account for the effects of inflation and changing construction
market conditions at the anticipated time of design and construction.
The cost estimates for CIP projects include the following allowances:
•
30 percent contingency for unknowns.
•
8.3 percent sales tax.
•
25 percent allowance for engineering, legal, and construction administration costs.
The costs are based on recent actual costs for similar improvements. The final costs of
each project will depend on actual labor and material costs, site conditions, productivity,
competitive market conditions, final project scope, implementation schedule, and other
variable factors. Before final project budgets are developed, new estimates should be
made using the most up-to-date, project-specific cost infonnation available.
Gravity Sewers
Gravity sewer improvements shown in Table 9-1 include those improvements necessary
to provide capacity for plarmed growth, and rehabilitation and replacement projects to
ensure continued service for existing customers.
Most of the gravity sewer
improvements are needed to provide for plarmed growth.
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Sewer Main Lining and Replacement - Leak Program. The City has an ongoing
sewer lining and/or sewer replacement program for older, leaking sewers. The majority
of these sewers are located at the back side of lots. Lining the existing sewers has the
lowest impact and best value to the residents. The City plans to spend approximately $1
million per year through 2022 for the Sewer Main Lining and Replacement Program.
Based on recent contracts, it costs approximately $501 ft. to line existing mains. This
would allow for lining of 20,000 feet per year or 200,000 feet by the end of2013. There
are currently approximately 500,000 feet of deteriorating, aging 8-inch concrete lines. It
might be desirable to seek additional funding sources in order to accelerate the Sewer
Main Lining and Replacement Program.
Leslie Road - Badger 27-inch Trunk Sewer. This project will provide sewer service to
areas along the south side of Badger Mountain to the 1-82 interchange and areas south of
the existing Broadmoor lift station by installing 6400 feet of 27-inch sewer main. Some
portions of this area are within current City limits while other portions are currently being
considered for addition into the City'S Urban Growth Area boundary. The proposed
trunk sewer would empty into the proposed Bellerive Lift Station and then routed to a
portion of the collection system capable of handling the high volumes. Construction of
this trunk will enable the elimination of the Willowbrook Heights lift station.
Previous comprehensive sewer plans proposed constructing a trunk sewer along the West
Amon wasteway near Broadmoor Street to provide gravity sewer service for the abovementioned area. This alignment is no longer considered feasible due to existing
development and the difficulty in obtaining permits to construct a sanitary sewer through
the area.
During consideration of the alternatives it was determined the Broadmoor trunk sewer at
1.0 mgd did not have adequate capacity to serve the future flows from the full
development of the area described above. Other lines in the area were also inadequate to
handle the future flows as the development of other portions of the City place a higher
load on the existing system.
It is anticipated this project will be driven by development needs for the area, and should
be constructed as the area develops. The estimated cost of this project, $2.2 million, is
based on value of $340/ft due to the size, depth and proximity to the wasteway.
Upper North Interceptor Capacity Improvements. The Upper North interceptor
(UN!) was constructed to divert flow from sections of the collection system routed
through the North Richland well field . The line through the well field is laid at a flat
slope and has a limited capacity. After construction of the upper north interceptor two
connections emptying into the Upper North interceptor become obstructed and
surcharged when there were high flows in the interceptor. This limits the amount of flow
able to be diverted from the well field line. Improvements at these connections will
increase the capacity of the Upper North interceptor allowing more flow to be diverted
from the well field as well as being able to handle higher volume from the north portion
of the City.
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This project will prevent the connections from surcharging and allow higher flows to be
diverted from the well field line. The project is scheduled for 2007. If higher loads on
the UNI are experienced sooner, the timetable may need to be accelerated.
Logston Boulevard 21-inch Sewer Trunk. The City of Richland owns much of the
6,000-acre Horn Rapids triangle in the northwest portion of the City and is aggressively
promoting its development. Logston Boulevard trunk is 8,500 feet of21-inch line and is
the next trunk needed to provide service to this area. The force main from the
Framatome lift station currently empties into the Upper North interceptor. The lift station
force main will be rerouted into the Logston line. It is anticipated the project will cost
$1.913 million or $225 per foot. Groundwater. will have an impact on this project and
will increase the costs. This should be offset somewhat by the absence of required
roadway improvements. Current demands on development of the area suggest the project
will not be needed until 2010.
East Amon Wasteway. Sewage from drainage basin R will be routed to the proposed
Bellerive pump station. This area is zoned as low-density residential. It is anticipated the
East Amon wasteway trunk sewer will be constructed by developers to provide service as
growth in this area occurs. The proposed trunk will consist of 8-inch and lQ-inch
diameter pipe.
Duportail Sewer Relocation. The existing sewer line in the Duportail right-of-way in
the City View area will need to be re-routed to match the final alignment of the proposed
roadway. This project is scheduled for completion in 2004 and is estimated to cost
$100,000.
SR 240 West Extension. There are currently four phases proposed for this project. This
project is driven solely by development demands. It is anticipated this line will serve the
remainder of the Horn Rapids triangle.
Phase one of the project will construct 2700 feet of 18-inch sewer from the Horn Rapids
housing development along SR 240. Estimated cost for this portion is $540,000 or $2001
ft. and is scheduled for 2011.
Phase two of the project will construct 4900 feet of 18-inch sewer from the Horn end of
phase one along SR 240 to Twin Bridges road. Estimated cost for this portion is
$980,000 or $2001 ft. and is scheduled for 2013.
Phase three ofthe project will construct 7200 feet of 18-inch sewer from the end of phase
two along SR 240. Estimated cost for this portion is $1.4 million or $2001 ft. and is
scheduled for 2015.
Phase four of the project will construct 5700 feet of 12-inch sewer from the end of phase
three along SR 240 and is the final leg of the project. Estimated cost for this portion is
$1.05 million or $1851 ft. and is scheduled for 2017
Battelle 12-inch Sewer Extension. This project is intended to extend the 12-inch line in
Battelle Boulevard for 3000 feet west of Kingsgate. The project is estimated at $450,000
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or $1501 ft. Construction of this project will allow the use of a larger portion of the Horn
Rapids Triangle and increase the marketability of the City to potential industries and is
scheduled for 2009.
Lift Stations and Force Mains
The City's ClP includes three projects intended to upgrade or replace the system
pumping facilities.
Broadmoor Lift Station Replacement. The existing Broadmoor lift station is in a poor
location and has been in need of repair for some time. This project will replace the lift
station with a new one in a more accessible location. It will continue to serve the same
area as the existing lift station. Previous plans called for diverting the flows from the
Leslie Road-Badger trunk into this lift station. However, current development of this area
makes this unfeasible. Diverting the flows currently being handled by the Broadmoor lift
station into the proposed Bellerive lift station is not cost effective due to the configuration
of the collection system. Estimated cost for this project is $400,000 and is scheduled to
begin this year and completed in 2004.
Bellerive Lift Station and Force Mains. The proposed Bellerive lift station will receive
the flows from the Leslie Road-Badger trunk and pump them to a location in the existing
sewer system able to handle the expected loading. It is most cost effective to construct
this lift station in phases. lnitiall y there will not be a high demand for lift station
capacity, so the first phase will be sized to serve an area within the City limits limited by
the capacity of the downstream gravity sewer. The cost for the first phase of the lift
station is estimated at $200,000. The 6000 feet of 6-inch force main is scheduled for
construction in 2004, in order to be in place before Bellerive Drive is reconstructed. The
cost of the force main is estimated at $240,000 or $401 ft. The lift station is scheduled for
construction in 2008. Development of the area may require earlier construction.
As development progresses, demand for a larger capacity lift station will bring about the
need for phase two of the project. An upgrade to the lift station will bring it to ultimate
capacity of 4. 7 MGD and will cost an estimated amount of $700,000. It will be necessary
to construct 10,700 feet of 15-inch force main along Leslie Road to a point in the gravity
system able to handle the flows from the larger lift station. Costs for this second phase of
the force main are estimated at $1.2 million or $1121 ft.
Lift Station Rehabilitation. Due to age it will be necessary to replace or repair existing
lift stations from time to time. Operation and maintenance funds can only make repairs
to the stations. Ultimately they will wear out and require replacement. Funding these
projects at $200,000 per lift station allows the replacement of existing lift stations on the
order of one every five years as needed.
Battelle Force Main Replacement. The existing Battelle force main is an 8-inch
asbestos cement line, which conveys flows from the Framatome lift station to the gravity
collection system at the north part of town. Construction of an extension of Battelle
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Boulevard will require the existing force main be lowered. It is most cost effective to
replace the force main before the new road is constructed, along roughly the same
alignment. The force main will require a new boring of the existing railroad in order to
connect to the collection system. The cost estimate is $75,000.
Wastewater Treatment Facility
The Richland Wastewater Treatment Facility Capacity Assessment Report by Brown and
Caldwell, dated June 2003, identified a number of plant improvements to enhance overall
plant operability and flexibility, and reduce operating costs. The overall plant capacity
limit of 11.4 million gallons per day is not expected to be reached within the next 20
years. This presumes the following projects are done. The schedule of the wastewater
treatment facility improvements is derived from plant flow proj ections discussed in
Chapter 8 of the 2003 report.
Conversion to Anoxic Selector. The current maximum plant capacity is estimated to be
about 8.8 mgd due to solids loading limitations to the secondary clarifiers, assuming one
aeration basin and two secondary clarifiers are in service. By retrofitting the existing
aeration basin to an anoxic selector configuration, sludge settleability is expected to
improve, because the selector will select against filamentous organisms. This
improvement alone will increase the plant capacity to about 9.1 mgd, when the next
constraint relating to the digester capacity occurs. Addition of an anoxic selector will
reduce the proliferation of foam causing organisms and, because the existing aerators will
be replaced with a more efficient fine pore aeration system, aeration capacity will be
increased. With the aeration basins retrofitted for Anoxic Selector configuration, a lower
operating solids retention time (SRT) is recommended to reduce aeration requirements
and to allow more rapid removal of any foam-causing organisms. Currently, the
secondary system is typically operated at an SRT of about 10 to 15 days. It is expected
the SRT could be reduced to 5 days without any negative impact on effluent quality.
This improvement may also include replacement of the existing aeration blowers with
new blowers. Thus, the blower air supply limitation predicted to occur at the higher plant
flow of about 13 mgd would also be eliminated. To ensure positive elimination of
filamentous organisms from the system, equipment to remove surface foam is also
included in this improvement.
Estimated cost for this project is $1,788,000. Design began in 2003 with construction to
follow in 2004.
Digested Sludge Storage Tank. By sending both primary sludge and thickened waste
activated sludge to the digesters and operating them in series, with the second digester
serving as a sludge storage tank, the digester capacity will limit peak month plant flow to
about 9.1 mgd. This bottleneck can be removed by operating the digesters in parallel.
However, there will then be no backup digester and no sludge storage capability. A new
digested sludge storage tank will be needed.
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Improvements to the digesters proposed in the Solids Process Engineering Services Final
Report dated September 2001, included installing submerged fixed covers on the
digesters primarily to mitigate digester foaming. Implementation of the proposed anoxic
selector is expected to reduce the proliferation of filamentous organisms in the system,
thus eliminating the need for submerged fixed covers. Future digester improvements will
add mixing and sludge withdrawal
Estimated cost for this project is $1,125,000, with design to begin
construction in 2015.
III
2014 and
UV Disinfection Facility. Changes in the Washington State Department of Ecology
regulations are expected to require the use of chlorine as a disinfectant be discontinued.
In the place of chlorine disinfection, ultraviolet (UV) light will be used to treat
wastewater effluent. Construction of the UV facility is estimated to cost $1.5 million and
would be designed and constructed as new regulations require. Presently this is expected
in 2012.
PLC Control Replacement Project. The existing Westinghouse PC-700 programmable
logic controllers (PLCs) control the plant processes and instrumentation at the WWTF
and employ 20-year old technology. Westinghouse no longer directly supports this
equipment, which leaves the City increasingly vulnerable for proper operation and
maintenance. All support for this equipment has been sold to third-party companies that
are not as familiar with the equipment and who mayor may not continue to support
Westinghouse equipment. The PLC replacement project will require all the labor, wiring,
and parts necessary to replace the PLCs in Building 6 at the WWTF. The estimated cost
for this project is $516,000.
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