HomeMy WebLinkAbout02/17/2004, C2 - PILOT PLANT STUDY FOR NEW SEDIMENTATION PROCESS AT THE CITY'S WATER TREATMENT PLANT I -
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CITY OF SAN LUIS O B I S P O
FROM: John Moss, Utilities Direct0
Prepared By: GaryHenders , Water Division Manager ,v.%4
SUBJECT: PILOT PLANT STUDY FOR NEW SEDIMENTATION PROCESS AT
THE CITY'S WATER TREATMENT PLANT
CAO RECOMMENDATION
1. Approve the Amendment No. 2 to the contract with Black and Veatch to conduct the pilot
plant study of the Actiflo process at the Water Treatment Plant for an additional
compensation of$76,185.
2. Authorize the transfer of$104,785 from Water Fund Working Capital to the project account
to fund the contract amendment and additional associated costs.
DISCUSSION
Background
On November 18, 2003, the City Council considered the recommendations in the Preliminary
Design Report for the Water Treatment Plant Master Plan Improvements. The Council approved
the recommended improvements at the plant to increase operational flexibility and enhance
treatment capabilities. A component of the approved scope of services with Black and Veatch
was an evaluation of a new sedimentation process called"Actiflo".
The City currently has a limitation at our water treatment plant based on the current
sedimentation process. The capacity of the existing sedimentation basin is rated at 8.0 million
gallons per day (mgd) while the total plant capacity is 16 mgd. To achieve the total 16.0 mgd
capacity, water from Whale Rock by-passes the sedimentation process and goes directly to the
filters. This process is referred to as "direct filtration" and is only allowed for high quality water
with low turbidities such as the water we receive from Whale Rock.
As part of their Phase II services, Black and Veatch have completed the `Ballasted Flocculation
Evaluation" report for the water treatment plant. The evaluation included an analysis of utilizing
either an additional conventional sedimentation basin or installation of the Actiflo ballasted
flocculation process within the existing flocculation structures. The evaluation recommends
proceeding with a pilot plant study to further evaluate the potential cost savings and water quality
improvements that could be achieved by using the Actiflo ballasted flocculation technology. The
pilot plant study will involve leasing a small package plant from U.S. Filter for five weeks to
allow actual onsite treatment of a small side stream of raw water from Salinas and Whale Rock.
The study will evaluate improved removal rates of constituents from the water and identify I
Council Agenda Report—Water Treatment Plant Pilot Study
Page 2
additional cost saving which may be achieved through reduced chemical or ozone dosages as a
result of the high removal efficiencies associated with the Actiflo process.
The Actiflo process may significantly increase the removal rate of total organic carbon. The
federal regulations require a certain percentage removal rate. The current water treatment plant
meets the removal requirements but not by a large amount. Enhanced removal rates would
provide a larger buffer to insure regulations are met. The Actiflo process would also likely
reduce formation of disinfection byproducts which have seen more stringent regulations over the
past decade.
Summary
The `Ballasted Flocculation Evaluation" prepared by Black and Veatch recommends proceeding
with a pilot plant study for the Actiflo process. The five week study will evaluate the
effectiveness of the Actiflo process in treating raw water from Whale Rock and Salinas
Reservoirs.
FISCAL IMPACT
Amendment No. 2 to the contract' with Black and Veatch will increase the maximum
compensation by $76,185. This amount includes the cost for the rental of the Actiflo pilot unit
and engineering support but excludes site preparation, power and piping connections, and water
quality testing fees. The additional City expenses are estimated to cost approximately $28,600.
The total cost for the pilot study is $104,785 which will need to be appropriated from Water
Fund Working Capital. There is sufficient available working capital in the Water Fund to fund
the contract and still meet minimum reserve policy levels.
ATTACHMENT:
1. Amendment No. 2 to Agreement for Consultant Services with Black and Veatch
* Full copy of the Water Treatment Plant Improvement Project Ballasted Flocculation
Evaluation Report is in the Council reading file.
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AMENDMENT 2 TO AGREEMEN r ATTACHMENT I
THIS AMENDMENT TO AGREEMENT is made and entered in the City of San Luis Obispo on this
day of by and between the CITY OF SAN LUIS.OBISPO,a municipal
corporation,hereinafter referred to as City,and BLACK AND VEATCH,hereinafter referred to as Consultant.
WITNESSETH:
WHEREAS, on February 26, 2003 the City entered into an Agreement with Consultant for preparation of
the preliminary design report for the Water Treatment Improvement Project;and
WHEREAS,on November 24,2003 the City entered into an Agreement with Consultant for preparation of
the final plans and specifications for the Water Treatment Improvement Project;and
WHEREAS, the scope of work in Exhibit A of Amendment 1 included an optional Subtask (820) for a
Ballasted Flocculation Pilot Study which the City desires to proceed with following the evaluation provided under
Amendment 1 for this potential water treatment process improvement.
NOW THEREFORE, in consideration of their mutual promises, obligations and covenants hereinafter
contained,the parties hereto agree as follows:
1. For providing the services as specified in Exhibit A of Amendment 1 under Subtask 820,City will
pay and Consultant shall receive additional compensation of$76,185 for a total sum not to exceed$826,800.
2. All other terms and conditions of the Agreement remain in full force and effect.
IN WITNESS WHEREOF, the parties hereto have caused this instrument to be executed the day and year
first written above.
ATTEST: CITY OF SAN LUIS OBISPO
By.
Lee Price,City Clerk David F.Romero,Mayor
APPROVED AS TO FORM: CONSULTANT
By:
Jona well,City Attorney