Amendment_0006_-_Durham_Spec_Section_11355_Revised_15_Aug_2018.pdf

THM Removal System 60445033 Durham Meadows Waterline Remedial Design Section No. 11355-1

SECTION 11355

THM REMOVAL SYSTEM

PART 1 – GENERAL

1.01 SCOPE

A. These specifications provide the requirements to furnish, install and place into operation a trihalomethanes removal system (THMRS) consisting of floating spray equipment, submersible mixing equipment, and a forced-air injection blower for the Cherry Hill Tank in Durham, CT for the Middletown, CT Water Department. The system shall be designed to achieve a minimum of 40% reduction in total THM removal based on a maximum 750 GPM feed to the tank and a future design maximum flow through the tank of 440,000 gallons per day with 80 µg/L THM concentration.

B. The proposed Cherry Hill above ground concrete tank shall be 45’ diameter x 78’overall height with a capacity of 880,400 gallons. The tank will have two 48-inch by 48-inch hatches located on opposite ends of the domed roof. A 16" inlet and 16" outlet will be located on the tank floor. Initially the average flow rate will be 92,000 gallons per day with a maximum flow rate of 234,000 gallons per day and a maximum fill rate estimated at 750 gallons per minute from the Long Hill pump station in Middletown. A booster chlorination system to be provided under this Contract will be installed at the Long Hill pump station, approximately 8,800 feet upstream.

C. The Contractor shall provide all equipment and materials as specified and indicated on the drawings.

D. CONTRACTOR shall furnish and install concrete blower pad as shown on the Drawings.

E. CONTRACTOR shall furnish and install acoustical enclosure as specified in this Section.

F. CONTRACTOR shall furnish and install Sch 10 stainless steel 12-inch diameter ductwork and use flexible couplings at blower discharge and outlet at top of tank as shown on the Drawings.

1.02 REFERENCES

A. Occupational Safety and Health Administration, OSHA

B. Department of Transportation, DOT

C. Underwriters Laboratories Inc., UL 508

D. NSF / ANSI Standard 61

E. National Electrical Code, NEC

F. National Electrical Manufacturers Association (NEMA):

1. 250: Enclosures for Electrical Equipment (1000 Volts Maximum).

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2. ICS 1: Industrial Control and Systems General Requirements.

3. MG1: Motors and Generators.

1.03 CONTRACTOR SUBMITTALS

A. NSF Certification

1. Copies of the NSF-61 certified listing for all material being placed inside the tanks and headspace, including the motor power cable and penetration fittings.

A. Installation, Operations, and Maintenance Manuals shall be obtained and submitted. The following sections shall be included:

1. General equipment specifications and data sheets

2. Installation, start-up, operation, and maintenance instructions

3. Factory-recommended maintenance schedule and list of recommended spare parts

4. Wiring diagrams of field connections with identification of terminations between local panel, junction boxes, equipment items, instrument devices and the like.

5. Electrical schematics and interconnection wiring diagrams.

6. Control Panels:

a. Bill of materials.

b. Front elevations, with and without door.

c. Elementary wiring connection diagrams.

7. List of equipment or tooling necessary for diagnostics, trouble-shooting, repair or general maintenance

8. Shop drawings for the circulation equipment.

9. A copy of the warranty statement.

1.04 QUALITY ASSURANCE

A. The systems shall be tested prior to deployment. Certification of this completed testing shall accompany the equipment documentation.

B. The THMRS equipment shall be designed to operate continuously, all day and all night.

C. THMRS shall have no visual defects, and shall have high quality welds, assembly, and corrosion resistant finish.

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D. The manufacturer of the equipment shall have extensive experience in the production of such equipment, and the equipment shall be manufactured in the continental United States.

E. For factory delivery and installation, services shall be performed by full time factory employees experienced in the operation of this equipment and who have completed OSHA safety trainings applicable to this type of installation.

1.05 ACCEPTABLE MANUFACTURERS

A. Medora Corporation, Dickinson, ND.

B. Or equal.

1.06 WARRANTY

A. From the period of substantial completion and ending on the time periods listed below, the THM Removal System and appurtenances are warranted to be free from defects in material and workmanship.

1. Minimum two (2) years on all supplied parts and labor.

1.07 FIELD SERVICES

A. Factory Personnel. The installation and startup shall be performed by full time factory employees trained in the operation of the THMR floating spray equipment.

B. Safety. Installation personnel shall have received job-specific safety training on (a) Working over Water, (b) Boating Safety, (c) Disinfecting Procedures, (d) Confined Space Entry, (e) Fall Protection, (f) Self Rescue, and (g) DOT Compliance.

C. Safety Equipment. Installation personnel shall be equipped with job-specific safety equipment to complete the installation of THMR floating spray equipment following all OSHA safety regulations. Safety equipment shall include confined space, fall protection, rescue, decontamination, and communication tools such as (air monitor, ventilation fan, tri-pod, winches, FBH’s, retractables, ropes, lanyards, descenders, radios, hard hats, step pools, disinfectant sprayer, etc.)

PART 2 – PRODUCTS

2.01 SYSTEM PERFORMANCE AND FEATURES

A. Units Required. To meet the project objectives, the following equipment shall be installed:

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Quantity Equipment Equipment Tag

Voltage Horsepower Location

One Floating Spray Nozzle Equipment (Surface Aerator): Medora SN5 Model or Equal.

SN.P-1 240VAC,

60Hz

5 HP

45’ diameter x 78’ tall above ground concrete tank (880,400 gallons)

One Submersible Mixer:

Medora GS-12 Model or Equal.

MIX-1 120VAC,

60Hz

0.5 HP

45’ diameter x 78’ tall above ground concrete tank (880,400 gallons)

One

Forced Air Injection Blower: for 750 CFM at 5 w.c. inches, Spenser Single Stage Scroll Blower (as provided by Medora) or Equal.

BLW-1 240VAC,

60 Hz

2 HP

Pad installation

B. An unobstructed hatch opening of at least 24 inch diameter (61cm) round is required for installation of the floating spray and submersible mixing equipment.

C. The THMRS floating and submersible equipment shall be constructed primarily of Type 316 stainless steel, pickled or passivated. All equipment shall be of NSF/ANSI Standard 61 approved materials and rated for contact with potable water. The system shall include the following features:

1. The floating spray nozzle equipment and the mixer shall each be mechanically operated by a submersible motor that meets the following criteria:

a. Direct Drive, with no gearbox and no lubrication maintenance required.

b. Designed for submersible operation.

c. Continuous Operation without overheating or compromising motor life expectancy.

d. *deleted*

e. Provide motors rated at voltages specified in Section 2.01(A).

2. Provide BLW-1 motor in accordance with Section 16220.

3. The floating spray nozzle equipment shall be 316 stainless steel, supplied with a horizontal, low velocity intake capable of being positioned at the lowest elevation of the tank or reservoir floor. The intake level setting shall bring water into the floating spray equipment at a horizontal layer within 1 inch (2.5 cm) of the tank floor. The intake shall include a singular hose of adequate length to reach the required intake depth setting.

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4. The floating spray equipment shall be equipped with a nozzle assembly sized specifically for the pump capacity output. Constructed of 316 stainless steel for optimal corrosion resistance and long wear life.

5. Forced Air Injection: The THMRS shall be provided with one turbine blower with TEFC motor capable of 750 CFM flow, CE, UL listed and CSA certified motor with NEMA Class F insulation. Blower to be mounted on type 316 stainless steel base and skid frame, adaptable to mounting on concrete pad next to the tank, as shown on the drawings, sized according to the blower manufacturer’s recommendations.

Appropriate ducting to connect the blower to the top of the tank shall be supplied by the general contractor as directed by the THMRS supplier.

D. Maintenance Requirements. The THMRS equipment shall operate normally with the following maintenance features.

1. No scheduled lubrication is required of any system components including motor.

2. No spare parts shall be required to be kept on hand.

2.02 CONTROL SYSTEM:

A. Provide BLW-1, MIX-1, and SN.P-1 each with a local control panel as specified and indicated.

1. Enclosure: NEMA 1.

2. Provide UL 508A listed control panels and components.

3. Provide enclosure with main circuit breakers, motor starters, reset buttons, fused control circuit transformer, relays, switches, contacts, indicating and alarm lights and all necessary appurtenances, completely factory wired to provide a coordinated and operating set of controls.

4. Provide magnetic motor starters with overload protection and manual reset.

5. Red running lights, green off/ready lights, and amber lights for alarms.

6. RUN-OFF-AUTO selector switches.

7. Run time meters.

8. Provide dry alarm contacts for remote indication of the following:

a. Not In Auto

b. Fault

c. Running

9. Provide terminal board for all external circuits.

10. Operation:

a. In AUTO the equipment shall operate continuously.

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b. Provide shutdown of equipment on fault detection.

2.03 ACOUSTICAL BLOWER ENCLOSURE

A. Provide sound attenuated and weather-proof outdoor enclosure.

1. Rigidity wind test equal to 150 mph.

2. Roof load equal to 50 psf.

3. Rain test equal to 5 in. per hr.

4. Certified to meet Uniform Building Code.

B. Building to consist of roof, two (2) side walls, and two (2) end walls of prepainted steel stressed-skin construction, door and door frame, lifting rings, mounting frame, insulation, electrical package, louvers, exhaust fan, intake filter mounting bracket, and other appurtenances to make complete installation. Enclosure to be coordinated with blower manufacturer/supplier to include:

1. Roof:

a. One piece roof sheet, min. 0.040 in. thick steel alloy, with extruded recessed side and end rails.

b. Roof bows, extruded "I" beams, spaced as required to carry loads.

2. Walls:

a. Posts to be extruded steel sections, sized and spaced as required to carry loads.

b. Panels to be min. 0.045 in. thick steel sheet, mill-prepainted, inside and outside, and riveted to posts.

3. Panel Frame:

a. Provide welded frame of extruded alloy, riveted to side panels.

b. Provide removable maintenance panels to form weathertight seal, with stainless steel locks.

c. All panels, doors and other openings shall be tight fitting to prevent entry of mice or other rodents.

4. Mounting Frame:

a. Provide steel perimeter mounting frame for mounting onto concrete pad.

5. Insulation:

a. Provide semi-rigid fiberglass (thermoacoustic) insulation.

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b. Provide sound attenuation for a 25 dBA noise reduction from the interior to the exterior of the enclosure.

6. Louvers:

a. Provide louvers and dampers for ventilation air. Provide insect screens.

b. Fixed louvers, all aluminum construction, riveted into aluminized steel frame to form rigid, water resistant assembly. Motorized dampers as specified hereinafter.

c. Properly size louvers and dampers to allow sufficient ventilation air with maximum 0.5 in. water restriction. Coordinate with fan manufacturer.

7. Intake Air Filter Mounting Bracket:

a. Provide suitable bracket to secure fan inlet air filter on the exterior of the enclosure.

b. Coordinate with fan manufacturer as required.

C. Access:

1. Large cable entry area for installation ease.

2. Panels located convenient to controls and service areas.

3. Double panels on both sides.

4. Vertically hinged doors allow 180º opening rotation.

5. Drains piped to exterior of enclosure and terminated with drain valves.

6. “Lift-off” hinges allow doors to be removed if required.

D. Security and Safety:

1. Lockable access doors with keys.

2. Roof outlet for fan intake filter.

3. Stub-up cover sheets for rodent proofing.

E. Transportability:

1. Lifting points on base frame.

2. Optional tested and certified single point lifting facility.

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PART 3 – EXECUTION

3.01 INSTALLATION

A. The CONTRACTOR shall furnish services of a factory-trained installer or crew having experience with installation procedures as well as operation and maintenance requirements for the type of equipment installed under these specifications. Equipment must be able to be installed through a 48x48 inch hatch.

1. The THMR floating spray equipment manufacturer shall have capability to provide Installation, Startup, and On-Site Water Testing Services to insure (a) proper equipment spatial placement in the reservoir, and (b) proper pump placement and floating spray discharge setting.

2. The field services shall be performed by full time factory employees experienced in the operation of this equipment, and who have completed safety trainings required for this type of installation in compliance with OSHA regulations including (a) Working over Water, (b) Boating Safety, (c) Disinfecting Procedures, (d) Confined Space Entry, (e) Fall Protection, (f) Self Rescue, and (g) DOT Compliance.

3. Within 30 days following installation, the manufacturer shall provide an installation report detailing as described in submittal section.

4. The THMR floating spray equipment manufacturer shall provide the following support services to the Contracting Officer under this Contract:

a. A minimum of eight two-member factory crew service hours.

b. Customer service staff shall include engineers and science personnel that are trained for assistance in this application.

B. The Tank Supplier shall perform tank penetrations and securing any materials to the tank.

1. Cables will be run through a conduit which will be secured to the outside of the tank.

C. Tank penetrations shall conform to the following:

1. Fittings shall be water tight.

2. Fittings shall be sufficient in diameter to allow cable to pass through.

3. Strain relief for power cables shall be part of the CONTRACTOR-supplied fittings.

4. Coating around tank penetrations shall be recoated to match existing coating in both material and color on both the dry side and wet side of each tank.

5. Tank penetration will be performed adjacent to the hatch on the dome of the tank.

D. Installation of wet-side components shall be performed by experienced installation personnel with confined space training while the tank is full, but isolated from the system.

E. Before being placed back into service tank shall be chlorinated and tested in accordance with the provisions of SECTION 13225, PRESTRESSED CONCRETE TANKS. The

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CONTRACTOR shall clean the floor of the tank and interior area of the tank wall where the penetration occurs as need for proper installation.

3.02 TRAINING

A. The THM Removal System manufacturer staff or their representatives will provide instruction on the safe and proper operation of the mixer to CONTRACTING OFFICER.

This training will reference the operations manual provided with equipment, and show how to check the equipment to ensure it is operating properly. Training shall take place at the time of installation. As part of this training, the manufacturer shall instruct the CONTRACTING OFFICER to the optimal speed of mixer operation for mixing.

END OF SECTION