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EXHIBIT B

PRIMARY AND SECONDARY DIGESTERS CLEANING
IFB0285-083117

SCOPE OF WORK

The Nashua Wastewater Treatment Facility (NWTF) is a 16 MGD (design capacity) that
normally operates at around 11-12 MGD during dry (no rain) conditions. The plant has a 1.3
million gallon (MG) primary digester and a 0.25 MG secondary digester. Attached are more
details on the primary and secondary digesters. These digesters were last cleaned out in 2006
and 2013, respectively. Both digesters are in need of complete cleaning. This bid will result in a
service contract awarded to the lowest responsible bid provided the bidder can meet the
minimum requirements set forth in the bid document.

The NWTF uses a blended sludge of approximately 60% primary and 40% secondary solids to
feed an anaerobic digester which stabilizes and reduces the volume of solids entering. The
primary digester is an egg shaped steel vessel where the majority of the sludge digestion and gas
production occurs. It overflows after an approximate 15-day retention time to an adjacent
secondary digester of much smaller volume.

In addition to cleaning out both the primary and secondary digesters, the contractor will be
required to dewater incoming primary and secondary sludge to the plant while the digester is
being cleaned. The scope of work involves the contractor providing sludge pumps, hoses,
portable centrifuge, screening, and container boxes to hold sludge & screenings for both
digesters and incoming sludge.

The contents of the secondary digester should be dewatered first so that the sludge can be
dewatered and meet class B sludge for land application. However, the sludge in digester has
more inorganic material (mostly grit and ground up plastic material) and should be screened to
remove the inert object. This sludge will be removed by NWTF’s biosolids truck hauler, Casella
Organics.

The NWTF contract with Casella is to haul off Class B sludge. Additional costs for Casella to
remove non-class B sludge are being negotiated between. The NWTF will arrange to have all
sludge produced during the dewatering process removed by Casella. The contractor is expected
to have the capability to transport dewatered sludge from the dewatering equipment to trailers
provided by Casella. The contractor shall work closely with Casella and plant management on
informing and scheduling the removal of full trailers.

Page 1 of 6

EXHIBIT B

Sequence of Operation

The sequence of operation stated below is based on information from the past digester cleaning
and plant knowledge on it. The goal is to dewater the sludge in the digesters and incoming
sludge in the shortest time possible while meeting all permit requirements. Should a contractor
have a better method to conduct the dewatering it should be discussed with NWTF plant
management and a new procedure may be developed. In addition, the sequence stated below is a
guideline and is subject to change if a better method or any obstacle, such as pump failure,
prohibits or changes how a step is to be conducted.

One week prior to starting the NWTF will dewater the secondary digester to the
extent possible.

At start the sludge holding tanks will be lowered as much as possible to allow for
incoming sludge.

Contractor shall setup dewatering equipment to dewater incoming sludge from the
sludge holding tanks.

Contractor shall setup dewatering equipment for dewater sludge in the primary and
secondary digesters.

Prior to start of dewatering the primary digester the remaining contents in the
secondary digester shall be screened and dewater. A much of the material possible in
the bottom of the secondary digester shall be removed. This will involve opening the
manway and hosing/diluting heavy material as the base so it can be pumped to
dewatering equipment.

Following cleanout of secondary digester, the NWTF will open valves and fill the
secondary digester. The cleanout of the primary digester will occur by transporting
sludge from the primary tank to the secondary tank.

The primary digester will be pumped out as much as possible. Once all the sludge
that can gravity feed to the secondary digester is complete the remaining sludge in the
bottom of the digester will be drained back to the sludge holding tanks or an influent
sewer manhole per direction by the NWTF. The final cleanout of the primary tanks
may require flushing water from the plant water system following proper aeration of
the vessel from the top man entry opening as described in step 8.

Gas flow valves from the primary digester will be closed and the manway hatch at top
opened. Contractor shall monitor levels of carbon dioxide and methane in the tank,
follow all OSHA regulations pertinent to ventilation needed for an explosive gas, and
ensure continuous gas monitoring throughout the inspection. Once determined it is
safe to enter, the contractor will inspect the inside of the structure using a camera.
The contractor shall have his own camera equipment or subcontract it to a sewer
video company. Camera shall have sufficient cable to be lowered to carefully inspect
the base area of the tank, about 100 feet deep from top to the bottom of the conical
section below grade. Pictures taken or videos shall be clear so that plant personnel
can review it and decide if any correction action is needed.

Page 2 of 6

EXHIBIT B

Once the primary digester has been cleaned out and inspected, it will be brought back
on line. The remaining 200,000 (+/-) gallons in the secondary digester may be
pumped back to the primary digester for potential use as feed sludge for the primary
tanks if found suitable for seed sludge (NWTF will test the sludge and make this
determination). Should be sludge remaining in the secondary digester be found not
suitable for seed for the primary digester, it will be dewatered per direction by the
contractor. If the sludge is found to be suitable, it shall be screens and pumped back
to the primary digester.

As soon as incoming sludge is being fed back to the digester, the dewatering
operation of the incoming sludge will cease. Similarly, there will no further
dewatering of the primary or secondary sludge so that operation will cease.

Page 3 of 6

EXHIBIT B

Nashua Wastewater Treatment Plant Responsibilities

The NWTF will cither provide 480V, 3 ph, 100 amp service or a portable generator

capable of providing this power.
The NWTF electrician will connect the contractor’s equipment to the service connection

or portable generator.

Plant water (non-potable) will be available to use from nearby yard hydrant(s). Water
pressure is around 100psi. NWTF will provide hoses and nozzles for contractor use in
cleaning and diluting as necessary.

The NWTF will dewater the secondary digester to the extent possible prior to start of
dewatering by contractor.

The NWTF will transport sludge from the primary digester to the secondary digester to
the extent possible.

Page 4 of 6

EXHIBIT B

Tank Specifications and Relevant Information

1. Primary Digester (constructed in 1999)
Elevation at top of structure — 104.5 ft
Elevation at bottom — 10.75 ft
Elevation at ground — 30 (+/-) ft
Height from ground to top of structure — 74.5 (+/-) ft
Depth of structure below ground — 19.25 (+/-) ft
Shape — Egg
Material — Steel, insulated with fiberglass wrap on outside
Liquid Height — 97 (+/-) ft
Diameter (maximum) — 67 (+/-) ft
Volume — 1,300,000 gal (maximum)

2. Secondary Digester (constructed in 1999)

Elevation at top of structure — 54 (+/-) ft
Elevation at bottom of tank — 23.7 ft
Elevation at ground — 30 (+/-) ft

Height from ground — 24 (+/-) ft

Shape — cylindrical, conical below grade
Material - Steel (not insulated)

Design liquid height — 13 feet (above ground)
Diameter — 60 ft

Volume — 2750,000 gal (maximum)

3. Sludge Storage Tanks
Number of tanks — 5

Location — north end of Process Building (adjacent to sludge dewatering)
Elevation at top of tank — 50.5 (+/-) ft

Elevation at bottom of tank (low point) — 20 ft

Elevation at ground — 32 (+/-) ft

Height from ground — 18.5 (+/-) ft

Shape — rectangular

Tank Dimension — 14ft x 28ft, depth — 25 ft

Material - concrete

Volume per tank — 46,300 CF

Page 5 of 6

EXHIBIT B

Page 6 of 6

City of Nashua, New Hampshire
Division of Public Works

Primary and Secondary Digestor Cleaning
Addendum 2 - Revised August 28, 2017

EXHIBIT C

BS - 1 of 2

a Quantity Units Item Description Unit Price Total Price
1 1 LS ___|Mobilization $19,110.00 $19,110.00
2 200 dry tons |Dewater contents of primary and secondary digester

(minimum of 28% cake) $389.00 $77,800.00
3 1 LS ___|Interior cleaning/inspection of secondary and

primary digesters $5,300.00 $5,300.00
4 400 dry tons |Dewater incoming primary and secondary sludge

(minimum of 28% cake) $309.00 $123,606.00
5 1 LS ___/Crane Costs $5,200.00 $5,200.00
6 1 LS __ |Portable Generator and Fuel $6,300.00 $6,300.00

TOTAL BID PRICE FIGURES $237,310.00

Contractor:

Date:

Address:

Phone:

Fax:

Email Address:

TOTAL BID PRICE WORDS - BASE BID

Two Hundred Thirty-Seven Thousand Three Hundred Ten Dollars and

Zero Cents

Denali Water Solutions, LLC

SL/L Of, J Drews Oflan.

Authorized Signature:

r
2-28 -/ 7
3308 Bernice Avenue, Russellville, AR 72802
(479)-498-0500 Local{ 413)-530-4386

Local (413)-247-9657

dohara@wecareorganics.com
ae Se Eee

BS - 2 of 2

3308 Bernice Avenue

Russellville, AR 72802

PO Box 3036 = Russellville, AR 72811
Phone: 479-498-0500

tas Aen
a VA : E a

September 4, 2017

City of Nashua, New Hampshire
229 Main Street
Nashua, NH 03060-2019

RE: Primary and Secondary Digesters Cleaning
IFB0285-083117

Denali Water Solutions is pleased to submit the enclosed bid to provide the referenced services
at the Nashua Wasterwater Treatment Facility at 2 Sawmill Road.

Attached please find the Bid Bond requirement of 5% of the total bid as requested.

Should you have any questions or need additional clarification, please feel free to call J. Drew
O’Hara, Senior Vice President directly at 413-530-4386 (cell). Also feel free to examine the
Denali Water Solutions website at www.denaliwater.com which has additional information.
Denali Water Solutions appreciates the opportunity to submit the enclosed bid.

Respectfully Submitted.
DENALI WATER SOLLUTIONS, LLC

jhe OK me

A
i/

J. Drew O’Hara

Vice President — Dredging and Dewatering

Document A310 ™ — 2016

Conforms with The American Institute of Architects AIA Document 340

Bid Bond

CONTRACTOR: SURETY:
(Name, legal status and address) (Name, legal status aid principal place af business)
Denali Wa : Westchester Fire Insurance Company
enali Water Solutions LLC 436 Walnut Street, P.O. Box 10000
3308 Bernice Avenue Philadelphia, PA 19106 legal consequences. Consultation
Russeliville, AR 72802 Malling Address for Notices with an attorney is encouraged
with respect to its completion or
OWNER: 436 Walnut Street, P.O. Box 1000 modification.
(Neune, legal status and address) Philadelphia, PA 19106 Any singular reference to
City of Nashu, NH Department of Public Works Contractor, Surety, Owner or
. other party shall be considered
229 Main Street plural where applicable.

Nashua, NH 03061

BOND AMOUNT: $ 5% Five Percent of Amount Bid

PROJECT:
(Name, location or address, and Project nunitber, ifam)

IFB0285-083117; Primary and Secondary Digesters Cleaning

The Contractor and Surety arc bound to the Owner in the amount set forth above, for the payment of which the Contractor and Surety bind
themselves, their heirs, executors, administrators, successors and assigns, jointly and severally, as provided herein. Tho conditions of this
Bond are such that if the Owner accepts the bid of the Contractor within the time specified in the bid documents, or within such tinve period
as may be agreed to by the Owner and Contractor, and the Contractor cither (1) enters into a contract with the Owner in accordance with
the terms of such bid, and gives such bond or bonds as may be specilied in the bidding or Contract Documents, with a surety admitted in
the jurisdiction of the Project and otherwise acceptable to the Owner, for the faithful performance of such Contract and for the prompt
payment of labor and material furnished in the prosecution thereof or (2) pays to the Owner the difference, not to exceed the amount of
this Bond, between the amount specified in said bid and such larger amount for which the Owner may in good faith contract with another
party fo perform the work covered by said bid, then this obligation shall be null and void, otherwise to remain in full force and effect. The
Surety hereby waives any notice of an agreement belween the Owner and Contractor to extend the time in which the Owner may accept the
bid. Waiver of notice by the Surety shall not apply to any extension exceeding sixty (60) days in the aggregate beyond the time for
acceptance of bids specified in the bid documents, and the Owner and Contractor shall obtuin the Surely’s conseni for an extension beyond
sixty (60) days.

If this Bond is issued in connection with a subcontractor's bid to a Contractor, the term Contractor in this Bond shall be deemed to be. me

igh Ee

Subcontractor and the term Owner shall be deemed to be Contractor. mae
When this Bond has been furnished to comply with a statutory or other legal requirement in the location of the Project, any pr : at

this Bond conllicting with suid statutory or legal requirement shall be deemed deleted herefrom and provisions conforming fF.” seine
statutory or other legal requirement shall be deemed incorporated herein, When so furnished, the intent is that this Bond she "St

asa statutory bond snd nol as a common law bond. | ese
Signed and sealed this Sth day of September, 2017 ae Ta %

a Denali Water Solutions LLC
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(Vimess) Sharon A Foulk

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