County-Specs-02730-Sanitary-Sewer.pdf

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SANITARY SEWER

SECTION 02730

GREENVILLE COUNTY

PUBLIC WORKS

STANDARD SPECIFICATIONS

SECTION 02730

SANITARY SEWER

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RELATED DOCUMENTS: Attention is directed to related sections of the Specifications, as they pertain to to the guidelines, materials, and methods described in this section. Also, the General Provisions and Special Provisions of the Contract shall apply to all Sections of the Work.

1.0 GENERAL

a. General Requirements: This section includes furnishing all labor, materials, and equipment for the installation of all underground sewer lines, manholes, other appurtenances and structures as required for this project including clean up, testing and traffic maintenance.

b. Layout and Elevations: The layout of underground lines and invert elevations at governing points are shown on the drawings.

c. Connections and Changes in Direction: All connections and changes in direction shall be made with standard fittings or at manholes as shown on plans.

d. Compliance with Applicable Regulations: In addition to the requirements of these

Specifications, all work shall comply with the requirements of current regulations of all governing authorities.

e. Limits of Construction: All work will be confined to the limits of street rights-of-way (existing and new) and utility easements as defined on the plans.

f. Adjustment of Manhole Tops: Tops of all manholes located within rough graded areas to be paved shall be set 6 inches above rough grade. All other manhole tops shall be placed above natural grade at the direction of the County Engineer. Manhole tops shall be adjusted to finished grade with a maximum of 5 courses of brick masonry or reinforced concrete grade rings. The maximum height adjustment with brick or rings shall be 13-1/4 inches.

i. Backfill and Compaction of Trenches in Traffic Areas: Backfill of all trenching in roads shall be compacted to 95% of maximum density obtainable according to the Standard Proctor test, AASHO T-99. In addition, trenches in existing or proposed roads shall be compacted to 100% maximum density in the upper 18" of the trench.

j. Backfill and Compaction of Trenches in Non-Traffic Areas: Backfill of trenching under proposed and existing right-of-way limits shall be compacted throughout the entire depth of the trench.

All other trenching shall be overfilled with excess material to provide for settlement.

k. Traffic Control: The Contractor shall be responsible for conducting all work in streets, roads, and highways in accordance with any and all Regulatory Authorities' current requirements. As a minimum, for any work in State Highways, the Contractor shall meet the requirements of Traffic Controls for Street and Highway Construction and Maintenance Operations, Part V of the South Carolina Manual on Uniform Traffic Control Devices for Streets and Highways - 1982, latest revision.

g. Replacement of Damaged Paving, Utilities, or Structures: The Contractor shall replace all existing paving, utilities, and other structures which are damaged by the work or the Contractor's operations under this contract to the satisfaction of the County and in accordance with details on plans or with requirements by other governing bodies such as the State Highway Department or others. In no case shall the replacement be of lesser quality than the original installation.

h. Existing Underground Utilities: With respect to existing underground utilities, the following shall apply during the course of the project:

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1. Precautions: Special precautions shall be taken by the Contractor to avoid damage to existing overhead and underground and underground utilities owned and operated by public or private utility companies or being newly constructed.

2. Limitations of Available Information Shown on Plans: With particular respect to existing underground utilities, all available information concerning their location has been shown on the plans. While it is believed that the locations shown are reasonably correct, neither the Design Engineer nor the County Engineer can guarantee the accuracy or adequacy of this information.

3. Coordination with Public Utilities Prior to Beginning Work: Before proceeding with the work, the Contractor shall confer with all public or private companies, agencies, or departments that own and operate utilities in the vicinity of the construction work. The purpose of the conference, or conferences, shall be to notify said companies, agencies or departments of the proposed construction schedule, verify the location of, and possible interference with, the existing utilities that are shown on the plans, arrange for necessary suspension of service, and make arrangements to locate and avoid interference with all utilities (including house connections) that are not shown on the plans. The County shall have no objection to the Contractor arranging for the said utility companies, agencies, or departments to locate and uncover their own utilities; however, the Contractor shall bear the entire responsibility for locating and avoiding or repairing damage to said existing utilities.

4. Palmetto Utlitity Protection Service: The Contractor shall notify Palmetto Utility Protection

Service at 1-800-922-0983 at least 3 days prior to digging on the site.

5. Pipe Locator: It is suggested that the Contractor locate all unknown metallic hazards, namely buried pipe, metals, etc., by using a pipe locator.

6. Protection of Existing Utilities: When existing utilities or appurtenant structures, underground or above ground, are encountered, they shall not be displaced or disturbed unless necessary, and in such case shall be replaced in as good or better condition than found as quickly as possible.

7. Permanent or Temporary Relocation of Utilities: Permanent or temporary relocation and replacement of all utilities and appurtenant structures to accommodate the construction work shall be at the Contractor's expense.

2.0 MATERIALS

Note: All ASTM references shall be the latest version for the specific product.

a. Concrete: Concrete shall be 3000 psi mix using Portland Cement ASTM C-150, Type I, sand

ASTM C-33 and coarse aggregate ASTM C-33. Ready-mixed concrete shall meet the requirements of ASTM C-94.

b. Welded Wire Fabric: Welded wire fabric shall conform to ASTM A-185.

c. Rebar: Reinforcing bars shall conform to ASTM A-615, new billet steel, intermediate grade.

d. Water: Water shall be potable, clean, free from oils, acids, alkalies, or organic or deleterious substances.

e. Masonry Materials: Masonry materials for manholes are detailed on plans as common clay or concrete brick. Concrete manhole block and pre-cast sections are equally as acceptable, subject to shop-print approval by the Engineer and County Authorities.

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1. Common Brick: Common brick shall be standard size 2-1/4" x 3-3/4" x 8" shale or clay, hard, sound, well burned, free from lime or other unsuitable materials, ASTM C-32, Grade

MM.

2. Concrete Brick: Concrete brick for sanitary manholes shall be standard size, ASTM C-90, Class A.

3. Concrete Block: Concrete block for sanitary manholes shall comply with ASTM C-139.

4. Precast Manholes: Precast concrete manhole sections shall be 4000 psi concrete, tongue and groove, steel fabric reinforced, cement mortar joints bitumastic sealed, in accordance with ASTM C-478. Precast manholes shall have a conical top, coursed with brick. Precast bottoms are permissible. Handling holes shall be plugged with mortar or stoppers. Rubber gaskets with stainless steel clamps shall be supplied to tie the pipes to the manhole pipe openings, and shall meet the requirements of ASTM C-923.

5. Portland Cement: Portland cement shall be from an approved manufacturer, ASTM C-150, Type 1.

6. Sand: Sand shall comply with ASTM C-144.

7. Flexible Butyl Resin Sealant: Flexible Butyl Resin Sealant shall comply with AASHTO specification M-198 B, similar to Butyl Tite or ConSeal or approved equal.

8. Mortar: Mortar for drainage structures shall be 1 part of Portland Cement, 10% hydrated lime, 2 parts sand by volume, mixed with sufficient water to form a plastic mortar.

9. Lime: Lime shall be hydrated, ASTM C-207, Type N.

10. Water: Water for masonry material shall be potable, free of suspended matter, injurious amounts of acids or alkalies, and contain no industrial or domestic wastes.

f. Vitrified Clay Pipe: Vitrified clay pipe for sanitary sewers and drain lines, shall be extra strength conforming to ASTM C-700 bell and spigot type. VCP joint quality shall equal requirements of ASTM C-425 as a minimum. VCP must be installed in accordance with ASTM C-12.

g. PVC Pipe: PVC gravity sanitary sewer pipe and related fittings shall be manufactured in accordance with all the requirements of ASTM D-3034 SDR 35, Type PSM polyvinyl chloride sewer pipe and fittings. PVC gravity sewer pipe shall be used as required on plans and shall be supplied in 13.0 foot normal lengths with laying bell-and-spigot joints. All fittings shall use rubber gaskets which conform to the requirements of ASTM F-477. PVC pipe must be installed in accordance with ASTM D-2321. Perforated PVC pipe for septic tank fields shall conform to ASTM F-405.

h. Cast Iron Rings and Covers: Cast iron manhole rings and covers are to be Sumter Machine

Company ring No. MF-11 and cover No. MC-18, Dewey Bros., Inc., No. MH-RCR-1, or an approved equal meeting the requirements of ASTM A-48.

i. Ductile Iron Pipe and Fittings: Ductile iron pipe shall be manufactured in accordance with ASTM

A-746 standard specification for ductile iron gravity sewer pipe. The minimum class pipe shall be Class 50 and shall be designed for an 8-foot minimum cover and a Type I laying condition.

Pipe joints shall be the "Push-On" type manufactured in accordance with AWWA Standard C- 111-79. Fittings shall be ductile iron and rated as a minimum of equal the pressure rating of the pipeline.

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j. Sewer Laterals: Pipe for sewer laterals shall be SCH 40 PVC conforming to ASTM D-1785 and ASTM D-2665 and Cast Iron Soil Pipe shall be service weight hub and spigot meeting Federal Specifications WW-401. Where boring is specified, cast iron soil pipe shall be used. The joints shall be rubber type elastomeric as per ASTM C-425. A minimum grade as specified by the South Carolina Building Code, plumbing, shall be maintained. Sewer laterals 4 inches in diameter shall be connected to the main by means of an in-line wye or a tap and saddle, installed over a hole cut in the top quadrant of the main at an angle of 45 degrees with respect to the direction of flow. The hole shall be cut with a mechanical hole cutter designed for the particular use and rendering a smooth, uniform cut with no damage to the main. Each lateral shall be sealed at the end with an approved watertight plug. Cleanout stack and cap shall be in accordance with the Construction Detailed Drawings.

k. Steel Casing Pipe: Casing pipe used at bore locations shall be seamless steel, ASTM A-

139.80, Grade B with a minimum yield strength of 35,000 psi.

3.0 PIPE TRENCH EXCAVATION

a. Classification: Excavation shall be classified as either "common excavation" or "rock excavation". "Rock excavation" shall be such materials which cannot be removed by means other than by blasting or with air hammer. Materials which can be removed by ripping shall not be considered "rock excavation". "Common excavation" shall include all types of materials that do not fall into the category of "rock excavation" as defined above. Classification of excavation shall be determined by the County Engineer. It shall be the Contractor's responsibility to notify the County Engineer when rock excavation is encountered. The Contractor will not be credited for any rock quantities excavated before such notice is given.

b. Blasting Insurance: If conditions are such that blasting or any use of explosives is required, the

Contractor, prior to blasting, shall submit to the Engineers satisfactory evidence of blasting and explosives insurance in the amounts of bodily injury and property damage insurance required in the Special Conditions and shall prove to the satisfaction of the Engineers the experience and capability of the Contractor's organization to safely handle and perform such operations.

c. Qualifications and Safety for Blasting: Handling and storing of blasting materials shall be performed only by qualified persons skilled in such work. Adequate precautions shall be taken to prevent accidents, injury to persons, or damage to property. Qualification of blasting operations personnel and safety precautions shall be in full compliance with local codes governing such operations.

d. Required Trench Dimensions: Full responsibility for the excavation and side slopes of all trenches shall rest with the Contractor. The trench shall be excavated to provide a safe work area to place the pipe, to a depth, to permit installation of the pipe along the lines and grades shown on the drawings. The width of the trench shall be sufficient to allow thorough compacting of the backfill under and around the pipe, and in no case shall be less than 18" greater than the outside diameter of the barrel of the pipe. Where excavation is in rock, the rock shall be removed to a depth below grade of at least 4" for pipes smaller than 30" diameter, and 6" for pipes 30" in diameter and larger; and before laying the pipe, the trench shall be refilled to grade with earth, sand, gravel or other suitable material, firmly compacted to provide proper bedding for the pipe.

e. Measurement of Rock Excavation: Measurements for payment of rock excavation shall not extend more than 6 inches below the pipe invert nor more than one (1) foot on each side of the pipe outside diameter for trenches less than six (6) feet deep. For deeper trenches measurement for rock payment quantities to be established by the County Engineer and Contractor prior to excavation.

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f. Trench Advancement: The amount of trench excavated ahead of pipe laying shall be subject to the approval of the County Engineer.

g. Trenching through Traffic Areas: The Contractor shall do all necessary bracing and bridging to maintain traffic during construction through areas affected by trenching.

h. Removal of Unsuitable Material: If directed by the County Engineer, soft, mucky, or otherwise unstable or unsuitable material in the trench bottom shall be removed and replaced with crushed stone or stabilized with crushed stone.

4.0 BRACING, SHEETING AND SHORING

a. General Requirements: The sides of all trenches and excavation shall be adequately braced and sheeted to protect personnel, structures and property from slides, cave-ins, or settlement and to maintain the work clear of all obstructions. Bracing, shoring and sheeting shall comply with all applicable safety regulations governing the work. Full responsibility for the design, type and strength of shoring, sheeting and bracing shall rest with the Contractor.

b. Removal of Shoring Materials: Sheeting, shoring or bracing materials shall not be left in place unless otherwise shown on the plans or ordered by the County Engineer. Such shall be removed in such manner that no danger of damage will occur to structures or property, public or private, and so that cave-ins or slides will not take place. Wood sheeting shall be left in place until backfill has been brought to a level 12 inches above the top of the pipe. It shall then be cut off and the upper portion removed before backfilling continues. Steel sheeting may be pulled in a manner approved by the County Engineer.

c. Clean-Up: All holes and voids left in the work by the removal of sheeting, shoring, or bracing shall be filled and thoroughly compacted.

5.0 PIPE LAYING

a. Handling: Pipe shall be carefully handled and placed to prevent breakage or other damage.

b. Alignment: All pipe shall be laid to a true straight line and uniform grade between angles or manholes, and shall in all cases rest on a firm bed, with bells laid up hill.

c. Resilient Joints For Clay Pipe: Resilient joints in clay pipe and fittings shall be made up in strict accordance with the manufacturer's directions.

d. Elevation Control: Laser Beams shall be used for grading pipe trenches and setting pipe. Pipe invert elevations at each manhole shall be checked by traditional survey methods using known benchmark(s). Manhole top elevations shall be set and adjusted by traditional survey methods using known benchmark(s).

e. Invert Elevations: All grades shown as pipe elevations are, unless otherwise noted, to the bottom of inside of pipe.

f. Horizontal Separation of Sewer and Water Mains: Water mains shall be laid at least 10 feet laterally from existing or proposed sewers, unless local conditions or barriers prevent a 10-foot lateral separation in which case the water main shall be laid in a separate trench, with the elevation of the bottom of the water main at least 18 inches above the top of the sewer.

Distance measured is outside diameter to outside diameter.

g. Vertical Separation of Sewer and Water Mains: Whenever it is necessary for a water main to cross over a sewer, the water main shall be laid at such an elevation that the bottom of the

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water main is at least 18 inches above the top of the sewer, unless local conditions or barriers prevent an 18-inch vertical separation in which case both the water main and sewer shall be constructed of ductile iron and with joints that are equivalent to water main standards for a distance of 10 feet on each side of the point of crossing. Whenever it is necessary for a water main to cross under a sewer, both the water main and the sewer shall be constructed of ductile iron and with joints equivalent to water main standards for a distance of 10 feet on each side of the point of crossing, while maintaining a minimum of 18" vertical separation. A section of water main pipe shall be centered at the point of crossing. Distance measured is outside diameter to outside diameter.

h. Vertical Separation of Sewer and Storm Drains: When a sanitary sewer main must cross over or under a storm sewer, a vertical separation of 18 inches shall be maintained unless both lines are of ductile iron or encased in concrete. Distance measured is outside diameter to outside diameter.

i. Cleaning of Pipe: Pipe lines shall be kept cleaned out as the laying progresses and open ends kept securely stoppered.

k. Dewatering of Trenches: The Contractor shall do all pumping necessary for dewatering trenches and to provide proper work conditions for installation of pipe and appurtenances. Pipe shall be installed on dry, stable trench bottom.

l. District Standards: All sanitary sewer pipe and pipe bedding shall be installed in accordance with the applicable Sewer District or governing authorities' requirements.

6.0 BACKFILLING

a. Controlled Backfill: Controlled backfill, using fine material, shall be placed up to 18 inches above top of pipe in 6 inch layers and thoroughly mechanically tamped. Except in roadway areas, balance of backfill may be placed with the aid of dump trucks, bulldozers, cranes or other equipment, all subject to approval by the County Engineer. Where pipeline is located under paved roads or streets or within the right-of-way of these public thoroughfares, the backfill shall be consolidated in such a manner as to provide an unyielding foundation and excess materials shall be removed. Class I or Class II backfill materials as listed in ASTM D- 2321 are to be used with PVC sewer pipe. Where high water tables or flowing water is or is likely to be present, Class I materials are to be used.

b. Succeeding Layers: Succeeding layers of backfill above the controlled backfill may contain coarser materials, and shall be free from brush or any other perishable or objectionable matter that would prevent proper consolidation or that might cause subsequent settlement, and shall be compacted thoroughly by use of mechanical tampers.

c. Compaction in Roadways: Compaction of trench excavations within roadway areas shall be no less than 95% of maximum density at optimum moisture content. The top 18" of backfill under roads shall be compacted to 100% of this specification. The method of test for maximum density shall be in accordance with AASHO T-99 (Standard Proctor Test). The material to be compacted shall be of the proper moisture content to obtain the prescribed density. The Contractor shall retain the services of an independent testing laboratory to perform all tests required under this section. Areas which do no meet the compaction requirements specified above shall be excavated and re-compacted. The cost of the initial test shall be paid for by the Contractor and any tests required as a result of improper compaction shall be paid for by the Contractor.

d. Maximum Stone Size: No stone larger than 6 inches in its greatest dimension shall be used in any part of the backfilling above the controlled backfill.

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e. High Traffic Areas: Where it is important that the surface of the backfill be made safe for vehicular traffic as soon as possible, or where a permanent pavement is to be placed within a short time, the upper 12 inches of backfill shall be of approved moist material, thoroughly compacted to at least 95% maximum soil density in thin (4 inch) layers by tamping, and shall be brought to the required subgrade.

f. Insufficient Fill Quantity: Any deficiency in the quantity of material for backfilling the trenches or for filling depressions caused by settlement, shall be supplied by the Contractor from onsite borrow.

j. Restoration of Lawn and Landscaped Areas: Where trenching operations occur on "cultivated" grassed or landscaped areas, privately or publicly owned, or where the Contractor's operations disturb the operations of other Contractors on the project, the Contractor shall restore said property to its original state.

7.0 TESTING

a. General Requirements: After completion of any section of sewers and appurtenances, the pipe, joints and alignment shall be true to line and grade and joint surfaces shall be smooth. There shall be no visual leakage and the sewer shall be completely free from any cracks.

b. Visual Testing: All sewer installation shall be visually inspected from manhole to manhole by the use of mirrors and/or TV cameras. All lines shall exhibit a fully circular cross section, and shall be free of ponding, obstructions, and structural & surface defects. All deficiencies shall be corrected by the contractor prior to acceptance.

c. Air Testing: All sewer installation must be air tested in accordance with ASTM C-828, latest edition, in the presence of the Sewer District inspector with copies of the results sent to the Sewer District and County Engineer.

d. Deflection Testing: All PVC sewer installation shall be measured for vertical ring deflections.

Deflection tests must be performed from manhole after the major portion of the initial soil consolidation has occurred, normally after 30 days, but not more than 12 months. The vertical ring deflection shall not exceed 5% of the vertical internal pipe diameter in any section measured, i.e. manhole to manhole. All pipe exceeding this deflection shall be considered to have reached the limit of their service ability and shall be relaid or replaced by the Contractor at no additional cost to the County. Deflection tests shall be accomplished by using a deflectometer, which will produce a continuous record of pipe deflection or by pulling a mandrel, sphere or pipe type (go/no-go) device through the pipe line. The diameter of the go/no-go device shall be 95% of the undeflected inside diameter of the pipe.

e. Infiltration Testing: Infiltration or exfiltration shall not exceed 200 gallons per hours per inch of diameter per mile of sewer. The maximum allowable for pipe 50" in diameter and larger shall be 10,000 gallons per 24 hours per mile. The Contractor shall make infiltration tests as directed by the Sewer District Engineer when the groundwater level is 18 inches or more above the top of the pipe.

e. Exfiltration Testing: When normal groundwater is not at a level to permit infiltration tests, the

Contractor may be required to make exfiltration test at the discretion of the Sewer District Engineer. The method shall be to the satisfaction of the Sewer District Engineer. The tests may be made by filling the pipe or sections thereof with water to a head of two feet above the top of the pipe and observing the amount of water required to maintain this level or by air testing lines.

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f. Manhole Tightness: There shall be no active leakage or seepage at manholes. The manholes shall be vacuum tested in accordance with ASTM C-1244-93 in the presence of the Sewer District inspector.

g. Testing to be Provided By the Contractor: All labor, materials, equipment, water, and services required for cleaning and testing shall be provided by the Contractor and at the expense of the Contractor. No separate payments will be made to the Contractor for cleaning or testing under either unit price or lump sum contracts.

h. Repair of Defective Areas in System: Sewer lines and appurtenances shall not be considered ready for acceptance until all provisions of the Contract Documents have been met, until all tests have been satisfactorily made, until final inspection of the work has been made by the Sewer District inspector, and until all defects have been corrected to the satisfaction of the Sewer District inspector. In case infiltration or exfiltration exceeds the specified rates, the sewers shall be repaired by the Contractor at no cost to the County until they will comply with the specified rates. Any defects determined during inspections by the Sewer District inspector shall be corrected by the Contractor to the satisfaction of the Sewer District and at no cost to the County.

8.0 CLEAN-UP

a. General Requirements: The sewer shall be clean on the inside and free from protruding joint materials, deposits of sand, mortar, earth, or other materials or debris on the inside of the pipe.

Sewer lines and manholes shall be flushed and washed down if requested by the Engineer. On the site, the Contractor shall remove all excess material from excavations to points designated by the County Engineer, and clean the work areas of all debris collected during the construction.

9.0 EROSION CONTROL

a. General Requirements: The disturbed areas of large ditch and stream banks shall be riprapped each bank and each side of pipe centerline. Minimum total width riprapped shall be 12 feet. Stone may be from trench excavation, but shall have a minimum dimension of 12 inches.

10.0 GRASSING

a. General Requirements: The unpaved areas disturbed by construction of sewers shall be cleaned up, fine graded and grassed upon completion of the backfill/compaction operations.

END OF SECTION