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To:

From:

Re:

G. Motion:

Attachments:

Discussion:

City of Nashua, Public Works Division

Board of Public Works Meeting Date: June 22, 2017

Noelle Osborne, Plant Operations Supervisor
Wastewater Department

Change Order #2 - Siphon Covers Installation project

To approve Change Order #2 for the installation of new siphon and manhole covers
project to William P. Davis Excavation, LLC, of Portsmouth, NH in amount of
$16,617.50. Funding will be through: Department: 169 Wastewater — Account
Classification: 54 Property Services.

Change Order 2

The vortex structure at the wastewater treatment facility is designed to dissipate energy in
the wastewater flow where the Salmon Brook Interceptor meets the South Merrimack
Interceptor. The vortex structure consists of an 8-foot diameter top section and a lower 4-
foot diameter section that extends over 30 feet deep. Upon original installation of the
vortex, the access manhole was not centered over the vortex, leaving no access to clean
the vortex. A new, larger opening centered over the vortex structure is needed.

The new concrete top slab will have a centered hatch opening and built-in safety grate.
William P. Davis Excavation, who completed the work for the siphon cover upgrades
project, was requested to put together a cost proposal for a new top slab on the vortex.
Davis Excavation is ideally situated for this work from their experience with the
installation of new hatch and safety grates during the siphon cover upgrades project.

Davis Excavation was awarded the siphon project in January 2017 in the amount of
$49,875. Change order 1 for the installation of new bolts to replace the existing stripped
bold on covers increased the contract amount by $4,996.20 to a new total amount of
$54,871.20. This change order is in the amount of $16,617.50 brings the new total
contract amount to $71,488.70.

Davis Excavation has satisfactorily completed the siphon cover installation project within
the project schedule and on budget. Their costs are considered reasonable and they will
be able to start in timely manner when requested to do so by the Wastewater Department.

CHANGE ORDER
No. 1

PROJECT: Upgrade of Sewer System Siphon Covers

OWNER’S CONTRACT NO:_ RFP1087-120916

EXECUTED CONTRACT DATE: February 1, 2017

DATE OF ISSUANCE: June 27, 2017 EFFECTIVE DATE: Upon City Approval
OWNER: City of Nashua, NH

OWNER’s Purchase Order NO.: 131720

CONTRACTOR: William P. Davis, Excavation LLC

ENGINEER: DPW Engineering

You are directed to make the following changes in the Contract Documents:

Description:

» Replace existing vortex structure top slab with new center access top slab with hatch
» Time Extension to complete Change Order #2

Attachment:

> William P. Davis, LLC Change Order #002 Proposal dated May 24, 2017

Change Order #2 1 of 2
Upgrade of Sewer System Siphon Covers

Summary

CHANGE IN CONTRACT PRICE:

Original Contract Price

$49,875.00

CHANGE IN CONTRACT TIMES:
Original Contract Times

Substantial completion: April 28, 2017
Ready for final payment: May 26, 2017

Net changes from previous Change Orders

$4,996.20

Net change from previous Change Orders

none

Contract Price prior to this Change Order

$54,871.20

Contract Times prior to this Change Order

Substantial completion: April 28, 2017
Ready for final payment: May 26, 2017

Net Increase (deerease} of this Change Order

$16,617.50

Net Increase (deerease} of this Change Order

Substantial completion: September 1, 2017
Ready for final payment: September 31, 2017

Contract Price with all approved Change Orders

Contract Times with all approved Change Orders

$71,488.70 Substantial completion: September 1, 2017
Ready for final payment: September 31, 2017
RECOMMENDED: ACCEPTED: APPROVED:
By: By: By:

DPW Engineering Name Mayor Jim Donchess
Engineer Contractor Owner
(Authorized Signature) (Authorized Signature) (Authorized Signature)

Date: Date: Date:
Change Order #2 2 of 2

Upgrade of Sewer System Siphon Covers

Change Order Form
Change Order #002 - 5/24/2017

Project: Upgrade of Sewer System Access Covers
Location: Nashua, NH

Description: Replace existing vortex structure top slab with new center access top slab with hatch.

Saw cut and remove pavement (18’x18’) on and around existing structure. Excavate to expose entire top slab section.
Drill & install lifting points. Crane onsite to remove existing top slab and set new top slab in place. Existing top slab
will be demolished onsite and concrete ruble to be disposed of. Form and caste in place new H20 rated aluminum
access hatch w/ safety grate to finish grade. Backfill, compact, and fine grade. Place 4” asphalt patch to match
existing grades.

> Total Summary:

Materials: $5,090.00
Rental / Subcontractor: $4,400.00
Labor: $4,960.00
Overhead / Profit 15% = $2,167.50 $2,167.50
Total: $16,617.50
Contract Time Extension: TBD

> Material:

Precast Top Slab 1 EA @ $1,150.00 $1,150.00
Concrete / Rebar / Form 1 EA @ $725.00 $725.00
Lifting Anchors 1 EA @ $290.00 $290.00
H20 42”X42” Hatch 1 EA @ $2,925.00 $2,925.00
Sub Total $5,090.00

> Rental / Subcontractor:

2500LB Hammer W/ Machine 1 Day @ $975.00 $975.00
Vio 45 Ex 3 Day @ $275.00 $825.00
C6500 Dump Truck 12 HR @ $75.00 $900.00
Service Truck W/ Tools 4 Day @ $175.00 $700.00
Crane 1 EA @ $1,000.00 $1,000.00
Sub Total $4,400.00
> Labor:
Supervisor 32 Hours @ $65.00 Per $2,080.00
Labor 32 Hours @ $45.00 Per $1,440.00
Labor 32 Hours @ $45.00 Per $1,440.00
Sub Total $4,960.00

nn a 1 TAA MSA EZ,

Authorized Signature:

WILLIAM P DAVIS EXCAVATION LLC

PO BOX 758 - HAMPTON, NH 03843

(2 THE CITY OF NASHUA the Gate City’

Financial Services

Purchasing Department

PASI SE rt wee me sete entree

June 29, 2017
Memo #18-004

TO: MAYOR DONCHESS
FINANCE COMMITTEE

SUBJECT: | PUMP STATION UPGRADES DESIGN SERVICES — FINAL DESIGN (VALUE:
$461 569)
DEPARTMENT: 169 WASTEWATER; FUND: WASTEWATER

Please see the attached communication from Noelle Osborne, Wastewater Department Operations
Supervisor, dated June 22, 2017 for the information related to this purchase.

Pursuant to NRO § 5-83 Professional Services (A) In the purchase of accounting, architectural, auditing,
engineering, legal, medical and ambulance services and purchases of independent professional
consultant services for personnel, data processing, actuarial, planning, management and other
comparable purchases competitive bidding shall not be required.

The Wastewater Department Operations Supervisor, Board of Public Works (6/22/2017 BPW meeting)
and the Purchasing Department recommend the award of this contract in the amount of $461,569 to
Woodard & Curran of Portland, ME.

ey

fe ra
— Dan Kooken
Purchasing Manager

Respectfully,

Coc: N Osborne L Fauteux

229 Main Street e Nashua, New Hampshire 03061 © Phone (603) 589-3330 e Fax (603) 589-3233

From:

Re:

I. Motion:

Attachments:

Discussion:

City of Nashua, Public Works Division

Board of Public Works Meeting Date: June 22, 2017

Noelle Osborne, Plant Operations Supervisor
Wastewater Department

Pump Station Upgrades Design Services — Final Design

To approve the contract award for final design phase of the Pump Station
Upgrades to Woodard & Curran of Portland, ME in amount not to exceed
$461,569. Funding will be through: Department: 169 - Wastewater; Fund:
Wastewater; Activity: Pump Station Upgrades.

Pump Station Upgrades ~- Final Design Phase-Scope of Work and Fee

There are fourteen (14) City owned pump stations throughout Nashua. These
pump stations are all the original installations which range from 30-55 years
old. Complete upgrades of all pump station are needed, which includes new
communications to the Wastewater Treatment Facility’s SCADA program.

Woodard & Curran was hired initiaiiy to perform a preliminary evaluation and
provide recommendations of the upgrades needed at all 14 locations.
Following the preliminary phase work they completed a 30% design of this
project. This work included most of the survey and geotechnical work needed
to move into final design.

Woodard and Curran will next complete the final design, prepare construction
bidding documents and assist with the construction bidding phase. We
recommend continuing this work with W&C since they have performed the
previous work competently and within budget. Their costs for the final design
was negotiated and is now reasonable for the scope of work involved. This
project is eligible for a 20% State Aid Grant from the New Hampshire
Department of Environmental Services.

B. The Contractor shall protect the sub-grade beneath new structures and pipes from
frost penetration when freezing temperatures are expected.

PART 2 - PRODUCTS

2.01 MATERIAL:

A. CRUSHED GRAVEL:
The Gravel Road Base will be NHDOT - Item 304.3 Crushed Gravel, or Item 304.4
Crushed Stone (Fine Gradation).

B. TRENCH BACKFILL MATERIALS:
Trench backfill shall be material excavated from the trench that is granular, well
graded friable soil; free of pavement, rubbish, ice, snow, tree stumps, roots, clay
and organic matter; with 30 percent or less passing the No. 200 sieve; no stone
greater than two-third (2/3) loose lift thickness, or six inches, whichever is smaller.

C. SEWER AND DRAIN PIPE BEDDING MATERIAL

1. Sewer and drain pipe bedding material shall be Crushed Stone meeting the ASTM
C33/C33M stone size No. 67.

2. Sand Blanket material for sewer and drain pipe shall be graded sand free from
organic materials, graded such that 100 percent passes a '¥2-inch sieve and a
maximum of 15 percent passes a #200 sieve.

PART 3 — EXECUTION

3.01 DISTURBANCE OF EXCAVATED AND FILLED AREAS DURING
CONSTRUCTION:

A. Contractor shall take the necessary steps to avoid disturbance of sub-grade during
excavation and filling operations, including restricting the use of certain types of
construction equipment and their movement over sensitive or unstable materials,
dewatering and other acceptable control measures.

B. All excavated or filled areas disturbed during construction, all loose or saturated soil,
and other areas that will not meet compaction requirements as specified herein shall
be removed and replaced with a minimum 12-inch layer of compacted crushed stone
wrapped all around in non-woven filter fabric. Costs of removal and replacement
shall be borne by the Contractor.

C. The Contractor shall place a minimum of 12-inch layer of special bedding materials
and crushed stone wrapped in filter fabric over the natural underlying soil to stabilize
areas which may become disturbed as a result of rain, surface water runoff or
groundwater seepage pressures, all at no additional cost to the Owner. The
Contractor also has the option of drying materials in-place and compacting to

2022 Sewer Replacement Project Earthwork
Nashua, NH 02300-3

COMMITMENT & INTEGRITY 47 Hutchins Drive T 800.426.4282?

DRIVE RESULTS Portland, Maine 04102 VT A07 774.2142
www.woodardcurran.com F 207.774.6635
FINAL DESIGN

, PUMP STATIONS UPGRADE PROJECT
a NASHUA, NH
<a

be \ —-—-s BACKGROUND

EoRAe The City of Nashua has fourteen pump Stations of different sizes, types and ages. Like many
other cities Nashua decided to review and upgrade all pump stations for reasons including but
not limited to: ensure proper and reliable operation to limit sanitary sewer overflows, address
failing force mains, meet current safety standards, improve ease of maintenance and
accessibility for staff at each station, and take advantage of new technology for the betterment
of the community. In many stations, the pumping and controls equipment is beyond its
expected life. After an RFQ process and interviews, Woodard & Curran was selected to
complete this project to review and upgrade the City’s pump stations.

PREVIOUSLY COMPLETED WORK

The investigation phase of the project was approved by the Board of Public Works in October
2015 and a multiday investigation took place with Woodard & Curran engineers and plant
management and staff in November 2015. The summary report for this investigation was
delivered to the City in January 2016 and presented to city management and wastewater
treatment plant staff on March 9, 2016.

The preliminary design phase of the project was approved by the Board of Public Works in July
2016 and a Design Basis Report (DBR) was delivered to the City and presented to city
management and wastewater treatment plant staff on January 19, 2017. The DBR presented
the City with recommended upgrade options and estimates of probable construction cost for
each station based on preliminary engineering analysis of layout, mechanics, hydraulics and
constructability. The city was able to use this information to make decisions on how to proceed
so Woodard & Curran could continue to the final design phase. The City provided Woodard &
Curran with a memorandum dated February 10, 2017 summarizing the City’s design decisions
relative to the recommendations included in the DBR and outlining additional design requests.

Since the City’s February 10, 2017 memorandum, Woodard & Curran has completed additional
preliminary design tasks to evaluate several of the City’s design requests at the Northgate and
Spalding stations. A site visit was conducted on March 30, 2017 with city wastewater
treatment plant staff and structural and electrical engineers from Woodard & Curran. The
purpose of this site visit was to conduct a more extensive condition assessment of the
structural and electrical components of the pump station to verify that the City’s current
upgrade design objectives could be achieved relative to upgrading, as opposed to fully
replacing, the pump station. Site visits were also conducted on April 17, 2017 to Trestle Brook
and Santere pump stations to perform structural observations and assessments of the wet
wells and dry wells at each station and for the building at Trestle Brook.

On April 13, 2017 a teleconference was conducted including city wastewater staff, the city’s
hydraulic modeling consultant Hazen and Sawyer and Woodard & Curran to discuss modeling
results related to the preliminary design to eliminate the Spalding pump station.

A
WOODARD
S& CURRAN

Between May 1s‘ — 3 soil borings were completed by New England Boring Contractors within
the Nashua River as part of the Northgate force main replacement preliminary design.

PROPOSED FINAL DESIGN

The final design phase (as presented in the following scope) will be proceed to 100% final
design and bidding of upgrades to the pump stations according to Woodard & Curran’s
recommendations included in the Design Basis Report (draft report issued January 2017;
revised report issued June 2017). The June 2017 version of the Design Basis Report has
incorporated the City’s design directives provided in their memorandum summarizing design
decisions (February 2017).

Woodard & Curran intends to use three (3) subconsulltants to provide services in support of
the final engineering design. These consultants include a geotechnical firm to evaluate the
results of geotechnical exploration and testing and to provide detailed engineering analyses
relative to the foundation design of new structures and relative to the design of horizontal
drilling for a new force main pipeline; a HVAC & plumbing consultant to design upgrades to
HVAC and plumbing systems (as required); and a specialty consultant to complete a radio
propagation study to assess radio communications for pump stations that cannot be directly
served by fiber optic communications.

Final design will include engineering drawings and specifications prepared in compliance with
NHDES Clean Water State Revolving Fund requirements. Final design documents will be
prepared according to a 60%, 90% and 100% (bid-ready) milestone schedule. The 60% and
90% submittal packages will be provided to the City for review and comment prior to preparing
the 100% design documents for bidding. Woodard & Curran will also provide standard internal
Technical Advisory Team (TAT) and Quality Assurance/Quality Control (QA/QC) reviews at
these milestones. Design review meetings will be held with city management and wastewater
treatment plant staff following document submissions to the City at the 60% and 90%
milestones to discuss the City’s review comments.

FINAL DESIGN - DETAILED SCOPE OF SERVICES

The final design project includes the following general components as described below in detail:

e Project Management

e Final Design Engineering & Bid Documents
2 Permitting

e Cost Estimating

e Bidding Assistance

Project Management

This task occurs concurrently with the other tasks outlined in the Scope of Services and includes those
tasks necessary to inform the City of the project's needs; monitor and control the design process:
coordinate information and meetings; coordinate with subcontractors and in-house design staff; reach
timely decisions to meet the project schedule; reports to the City on the progress of the project and
Status of schedule and budget; and technical oversight of project activities. Engineer will attend

City of Nashua (P228730.19) 2 Woodard & Curran
Attachment 1 June 5, 2017

a. &,

OODARD
& CURRAN

regularly scheduled meetings with city staff as appropriate to discuss project progress and issues
related to design of the project.

Final Design Engineering & Bid Documents

Pump station and force main upgrades will be designed to the TR-16 industry standards capable of
accommodating the design flows from the contributing sewershed area. Woodard & Curran will work
with the City to specify pump station components interchangeable to current City standards.

Design documents will be prepared based on the technical recommendations included in the Design
Basis Report and will include construction drawings and specifications. Drawings will depict the work to
be done at a scale of 1” equals 40” horizontal and 1” equals 4’ vertical for pipeline plan and profile
sheets. Detail sheets, pump station site plan and specialized design plans shall be at scales as
determined by the Engineer. Specifications shall be based on the Engineers Joint Contract Documents
Committee (EJCDC) format. Engineer will provide drawings to the City for review at the 60% and 90%
design milestones in order to review progress and solicit input from City staff on the design.

Bidding documents will include final specifications and drawings and be delivered to the City and
NHDES, in two submittals: 90% Design Documents and Final Design Documents. Final bidding
documents will incorporate review comments on the 90% documents received from the City and
NHDES. Bidding documents will be developed in accordance with NHDES SRF requirements.

Permitting

Prepare and submit one (1) Wetland Utility Maintenance Notification (UMN) and one (1) Permit by
Notification (PBN) to NHDES relative to the proposed pump station upgrade and force main
replacement at the Northgate pump station, including necessary effort during the permitting and
approvals process to respond to questions and requests by NHDES.

Cost Estimating

Prepare Engineer's Estimates of Probable Construction Cost for deliverables at the 60%, 90% and
100% design milestones. Cost estimates will be based on industry construction estimating standards
and provided with a tabular summary.

Bidding Assistance

Following authorization to advertise by NHDES, Woodard & Curran staff will coordinate with the City for
publication of the bid advertisement; attend a pre-bid conference; review written questions from
contractors; issue addenda; attend the bid opening; prepare a bid tabuiation; evaluate the bids and
provide a recommendation to the City to award the construction contract. At the point of contract award
by the City, the Final Design Engineering scope of work will end and a future SRF Eligible Construction
Phase Services scope will begin.

City of Nashua (P228730.19) 3 Woodard & Curran
Attachment 1 June 5, 2017