CR 09-030 Approve Facility Plan for Lift Station No. 4G 1TY OP
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April 7, 2009 NOPKINS Council Report 2009 -030
Approve Facility Plan for Lift Station No. 4
Proposed Action
Staff recommends adoption of the following motion: Approve Resolution 2009 -016
Resolution Approving Facility Plan for Lift Station No. 4.
Overview
The 2008 Comprehensive Utility Plan identifies the rehabilitation of Lift Station No 4 on
Meadowbrook Drive as a necessary improvement needed within the next few years.
With the availability of federal stimulus dollars for water and wastewater projects, it is
prudent to apply to this funding source. Approval of the attached facility plan is a
necessary component of the application process.
The facility plan recommends rehabilitation of this lift station with new pumps, cover and
hatch, structural lining, valve vault, and appurtenances. The estimate cost of the
improvements is $156,652.
Funding will be from the State Revolving Fund which provides assistance for water
pollution control projects. In Minnesota, the fund provides low interest loans and grants
for these projects. Given the additional resources available because of the federal
stimulus package, lower interest rates or higher grant amounts are anticipated. The exact
mix will not be known until the funding is awarded. A decision about proceeding with
the project will be made at that time.
Supporting Information
• Facility Plan Text
• Resolution 2009 -016
e olm R. Bradford, P.E.
City Engineer
Financial Impact: $00 Budgeted: Y/N N/A Source: Related Documents (CIP, ERP, etc.): 2008
Comp Utility Plan Notes:
LIFT STATION NO.4 REHABILITATION FACILITY PLAN
HOPKINS, MINNESOTA
MARCH 2009
T16.100824
I hereby certify that this plan, specification or report was prepared by me or under my direct supervision, and that I
am a duly Licensed Professional Engineer under the laws of the State of Minnesota.
Signature: X �a
Typed or Printed Name: Marcus A. Thomas
Date '7 67 (0
Reg. No. 26499
BOLTON & MENK, INC.
CONSULTING ENGINEERS & LAND SURVEYORS
TABLE OF CONTENTS
Section Page
1. General ............................................................. ............................... 1
2. Existing Conditions .......................................... ............................... 1
3. Proposed Improvements .................................. ............................... 2
4. Recommendations, Financing, and Implementation ....................... 3
LIST OF APPENDICES
Appendix Page
A. Estimated Cost of Improvements ..................... ............................... 5
B . Figures ............................................................. ............................... 7
C. Draft EIW ........................................................ ............................... 10
D. Information Presented at the Public Hearing ... ............................... 18
E. Council Resolution .......................................... ............................... 26
City of Hopkins, Minnesota — T16.100824
Lift Station No. 4 Rehabilitation Facility Plan
Page
Prepared by Bolton & Menk, Inc.
1. General
This report is intended to provide the City of Hopkins, Minnesota with necessary information
regarding the City's Lift Station No. 4. The purpose of this report is to assist the City in
determining priorities as well as plan, fund, and construct appropriate improvements for the
lift station.
2. Existing Conditions
The City of Hopkins' Lift Station No. 4 is located in a cul -de -sac on Meadowbrook Road
south of Goodrich Street. The lift station serves 160 homes, Meadowbrook Golf Course, and
St. Johns Church & School. The area is fully developed and there are no plans for future
sewer extensions, land use changes, or other development. The lift station is located such that
it is operable during a 25 -year and 100 -year flood event.
Effluent from this facility flows north to Excelsior Boulevard where it enters a gravity
sanitary sewer main. The City sewer system then conveys these flows to the Metropolitan
Council's sewer system. Ultimately, the wastewater generated by the study area is treated at
Metropolitan Council's Metropolitan Wastewater Treatment Plant.
Lift Station No. 4 has been in place since 1954 and the current pumps are approaching the
end of their useful life spans. A rehabilitation project was undertaken in 1991 when the
pumps and controls were replaced. During this rehabilitation the lift station was converted
from a wet well -dry well system to the current submersible pump system. The life
expectancy of the current pumps installed is assumed to be 15 to 20 years, as is typical with
submersible pumps for lift stations.
Lift Station No. 4 is a duplex station, implying that it utilizes two pumps alternating between
cycles to transfer flow through the forcemain. Pump down tests found the average pumping
rate for lift station Pump No. 1 to be 352 gpm. The average cycle time for Pump No. 1 was
found to be 2.3 minutes. Similarly, the average pumping rate and average cycle time for
Pump No. 2 in Lift Station No. 4 were 346 gpm and 2.1 minutes, respectively. These pumps
were found to provide an average flow velocity between 3.9 and 4.0 fps in the effluent six-
inch diameter forcemain.
City of Hopkins, Minnesota — T16.100824
Lift Station No. 4 Rehabilitation Facility Plan
Page 1
Prepared by Bolton & Menk, Inc.
During a survey of the City lift stations in spring of 2008, Lift Station No. 4 was documented
exhibited signs of infiltration in a joint of the structure. The top hatch of the structure also
appeared to be allowing inflow from the street during rain events. The hatch also does not
appear to meet H2O service loading criteria for traffic as is recommended by the American
Association of State Highway Transportation Officials (AASHTO). Given the location of the
lift station, the hatch should be required to meet this recommendation. In addition to these
problems, the cable supports and chain hooks in the lift station are badly rusted and must be
replaced.
3. Proposed Improvements
Lift Station No. 4 is a critical piece of infrastructure in the City of Hopkins. The pumps
within the lift station are approaching their life expectancy. As the pumps approach their life
expectancy age, it can be assumed the pumps are less reliable. The pump cycle time for each
pump was determined to be just over two minutes. Current engineering guidelines suggest
pump cycle times should be over three minutes for each pump in a duplex station. A higher
cycle time allows the lift station to be more efficient and therefore have lower operation
costs.
Failure of these pumps will result in sewer backups into residential properties. To prevent
these failures from occurring, replacement of these pumps or an alternative solution is
desirable. Two alternatives for correcting the existing infiltration problem in the lift station
were considered; full replacement of the lift station and rehabilitation of the existing facility.
Both alternatives could solve the problems Lift Station No. 4 is facing. The second
alternative, rehabilitation, could do this with lining the interior of the structure with a sulfate
resistant cement to eliminate infiltration. The top slab and hatch could also be easily
replaced. Both alternatives would have the same operation and maintenance costs, therefore,
rehabilitation of the existing lift station would be less expensive as the initial costs would
clearly be less expensive.
The rehabilitation of Lift Station No. 4 will provide new pumps, interior structure lining, a
valve vault, new controls, a new watertight hatch, new chain hooks, and new cable supports.
City of Hopkins, Minnesota — T16.100824 Page 2
Lift Station No. 4 Rehabilitation Facility Plan Prepared by Bolton & Menk, Inc.
The recommended pumps would be equivalent replacements to the existing pair. Two -10
horsepower pumps are proposed for installation. The pumps should be selected and installed
such that the cycle time is greater than three minutes unless this increased cycle time could
result in backing up the influent gravity sewer main. A new top slab with a watertight hatch
capable of meeting AASHTO H -20 loadings built in is proposed to replace the old top slab.
The existing wet well of the lift station is also proposed to be sand blasted, grouted, and lined
with an epoxy based resin to minimize or eliminate infiltration into the structure.
4. Recommendations, Financing, and Implementation
In the previous sections the existing lift station and proposed improvements were analyzed in
terms of condition and service needs. It was determined that the rehabilitation of Lift Station
No. 4 provides a more cost - effective long term solution than replacement of the lift station. It
was also determined that the lift station needs improvements if it is to be reliable and relieve
the concern regarding potential backups. Furthermore, it was also determined that the
existing lift station is currently inefficient in its pumping and improvements can be made to
reduce operational costs. Based on these conditions, it is recommended the City of Hopkins
construct the previously discussed proposed improvements as funding becomes available.
The estimated total cost of the proposed improvements is $156,652.00. A more specific
breakdown of the estimated costs for each item is provided in the appendix. Financing
options include applying for a State Revolving Fund load through the Public Facilities
Authority, the City Sewer Fund, selling bonds, or assessing to benefitting properties.
A likely source of funding for this project is the State Revolving Fund. The State Revolving
Fund was created under a provision from the Federal Clean Water Act to provide financial
assistance for water pollution control projects. Minnesota's revolving loan program provides
loans to municipalities for planning, design, and construction of wastewater facilities. The
Department of Trade and Economic Development's Public Facilities Authority administrates
the loan application and distribution of funds. The loans are available for a twenty -year
period. Due to the recent economic stimulus programs instituted by the Federal government,
the fund has an increased quantity of loan dollars to distribute. This project may be eligible
for funding as it may meet the minimum criteria after it is lowered by the stimulus.
City of Hopkins, Minnesota — T16.100824 Page 3
Lift Station No. 4 Rehabilitation Facility Plan Prepared by Bolton & Menk, Inc.
A schedule for implementation of these improvements is shown below. The schedule
assumes funding is available through the Revolving Loan Fund in 2009.
City of Hopkins, Minnesota — T16.100824 Page 4
Lift Station No. 4 Rehabilitation Facility Plan Prepared by Bolton & Menk, Inc.
Item
Date
1.
Approve Facility Plan and Submit to MPCA
March 2009
2.
Receive Confirmation of Funding from MPCA
April 2009
3.
Prepare Plans and Specifications
April 2009
4.
Authorize Bids
May 2009
5.
Award Project
June 2009
6.
Construction
June — July 2009
City of Hopkins, Minnesota — T16.100824 Page 4
Lift Station No. 4 Rehabilitation Facility Plan Prepared by Bolton & Menk, Inc.
Appendix A
Estimated Cost of Improvements
PRELIMINARY ENGINEER'S ESTIMATE
LIFT STATION NO.4 REHABILITATION
CITY OF HOPKINS, MINNESOTA
BMI PROJECT NO. T16.100824
F:\ Civil \HOPK \T16100824\LS 4\ExcelgLS4 Prelim Estimate.xls)Project Cost Est.
February 19, 2009
ITEM
NO.
ITEM
ESTIMATE
BID
QUANTITY
UNIT
UNIT
PRICE
TOTAL
1
MOBILIZATION
1
LS
$3
$3,300.00
2
REMOVE BITUMINOUS PAVEMENT
260
SQ YD
$6.00
$1,560.00
3
COMMON EXCAVATION EV P
60
CU YD
$22.00
$1,320.00
4
SUBGRADE EXCAVATION (EV)
40
CU YD
$25.00
$1,000.00
5
SELECT GRANULAR BORROW CV
40
CU YD
$30.00
$1
6
CLASS V AGGREGATE BASE C
55
CU YD
$30.00
$1
7
1.5' BITUMINOUS WEAR COURSE
22
TON
$90.00
$1,980.00
8
2.5' BITUMINOUS NON -WEAR COURSE
39
TON
$80.00
$3,120.00
9
BITUMINOUS MATERIAL FOR TACK COAT
16
GAL
$3.25
$52.00
10
LAWN TYPE SOD
100
SQ YD
$5.50
$550.00
11
TOPSOIL BORROW CV
15
CU YD
$35.00
$525.00
12
SILT FENCE
150
LIN FT
$2.50
$375.00
13
TRAFFIC CONTROL
1
LS
$300.00
$300.00
14
3" BITUMINOUS DRIVEWAY PAVEMENT
25
SQ YD
$60.00
$1
15
REHABILITATE LIFT STATION
1
LS
$95,500.00
$95,500.00
SUBTOTAL
$113,932.00
CONTINGENCIES 10%
$11,390.00
SUBTOTAL CONSTRUCTION COSTS
$125,322.00
ENGINEERING & ADMINISTRATION 25%
$31,330.00
TOTAL
$156,652.00
CITY OF HOPKINS
HENNEPIN COUNTY, MINNESOTA
RESOLUTION NO. 2009 -016
RESOLUTION APPROVING FACILTY PLAN FOR LIFT STATION NO. 4
WHEREAS, the City of Hopkins completed a comprehensive utility plan in 2008, and
WHEREAS, the utility plan recommends rehabilitation of this lift station, and
WHEREAS, the use of MN State Revolving Fund financing requires the approval of a
facility plan and that such plan has been completed and reviewed by the public and the
City Council,
NOW, THEREFORE, BE IT RESOLVED, by the City Council of the City of Hopkins,
Minnesota:
1. The City of Hopkins approves the facility plan for Lift Station No. 4 Rehabilitation
dated March 2009.
Adopted by the City Council of the City of Hopkins this 7 day of April, 2009.
In
ATTEST:
Eugene J. Maxwell, Mayor
Terry Obermaier, City Clerk