Technical Exhibit AD Div 44 Pollution Control Equipment.pdf

DUST COLLECTION SYSTEM 441116.10- 1

SECTION 441116.10 – DUST COLLECTION SYSTEM

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

A. Drawings and General Provisions of the Contract, including General and Supplementary Condition and Division 01 Specification Sections, apply to this Section.

1.2 SCOPE

A. Furnish and install, where shown on the Plans, a high efficiency filter type dust collector with integral blower sized for design air flow of 500 CFM – 5,000 CFM as specified on the Drawings.

1.3 SUBMITTALS

A. Submit manufacturer’s technical product data for unit dust collector showing dimensions, capacities, specifications, ratings, motor electrical characteristics, finishes of materials and installation instructions.

1.4 QUALITY ASSURANCE

A. AMCA Compliance: Provide unit dust collector in accordance with AMCA Standards.

PART 2 - PRODUCTS

2.1 EQUIPMENT

A. Dust collector shall be self-cleaning type complete with cotton filters, backward inclined blower, motorized shaker, factory wired controller and external discharge silencer.

Manufacturer’s literature shall state that dust collector and selected filter spacing is designed for the collection of wood dust.

1. Dust collector shall be airtight, all steel construction with sealed seams and gasketed quick opening doors with 1/4 turn knobs. Housing shall be a minimum of 14 gauge mild steel. Unit shall consist of a filter section and a funnel bottom section without slide gates or doors to allow downflow of dust directly into 55 gallon drum assemblies furnished by the manufacturer. Inlet, with baffle, shall be centered on the rear of the unit, for even distribution of dust to the drums. Designs with inlet on narrow side shall not be accepted.

Include an explosion relief vent, in the dirty section of the filter housing, per NFPA No.

68 and No. 664.

DUST COLLECTION SYSTEM 441116.10- 2

B. Unit shall include a multi-pocket filter modules, which is sewn from 8 ounce cotton sateen fabric designed to deliver in excess of 99.5 percent efficiency by weight on industrial dusts.

The filter module shall have rigid insert separators to prevent collapse of filters and loss of the effective filter area. Flat shaker fingers located at the bottom of the filter module shall prevent adjoining pockets from touching one another and blanking off. The filter pocket spacing shall be of the wide spacing type (1-1/2 inch) to permit the collected dust to be shaken off the filters freely and recommended by the manufacturer for the collection of wood dust. Fabric media with narrow spacing or pleated cartridges will not be accepted.

1. Total airflow to the filter fabric area (air to cloth ratio) shall not exceed 10 CFM per S.F.

2. Each filter module shall be secured in place by two lever, operated over-center, locking mechanisms to assure a positive seal and allow for easy removal of filters from outside of the unit, without tools. Designs which require entry into the unit (confined space), for filter maintenance, are not acceptable.

C. Filters shall be cleaned automatically after a fifteen second delay following the shutdown if the blower, by the oscillating action delivered by the motorized eccentric driven shaker assembly, which imparts a vibratory force throughout the entire surface of each individual fitter pocket to dislodge the dust. Shaker motor shall be 2 HP-10 HP determined by design air flow.

1. Operation of the automatic shaker shall be controlled by a solid state, dual mode timer with adjustable shaker cycle range from 1.8 – 180 seconds. Magnetic starters with overload relays for the blower and shaker motor and control transformer shall be factory wired in a NEMA 4 control panel mounted on the unit for single point wiring. Also included shall be a pushbutton station for remote mounting.

D. The control panel wiring shall be either UL or ETL labeled for compliance with 508A. Control

Panels not labeled by dust collector manufacturer shall be labeled, in field, by a certified UL or ETL representative, prior to placing equipment in operation.

E. The integral non-sparking AMCA Type C direct drive blower shall be located on the clean air side of the filters, top mounted at the factory and be of the backward inclined design with a dynamically balanced impeller. It shall be driven by a motor sized according to design air flow.

The blower shall be tested in accordance with AMCA Standard 210. A factory-supplied cover shall protect the motor cooling fan from ice.

F. Discharge noise from the blower shall be attenuated by an external field supported dust silencer fabricated with 4.75 lb. density inorganic mineral or glass fiber. This media shall be protected from erosion by the air flow through the use of galvanized perforated metal with aerodynamic leading and trailing edges to insure maximum acoustical insertion loss at minimum static pressure drop. Lining of the fan scroll, instead of an external silencer, shall not be accepted.

Include factory installed bird screen on discharge of silencer.

G. Interior and exterior carbon steel surfaces shall be painted with one coat of heat cured gray powder spray or interior and exterior primed with red oxide and exterior finished with alkyd resin gray enamel paint.

DUST COLLECTION SYSTEM 441116.10- 3

H. Electrically interlock each woodworking machine with the dust collector so that, when a machine is turned on, the dust collector comes on automatically. Include manual override, to permit use of floor sweeps, without having any equipment energized.

I. Provide a start/stop station with 2-position selector switch (automatic/manual) and an adjustable delay timer that will keep the dust collector on for 15 – 120 seconds after the last machine is switched off, to minimize dust collector cycling and allow the dust in the duct system to be evacuated.

J. All wiring shall be centralized at the circuit breaker panel, for each of installation and expansion for future machines. The interlock shall not require hard wiring at the machines, modification of the motor starters or special auxiliary contacts.

K. Furnish the UL labeled Dust Switch.

PART 3 - EXECUTION

3.1 INSTALLATION

A. The Dust Switch shall mount next to the circuit breaker panel and be electrically interlocked with the operation of the machines in the shop and the dust collector. It shall be furnished with current transformers that are installed in the circuit breaker panel and a 3-hole (outhouse) pushbutton station, that includes “on”, “off”, and a 2-position selector switch for “auto” or “manual”.

B. Selector switch is set to “auto” (normal position – dust collector and machines are interlocked).

1. Switching on any shop machine will start the dust collector fan.

2. When the last machine is switched off, the dust collector fan will remain on for an additional 60 seconds, to prevent cycling of motor, if only one machine is on at a time and allow ducts to be evacuated of dust. (Delay is adjustable from 12 seconds to 2-1/2 minutes).

3. The motorized filter shaker is activated for 30 seconds (adjustable from 5 seconds to 1- 1/2 minutes), 15 seconds after the dust collector fan is switched off.

C. Selector switch is set to “manual” (dust collector and machines operate independently).

1. Pressing the “start” button on the Dust Switch pushbutton station starts the dust collector fan.

2. Pressing the “stop” button on the Dust Switch pushbutton stops the dust collector fan.

3. The motorized filter shaker is activated for 30 seconds (adjustable from 5 seconds to 1-

1/2 minutes), 15 seconds after the dust collector fan is switched off.

D. Install dust collector system according to manufacturer’s written instructions.

E. Training: Provide training in use of equipment by a factory trained representative.

END OF SECTION 441116.10

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 1

SECTION 444100 – PACKAGED WASTEWATER TREATMENT SYSTEM

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section.

1.2 SUMMARY

A. Section includes:

1. General Requirements for providing and installing a complete and functioning packaged wastewater treatment aeration system.

B. Related Requirements:

1. Section 033000 ‘Cast-In-Place Concrete’ for concrete tanks.

2. Section 023000 ‘Earth Moving’ for excavating, backfilling and grading.

3. Section 034100 ‘Precast Structural Concrete’

1.3 PRE-INSTALLATION MEETINGS

A. Pre-Installation Conference: Conduct conference at Project site.

1.4 SUBMITTALS

A. Product Data: for each type of product.

1. Include manufacturer’s material specifications, construction details, dimensions of individual components and all accessories required for a complete, packaged, wastewater treatment, aeration type system either above ground or below.

B. Shop Drawings:

1. Sewage Treatment Plant Layout Drawings

Show the complete assembly of the plant with all components, equipment, and parts, each with an assigned number corresponding to the plant manufacturer's parts list.

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 2

2. Sewage Treatment Plant Component Drawings Show construction details for each component and piece of equipment, including aeration tank, settling tank, aerobic digester, chlorine contact tank, blower assembly, diffuser layout, pump assemblies, comminutor assembly, mechanical aerator assembly, support slab, mechanical sludge collector assembly, chlorinator assembly, hypochlorinator assembly, appurtenances, and all piping and wiring.

3. Diffuser Layout Drawings Show construction details for the diffuser layout including diffusers, diffuser holders and diffuser holder assemblies blower assembly, and air piping layouts.

4. Mechanical Aerator Drawings Show manufacturer's suggested geometry in sufficient detail for construction. Show construction details for the mechanical aerator assembly, including shroud and draft tube (if used).

5. Excavation and Backfilling Include specific instructions for excavation and backfilling as interrelated to plant installation and any special concrete work necessary for setting of settling tanks.

C. Maintenance Data

1. Manufacturer’s written instructions for maintaining and operating the system.

1.5 QUALITY ASSURANCE

A. Manufacturer List of Prior Installations

Submit a list of installations where plants of similar type as herein specified have been constructed, including the date of construction and capacity of the plant. Certify that the plant furnished and installed is the latest model and that spare parts are available.

B. Package Sewage Treatment Test Reports

A certified test report by NSF or an independent laboratory for the package sewage treatment plants shall accompany all proposals. This certification shall include a true copy of the tests performed as stated in paragraph entitled "Quality Control," and shall state whether any deviations from the tests required were made. It shall also state what effects, if any, plant size or capacity will have on the results of the plant tested. This certification shall be signed by at least two officials of the organization making the tests.

1.6 DELIVERY AND STORAGE

A. All equipment and parts shall be packaged for shipment to prevent breakage, damage or cause out-of-adjustment calibration, readings, or controls. Materials delivered to the site shall be inspected for damage and shall be unloaded and stored with a minimum of handling. Only structural steel members, steel plates, boxes, channels, weirs and baffles may be stored outdoors, off the ground, and under a weathertight covering. All equipment shipped separately and not mounted on the plant shall be stored indoors, off the floor. The area shall be dry with adequate ventilation, free from dust or water, and shall permit easy access for inspection and handling.

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 3

B. Prefabricated steel plants shall be lifted off the truck at the site and placed on the prepared concrete slab. During inclement weather, the Contractor shall cover the plant until such time that an inspection can be made of the equipment delivered to assess any damage, if any has occurred in transit. The Contractor shall be responsible for material delivered and stored at the site or other location. Contractor shall take measures for security of the equipment and it will be his sole responsibility up to the time of acceptance of the plant by the Owner.

PART 2 - PRODUCTS

2.1 MANUFACTURERS

A. Manufacturers: Comply with Requirements.

2.2 SYSTEM DESCRIPTION

A. The sewage treatment plant (STP) shall include comminutor aeration tank, settling tank, chlorine contact tank, aerobic digester, aeration equipment, other related facilities. Duplicate plants of equal size having a combined capacity equal to the average design flow specified are acceptable. The plant shall be basically of steel construction, (1,000 GPD – 500,000 GPD), (1.0 MGD – 5.0 MGD for Municipal systems), either prefabricated or field-erected; or shall be of concrete construction, (10,000 GPD – 500,000 GPD), (1.0 MGD – 5.0 MGD for Municipal systems) either precast or cast-in-place; or shall be of fiberglass (1,000 GPD – 1,500GPD). It shall be complete and self-sufficient except for electric power, water supply, and chlorination agent.

B. Unless otherwise specified, all materials and equipment shall be new and be standard commercial products in regular production by the manufacturer, and suitable for the required service. The sewage treatment plant shall include the following systems and components: A diffused air aeration system or mechanical aerator(s) for the aeration tank and the aerobic digester; mechanical sludge collection equipment (if used) for the settling tank; froth control system for the aeration tank; sludge pumps in the settling tank and the aerobic digester for sludge transfer; scum removal system for the settling tank; a comminutor at the plant inlet; a chlorinator, hypochlorinator, and all necessary piping. All structural steel shall conform to ASTM A 36/A 36M. Al submerged steel members shall have minimum thickness of 1/4 inch.

Reinforced concrete slab shall be designed and constructed for all-steel treatment plant.

C. The following factors should be considered in determining whether plant will be above ground

(at finished grade) or below ground (below finished grade):

1. Gravity flow to plant is to be preferred; need for pumping sewage to plant should be avoided.

2. Elevation should be such as to avoid flooding from surface runoff.

3. Plant should be not less than 3 feet above water table.

4. Plant should be installed below ground in cold locations to prevent freezing; however, concrete plant offers somewhat more protection against freezing than steel.

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 4

5. Aesthetic considerations.

6. Extremely aggressive soil conditions.

7. Initial cost savings resulting from aboveground installation.

8. Projected relocation of plant.

2.3 TANKS

A. Plans shall include aeration tank, settling tank, aerobic digester tank, and chlorine contact tank.

Tanks may be separate or contiguous with a common partition between. Plant structure and separate tank structures shall be designed to withstand hydrostatic pressures and seismic loading when installed above grade and filled to normal operating liquid level soil pressures (as indicated by Owner-furnished soil borings) when installed below grade, backfilled, and dewatered; and seismic loading when installed below grade, backfilled, and filled to normal liquid operating level. The seismic design shall be based on a load of 133percent of the combination of the weight of the plant filled to normal operating liquid level plus the seismic loading for the Seismic Zone where the project is located. Forces from seismic loading shall be determined by using the basic formula V = ZKCW, where K= 2.0, C = 0.1, and W is the weight of the tank plus its effective content. The plant and support slab shall have sufficient mass to overcome flotation forces when the entire plant is dewatered. Provisions shall be made for dewatering of individual tanks or compartments and entire plant. Shear gates shall be provided for closure of submerged openings in tank partitions.

2.4 STEEL TANKS

A. Tanks shall be suitable for support by and anchorage to a concrete base. Steel tools shall be in accordance with the applicable requirements of AWWA D100 for shop fabrication and welding of AWWA D100. All shop welding shall be done by a qualified welder. Steel tank walls and bottom shall be structural steel plate. All structural steel shapes used for reinforcing and bracing shall be 6 mm 1/4 inch in the thinnest section. Placement of reinforcing and bracing shall not adversely affect performance characteristics with aeration tank. All welded steel structural members shall be joined by electric arc welding with fillets of adequate section for the joint involved. All sides, compartment partitions, tank bottoms, braces, and corners shall be continuously welded inside and out and ground smooth before priming. Water tightness shall be provided by means of welding. Common partitions shall be reinforced to withstand pressures resulting from liquid level differentials which would occur when any individual compartment(s) is dewatered while contiguous compartments remain at normal operating liquid level.

2.5 CONCRETE TANKS

A. Concrete plant is considered as plant having outer walls of concrete regardless of material used for interior walls or partitions Concrete work includes concrete plant walls, partitions, and bottom; support slab for all-steel plant or concrete bottom for steel wall plant; and concrete pad for equipment support. Results of Owner-made soil bearing tests will be furnished to the Contractor.

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 5

B. Design shall meet local codes.

C. Design Specifications: ACI 318.

D. Concrete used in the manufacturer of the various structural components of the precast concrete tanks shall be factory batched.

E. Portland Cement shall be Type I, II, or III conforming to ASTM C-150.

F. Coarse aggregate shall consist of 1/2 inch or 3/4 inch nominal well graded crushed or native stone conforming to ASTM specification C-33.

G. Air entrainment admixture shall conform to ASTM C260. The air-entrained content shall be not less than 4 percent not greater than 7 percent.

H. A high-range water reducer shall be used and shall conform to ASTM C494 type A or F.

Concrete shall be placed at the slump and water/cement ratio of ASTM requirements.

I. The concrete used for the structural components shall attain a minimum 28-day compressive strength of 4,500 psi.

J. Reinforcing

1. Reinforcing steel shall be new billet steel meeting the requirements of ASTM A615 or ASTM A706. Welded wire fabric shall conform to ASTM A185.

2. Minimum cover over reinforcement shall be 1 inch. Minimum bar lap shall be 30 bar diameters.

3. All reinforcement shall be free from loose rust, oil, and contaminates which reduce bond.

Any foreign material shall be removed by suitable means prior to installation.

4. Provide supports for reinforcement including chairs, bolster bars, and other devices for spacing and securing reinforcing in accordance with CRSI requirements. Legs of all supports in contact with exposed-to view surfaces shall be plastic coated in accordance with CRSI, Class I.

2.6 FIBERGLASS TANKS

A. Tank material is Isophthalic polyester resin with glass fiber reinforcement. Single, double or triple wall construction with integral ribs. Tanks conform to UL Standard 1316 and AINSI/AWWA D120 Thermosetting Fiberglass Reinforced Plastic Tanks.

2.7 AERATION EQUIPMENT

A. The aeration system shall be of the diffused air type or fixed mechanical aeration type capable of transferring not less than 0.45 kg 1.0 lb of oxygen to the mixed liquor per pound of 5-day BOD aeration tank loading and maintaining complete suspension of all sludge solids throughout the entire aeration tank. The aeration equipment shall completely mix the contents of the aeration tank so that the velocity in any part of the tank shall be not less than 0.18 m/s 0.6 fps.

The aerator shall have sufficient mixing capacity to thoroughly mix the wastewater throughout the tank depth, to maintain essentially equal D.O. concentration within the basin, and to

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 6

maintain the biological floc in suspension in concentrations of up to 4,000 mg/l. Minimum acceptable velocity throughout the basin is 0.18 m/s 0.6 fps.

2.8 SLUDGE AND SCUM COLLECTION AND TRANSFER EQUIPMENT

A. Sludge and scum collection and transfer equipment shall include sludge transfer pump(s), mechanical sludge collection equipment (if used), scum collection and transfer system, and supernatant transfer. Settling tanks with hopper bottom and side walls having slope of not less than 1.05 rad 60 degrees with the horizontal need not be provided with mechanical sludge collection equipment.

2.9 PIPING

A. Piping System Materials

1. Steel Piping: Steel pipe for sizes 100 mm 4 inch diameter and smaller shall be standard weight zinc-coated steel pipe conforming to ASTM A 53/A 53M, with fittings of cast iron conforming to ASME B16.4, Type II. Steel pipe for sizes 5 inch diameter and larger shall be seamless or electric-resistance welded, standard-weight, black steel pipe conforming to ASTM A53/A 53M, Grade B. Joints for pipes sizes 2 inch diameter and smaller shall be screwed joints. Joints for pipe sizes 63 mm 2 1/2 inch through 4 inch diameter shall be screwed or flanged. Flanges shall conform to, ASME B16.5, or AWWA C207. Bolts and nuts for flanged connections shall conform to the requirements specified in AWWA C207. Gaskets shall be plain rubber gaskets 1/8 inch thick.

2. Cast Iron Piping: Cast iron piping shall be standard commercial grade cast iron pressure pipe and fittings shall be suitable for the purpose.

2.10 FLOW MEASURING EQUIPMENT

A. The effluent flow measuring equipment shall be V-notch weir and flowmeter.

2.11 ELECTRICAL CONTROL SYSTEM COMPONENTS

A. The system shall include enclosure; main and branch circuit breakers; starters, contactors, and reset buttons; selector switches, push buttons, and pilot lights; circuit control items for electrical control of the various plant components; and all necessary wiring and tubing. Electrical control system shall be in accordance with NEMA ICS 1. Design, fabrication and installation of all electrical components shall be in accordance with requirements of NFPA 70. Electrical controls shall be mounted in outdoor weatherproof enclosure, NEMA 3R or indoor enclosure, NEMA 1 OR NEMA 12. Enclosure shall be divided into compartments. Compartment for time clock and timers shall be separate and isolated from that housing other electrical components, except that lighting circuit breaker may be included therein. Electrical controls shall be wired so that the various items of plant equipment can be operated either manually and/or automatically to achieve the sequence of operation specified hereinafter. All electrical control system components shall be completely wired and mounted in the enclosure at the manufacturer's plant

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 7

and tested prior to shipment from the factory. All push buttons, selector switches, and indicating lights shall be installed on the outside of the door(s), properly identified with laminated phenolic name plates. All components on outside of enclosure and on internal panels shall be identified by engraved laminated phenolic legend plates.

2.12 APPURTENANCES AND ACCESSORIES

A. As indicated on drawings.

2.13 UTILITIES SERCVICE CONNECTIONS

A. Water line: Shall be a 25 mm one inch copper water line extending from a point not less than 5 feet from the treatment plant to the hypochlorinator housing or chlorinator. A one inch valve in a frost-proof valve box shall be provided below grade. A 3/4 inch hose bibb shall be provided in the hypochlorinator or chlorinator housing.

B. Electrical Service: An electric service line shall be provided from a point not less than 5 feet from the treatment plant to the electrical control system enclosure.

2.14 CATHODIC PROTECTION

A. Cathodic protection shall be provided for the steel-fabricated sewage treatment plant when installed below grade. This protection shall consist of installing one 17 pound magnesium anode package not less than every 25 feet along the outer steel shell of the plant. The anodes shall be securely connected with solderless electrical connectors to the shell with not less than No. 8 copper wire, factory installed.

2.15 TREATMENT AND PAINTING

A. Except as otherwise specified, equipment shall be treated and painted in accordance with the manufacturer's standard practice. All exposed surfaces of ferrous metals, other than piping, including those to be submerged, shall be sandblasted in accordance with SSPC SP 6/NACE No.3 and shop coated with two coats of epoxy polyamide conforming to SSPC Paint 16 applied to a minimum dry film thickness of 8 mils per coat. The maximum time between coats shall be 72 hours. The following items shall be finished in accordance with manufacturer's standard practice suitable for end use environment: blowers, motors, gearmotors, motor-driven speed reducers, shafts, comminutor, chlorinator or hypochlorinator and pushbutton stations.

B. Aluminum shall have an AA-CC-22-A41 finish. Stainless steel, stellite and nonferrous metals shal l not be coated. Exposed surfaces of concrete tanks shall be provided with two coats of rubber-based paint, gloss or semi-gloss, conforming to CID A-A-3120. Blower housing, chlorinator or hypochlorinator housing, and electrical control system enclosure shall be cleaned and sanded. Any external marks or scratches that remain after sanding shall be filled with an epoxy plastic resin and then ground smooth leaving a smooth level surface. All surfaces of housings and enclosures shall be coated with zinc-molybdate primer conforming to FS TT-P- 645, and finish coat conforming to MIL-PRF-24635 or FS TT-E-1593, color as directed. All

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 8

exterior surfaces of piping which subject to total or intermittent submersion shall be given a vinyl paint system in accordance with SSPC PS 4.02. All exterior surfaces of piping that is not subject to submersion or which is buried shall be given a coal tar coating system in accordance with SSPC PS 10.01.

2.16 ELECTRICAL REQUIREMENTS

A. Electrical components of mechanical equipment and systems such as motors, starters, chart drives, electrical disconnecting (isolating) means, and controls shall be provided under this section and shall be as specified herein and as necessary for complete and operable systems.

Motors shall conform to NEMA MG 1. Interconnecting wiring for factory-wired plant components shall be provided as an integral part of the plant. All interconnecting power wiring and conduit for field erected plant components and control wiring, rated over 100 volts, and conduit shall conform to the requirements of Division 26. Wiring of signal circuit shall be provided as recommended by the equipment manufacturer. The work shall be in accordance with NFPA 70.

2.17 SOURCE QUALITY CONTROL

A. All factory tests shall be conducted by the manufacturer of the package sewage treatment plant in the presence of the Owner.

PART 3 - EXECUTION

3.1 DESIGN

A. The Sewage Treatment Plant shall be capable of treating an average design flow as indicated on the drawings of gallons per day of domestic sewage, having a 5 day (BOD) loading, as indicated on the drawings, milligrams/liter (mg/l), and total suspended solids, as indicated on the drawings (mg/l). The raw sewage shall first pass through a comminutor, screening basket, and an influent distribution channel into an aeration tank of adequate capacity to provide not less than hours detention time (as indicated on drawings) and a maximum organic loading not to exceed amount indicated on drawings, pounds 5 day BOD per 1,000 cubic feet of aeration tank volume at average design flow rate. Sewage shall then pass on to a settling tank of adequate capacity to provide not less than the hours detention time as indicated on drawings, and a surface settling rate not to exceed GPD per square foot as indicated on the drawings, at average design flow rate. The settled sludge shall be collected by a mechanical sludge collector and be recirculated back to the aeration tank where it is to be rapidly and thoroughly mixed in with the aeration tank contents, or wasted to the aerobic digester. The effluent from the settling tank shall be discharged to a chlorine contact tank of adequate capacity to provide a detention time of not less than 15 minutes at peak flow and then to outfall. The aerobic digester shall have a capacity of not less than 2 cubic feet per capita. Aeration shall be by diffused air or mechanical aeration.

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 9

3.2 SLUDGE COLLECTION AND TRANSFER SYSTEM

A. Sludge transfer shall be accomplished by: Separate pumps for return sludge and waste sludge with valved control on discharge side or One pump with valved connections for return sludge and waste sludge.

3.3 AIR BLOWER ASSEMBLY

A. Air blower assembly shall include air blower, blower driver, V-belt drive (for positive displacement blower), housing and accessories.

3.4 FROTH CONTROL SYSTEM

A. The froth control system shall include pump, piping spray nozzles, valves, and discharge strainer. The pump shall pump clarified effluent from the upper part of the settling tank to the spray nozzles in the settling tank. A strainer shall be located on the discharge side adjacent to the pump. A hose bibb easily accessible from the walkway shall be provided in a branch from the froth control system main line piping. A gate valve shall be provided in the froth control system main line piping immediately adjacent to the hose bibb branch on the downstream side.

3.5 HYPOCHLORINATOR ASSEMBLY

A. Hypochlorinator shall pump hypochlorite solution from the solution tank through tubing to the diffuser located in the chlorine contact tank. Hypochlorinator assembly shall include feed pump with motor, hypochlorite mixing tank, hypochlorite solution tank, timer, heater suction and discharge tubing, diffuser, and housing. Hypochlorinator assembly shall be readily accessible and located adjacent to the chlorine contact tank.

3.6 CHLORINATOR ASSEMBLY

A. Chlorinator shall receive chlorine gas from chlorine cylinders and water from the water supply system and discharge chlorine solution through piping to the diffuser located in the chlorine contact tank. Chlorinator assembly shall include chlorinator, scale, chlorine gas manifold, flexible connector, water piping, chlorine solution piping, vent tubing, vacuum signal tubing, diffuser, and housing.

3.7 COMMUNITOR AND BAR SCREEN UNITS

A. The communitor and bar screen assembly shall be complete and self-contained and so arranged that whenever the comminutor is not operating, all sewage shall be diverted automatically through the bar screen before it enters the plant, and whenever the comminutor is operating, all sewage is directed through the comminutor.

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 10

3.8 SCREENING BASKET

A. There shall be furnished and installed at the plant influent, a readily removable, fabricated steel screening basket, sized for maximum flow, which shall be located so that the total volume of incoming raw sewage will be screened before it enters the plant. The basket shall be fabricated from 3/16 inch diameter 302 stainless steel wire or 8 inch hot-rolled steel bars with one inch space between bars.

3.9 INSTALLATION

A. Installation work shall include construction of the concrete support slab(s); setting and anchoring of the treatment plant; construction of concrete pads for equipment not mounted on the plant; field installation of plant equipment, accessories, and appurtenances shipped unmounted to the project site; installation of piping from blowers to air header, piping connections to plant inlet and outlet, and installation of water service line; and installation of electrical wiring from electrical control system enclosure to motors and installation of electrical service to the electrical control system enclosure. The installation work covered by this section also includes earthwork operations as interrelated to plant installation. Except as modified or amplified herein, sewage treatment plant shall be installed in accordance with the recommendations of the manufacturer of the plant.

B. Manufacturer's Representative: The Contractor shall procure the services of an engineer representative of the manufacturer of the major portion of the treatment plant who is also familiar with the other equipment furnished. The representative shall inspect the equipment after erection, make adjustments in placing the equipment in operation, and shall be present during final inspection, start-up, and acceptance test.

C. Adjustments shall be carried out in accordance with product manufacturer's instructions as furnished by the plant manufacturer.

3.10 FIELD TESTS AND INSPECTIONS

A. The Owner’s Project Manager shall conduct field inspections and witness field tests specified in this specification. All defective equipment, materials, or workmanship disclosed as a result of the tests given herein shall be corrected by the Contractor at no cost to the Owner.

B. All mechanical and electrical units shall be operated and tested as specified herein. Should any defects that occur before or during the tests, shall be remedied and changes or replacement of equipment shall be made as may be necessary to comply with these specifications.

C. Plant Start-Up: Before allowing any liquid to discharge into the tanks, all tanks, chambers, channels, launders, piping and pieces of equipment shall be clean and free of any debris such as pieces of wood, concrete or leaves. Manufacturer's representative shall be present at plant start-

up. The Owner’s representative will also be present so that he will become familiar with each piece of equipment and its proper operation and function. The manufacturer's manual on operation and maintenance shall be followed, step by step, so that as each piece of equipment is put into operation, the manufacturer's representative shall explain in detail its function. Once the plant is filled with water or sewage, the flow diagram furnished shall be followed and checked

PACKAGED WASTEWATER TREATMENT SYSTEM 444100 - 11

out with the on-site inspection. The adjusting of equipment shall be made as required. The plant shall be examined to determine if it is structurally sound. All defects noted shall be reported and corrected. If no defects are detected, this shall be reported.

END OF SECTION 444100