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EXHIBIT B
The H.L. Turner Group Inc.

27 Locke Road Concord, NH 03301 : 603.228.1122 hiturner.com

May 11, 2022

Mr. Timothy Cummings

Director of Economic Development
City of Nashua

229 Main Street

Nashua, NH 03060

SUBJECT: Proposal for Engineering Design Services
Nashua Riverfront Development Project
Nashua, New Hampshire

Dear Mr. Cummings:

Per your request, The H.L. Turner Group Inc. (TTG) offers the following proposal to the City
of Nashua (City) to provide certain final engineering design in conjunction with the City’s
Nashua Riverfront Development Project.

As the City is aware, TTG has been part of the project design team providing overall project
flood resiliency engineering and structural engineering design for the elevated walkway
portions of the project. The basis for final engineering design is shown and described on the
VHB, February 2, 2022, Nashua Riverfront Preliminary Design Plans and in the Preliminary
Design Narrative that was submitted to the City on the same date.

The following Scope of Services presents a general description of the TTG final engineering
work and follows the project scope breakdown identified in the VHB Preliminary Design
Narrative. Attachment A to this proposal is a breakdown of the man-hour effort to
complete the engineering and CAD work to prepare the final engineering design plans.
Construction plans and technical specifications will be prepared once permit comments are
received from the required regulatory agencies and the City’s Construction Manager (CM)
comments on the final engineering plans. The extent of comments is unknown at this time.
An allowance will be identified and carried in the TTG fee estimate.

SCOPE OF SERVICES

The following are considered basic services for the final design engineering scope:

Segment 1 — Cotton Mill Bridge ADA Ramp

No TTG final engineering required.

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Segment 2 - Path and Riverbank Enhancements

2.1 TTG will perform additional river normal and flood analyses to evaluate the flood
resiliency of Tighe & Bond’s riverbank protection system(s) and modifications to the
park and boardwalk alignment to avoid conflicts with the Eversource substation.

Segment 3 — Substation Screening

3.1 TTG will perform final and structural design for the metal screening structure based
on Payette Architect’s March 6, 2022 design.

3.2 TTG will perform preliminary (recently completed) and final structural design for the
screening structure foundation. Prepare final engineering plans and specifications

for review and approval by the City.

Note: A new or revised foundation design different from the preliminary design is
required as Eversource is not in agreement with the TTG preliminary design.

3.3 TTG will perform additional river normal and flood analyses to evaluate flood
resiliency of Tighe & Bond's riverbank (cove) protection system(s).

Segment 4 — Boardwalk Connector

4.1 Perform river engineering analyses using the river model to determine scour, debris
and ice loading impacts for flood resiliency.

4.2 Perform structural design of the pile and pile foundation, the boardwalk/pile
connection, and other structural connections/details.

4.3 Prepare final engineering plans and specifications for City review and approval.

Segment 5 — Multi-Use Path Connector

5.1 Evaluate the proposed riverbank protection system by VHB or others for the
potential of erosion and scour using the river hydraulic model to determine bank
velocities and soil shear.

Segment 6 — $3 Main Street Boardwalk

6.1 Redesign the walkway piles consistent with avoiding the siphon sewer facility and
geotech recommendations being sought as part of final engineering design.

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6.2 Verify using the river hydraulic model that there continues to be “0.00 ft rise” with
the redesigned elevated walkway piles.

6.3 Develop structural details for the boardwalk/pile and associated connections.

6.4 Evaluate the proposed riverbank protection under the boardwalk and around the
piles by VHB or others for the potential of erosion and scour using the river
hydraulic model to determine bank velocities and soil shear.

6.5 Prepare final engineering drawings and specifications for City review and approval.

Segment 7? — Riverfront Path Along BAE Property

7.1 Evaluate the proposed riverbank slope stabilization being proposed by VHB or
others far the potential of erosion and scour using the river hydraulic model to
determine the bank velocities and soil shear.

Segment 8 — New River Crossing (Pedestrian Bridge)

8.1 Evaluate, using the river hydraulic model, the impacts to the floodway and the “0.00
ft rise” criteria based on moving the bridge abutment to avoid interference with the
sewer interceptor.

8.2 Provide findings and recommendations on the bridge abutment relocation, and
impacts to erosion and scour to the river side slopes and channel.

Segment 9 — Southside Trail Improvements

No TTG final engineering required.

Segment 9-A — $8-60 Main Street to ADA Ramp Behind Library

No TTG final engineering required.
Segment 9-B — Library ADA Ramp to PanAm Bridge
No TTG final engineering required.

Segment 9-C — PanAm Bridge to Temple Street

No TTG final engineering required.

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Segment 10 —- Replace and Widen ADA Ramp Below Library

No TTG final engineering required.

Segment 11 — 58-60 Main Street Boardwalk and Ramp

11.1

11.2

11.3

11.4

11.5

Design the final boardwalk bracket connections for the building.

Design the transition corner from the bracketed boardwalk to the parking lot ramp.
Design the ramp boardwalk and supporting piles.

Evaluate riverbank slope protection for erosion and scour.

Prepare final drawings and specifications for City review and approval.

Segment 12 — Bicentennial Park Renovation

12.1

12.2

12.3

12.4

Coordinate and resolve the interface connection between the park and the 4 Water
Street boardwalk with Halvorson/Tighe & Bond.

Design the modified retaining wall and other foundation structures for the park —
4 Water Street interface including consideration of the existing underground
utilities.

Evaluate river erosion and scour potential at the retaining wall interface.

Prepare final design drawings and specifications.

Segment 13 — 4 Water Street Boardwalk

13.1

13.2

13.3

13.4

13.5

13.6

Design the boardwalk river piles and building connections.
Design boardwalk structural details and pile connections.

Coordinate the final design of the expanded boardwalk with Halvorson/Tighe &
Bond where Renaissance Park and the new floating dock gangway ramp meet.

Design the details of the expanded boardwalk section.
Design the new retaining wall and river pile supports for the expanded walkway.

Design the new floating dock river piles.

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13,7 Design the new floating dock and gangway system including intermediate supports.

13.8 Re-examine the “0.00 ft rise” river model with the final design pile features to
confirm conformance.

13.9 Use the river model to assess pile erosion and scour, ice, and woody/miscellaneous
debris loadings.

13.10 Prepare final design drawings and specifications for City review and approval.

Segment 14 — Renaissance Park Improvements

14.1 Coordinate final park layout with the City and Halvorson/Tighe & Bond to minimize
the length and extent of the river walls and river slope embankment.

14.2 Perform additional river modeling to verify river wall and embankment grading do
not violate the “0.00 ft rise” flood level criteria. Use the river model to determine
velocity, scour and erosion potential as parameters in designing the final
embankment surface treatment(s).

14.3. Design the structural and geotechnical aspects of the new river retaining wall
including any special support(s) over the existing 30-inch City stormwater drain line.

14.4 Design the geotechnical, hydraulic, and structural elements of the proposed river
embankment.

14.5 Prepare final design plans and specifications for City review and approval.

Segment 14 — Revised Water Street and Factory Street Parking Layout

No TTG final engineering required.

Permitting Support

TTG will provide permitting support to the City in the Implementation of permit terms and
conditions within its final engineering design.

ADDITIONAL SERVICES

The following are considered additional services that are not considered final engineering
design; but, will be needed to complete the final engineering phase of this project:

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A.l Geotechnical Analyses & Recommendations

TTG intends to subcontract the geotechnical engineering work to SLR International
(formerly HTE Northeast, Inc.) out of Bedford, NH. TTG has performed many similar
water/land projects with SLR support.

SLR will provide reasonably conservative geotechnical analyses and recommendations for
the TTG final design structures. It is TTG’s understanding that prior to construction, the City
will obtain (at the direction and approval of TTG/SLR} new subsurface (land and water)
borings. Data from the borings will be used to confirm; or adjust SLR foundation
recommendations.

If the TTG designs change, the City will be notified and a scope and budget for any redesigns
provided.

A.2 — Spot Field (Instrument) Surveys

Certain design details (Bicentennial Park — 4 Water Street elevated boardwalk interface,
new retaining wall under the expanded deck where 4 Water Street’s elevated boardwalk
meets Renaissance Park/dock gangway, the substation screening foundation, etc.) will
require more “in-situ” ground elevation points and existing structure feature information.
TTG will be requesting 2 to 3 days of HSI field survey crew time to obtain this information
for TTG.

A.3 - Project Progress Meetings

In addition to the design coordination meetings identified in the scope for “basic” final
engineering design services, TTG has estimated 12 project progress meetings with the City
and its project representatives, to present ongoing design results, discuss budget/schedule
status, and identify potential problems. We expect these meetings would be 1 to 2 hours in
length and involve two TTG project staff to prepare, attend/present, and provide certain
meeting follow-up.

A.4 - Construction Manager (CM) Coordination

TTG understands the City plans on utilizing a CM to assist it in implementing the Riverfront
Project. It is likely the CM will be issuing RFls, Requests for Clarifications, and doing value
engineering assessments of the TTG final engineering design. T7G recognizes that time will
need to be allocated to coordinate with the City CM; but the extent and scope is
undefinable at this time.

Our services for this project will be provided in accordance with the attached “Standard
Conditions for Engagement” dated January 1, 2022.

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ITEMS NOT INCLUDED
1. More meetings than identified in basic and additional services.

2. Construction drawings and specifications. (Note: At this time the City has not
defined the scope or method of project delivery, or its phasing, which would dictate
the criteria of scope and extent of these construction documents}. Segments 3, 4, 6
& 11-14 all other drawings and specs.

3. Changes to the final engineering designs that are a result of issued state, federal or
city permit conditions.

4. RFls as part of any ongoing project permit application process.

5. Coordination with the City CM regarding the scope, fees and budgets, and
scheduling of TTG’s final engineering design.

& Work currently being performed by others.

FEE

We propose to invoice for our services on an hourly basis per the attached “Standard Fee
Schedule and Payment Terms” dated January 1, 2022. Invoices will be submitted monthly.

A total not-to-exceed budget for the scope of work identified as “basic” final engineering
design services is $286,340. The total allowance estimate for “additional” services to
support the final engineering design is $118,000.

Attachment A is a Fee Summary Sheet line iteming and totaling the fees for “basic” and
“additional” services.

Attachment B is a Fee Breakdown providing labor and expense estimates per the Scope of
Services for the “basic” and “additional” services.

SCHEDULE

To be determined with the City.

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CLIENT RESPONSIBILITIES

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Owner/Contractor contract documents (except technical documents) and/or
purchase order, in order to solicit for and enter into a construction contract with a
Contractor or Construction Manager.

Solicit, administer, and award bids for construction implementation of this project.

Provide construction administration and supervisions of Contractor or Construction
Manager.

Obtain federal, state, and local permits and approvals necessary for the
implementation of this work.

Pay permit fee(s} for the new boring plan State Wetlands Permit or any other permit
fees that may be required.

Issues dealing with hazardous materials.

TURNER

GROUP

CONTRACT FORM

Please sign and return these originals as your acceptance of the above scope and terms,
including noted attachments, and your authorization to proceed. Please also provide a
purchase order or equivalent accounting number, if applicable, at the end of this letter in
order to allow us to proceed.

in the event the City (Client) issues a purchase order or other instrument related to TTG’s
(Consultant's) Services, it is understood and agreed to that such document is of the Client’s
internal accounting purpose only, and shall in no way modify, add to, or delete any of the
terms and conditions of the agreement. If the Client does issue a purchase order or other
similar instrument, it is understood and agreed to that the Consultant shall indicate the
purchase order number on the invoices sent to the Client.

We appreciate the opportunity to present this proposal and look forward to providing
continued assistance to the City with this project. If you have any questions, please do not
hesitate to contact John Lavigne at (603) 228-1122, ext. 149 or Gerard Blanchette at ext.

120.
Sincerely,

THE H.L. TURNER GROUP INC.

edn R. lermanen'y Aral Mok

John R. Lavigne, Jr., PE, CPM Gerard R. Blanchette, PE, LEED°AP, NCEES
Lead Civil Engineer President
JRL/sai

Attachments: A- Fee Summary Sheet
B — Fee Breakdown
C ~ Standard Fee Schedule & Payment Terms, January 1, 2022

TURNER
GROUP

Attachment A

Fee Summary Sheet