HomeMy WebLinkAbout10 TETRA TECH AGMNT 12-5-05
AGENDA REPORT
Agenda Item
Reviewed:
Finance Director
~
l!
City Manager
MEETING DATE:
DECEMBER 5, 2005
TO:
WilLIAM A. HUSTON, CITY MANAGER
FROM:
PUBLIC WORKS DEPARTMENTIWATER SERVICES DIVISION
SUBJECT:
APPROVAL OF AMENDMENT NO.1 TO CONSULTANT SERVICES
AGREEMENT WITH TETRA TECH, INC. FOR RAWLINGS RESERVOIR
REPAIR AND REPLACEMENT PROJECT (CIP NO. 6136)
SUMMARY
Approval of Amendment No.1 to Consultant Services Agreement with Tetra Tech, Inc. is for
additional engineering services for the Rawlings Reservoir Repair and Replacement Project (CIP No.
6136). A preliminary design investigation along with geotechnical studies coordinated by Tetra Tech,
Inc., has revealed several significant unforeseen project site conditions that will necessitate
additional engineering design work. The services will include modification of previous reservoir
design alternatives, engineering for a retaining wall investigation/design (including consultation with
a specialist for temporary vertical wall shoring/design/ construction), designing a drain line, and
preparation of legal descriptions and exhibits.
RECOMMENDATION
It is recommended that the City Council approve the change order in the amount of $166,519 for the
first amendment to the Consultant Services Agreement between Tetra Tech, Inc. and the City for
additional engineering design services for the Rawlings Reservoir Repair and Replacement Project
(CIP No. 6136) and authorize the City Manager and the Director of Public Works to execute the
amended Consultant Services Agreement on behalf of the City, subject to City Attorney approval.
FISCAL IMPACT
The City's Capital Improvement Program Budget for Fiscal Year 2005-2006 provides $1,058,515 for
this project (CIP No. 6136). The total cost for the proposed additional engineering services is
$166,519. The proposed adjustment will increase the existing contract amount of $277,000 to
$443,519.
BACKGROUND
The City originally entered into a Consultant Services Agreement on November 15, 2004 with Tetra
Tech, Inc. for engineering design and geotechnical services for the replacement of the Rawlings
Reservoir. In March 2005, the City received from Tetra Tech preliminary demolition plans for the
existing reservoir, a preliminary memorandum outlining alternative reservoir concepts, and a
geotechnical report. An existing retaining wall on the north side of the project site was found to be
monolithically part of the existing reservoir wall footing. This finding warranted the inclusion of a new
retaining wall to buttress the existing wall. This activity would affect the phasing and timing of the
demolition contract. Tetra Tech also advised the City of the need for a new drain line on Foothill
Boulevard to carry drain flow and potential overflow from the new reservoirs to the County storm drain
system.
Approval of Amendment No.1 to Consultant Services Agreement with Tetra Tech, Inc. for Rawlings
Reservoir Repair and Replacement Project (CIP No. 6136)
December 5, 2005
Page 2
In May 2005, Tetra Tech issued a memorandum summarizing their cost estimates for the new retaining
wall. Additionally, it was recommended that the City consider further shoring to address the retaining
wall issue along the northerly project boundary. Tetra Tech also informed the City about the presence of
a geologic shear zone which affected the reservoir foundation design. This finding changed the scope
and direction of the overall project design strategy.
In July 2005, Tetra Tech and the City met to discuss design alternatives for the proposed reservoirs.
Based on Tetra Tech's analysis, the City opted to reduce the proposed sizing of the two new
replacement reservoirs from 3.5 million gallon (MG) to 3.0 MG.
In August 2005, Tetra Tech prepared a proposal at the City's request which identified the following
tasks required to complete the project design:
Property vacation documentation
Drain line design
Design modification/smaller tanks
Initial shoring investigation analysis
Additional shoring investigation and design
$ 8,000
$ 24,000
$ 23,675
$ 10,844
$100.000
Total: $166,519
The Rawlings Reservoir Repair and Replacement Project (CIP No. 6136) is a critical link in ensuring the
City's operational and emergency water storage requirements. The proposed contract amendment will
allow the project engineering design to be completed in a timely manner.
G~.~
Director of Public Works/City Engineer
~
. .
Attachments: Amendment No.1 Proposal for Additional Services, Exhibit "A",
TDS: FJA: VS: cog: Amendment No.1 Rawlings Reservoir.doc.
AMENDMENT NO.1
to
CONSULTANT SERVICES AGREEMENT
between
THE CITY OF TUSTIN
and
TETRA TECH INC.
for
PRELIMINARY ENGINEERING DESIGN/PROJECT REPORT/FINAL DESIGN,
LEGAL DESCRIPTIONS, AND SHORING INVESTIGATION AND DESIGN
The City of Tustin (herein "CITY") and Tetra Tech Inc., (herein "CONSULTANT")
entered into an Agreement on November 15, 2004 (herein "Agreement") for engineering
Services for the Rawlings Reservoir Repair and Replacement Project (CIP No. 6136,
herein "Project"). Effective , CITY and CONSULTANT wish
to enter into this Amendment No.1 as follows:
SECTION 1.
PURPOSE
CITY has directed CONSULTANT to prepare legal descriptions and exhibits for
property vacation and annexation, design a drain line, provide additional engineering
design as needed to modify the design concept for the two (2) 3.5 million gallon (MG)
reservoirs to two (2) 3.0 MG reservoirs, provide engineering services for a retaining wall
investigation and design, including consulting with a specialist for the temporary vertical
wall shoring/design/construction work at the Rawlings Reservoir site.
SECTION 2.
SCOPE OF CONSULTANT'S SERVICES
CONSULTANT agrees to furnish to CITY those services, which have been
included within the CONSULTANT's proposal, dated August 19, 2005, and included
herein as Exhibit "A".
SECTION 3.
TIME FOR COMPLETION
CONSULTANT agrees to endeavor to complete the proposed additional services
by July 30, 2006.
SECTION 4.
COMPENSATION
Compensation for the proposed services shall not exceed $166,519.00 as set
forth in Exhibit "A" and progress payments will be made as set forth in Section 4 of the
original agreement.
All other terms and conditions of the Agreement shall remain unchanged and in
full force and effect.
IN WITNESS WHEREOF, the parties hereto have caused this Amendment No.1
to be executed the date first above written.
By:
By:
By:
William A. Huston, City Manager
City of Tustin
Tim D. Serlet, Director of Public Works/City Engineer
City of Tustin
Steve Tedesco, Division Senior Vice President
Tetra Tech Inc.
1'11;1 TETRA TECH, INC.
August 19, 2005
Mr. Tim Serlet
Director of Public Works/City Engineer
City of Tustin
300 Centennial Way
Tustin, CA 92680
Reference:
Proposal for the Additional Services for the Rawlings Reservoir Project
Dear Mr. Serlet
As you laJow, there have been several changes identified in the Rawlings Reservoir Project, for
tasks that are beyond the original scope of services in our Consultant Services Agreement. Over the
last four montha, we have provided for your review and consideration four proposed change orders.
Due to the identification of some significant site geology issues, it was agreed that we should
address those geotechnical concerns before deciding how to proceed with the proposed change
orders.
As we indicated to you, we have been able to quantify the geotechnical issues and are
recommending that the project proceed forward. Accordingly, we are also requesting your
consideration for the four change orders, which we have combined herein for your review. They are
described as follows:
Proposal for the PreparaJion of Legal Descriptions and Exhibits for Property Vacation and
Annexation at the Rawlings Reservoir Site
As described in our memorandum to you titled "Rawlings Reservoir Property Line and Foothill
Boulevard Right-of-Way," dated December 16, 2004, it has become evident from our document
research for the project that there are ownership questions concerning the land between Foothill
Boulevard and the City-owned Rawlings site. The City requested a proposal from Tetra Tech to
assist the City in addressing these issues.
Tetra Tech proposes to provide the following Scope of Work:
1. Have a title report prepared for this site identifying all ownership rights and encumbrances.
2. Prepare legal descriptions and exhibits for property vacation. We are assuming that two
reviews of the legal descriptions and exhibits will be required, one by the City and one by the
County.
16241 Laguna Canyon Road. Suite 200, Irvine. CA 92618
TeI949.727.7099 Fax 949.727.7097
www.tetratech.com
1'1:] TETRA TECH, INC.
Mr. Tim Serlet
August 19, 2005
Page 2
3. Prepare legal descriptions and exhibits for annexation into the City of Tustin. We are assuming
that two reviews of the legal descriptions and exhibits will be required, one by the City and one
by the County.
4. Meet with the City to review the ownership of the identified areas in question.
We are assuming that all processing of the legal descriptions and exhibits and preparation of legal
documents for ownership transfer (vacation) and annexation will be perfoIIl1ed by the City.
The proposed fee for the Scope of Work as described would be $8,000, as detailed in the attached
staff-hour and fee table.
Proposal for the Design of a Drain Line for the Rawlings Reservoir Project
As you laJow, there is no storm drain pipeline in Foothill Boulevard in the vicinity of the Rawlings
Reservoir Project. The proposed drain line will provide a means to carry water from the overflow
pipelines, from the drain pipelines and from the underdrain pipelines from the planned new
Rawlings Reservoirs to County Flood Control facilities in Foothill Boulevard for discharge. The
need for this pipeline was not determined until after the design of the reservoir project was initiated
and was not part of that work scope.
Our preliminary investigation has identified County Flood Control facilities approximately 850 feet
easterly of the reservoir site, near Newport Avenue, and approximately 2800 feet westerly of the
site, near Hewes Avenue. While it would appear that the 850-foot pipeline is the better choice,
there is minimal fall available from the base of the reservoirs to the storm drain. Thus, pumps might
be required to lift the flow for discharge. The alternative is a 2800-foot pipeline, for which
considerably more fall is available. We propose to investigate both alternatives and present our
findings and recommendations to the City in a technical memorandum for consideration, as further
described below.
Tetra Tech proposes to provide the following Scope of Work for the design of the drain line:
1. Collect and review existing street and utility plans for the pipeline alignment alternatives.
2. Meet with County staff to discuss the requirements for connection to the flood control facilities
near Newport Avenue and those near Hewes Avenue.
3. Prepare a draft technical memorandum presenting and comparing the drain line alternatives,
westerly to Hewes Avenue and easterly to Newport Avenue. Provide cost estimates, with
findings and recommendations. Submit five copies of the draft memorandum to the City for
review.
4. Meet with City to review the technical memorandum. Incorporate changes and prepare fmal
technical memorandum. Proceed with design of drain pipeline alternative as directed by City.
I1\: I TETRA TECH,INC.
Mr. Tim Serlet
August 19, 2005
Page 3
5. Prepare topographic survey of the street aligument and a map at a scale of 1 "= 40 feet. The
proposed survey would be performed by Coast Survey, the same sub-consultant that prepared
the Rawlings site survey for us. .
6. Prepare Plan and Profile Sheets and Details Sheet for drain pipeline and for connection to
draInage structure, including design calculations and details to meet County requirements.
7. Prepare technical specifications and cost estimate, and submit design plans and design
calculations to County for review. It is assumed that plan check fee will be paid by City.
8. Incorporate design plans and specifications into the Rawlings Reservoir design package and
contract documents for bidding.
The work would be prepared by the same design team and within the same time schedule as for the
other elements of the Project. The proposed fee for the Scope of Work as described would be
$24,000, as detailed in the attached staff-hour and fee table.
Proposal for Additional Engineering Effort to Change Design from 3.5 MG Tanks to 3.0 MG
Tanks for Rawlings Reservoir Project
In our July 21 meeting, we discussed the need for shoring the Rawlings Reservoir Project site
during constrnction. Options were discussed to mitigate shoring and reduce its impact on adjoining
developed and undeveloped property. The option that was selected by the City to reduce shoring
and its impacts was to decrease the size of each of the two proposed tanks from 3.5 to 3.0 million
gallons capacity. The magnitude of the shoring issues did not become evident until after completion
of the secondary geotechnical investigation, which began after design of the new tanks was in
process.
The secondary geotechnical investigation of the site was initiated after the review of prior
geotechnical reports indicated that there was a shear zone in the bedrock under the existing reservoir
which could impact the design of the new tanks. When the secondary geotechnical investigation
was started, work was stopped on the design of the new reservoirs. However, work had progressed
on some of the desigu drawings to approximately the 50% completion level. Unfortunately, a
significant portion of that design effort will need to be redone because of the reduction in size of the
two reservoirs.
Note that the revision work will only affect the drawings already in progress. The work and
drawings impacted are noted in the proposed Scope of Work as follows:
1. Revise structural calculations
2. Revise the following plan sheets:
a. Final Grading Plan
b. Reservoir Cross-Sections (2 sheets)
c. Domestic Water Yard Piping
d. Drain, Sub-drain and Storm Drain Yard Piping Sheet
I "It: I TETRA TECH,INC.
Mr. Tim Serlet
August 19, 2005
Page 4
e. Reservoir Foundation Plan
f. Reservoir Wall Section
3. Prepare revisions to Construction Cost Estimate
The proposed fee for the Scope of Work as described is $23,675, as detailed in the attached staff-
hour and fee table.
Proposal for Additional Services to Analyze Retaining Wall Requirements for Rawlings Reservoir
Project
As you laJow, Tetra Tech staff has worked to identify and evaluate the critical elements of the site
geology and the need for retaining walls during construction of the two proposed Rawlings
Reservoirs. In our meeting on July 21, we discussed the findings of the geotechnical investigation
to date as well as retaining wall issues and options. At the conclusion of the meeting, Tetra Tech
was asked to provide a proposal for engineeriIÌg services for the retaining wall investigation and
design, including consulting with an engineer who specializes in temporary vertical wall shoring
desigu and construction.
As we discussed, this proposed work is not part of the original project scope, and thus would be
additional services. Part of this additional work includes that which was recently completed to
identify the issues and evaluate options. The Additional Work already completed includes:
1. Analyzed desigu of existing retaining wall.
2. Performed geotechnical investigation of wall backfill.
3. Revised calculations based on geotechnical data and reanalyzed wall.
4. Met with drilling contractors to determine feasibility of constructing new wall in space between
existing reservoir and existing retaining wall.
5. Prepared engineer's estimate of probable construction costs for new caisson wall.
6. Prepared two design memorandums regarding analysis of wall.
The cost for the shoring investigation already completed is $10,844.
Concerning the purpose and intent of this Additional Work, our goal is to do the necessary work up
front during the design phase, in order to mitigate the risk of slope movement during the
construction phase. We believe that this is prudent to protect the City. Our experience has been
that, even with the constrnction contract documents structured to place the risk on the construction
contractor, if there is slope movement and losses, the affected party will sue the contractor, the City,
the engineer and any others remotely associated with the project.
In our effort to address this issue, we had meetings with Butier Engineering, a construction
engineering firm that specializes in temporary vertical wall shoring desigu and construction. Based
111: I TE'TRA TECH, INC.
Mr. Tim Serlet
August 19, 2005
Page 5
on those meetings and our experience on other reservoir projects, our recommendations are
described following.
We propose to perform additional geotechnical investigations and to prepare preliminary desigu of
shoring. The geotechnical work is necessary to confirm the soil conditions on the west, north and
east sides of the project, where shoring will be more extensive. That geotechnical information will
be used for shoring design. Thereafter, the geotechnical information and the shoring desigu
information will be incorporated into the construction contract documents for bidders. With this
information at hand, it is anticipated that the bidders will be able to submit bids with greater
certainty of the conditions. With greater certainty and understanding, bidders foresee less risk and
are able to submit more competitive bids.
The proposed scope of Additional Work is summarized as follows:
1.
Perform geotechnical investigation including soil borings on the west, north and east sides of
the site, laboratory soil testing and report preparation.
Retain the services of Butier Engineering as a subconsultant to provide consulting services
during design, bidding and construction phases concerning shoring issues
Retain the services of a shoring wall designer to prepare preliminary shoring wall design plans
and specifications for shoring. Note that different shoring designs will be required for each
side of the site, due to the differing conditions.
Provide additional Tetra Tech services to manage and coordinate the above.
Prepare draft design memorandum summarizing alternatives and recommendations for shoring
and review with City. Incorporate City's review comments and prepare final design
memorandum.
Incorporate design criteria/requirements into the contract plans and specifications based on the
alternative selected by the City.
2.
3.
4.
5.
6.
Due to time constraints, we do not have firm fee estimates for each of the above tasks. However,
based on discussions with Butier Engineering and our understanding of the work required, we
propose the following fee estimates for the above task:
Geotechnical Investigation
Butier Engineering, subconsultant
Shoring desiguer as subconsultant
Tetra Tech consulting services
$40,000 to
10,000
25,000 to
5.000 to
$80,000 to
$50,000
10,000
30,000
10000
$100,000
Total
Given the fact that we do not have firm proposals for the above, we recommend that the City budget
$100,000 for this work. As is noted above, we firmly believe that this investment up ftont will be
beneficial to the City, by mitigating risk, by reducing potential for time delays and by producing
contract documents with information that can result in more competitive bids.
1"1\ I TETRA TECH, INC.
Mr. Tim Serle!
August 19,2005
Page 6
Summary
The proposed change order items described above are summarized as follows:
Property vacation documentation
Drain line desigu
Design change for smaller tanks
Shoring investigation completed
Proposed shoring investigation and desigu
Total
$ 8,000
24,000
23,675
10,844
100.000
$166,519
We are available to meet with you to discuss these proposed change order items in greater detail.
Please call if you have any questions or want to schedule a meeting.
;ze~
Tom Epperson, P.E.
Divisional Vice President
~
Project Manager
TLE/SRC:cg
J :\03291 \OO30\Le_~.OO6src.doc( 1 00)
Attachment
cnv OF TUSTIN
PmpDsed Change °'.0' to< RawlIngs ReservDI, Pn> act
Staff-Hour Fee EsUmo"
To"" >1 51 I I I , u,~.1 '6,995
$918 $52 $90ö1
$270 $0,570 $R 840
$929 $50 $979
$1024 $1,024
$971 $50 $1,021
lit ï -W- $7.1:~ SO
24 24 $7.146
4 0 0 22 $1,"> i2.3R2
2 2 1 5 $520 $200 $720
tšI-- 36 0 $0 $100 $100
40 33 5 111 U4.970 $9022 $24 000
26 50 2 02 $9.206 $9 ..
4 16 0 29 $3017 $3,017
4 4 16 2$ S2529 $2,529
2 4 0 15 $1 S47 SI,547
2 4 0 15 S1,547 $1,547
0 0 0 24 $1.592 92
4 0 0 20 $1,052 $1,052
4 4 9 $1105 SIlOS
54 9R 56 > 219 "'3675 SO 5>3675
16 51.940 S1940
i SI65 $5,000 $5,165
4 0 14 S1,670 $1670
2 5 $765 S" $R13
-Ž-T 2 2 S270 $270
4 2 0 S906 "..
10 10 16 2 45 5 57% $ 5 041 5 10,1144
8
0
4
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