B08_Attachment_02_Phase_III_Septic_SOW_20230614.pdf

SCOPE OF WORK (SOW) – SEPTIC SYSTEMS

Minuteman National Historical Park

June 14, 2023

BACKGROUND AND PURPOSE:

Six structures (see map below) at Minuteman National Historical Historic Park are being rehabilitated for use as single family residences. These structures have historical significance to the park. Most structures have municipal water, telephone, and natural gas service. Some have existing sanitary systems which do not meet modern standards. One structure requires a new water treatment system for an existing well.

SCOPE AND OBJECTIVES:

In general, the scope of this project is to:

(1) provide Title 5 engineering services to develop the required drawings and specifications for the local jurisdictions having authority for permitting, inspecting, and approving the work for the sanitary systems. The drawings shall include but not be limited to creating the necessary site plans, elevations, cross sections, and specifications. The site work will include final layout of new systems, salvaging topsoil for reuse, demolition of existing septic tanks (if present), providing new self-contained grinder pump stations (if required), installing new sanitary systems at five structures, installing a new manhole at one structure and connecting to an existing leaching system, electrical service from main breaker panel to grinder pump stations and alarm panels, interior sanitary drain plumbing in basement of structures to tie house plumbing to septic systems complete. Work will also require site clean-up and disposal of debris and excess soil off-site, topsoil replacement, fine grading for drainage, and seeding, fertilizing, and mulching.

(2) work will include excavation and installation of a 48” dia. precast concrete manhole top with 24” cast iron manhole lid over an existing, abandon dug well adjacent to Rego House. No riser is required.

(3) work will also include a new water treatment system for an existing domestic water well to remain at Rego House. Contractor to supply new treatment system, testing, and new water piping to tie new treatment system to water well supply line coming into the basement of Rego House.

Some electrical work may be required to provide power to the new treatment system if required.

Work shall include running new conductors from an approved power source to a new receptacle located directly adjacent to treatment system.

An archeology monitor will be required, provided by the contractor to monitor all excavations.

SUPPORTING INFORMATION:

The following attachments are on file and will be provided upon request including the following:

1. Architectural drawings for the rehabilitation of structures:

a. East Quarter Schoolhouse

b. George Hall House

c. Inferrera House

d. Stow-Hardy House

2. Landscape drawings showing existing topography, general site plan, and wetland delineations at structures:

a. East Quarter Schoolhouse

b. George Hall House

c. Inferrera House

d. Stow-Hardy House

e. Joshua Brooks House

f. Rego House

3. Construction schedule for contractor rehabilitating structures.

4. Construction schedule for contractor rehabilitating trail.

5. Park schedule for scheduled events and staff contact list.

6. Wetlands delineation report.

PURCHASE ORDER REQUIREMENTS, DELIVERABLES, AND TIMELINE:

The following tasks are included in this contract:

Task #1 – Deliverable: Confirm Existing Conditions/Obtain Permits

Timeline Estimate: 60 days

1. Confirm existing conditions including inspections of basements in structures, work by other contractors, preliminary field staking. Basic topographic information supplied by government, wetlands delineation report supplied by government. Government to inform engineers and contractors of archeological concerns.

2. Investigate permitting requirements with local jurisdictions.

3. Develop drawings for the septic systems sealed by a State of Massachusetts licensed engineer. Engineering work shall include electrical and plumbing drawings for each structure as required.

4. Obtain all necessary permits.

5. Submit required documents to the contracting officer including but not limited to:

Copy of approved construction drawings and specifications with engineer’s seal.

Include plans, elevations, sections, details as needed, Include construction material descriptions and dimensions, Include openings in precast structures, covers, and pipe connections, Include electrical and plumbing work as required, Show that new construction is outside 100’ wetlands boundary.

a. Manufacturer's literature and certificates of compliance with the reference standards.

b. Product data sheets.

c. Manufacturers installation instructions.

d. Copies of permits.

e. O&M Manual(s) for packaged sewer pumping station.

f. Designation of Project Supervisor

g. Proposed work schedule

h. Accident prevention plan

i. Waste management plan

j. Tree protection plan

k. Topsoil, seed, and fertilizer certifications

Task #2 – Deliverable: Site Mobilization

Timeline Estimate: 5 days

1. Site mobilization to include but not be limited to:

a. Coordination with building contractor and/or trail contractor (if present).

b. Installation of erosion control measures.

c. Protection of all woody vegetation to remain.

d. Protection of existing pavement.

e. Protection of other existing site improvements.

f. Protection of wetlands and 100’ wetlands boundary.

g. Locate and protect existing underground utilities.

h. Staking for new work performed under this contract.

i. Delivery of materials to an approved staging area directly adjacent to work area.

j. Delivery of equipment.

2. All equipment mobilized on-site shall be free of excess soil and/or plant material collected off-site which could potentially contain exotic/invasive species.

3. Labor practices, tools and equipment shall meet or exceed OSHA requirements. In case of conflicts between Federal, State, and local safety and health requirements, the most stringent shall apply.

Task #3 – Deliverable: Septic System - East Quarter Schoolhouse

737 Lexington Rd.

Concord, MA 01742 Lot #4225 5 Bedroom House

GENERAL SCOPE OF WORK:

1. Demolition of existing septic tank. Plug exposed incoming and outgoing pipes. Backfill with approved, compacted material.

2. Install sanitary piping in basement of schoolhouse and stub out of building.

3. Connect 30 L.F. of 4” PVC from house sanitary line

4. Excavate and install one a 2,000-gallon (est.) precast concrete septic tank with risers and one distribution box.

5. Install secured cast iron manhole covers with frames on precast risers located on tank.

6. Connect tank to proposed distribution box and septic field with 12 L.F. 4” PVC.

7. Trench for 4” perforated PVC pipe w/ required fittings. Field shall be four (4) lateral runs of

79 feet each (assumed).

8. Stone backfill around tanks and pipes.

9. Place metallic warning tape over system.

10. Backfill with soil over and around new septic system. Place topsoil and perform lawn operations.

Task #4 – Deliverable: Septic System - George Hall House

831 Lexington Rd.

Concord, MA 01742 Lot #4229-5

Septic Field (Angle may vary to avoid trees)

Trail relocation by others

New Septic Tank

Existing septic tank to be removed

Schoolhouse

East Quarter Schoolhouse N.T.S.

North

6 Bedroom House

1. Install sanitary piping in basement of George Hall House and stub out of building.

2. Connect 35 L.F.4” PVC from house sanitary line stubbed out of house.

3. Excavate and install one 2,000-gallon (est.) precast concrete septic tank with risers and one distribution box.

4. Install secured cast iron manhole covers with frames on precast risers located on tank.

5. Connect tank to proposed distribution box and septic field with 15 L.F. 4” PVC w/ elbows.

6. Trench for 4” perforated PVC pipe w/ required fittings. Field to be four runs of 78.5’ assumed.

7. Stone backfill around tank and pipes.

8. Place metallic warning tape over system.

9. Backfill with soil over and around new septic system. Place topsoil and perform lawn

Task #5 – Deliverable: Septic System – Inferrera House

1087 Lexington Rd.

Concord, MA 01742 Lot #1087 4 Bedroom House

George Hall House N.T.S.

North

Septic Tank

New Septic Field

George Hall House

2. Install sanitary piping in basement of Inferrera House and stub out of building.

3. Connect 15 L.F.4” PVC from house sanitary line stubbed out of house.

4. Install one prepackaged grinder pump complete.

5. Provide power source for pump and alarm panel with two dedicated circuits from the main breaker panel.

6. Install 90 L.F. forced main between grinder pump and septic tank.

7. Excavate and install one 1,500-gallon (est.) precast concrete septic tank.

8. Install secured cast iron manhole covers with frames on precast risers located on tank and distribution box (three total).

9. Connect tank to proposed septic field with 90 L.F. forced main pipe

10. Trench for 4” perforated PVC pipe w/ required fittings. Field shall be four (4) lateral runs of

56 feet each assumed.

11. Stone backfill around tank and pipes.

12. Place metallic warning tape over system.

13. Backfill with soil over and around new septic system. Place topsoil and perform lawn

Inferrera House N.T.S.

North

Garage

Existing Septic Tank to be Removed

Inferrera House

Roadside Stand

Existing Walking Trail

New Septic Field

Septic Tank

Prepackaged Grinder Pump

Task #6 – Deliverable: Septic System – Joshua Brooks House

Timeline Estimate: 8 days

41 North Great Road Lincoln, MA 01773 Lot #109_3_0 4 Bedroom House

2. Install sanitary piping in basement of Joshua Brooks House and stub out of building.

3. Connect 10 L.F. of 4” PVC from house sanitary line stubbed out of house by others.

4. Install one prepackaged grinder pump complete.

5. Provide power source for pump and alarm panel with two dedicated circuits from the main breaker panel.

6. Install 125 L.F. forced main piping from duplex pump to proposed location of new septic tank.

7. Excavate and install one 1,500-gallon precast concrete septic tank and distribution box.

8. Install secured cast iron manhole covers with frames on precast risers located on tank and distribution box (three total).

9. Connect tank to proposed septic field with 4” PVC.

Joshua Brooks House N.T.S.

North

Prepackaged Grinder Pump

Joshua Brooks House

Force Main

Existing Septic Tank to be Removed

Septic Field

New Septic Tank

10. Trench for 4” perforated PVC sewer pipe w/ required fittings. Field shall be four (4) lateral runs of 56 L.F. each assumed.

11. Stone backfill around tanks and pipes.

12. Place metallic warning tape over system.

13. Backfill with soil over and around new septic system. Place topsoil and perform lawn

Task #7 – Deliverable: Septic System - Rego House

101 North Great Road Rd.

Lincoln, MA 01773 Lot #113_53_0

1. Demolition of two existing septic tank. Plug exposed incoming and outgoing pipes. Backfill with approved, compacted material.

2. Install sanitary piping in basement of Rego House and stub out of building.

3. Connect 130 L.F. 4” PVC from house sanitary line stubbed out of house by others.

4. Excavate and install one 1,500-gallon (est) precast concrete septic tank.

5. Install secured cast iron manhole covers with frames on precast risers located on tank.

Rego House N.T.S.

North

Rego House

Remove Existing Septic Tank

Garage

New Septic Tank

Remove Existing Septic Tank

Septic Field

Well To Be Capped

6. Trench for 4” perforated PVC sewer pipe w/ required fittings. Field shall be four lateral runs of 56 L.F. assumed.

7. Stone backfill around tank and pipes.

8. Place metallic warning tape over system.

9. Backfill with soil over and around new septic system. Place topsoil and perform lawn operations.

10. Install precast concrete cap on existing water well to secure top of well

11. Install water treatment system in basement of Rego House to treat drinking water from existing well.

Task #8 – Deliverable: Septic System – Stow-Hardy House

965 Lexington Rd.

Concord, MA 01742 Lot #4232

Force Main Adjacent Farm House

Edge of Pavement

New Manhole

Garage

Stow Hardy House N.T.S.

North

Stow Hardy House

Prepackaged Grinder Pump Edge of Vegetation

Stone Driveway

1. Connect to house sanitary line w/ 10 L.F. PVC. Pipe stubbed out of house by others.

2. Install sanitary piping in basement of Stow Hardy House and stub out of building.

3. Install prepackaged underground grinder pump complete.

4. Provide power source for pump and alarm panel with two dedicated circuits from the main breaker panel.

5. Install 75 L.F. forced main piping from duplex pump to proposed location of new septic tank.

6. Locate existing outgoing pipe at the edge of existing asphalt pavement which pitches towards an existing septic system, located on the opposite side of the paved driveway.

7. Excavate and install one 1,500-gallon (est) precast concrete septic tank at location of outgoing pipe.

8. Install secured cast iron manhole covers with frames and precast risers for tank (two required).

9. Stone backfill around tank and pump.

10. Backfill with soil over and around new septic system. Place topsoil and perform lawn

Task #9 – Deliverable: Selective Demolition

SITE CUT 4” SANITARY LINE

AND PLUG

DEMOLISH EXISTING

SEPTIC TANK

East Quarter Schoolhouse X X

George Hall House X No existing tank

Inferrera House X X

Stow-Hardy House No existing tank

Joshua Brooks House X X

Rego House X X – Two small tanks

1. Work consists of demolition and removal of the following:

a. Cut and plug existing 4-inch cast iron or plastic pipes.

b. Demolish existing septic tanks.

c. Pump out and clean existing septic tanks before demolition.

2. Comply with safety requirements for demolition, ANSI A10.6-90.

a. Keep dust to a minimum at removal site and on haul roads. Use sprinklers or water trucks as necessary.

b. Ensure safety of persons in demolition area. Provide temporary barricades as required.

c. Explosives shall not be used.

3. Protect from injury all vegetation in the area.

4. Salvage topsoil and stockpile for reuse.

5. Determine the exact location of existing underground utilities and perform Work in a manner that will avoid possible damage to them. Any utilities damaged by Work shall be immediately repaired to the satisfaction of the Government at no additional cost to the Government.

6. Backfill materials below topsoil layer shall be native soils, stone, gravel, or sand, free from debris, frozen materials, and roots and other organic matter. Place backfill material in horizontal layers not exceeding 8 inches in loose depth. Roll but do not compact each layer to a density equal to surrounding ground. Distribute concrete and masonry pieces in fill material in a way that ensures adequate compaction and at a depth that will not interfere with new construction and grading. Fill the voids with backfill material.

7. Lawns and any other pavement disturbed will be repaired by the Contractor to match original grades and finishes. Blend topsoil with original contours and provide free drainage flow.

8. Disposal of debris, vegetation and unused excavated materials at an approved disposal site is the Contractor’s responsibility and must be in accordance with Federal, State, and local regulations.

Provide copies of all permits required. Debris and rubbish shall be removed from the site daily.

If debris and rubbish is not removed daily, provide a storage container to contain the debris and rubbish. Clean site daily by depositing debris and rubbish into container.

Task #10 – Deliverable: Precast Concrete Structures

Timeline Estimate: Included in Task Items 3 - 8

SITE 1,500

GALLON

w/

RISERS

2,000

GALLON

w/

RISERS

DISTRUBUTION

BOX

MANHOLE

WITH CONE

TOP/LID

48” CONC.

TOP

WITH LID

East Quarter Schoolhouse

X X

George Hall House

X X

Inferrera House

X X

Stow-Hardy House

X

Joshua Brooks House

X X

Rego House X X X

Furnishing and installing precast reinforced concrete, two compartment septic tanks, outlet distribution boxes, manhole, flat top for a manhole and appurtenaces. Precast concrete units, risers, and lids to withstand HS-20 traffic loads.

PERFORMANCE REQUIREMENTS:

Comply with ACI 318, PCI MNL 120, "PCI Design Handbook, Manual for Quality Control for Plants and Production of Precast Concrete Products.

DELIVERY:

Handle Precast units carefully to ensure delivery at the project site in sound, undamaged condition.

Contracting Officer will reject damaged materials. Contractor shall replace damaged materials at no additional expense to the Government.

STORAGE:

Do not store materials directly on the ground. Adequately support to prevent damage.

PRECAST CONCRETE SEPTIC TANK AND DISTRIBUTION BOX:

1. FINISHES: Standard for formed surfaces

2. MANHOLES: 24” diameter cast iron opening with risers to grade and securable access lid with steel lift rings.

3. FILTER: Provision to install Filter in the outlet of the septic tanks to restrict discharge solids to

1/8-inch.

4. INLET AND OUTLET ACCESS: Match 4-inch dia. PVC pipes.

5. BEDDING AND BACKFILL: Fill to top of structures; ¾” stone. Salvaged topsoil above structures.

EXECUTION

1. Install precast units to lines and grades established in the field.

2. Inspect units for defects. Defective, damaged, or unsound units will be rejected by the Contracting

Officer.

3. Precast Concrete Units and other accessories shall, unless otherwise directed in the Special Provisions, be unloaded at the point of delivery, hauled to and distributed at the site of the project by the Contractor. They shall, at all times, be handled with care to avoid damage. In distributing the material at the site, each piece shall be unloaded opposite or near the place where it is to be laid in the trench.

INSTALLATION

1. Install precast concrete septic tanks according to ASTM C 891.

2. Shore and brace precast concrete units to maintain location, stability, and alignment.

3. Install precast units level and plumb.

4. Install filter in septic tank outlet. Secure filter to septic tank wall.

5. Clean exposed surfaces of precast concrete units after erection and completion of joint treatment to remove weld marks, other markings, dirt, and stains.

Task #11 – Deliverable: Root Barrier Fabric

Timeline Estimate: Included in Task Items 3 – 7

SITE ROOT BARRIER REQUIRED

East Quarter Schoolhouse

North and East sides of septic field (109 L.F.)

George Hall House

Northwest side of septic field (70 L.F.)

Inferrera House No root barrier required

Stow-Hardy House

No root barrier required

Joshua Brooks House

South sides of septic field (56 L.F.)

Rego House North, East, and South sides of septic field (142 L.F.)

Furnish all labor, materials, equipment, and incidentals required to install root barrier along portions of the septic field to provide both a physical and chemical barrier zone to restrict vegetative root encroachment as specified herein.

DELIVERY, STORAGE, AND HANDLING:

1. Product labels shall clearly show the manufacturer or supplier name, style number, and roll number and shall include a compliance statement certifying that all ingredients and inspection standards for this product have been met.

1. Root control product roll shall be wrapped with a protective EVOH bag and placed in a box that will protect the product from damage due to shipment, water, sunlight, and contaminants and to prevent premature release of herbicide. The protective wrapping shall be maintained during periods of shipment and storage.

2. During storage, root control product shall be elevated off the ground and out of direct sunlight. It shall remain sealed in EVOH protective bag inside shipping box at a temperature of not more than 110°F.

PHYSICAL AND CHEMICAL REQUIREMENTS:

1. Fibers used in the manufacture of a roll of root control barrier substrate fabric shall consist of long chain synthetic polyolefins (at least 95% by weight) and a UV stabilizer. They shall be formed into a stable network such that the filaments or yarns retain their dimensional stability relative to each other.

2. Nodules consisting of trifluralin, carbon black, and polyethylene compounded in a patented method utilizing time-released characteristics are permanently attached to the substrate fabric on 1-1/2” centers by a through injection molding process.

3. All substrate property values, with the exception of apparent opening size (AOS), in these specifications represent minimum average roll values (MARV) in the weakest principal direction (i.e., average test results of any roll in a lot sampled for conformance or quality assurance testing shall meet or exceed the minimum values provided herein). Values for AOS represent maximum average roll values.

4. Property values for the trifluralin are average run values.

PRODUCT DESCRIPTION:

Overall product major composition and ingredients:

Active – Trifluralin - 17.5% Inert - 100% Spunbonded Polypropylene, Polyethylene and Carbon – 82.5%

Minimum Values:

Characteristics English Metric Test Method

Unit Weight 3.9 oz/yd

130 g/m

ASTM D-5261 Grab Tensile Strength

130 lbs. 575 N ASTM D-4632

Elongation at Break 60% 60% ASTM D-4632

Puncture Strength 40 lbs. 175 N ASTM D-4833

Trap Tear 60 lbs 265 N ASTM D-4533

Permittivity 0.7 sec. 0.7 sec. ASTM D-4491

AOS (Max Value) 0.21 mm 0.21 mm ASTM D-4751

Ultraviolet Stability 70% @ 500 hrs 70% @ 500 hrs ASTM D-4355

INSTALLATION:

1. Fabric roll shall be unrolled and cut into required lengths. The fabric shall be placed by hand along the sides of the outermost trenches for the lateral lines. The fabric shall be held in place with nails and/or pins. Install fabric after lateral runs are placed but before backfilling operations. Assure fabric stays in place during backfill.

Task #11 – Deliverable: Facility Sanitary Sewers

Timeline Estimate: Included in Task Items #3 – #8

SITE Distance from building to pump or tank

Distance from pump or tank to septic field

Septic Field Laterals – 4” perf.

sewer pipe in 2’ wide trenches with 12” sidewalls*

East Quarter Schoolhouse

30’

PVC

12’

PVC

4 runs at 79’ each

George Hall House

35’

PVC

15’

PVC

4 runs at 79’ each

Inferrera House

15’

PVC

(90’ Forced Main)

4 runs at 56’ each

Stow-Hardy House

10’

PVC

(75’ Forced Main)

Tie into existing system

Joshua Brooks House

10’

PVC

(125’ Forced Main)

4 runs at 56’ each

Rego House

130’

PVC

15’

PVC

4 runs at 56’ each

*if space is limited due to trees, trails, wetland boundaries, previously unidentified utilities, etc., leaching chambers are an acceptable alternative to the 4” PVC laterals.

Task Includes:

1. All pipe and fittings.

2. Non-pressure couplings.

3. Cleanouts (if required).

PIPE:

PVC Type PSM Sewer Piping:

1. Pipe: ASTM D 3034, SDR 35, PVC Type PSM sewer pipe with bell-and-spigot ends for gasketed joints.

2. Fittings: ASTM D 3034, PVC with bell ends.

3. Gaskets: ASTM F 477, elastomeric seals.

NON-PRESSURE-TYPE TRANSITION COUPLINGS:

Comply with ASTM C 1173, elastomeric, sleeve-type, reducing or transition coupling, for joining underground non-pressure piping. Include ends of same sizes as piping to be joined and corrosion-resistant-metal tension band and tightening mechanism on each end.

Sleeve Materials:

1. For Plastic Pipes: ASTM F 477, elastomeric seal or ASTM D 5926, PVC.

2. For Dissimilar Pipes: ASTM D 5926, PVC or other material compatible with pipe materials being joined.

Unshielded, Flexible Couplings:

1. Description: Elastomeric sleeve with corrosion-resistant-metal tension band and tightening mechanism on each end.

CLEANOUTS:

Cast-Iron Cleanouts: ASME A112.36.2M, round, gray-iron housing with clamping device and round, secured, scoriated, gray-iron cover. Include gray-iron ferrule with inside calk or spigot connection and countersunk, tapered-thread, brass closure plug.

1. Top-Loading Classification: Light Duty

2. Sewer Pipe Fitting and Riser to Cleanout: ASTM A 74, Service class, cast-iron soil pipe and fittings.

PIPING INSTALLATION:

1. General Locations and Arrangements: Drawing plans and details indicate general location and arrangement of underground sanitary sewer piping. Location and arrangement of piping layout taking into account design considerations. Install piping as indicated, to extent practical. Where specific installation is not indicated, follow piping manufacturer's written instructions.

2. Install piping beginning at low point, true to grades and alignment indicated with unbroken continuity of invert. Place bell ends of piping facing upstream. Install gaskets, seals, sleeves, and couplings according to manufacturer's written instructions for using lubricants, cements, and other installation requirements.

3. Install proper size increasers, reducers, and couplings where different sizes or materials of pipes and fittings are connected. Reducing size of piping in direction of flow is prohibited

4. Install gravity-flow, non-pressure, drainage piping according to the following:

a. Install piping pitched down in direction of flow, at minimum slope of ¼” per foot from the building to the septic tank and 1/8” per foot from the septic tank to the distribution box and distribution box to lateral chambers unless otherwise indicated.

b. Install piping with 18” minimum cover.

c. Install PVC Type PSM sewer piping according to ASTM D 2321 and ASTM F 166.

5. Clear interior of piping and manholes of dirt and superfluous material as work progresses.

Maintain swab or drag in piping and pull past each joint as it is completed. Place plug in end of incomplete piping at end of day and when work stops.

PIPE JOINT CONSTRUCTION:

1. Join gravity-flow, non-pressure, drainage piping according to the following:

a. Join PVC Type PSM sewer piping according to ASTM D 2321 and ASTM D 3034 for elastomeric-seal joints or ASTM D 3034 for elastomeric-gasket joints.

b. Join dissimilar pipe materials with non-pressure-type, flexible couplings.

2. Pipe couplings with pressure ratings at least equal to piping rating may be used in applications below unless otherwise indicated.

3. Use non-pressure flexible couplings where required to join gravity-flow, non-pressure sewer piping unless otherwise indicated.

a. Unshielded flexible couplings for pipes of same or slightly different OD.

b. Unshielded, increaser/reducer-pattern, flexible couplings for pipes with different

OD.

c. Ring-type flexible couplings for piping of different sizes where annular space between smaller piping's OD and larger piping's ID permits installation.

CLEANOUT INSTALLATION:

1. Install cleanouts and riser extensions from sewer pipes to cleanouts at grade. Use cast-iron soil pipe fittings in sewer pipes at branches for cleanouts and use cast-iron soil pipe for riser extensions to cleanouts. Install piping so cleanouts open in direction of flow in sewer pipe.

a. Use Light-Duty, top-loading classification cleanouts in earth or unpaved foot-traffic areas.

2. Set cleanout frames and covers in earth. Set with tops to match surrounding grade.

IDENTIFICATION:

1. Arrange for installation of green warning tapes directly over piping and at outside edges of underground manholes.

a. Use detectable warning tape over nonferrous piping and over edges of underground manholes.

TRENCH/BED ABSORPTION-SYSTEM MATERIALS:

1. Filter Material: ASTM D 448, 3/4 to 2-1/2 inches, washed, crushed stone or gravel; or broken, hard-burned clay brick.

2. Cover for Distribution Pipe: Geotextile woven filter fabric, in one or more layers, for minimum total unit weight of 3 oz./sq. yd.

3. Fill Material: Soil removed from trench.

FIELD QUALITY CONTROL:

1. Inspect interior of piping to determine whether line displacement or other damage has occurred.

Inspect after backfill is in place, and again at completion of Project.

2. Submit separate report for each system inspection.

3. Defects requiring correction include the following:

a. Alignment: Less than full diameter of inside of pipe is visible between structures.

b. Deflection: Flexible piping with deflection that prevents passage of ball or cylinder of size not less than 92.5 percent of piping diameter.

c. Damage: Crushed, broken, cracked, or otherwise damaged piping.

d. Infiltration: Water leakage into piping.

e. Exfiltration: Water leakage from or around piping.

4. Replace defective piping using new materials and repeat inspections until defects are within allowances specified.

5. Reinspect and repeat procedure until results are satisfactory.

6. Test new piping systems, and parts of existing systems that have been altered, extended, or repaired, for leaks and defects.

a. Do not enclose, cover, or put into service before inspection and approval.

b. Test completed piping systems according to requirements of authorities having jurisdiction.

c. Schedule tests and inspections by authorities having jurisdiction with at least 24 hours' advance notice.

d. Submit separate report for each test.

7. Air Tests: Test sanitary sewerage according to requirements of authorities having jurisdiction, UNI-B-6, and the following:

a. Test plastic gravity sewer piping according to ASTM F 1417.

8. Leaks and loss in test pressure constitute defects that must be repaired.

9. Replace leaking piping using new materials and repeat testing until leakage is within allowances specified.

Task #12 – Deliverable: DIRECTIONAL DRILLING

Timeline Estimate: Included in Task Items #6 and #8

Work of this Section consists of directional drilling to install a force main at Stow Hardy and Joshua Brooks.

DRILLING FLUIDS:

1. Use a drilling fluids mixture composed of potable water and stabilizing agent – usually bentonite and/or polymer and/or appropriate additives continuously pumped into the drill bit.

Select the drilling fluid to: transport spoils; maintain temperatures of bits and transmitter; clean cuttings from the drill bit and reamers; reduce friction, pullback, and torque on drill rods and product pipe; stabilize the borehole; and reduce migration of drilling fluids in soil. Vary the fluid viscosity to best fit the encountered soil conditions. Do not use any other chemicals of polymer surfactants in the drilling fluids without written consent of contracting officer.

TRACER WIRE:

1. Electronic detection material for non-conductive piping products. Select tracer wire designated for HDD to conductively locate underground utility lines according to ASTM D-1248. Use either a continuous green sheathed solid conductor copper wire line (minimum 12 AWG for external placement) or coated conductivity tape. Select a minimum 12-gauge copper clad steel wire, able to withstand the installation tension along the entire length of the line.

HDPE PIPE:

1. HDPE sewer pipe to be smooth wall, light grey for future TV inspection. It shall be pressure rated for 125 psi. It shall meet the standards for tensile strength – ASTM D638 Type IV;

flexural modulus – ASTM D790; density – ASTM D1505; melt index – ASTM D1238. For bidding purposes, 2” ID pipe is specified. Joints and fittings shall be fusion welded. Once sewage pumping station is selected, pipe size shall be verified.

DRILLING OPERATIONS:

1. Prior to the start of the boring operation, provide a plan and schedule to the contracting officer showing the locations for setting up the drill rig. Submit this information at least 24 hours before the start of the pilot bore operations.

2. Drill the pilot hole along the path shown on the plans within the allowable tolerance of the type of utility. Provide and maintain instrumentation necessary to accurately locate the pilot hole (both horizontal and vertical placements).

3. Ensure adequate removal of soil cuttings and stability of the bore hole by monitoring the drilling fluid parameters such as the pumping rate, pressures, viscosity, and density during the pilot bore, back reaming, and product pipe installation.

4. Maintain proper disposition of drilling fluids and minimize inconvenience to park visitors and staff.

5. Ensure that all drilling fluids are disposed of or recycled in a manner acceptable to the appropriate local, state, or federal regulatory agencies. Remove any excess material upon completion of the bore.

6. Install all facilities such that their location can be readily determined by electronic designation after installation. Attach a continuous conductive tracking (tracer wire) materials, externally or integral with the product. Tracking conductors must extend two feet beyond the bore termini. Test conductors for continuity.

7. Within 48 hours of completing the installation, clean the work site of all excess slurry or spoils, demobilize equipment, and ensure that the site is safe and secured.

Task #12 – Deliverable: FACILITY PACKAGED SEWAGE PUMPING STATION

Timeline Estimate: Included in Task Items #6 and #8

Furnish complete factory-built and tested Wetwell/Drywell Grinder Pump Station, each consisting of grinder pump suitably mounted in a basin constructed of high density polyethylene (HDPE) with dimensions and capacities as indicated for site specific tasks, NEMA 6P electrical quick disconnect (EQD), pump removal system, stainless steel discharge assembly/shut-off valve, anti-siphon valve/check valve, each assembled in the basin, electrical alarm panel and all necessary internal wiring and controls. Component type grinder pump systems that require field assembly will not be acceptable due to the potential problems that can occur during field assembly. For ease of serviceability, all pump, motor/grinder units shall be of like type and horsepower throughout the system.

MANUFACTURER AND EXPERIENCE:

Grinder pump stations, complete with all appurtenances, form an integral system, and as such, shall be supplied by one grinder pump station manufacturer. The contractor shall be responsible for the satisfactory operation of the entire system. The equipment specified shall be a product of a company experienced in the design and manufacture of grinder pumps for specific use in low pressure sewage systems.

OPERATING CONDITIONS:

The pumps shall be capable of delivering 15 GPM against a rated total dynamic head of 0 feet (0 PSIG), 11 GPM against a rated total dynamic head of 92 feet (40 PSIG), and 7.8 GPM against a rated total dynamic head of 185 feet (80 PSIG). The pump(s) must also be capable of operating at negative total dynamic head without overloading the motor(s). Under no conditions shall in-line piping or valving be allowed to create a false apparent head.

WARRANTY:

A part(s) and labor warranty on the complete station and accessories, including, but not limited to, the panel for a period of 24 months after notice of Government’s acceptance. Any manufacturing defects found during the warranty period will be reported to the contractor by the Government and will be corrected by the contractor at no cost to the Government.

PUMP:

The pump shall be a custom designed, integral, vertical rotor, motor driven, solids handling pump of the progressing cavity type with a single mechanical seal. Double radial O-ring seals are required at all casting joints to minimize corrosion and create a protective barrier. All pump castings shall be cast iron, fully epoxy coated to 8-10 mil Nominal dry thickness, wet applied.

The rotor shall be through-hardened, highly polished, precipitation hardened stainless steel. The stator shall be of a specifically compounded ethylene propylene synthetic elastomer. This material shall be suitable for domestic wastewater service. Its physical properties shall include high tear and abrasion resistance, grease resistance, water and detergent resistance, temperature stability, excellent aging properties, and outstanding wear resistance. Buna-N is not acceptable as a stator material because it does not exhibit the properties as outlined above and required for wastewater service.

GRINDER:

1. The grinder shall be placed immediately below the pumping elements and shall be direct driven by a single, one-piece motor shaft. The grinder impeller (cutter wheel) assembly shall be securely fastened to the pump motor shaft by means of a threaded connection attaching the grinder impeller to the motor shaft. Attachment by means of pins or keys will not be acceptable. The grinder impeller shall be a one-piece, 4140 cutter wheel of the rotating type with inductively hardened cutter teeth. The cutter teeth shall be inductively hardened to Rockwell 50 – 60c for abrasion resistance. The shredder ring shall be of the stationary type and the material shall be white cast iron. The teeth shall be ground into the material to achieve effective grinding. The shredder ring shall have a staggered tooth pattern with only one edge engaged at a time, maximizing the cutting torque. These materials have been chosen for their capacity to perform in the intended environment as they are materials with wear and corrosive resistant properties.

2. This assembly shall be dynamically balanced and operate without objectionable noise or vibration over the entire range of recommended operating pressures. The grinder shall be constructed so as to minimize clogging and jamming under all normal operating conditions including starting. Sufficient vortex action shall be created to scour the tank free of deposits or sludge banks which would impair the operation of the pump. These requirements shall be accomplished by the following, in conjunction with the pump:

a. The grinder shall be positioned in such a way that solids are fed in an upward flow direction.

b. The maximum flow rate through the cutting mechanism must not exceed 4 feet per second. This is a critical design element to minimize jamming and as such must be adhered to.

c. The inlet shroud shall have a diameter of no less than 5 inches. Inlet shrouds that are less than 5 inches in diameter will not be accepted due to their inability to maintain the specified 4 feet per second maximum inlet velocity which by design prevents unnecessary jamming of the cutter mechanism and minimizes blinding of the pump by large objects that block the inlet shroud.

d. The impeller mechanism must rotate at a nominal speed of no greater than 1800 rpm.

3. The grinder shall be capable of reducing all components in normal domestic sewage, including a reasonable amount of “foreign objects,” such as paper, wood, plastic, glass, wipes, rubber and the like, to finely-divided particles which will pass freely through the passages of the pump and the 1-1/4" diameter stainless steel discharge piping.

ELECTRICAL MOTOR:

As a maximum, the motor shall be a 1 HP, 1725 RPM, 240 Volt 60 Hertz, 1 Phase, capacitor start, ball bearing, air-cooled induction type with Class F installation, low starting current not to exceed 30 amperes and high starting torque of 8.4 foot pounds. The motor shall be press-fit into the casting for better heat transfer and longer winding life. Inherent protection against running overloads or locked rotor conditions for the pump motor shall be provided by the use of an automatic-reset, integral thermal overload protector incorporated into the motor. This motor protector combination shall have been specifically investigated and listed by Underwriters Laboratories, Inc., for the application. Non-capacitor start motors or permanent split capacitor motors will not be accepted because of their reduced starting torque and consequent diminished grinding capability. The wet portion of the motor armature must be 300 Series stainless. To reduce the potential of environmental concerns, the expense of handling and disposing of oil, and the associated maintenance costs, oil-filled motors will not be accepted.

MECHANICAL SEAL:

The pump/core shall be provided with a mechanical shaft seal to prevent leakage between the motor and pump. The seal shall have a stationary ceramic seat and carbon rotating surface with faces precision lapped and held in position by a stainless-steel spring.

TANK AND INTEGRAL ACCESSWAY HIGH DENSITY POLYETHYLENE CONSTRUCTION:

1. The tank shall be a Wetwell/Drywell design made of high-density polyethylene, with a grade selected to provide the necessary environmental stress cracking resistance. Corrugated sections are to be made of a double wall construction with the internal wall being generally smooth to promote scouring. The corrugations of the outside wall are to be a minimum amplitude of 1-1/2" to provide necessary transverse stiffness. Any incidental sections of a single wall construction are to be 0.250” thick (minimum). All seams created during tank construction are to be thermally welded and factory tested for leak tightness. The tank wall and bottom must withstand the pressure exerted by saturated soil loading at maximum burial depth. All station components must function normally when exposed to 150 percent of the maximum external soil and hydrostatic pressure.

2. The tank shall be furnished with one EPDM grommet fitting to accept a 4.50" OD DWV or Schedule 40 pipe. The tank capacity shall be 70 gallons.

3. The Drywell accessway shall be an integral extension of the Wetwell assembly and shall include a lockable cover assembly providing low profile mounting and watertight capability.

The cover shall be high density polyethylene, green in color, with a load rating of 150 lbs per square foot. The accessway design and construction shall enable field adjustment of the station height in increments of 3" or less without the use of any adhesives or sealants requiring cure time before installation can be completed.

4. The station shall have all necessary penetrations molded in and factory sealed. To ensure a leak free installation no field penetrations will be acceptable.

5. All discharge piping shall be constructed of 304 stainless steel. The discharge shall terminate outside the accessway bulkhead with a stainless steel, 1-1/4” Female NPT fitting. The discharge piping shall include a stainless-steel ball valve rated for 235 psi WOG; PVC ball valves or brass ball/gate will not be accepted. The bulkhead penetration shall be factory installed and warranted by the manufacturer to be watertight.

6. The accessway shall include a single NEMA 6P Electrical Quick Disconnect (EQD) for all power and control functions, factory installed with accessway penetrations warranted by the manufacturer to be watertight. The EQD will be supplied with the required length of useable

Electrical Supply Cable (ESC) outside the station, to connect to the alarm panel. The ESC shall be installed in the basin by the manufacturer. Field assembly of the ESC into the basin is not acceptable because of potential workmanship issues. The EQD shall require no tools for connecting, seal against water before the electrical connection is made, and include radial seals to assure a watertight seal regardless of tightening torque. Plug-type connections of the power cable onto the pump housing will not be acceptable due to the potential for leaks and electrical shorts. A junction box shall not be permitted in the accessway due to the large number of potential leak points. The EQD shall be so designed to be conducive to field wiring as required. The accessway shall also include an integral 2-inch vent to prevent Sewage gases from accumulating in the tank.

CHECK VALVE:

The pump discharge shall be equipped with a factory installed, gravity operated, flapper type integral check valve built into the stainless-steel discharge piping. The check valve will provide a full-ported passageway when open and shall introduce a friction loss of less than 6 inches of water at maximum rated flow. Moving parts will be made of a 300 Series stainless steel and fabric reinforced synthetic elastomer to ensure corrosion resistance, dimensional stability, and fatigue strength. A nonmetallic hinge shall be an integral part of the flapper assembly providing a maximum degree of freedom to assure seating even at a very low back-pressure. The valve body shall be an injection molded part made of an engineered thermoplastic resin. The valve shall be rated for continuous operating pressure of 235 psi. Ball-type check valves are unacceptable due to their limited sealing capacity in slurry applications.

ANTI-SIPHON VALVE:

The pump discharge shall be equipped with a factory-installed, gravity-operated, flapper type integral anti-siphon valve built into the stainless-steel discharge piping. Moving parts will be made of 300 Series stainless steel and fabric-reinforced synthetic elastomer to ensure corrosion resistance, dimensional stability, and fatigue strength. A nonmetallic hinge shall be an integral part of the flapper assembly, providing a maximum degree of freedom to ensure proper operation even at a very low pressure. The valve body shall be injection-molded from an engineered thermoplastic resin. Holes or ports in the discharge piping are not acceptable anti-siphon devices due to their tendency to clog from the solids in the slurry being pumped. The anti-siphon port diameter shall be no less than 60% of the inside diameter of the pump discharge piping.

CORE UNIT:

The grinder pump station shall have a cartridge type, easily removable core assembly consisting of pump, motor, grinder, all motor controls, check valve, anti-siphon valve, level controls, electrical quick disconnect and wiring. The core unit shall be installed in the basin by the manufacturer. Field assembly of the pump and controls into the basin is not acceptable because of potential workmanship issues and increased installation time. The core unit shall seal to the tank deck with a stainless-steel latch assembly. The latch assembly must be actuated utilizing a single quick release mechanism requiring no more than a half turn of a wrench. The watertight integrity of each core unit shall be established by a 100 percent factory test at a minimum of 5 PSIG.

CONTROLS:

1. All necessary motor starting controls shall be located in the cast iron enclosure of the core unit secured by stainless steel fasteners. Locating the motor starting controls in a plastic enclosure is not acceptable. The wastewater level sensing controls shall be housed in a separate enclosure from motor starting controls. The level sensor housing must be sealed via a radial type seal; solvents or glues are not acceptable. The level sensing control housing must be integrally attached to pump assembly so that it may be removed from the station with the pump and in such a way as to minimize the potential for the accumulation of grease and debris accumulation, etc. The level sensing housing must be a high-impact thermoplastic copolymer over-molded with a thermo plastic elastomer. The use of PVC for the level sensing housing is not acceptable.

2. Non-fouling wastewater level controls for controlling pump operation shall be accomplished by monitoring the pressure changes in an integral air column connected to a pressure switch.

The air column shall be integrally molded from a thermoplastic elastomer suitable for use in wastewater and with excellent impact resistance. The air column shall have only a single connection between the water level being monitored and the pressure switch. Any connections are to be sealed radially with redundant O-rings. The level detection device shall have no moving parts in direct contact with the wastewater and shall be integral to the pump core assembly in a single, readily exchanged unit. Depressing the push to run button must operate the pump even with the level sensor housing removed from the pump.

3. All fasteners throughout the assembly shall be 300 Series stainless steel. High-level sensing will be accomplished in the manner detailed above by a separate air column sensor and pressure switch of the same type. Closure of the high-level sensing device will energize an alarm circuit as well as a redundant pump-on circuit. For increased reliability, pump ON/OFF and high-level alarm functions shall not be controlled by the same switch. Float switches of any kind, including float trees, will not be accepted due to the periodic need to maintain (rinsing, cleaning) such devices and their tendency to malfunction because of incorrect wiring, tangling, grease buildup, and mechanical cord fatigue. To assure reliable operation of the pressure switches, each core shall be equipped with a factory installed equalizer diaphragm that compensates for any atmospheric pressure or temperature changes. Tube or piping runs outside of the station tank or into tank-mounted junction boxes providing pressure switch equalization will not be permitted due to their susceptibility to condensation, kinking, pinching, and insect infestation. The grinder pump will be furnished with a 6 conductor 14 gauge, type SJOW cable, pre-wired and watertight to meet UL requirements with a FACTORY INSTALLED NEMA 6P EQD half attached to it.

ALARM PANEL:

1. Each grinder pump station shall include a NEMA 4X, UL-listed alarm panel suitable for wall or pole mounting. The NEMA 4X enclosure shall be manufactured of thermoplastic polyester to ensure corrosion resistance. The enclosure shall include a hinged, lockable cover with padlock, preventing access to electrical components, and creating a secured safety front to allow access only to authorized personnel. The enclosure shall not exceed 12.5" W x 16" H x 7.5" D.

2. The alarm panel shall contain one 15-amp, double-pole circuit breaker for the pump core’s power circuit and one 15-amp, single-pole circuit breaker for the alarm circuit. The panel shall contain a push-to-run feature, an internal run indicator, and a complete alarm circuit. All circuit boards in the alarm panel are to be protected with a conformal coating on both sides and the AC power circuit shall include an auto resetting fuse.

3. The alarm panel shall include the following features: external audible and visual alarm; push-to-run switch; push-to-silence switch; redundant pump start; and high level alarm capability.

The alarm sequence is to be as follows when the pump and alarm breakers are on:

a. When liquid level in the sewage wet-well rises above the alarm level, the contacts on the alarm pressure switch activate, audible and visual alarms are activated, the discrete output alarm signed shall be sent to the existing dialer, and the redundant pump starting system is energized.

b. The audible alarm may be silenced by means of the externally mounted, push-to silence button.

c. Visual alarm remains illuminated until the sewage level in the wet-well drops below the “off” setting of the alarm pressure switch.

4. The visual alarm lamp shall be inside a red, oblong lens at least 3.75" L x 2.38" W x 1.5" H.

Visual alarm shall be mounted to the top of the enclosure in such a manner as to maintain NEMA 4X rating. The audible alarm shall be externally mounted on the bottom of the enclosure, capable of 93 dB @ 2 feet.