1. Initial Backfill: Backfill placed beside and over pipe in a trench, including haunches to support sides of pipe.

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1 EXCAVATION, TRENCHING AND BACKFILLING SECTION 1 - GENERAL 1.1 SUMMARY A. This section includes grading, excavation trenching, dewatering and backfilling for pipeline installation, roadways, walkways, and drives including all excavations, formation of embankments, preparation of subgrade for pavements and finishing and dressing of graded earth areas, shoulders, and ditches. B. The intent and purpose of these specifications is to require a complete and satisfactory installation in every respect and any defects in material or workmanship shall be cause for the replacement and correction of such defect as directed by the Utility. 1.2 DEFINITIONS A. Backfill: Soil material used to fill an excavation. 1. Initial Backfill: Backfill placed beside and over pipe in a trench, including haunches to support sides of pipe. 2. Final Backfill: Backfill placed over initial backfill to fill a trench. B. Base Course: Aggregate layer placed between the subbase course and hot-mix asphalt paving. C. Bedding Course: Aggregate layer placed over the excavated subgrade in a trench before laying pipe. D. Borrow Soil: Satisfactory soil imported from off-site for use as fill or backfill. E. Dewatering system: System lower, control, remove, and dispose of ground water and permit excavation and construction to proceed on dry, stable subgrades. F. Drainage Course: Aggregate layer supporting the slab-on-grade that also minimizes upward capillary flow of pore water. G. Excavation: Removal of material encountered above subgrade elevations and to lines and dimensions indicated. 1. Authorized Additional Excavation: Excavation below subgrade elevations or beyond indicated lines and dimensions as directed by the Utility. Authorized additional excavation and replacement material will be paid for according to Contract provisions for changes in the Work. 2. Unauthorized Excavation: Excavation below subgrade elevations or beyond indicated lines and dimensions without direction by the Utility. Unauthorized excavation, as well as remedial work directed by the Utility, shall be without additional compensation. American States Utility Services Excavation, Trenching and Backfilling

2 H. Fill: Soil materials used to raise existing grades. I. Structures: Buildings, roadways, sidewalks, footings, foundations, retaining walls, slabs, tanks, curbs, mechanical and electrical appurtenances, or other man-made stationary features constructed above or below the ground surface. J. Subase Course: Aggregate layer placed between the subgrade and base course for hot-mix asphalt pavement, or aggregate layer placed between the subgrade and a cement concrete pavement or a cement concrete or hot-mix asphalt walk. K. Subgrade: Uppermost surface of an excavation or the top surface of a fill or backfill immediately below sub base, drainage fill, drainage course, or topsoil materials. L. Utilities: On-site underground pipes, conduits, ducts, and cables, as well as underground services within buildings. 1.3 PERFORMANCE REQUIREMENTS A. Dewatering system of shall be designed, furnished, installed, tested, operated, monitored, and maintained of sufficient scope, size, and capacity to control hydrostatic pressures and to lower, control, remove, and dispose of ground water and permit excavation and construction to proceed on dry, stable subgrades. 1.4 QUALITY ASSURANCE A. Compaction Testing shall be provided by a Geotechnical Engineer. The Geotechnical Engineer shall be contracted by the Utility or the Contractor, see Scope of Work for the project. 1.1 SUBMITTALS A. Dewatering System 1. Shop Drawings for the dewatering system shall show arrangement, locations, and details of wells and well points; locations of risers, headers, filters, pumps, power units, discharge lines, piezometers, and flowmeasuring devices; and means of discharge, control of sediment, and disposal of water. 2. Design Submittal for the dewatering system shall indicate compliance with performance requirements and design criteria, including analysis data signed and sealed by the qualified professional engineer responsible for their preparation. American States Utility Services Excavation, Trenching and Backfilling

3 1.5 PROJECT CONDITIONS A. Earth Moving Operations: 1. Utility Locator Service: Notify utility locator service for area where Project is located a minimum of two weeks before beginning earth moving operations. 2. Do not commence earth moving operations until plant protection measures specified in Division Section "Selective Tree and Shrub Removal and Trimming" are in place. 3. Do not commence earth moving operations until erosion and sedimentation control measures are in place as specified in Division Section "Sedimentation and Erosion Control". Do not commence with any type of earth denuding or disturbance prior to the issuance of an approved Erosion and Sedimentation Control permit by the appropriate State Agency and/or Base Directorate of Public Works. B. Dewatering System Requirements SECTION 2 MATERIALS 2.1 SOIL MATERIALS 1. Contractor shall engage a qualified land surveyor or professional engineer to survey adjacent existing buildings, structures, and site improvements, establishing exact elevations at fixed points to act as benchmarks. The benchmarks and record existing elevations shall be clearly identified. 2. During dewatering, the Contractor shall be regularly resurvey benchmarks, maintaining an accurate log of surveyed elevations for comparison with original elevations. Contractor shall promptly notify the Engineer if changes in elevations occur or if cracks, sags, or other damage is evident in adjacent construction. A. Contractor shall provide borrow soil materials when sufficient satisfactory soil material is not available from the excavation. B. Topsoil material shall be obtained from excavation of material suitable for topsoil or imported topsoil material: 1. Topsoil shall be natural, friable soil, with the characteristics of representative soils in the vicinity that produce heavy growth of crops, grass, or other vegetation. 2. Topsoil shall be free from roots, stones, and other materials that hinder grading, planting, and maintenance operations, and be free from objectionable weed seeds. American States Utility Services Excavation, Trenching and Backfilling

4 C. Satisfactory Soils 1. Satisfactory Soils are those designated with AASHTO Soil Classification Groups, A-1, A-2-4, A-2-5 and A-3 (or in accordance with ASTM D2487 soil classification groups GW, GP, GM, SM, SW, SP, SC.) as determined by the Utility. 2. Satisfactory material shall be free from roots, organic matter, trash, debris, frozen material or stones larger than three inches in any dimension. D. Unsatisfactory Soils 1. Unsatisfactory Soils are those designated with AASHTO Soil Classification Groups A-2-6, A-2-7, A-4, A-5, A-6, A-7 (or in accordance with ASTM D2487 soil classification groups GC, ML, MH, CL, CH, OL, OH, and PT) as determined by the Utility. 2. Unsatisfactory soils also include satisfactory soils not maintained within 2% of optimum moisture content at time of compaction. 3. Materials determined by the Utility to be too wet or too soft to provide a stable subgrade, foundation or fill will be classified as unsatisfactory regardless of soil classification. 4. The Utility may require the Contractor to condition the wet and/or soft soils to provide a stable subgrade, foundation, or fill. The Contractor shall recondition the materials at no additional cost to the Utility. E. Subbase Material shall be a graded mixture of natural or crushed gravel, crushed stone, and natural or crushed sand meeting the requirements of ASTM D 2940; with at least 90 percent passing a 1-1/2-inch sieve and not more than 8 percent passing a No. 200 sieve. F. Base Course shall be a graded mixture of natural or crushed gravel, crushed stone, and natural or crushed sand meeting the requirements of ASTM D 2940; with at least 95 percent passing a 1-1/2-inch sieve and not more than 6 percent passing a No. 200 sieve. G. Engineered Fill shall be a graded mixture of natural or crushed gravel, crushed stone, and natural or crushed sand meeting the requirements of ASTM D 2940; with at least 90 percent passing a 1-1/2-inch sieve and not more than 10 percent passing a No. 200 sieve. H. Stone Bedding shall be a graded mixture of natural or crushed gravel, crushed stone, and natural or crushed sand meeting the requirements of ASTM D 2940; with 100 percent passing a 1-inch sieve and not more than 8 percent passing a No. 200 sieve. I. Drainage Course material shall be a narrowly graded mixture of washed crushed stone, or crushed or uncrushed gravel; meeting the requirements of American States Utility Services Excavation, Trenching and Backfilling

5 SECTION 3 - EXECUTION 3.1 PREPARATION ASTM D 448, coarse-aggregate grading Size 57; with 100 percent passing a 1-1/2-inch sieve and 0 to 5 percent passing a No. 8 sieve. A. Protect structures, utilities, sidewalks, pavements, and other facilities from damage caused by settlement, lateral movement, undermining, washout, and other hazards created by excavation, trenching, and earth moving operations. B. Protect and maintain erosion and sedimentation controls during excavation, trenching, and earth moving operations. C. Protect subgrades and foundation soils from freezing temperatures and frost. Remove temporary protection before placing subsequent materials. 3.2 TOPSOIL STRIPPING AND STOCKPILING A. Areas designated for operations that contain a blanket of soil, which is more satisfactory for the growth of grass than the embankment material to be placed, shall be stripped to a depth of approximately four to six inches and placed in convenient stockpiles as directed in the field, for later use as a topsoil blanket on the new graded areas specified herein, or as designated. B. The stripping of material for use as topsoil shall be carefully determined and only the quantity of material required shall be stripped and stockpiled. C. Material stockpiled shall be placed in a satisfactory manner to provide positive drainage. D. When grading operations permit, instead of stockpiling, the topsoil shall be hauled and spread directly on the areas to receive topsoil. E. Topsoil shall be placed on all shoulders, slopes, ditches, and other earth areas graded under this contract, excluding borrow areas, unless otherwise specified on the plans. F. Topsoil shall be uniformly placed on these areas to a compacted depth of not less than three inches or more than four inches. G. The material shall be free from clods of soil, matted roots greater than ½ inch in diameter, and any other objectionable material which might hinder subsequent grass and mowing operations. H. The material shall be placed, leveled, and lightly compacted with at least one pass of a cultipacker, or other approved equipment weighing 100 to 160 pounds per linear foot of roller, to required cross sections, but shall be left one-tenth of a foot below the finished earth grade as specified in the section FINISHED EXCAVATION below. American States Utility Services Excavation, Trenching and Backfilling

6 3.3 DEWATERING (if required) A. Contractor shall provide temporary grading to facilitate dewatering and control of surface water. B. Contractor shall monitor dewatering systems continuously. C. Contractor shall protect and maintain temporary erosion and sedimentation controls, which are specified in Division "Erosion and Sedimentation Control during dewatering operations. D. Contractor shall install dewatering system utilizing wells, well points, or similar methods complete with pump equipment, standby power and pumps, filter material gradation, valves, appurtenances, water disposal, and surface-water controls. E. Well points or wells at shall be spaced at intervals required to provide sufficient dewatering. F. Filters or other means shall be used to prevent pumping of fine sands or silts from the subsurface. G. Before excavating below ground-water level, the dewatering system shall be placed into operation to lower water to levels required to install project facilities. The dewatering system shall be operated continuously until project facilities have been constructed and fill materials have been placed or until dewatering is no longer required. H. Contractor shall provide an adequate system to lower and control ground water to permit excavation, construction of structures, and placement of fill materials on dry subgrades. Sufficient dewatering equipment shall be installed to drain waterbearing strata above and below bottom of foundations, drains, sewers, and other excavations. I. Care shall be taken by the Contractor, to not permit open-sump pumping that leads to loss of fines, soil piping, subgrade softening, and slope instability. J. Contractor shall reduce hydrostatic head in water-bearing strata below subgrade elevations of foundations, drains, sewers, and other excavations. K. Contractor shall provide standby equipment on site, installed and available for immediate operation, to maintain dewatering on continuous basis if any part of system becomes inadequate or fails. L. If dewatering requirements are not satisfied due to inadequacy or failure of dewatering system, Contractor shall restore damaged structures and foundation soils at no additional expense to Owner. M. Contractor shall remove dewatering system from Project site on completion of dewatering. Well holes shall be filled or plugged with sand or cut off and capped a minimum of 36-inches below overlying construction. American States Utility Services Excavation, Trenching and Backfilling

7 3.4 EXCAVATION A. EXCAVATION GENERAL 1. Excavate to subgrade elevations regardless of the character of surface and subsurface conditions encountered. 2. Unclassified excavated materials may include rock, soil materials, and obstructions. No changes in the Contract Sum or the Contract Time will be authorized for rock excavation or removal of obstructions unless otherwise noted in the contract documents. 3. If excavated materials intended for fill and backfill include unsatisfactory soil materials and rock, replace with satisfactory soil materials. B. BORROW EXCAVATION (SELECT BACKFILL) 1. Where satisfactory materials are not available in sufficient quantities from the required excavation, approved materials shall be obtained from borrow areas. 2. Borrow excavation material shall be supplied by the Contractor from borrow areas located off the project site. 3. The work covered by this section shall consist of the excavation of approved material from borrow sources and the hauling and utilization of such material as required on the plans or directed by the Utility. 4. The borrow material shall be approved by the Utility and shall not contain roots, root mats, stumps, highly plastic clay or other unsatisfactory materials. 5. The material shall be a soil material which meets requirements of AASHTO Ml 45 for soil classification A-i-a, A-i-b, A-2-A, A-3 acceptable for select backfill. C. UNDERCUT EXCAVATION 1. When the Owner determines that the natural soil materials in areas where fill is to be placed, or in the finished graded subgrade roadway cross section, or in areas supporting structures or pipes, are determined to have a poor supporting value, the Utility may require the Contractor to remove the materials and backfill with approved properly compacted material to the finished graded section. 2. The Contractor shall conduct undercut operations in such a way that the Utility can take the necessary measurements before any backfill is placed. 3. Any material removed and backfilled without the approval of the Utility, and/or all necessary measurements taken, and/or to a depth, length or American States Utility Services Excavation, Trenching and Backfilling

8 width exceeding the dimensions shall not be considered undercut excavation and will not be paid for as undercut excavation. D. EXCAVATION FOR STRUCTURES 1. The Contractor shall excavate to indicated elevations and dimensions within a tolerance of plus or minus 1 inch. 2. If applicable, the Contractor shall extend excavations a sufficient distance from structures for placing and removing concrete formwork, for installing services and other construction, and for inspections. 3. Excavations for footings and foundations shall be done in a manner to not disturb bottom of excavation. Hand excavation to final grade shall be performed if necessary before placing concrete reinforcement. E. EXCAVATIONS AT EDGES OF TREE- AND PLANT-PROTECTION ZONES: 1. The Contractor shall excavate by hand to indicated lines, cross sections, elevations, and subgrades. Use narrow-tine spading forks to comb soil and expose roots. The Contractor shall not break, tear, or chop exposed roots or use mechanical equipment that rips, tears, or pulls roots. 2. The Contractor shall not cut main lateral roots or taproots; cut only smaller roots that interfere with installation of utilities. 3. The Contractor shall cut and protect roots according to requirements in Division Section "Selective Tree and Shrub Removal and Trimming." F. EXCAVATION FOR WALKS AND PAVEMENTS 1. The Contractor shall excavate surfaces under walks and pavements to indicated lines, cross sections, elevations, and subgrades. G. EXCAVATION FOR UTILITY TRENCHES 1. The Contractor shall excavate trenches to indicated gradients, lines, depths, and elevations. 2. The Contractor shall excavate trenches to uniform widths to provide 12 inches clearance on each side of pipe or conduit. Excavate trench walls vertically from trench bottom to 12 inches higher than top of pipe or conduit unless otherwise indicated. 3. Trench bottoms shall be hand graded to provide uniform and continuous bearing for the pipe along its entire length, with bell holes being dug for pipe bells. No ridges, sags, or undercutting will be allowed. Excess excavating below grade shall be backfilled with suitable material which shall be thoroughly tamped. American States Utility Services Excavation, Trenching and Backfilling

9 4. If approved by the Utility and subject to suitable soil conditions, the trench may be excavated a few inches below the established subgrade and backfilled with select material (from the excavation, if available) well compacted and so shaped as to give the pipes uniform bearing throughout their lengths at the established grade. Bell holes shall be dug to relieve the bells of load and to provide for completing the joints. 5. The Contractor shall excavate trenches 4 to 6 inches deeper than elevation required in rock or other unyielding bearing material, 3 to 4 inches deeper elsewhere, to allow for bedding course. 6. Where the material at grade is unstable, soft, and incapable of supporting the pipe, the trench shall be excavated below grade, as directed by the Utility, and refilled to grade with crusher-run stone or gravel to form a firm foundation for the pipe. Stone shall be compacted and graded to provide a stable foundation and a uniform bearing for pipe. 7. When authorized by the Utility, the Contractor shall dispose of material excavated from the trench that is unsuitable for backfill material. The Contractor shall provide and place select borrow material to replace unsuitable material for backfilling the trench as directed. 8. Should ground water be encountered in the bottom of the trench, causing the trench bottom to be unstable, the material, as directed by the Utility, shall be excavated below grade sufficiently to allow a bed of crushed rock or gravel to be place in which to bed the pipe. The crushed rock or gravel shall be placed up to the spring line of the pipe. The work shall be done as for unstable foundations. The depth of cut below grade shall be only the minimum amount to accomplish the purpose, and shall be as directed by the Utility. 9. The subgrade beneath the centerline of the pipe shall be finished to within 0.05 feet of a straight line between pipe joints to provide uniform bearing and support for the bottom quadrant of each section of the pipe. 10. Bell holes or coupling holes shall be excavated to the necessary size at each joint to eliminate bearing and permit joints to be made in an efficient, workmanlike manner. 11. Stones of three inches (3") or greater in any dimension, or as recommended by the pipe manufacturer, whichever is smaller, shall be removed. H. FINISHED EXCAVATION 1. All areas covered by the project, including excavated and filled sections and adjacent transition areas, shall be uniformly smooth-graded. The finished surface shall be reasonably smooth, compacted, and free from irregular surface changes. The degree of finish shall be that ordinarily obtainable from blade grader operations, except as otherwise specified. American States Utility Services Excavation, Trenching and Backfilling

10 2. Ditches shall be finished to permit adequate drainage. The surface of areas to be turfed shall be finished to smoothness suitable for the application of turfing materials. Surfaces shall be finished not more than 0.15 foot above or below the established grade and approved cross section. 3. In areas where the bulking of soil as a result of grassing operations will tend to retard surface drainage along the edge of pavements, the finished grades shall be left 0.1 foot below grade prior to grassing 4. Newly graded areas shall be protected from traffic and from erosion, and any settlement or washing away that may occur from any cause, prior to acceptance, shall be repaired and grades re-established to the required elevations and slopes. 5. Embankments and excavations shall be kept shaped and drained. Ditches and drains along subgrade shall be maintained in such a manner as to drain effectively at all times. 6. The finished subgrade shall not be disturbed by traffic of other operations and shall be protected and maintained by the Contractor in a satisfactory condition until subbase, base, or pavement is placed. The storage or stockpiling of materials on the finished subgrade shall not be permitted. 7. No base course or pavement shall be laid until the subgrade has been checked and approved, and in no case shall base, surfacing, or pavement be placed on a muddy, spongy, or frozen subgrade. 8. All work shall be conducted in accordance with the environmental protection requirements of the contract. I. UNAUTHORIZED EXCAVATION 1. The Contractor shall fill unauthorized excavation under foundations or wall footings by extending bottom elevation of concrete foundation or footing to excavation bottom, without altering top elevation. 2. The Contractor shall fill unauthorized excavations under other construction, pipe, or conduit as directed by the Utility and in conformance with the required Utility compaction specifications. 3. Lean concrete fill, with 28-day compressive strength of 3000 psi, may be used when approved by the Utility to fill unauthorized excavations. 3.5 SUBGRADE INSPECTION A. The Contractor shall proof-roll subgrade below the building slabs and pavements with a pneumatic tired tandem dump truck with a minimum load of 15 tons to identify soft pockets and areas of excess yielding. The Contractor shall not proof-roll wet or saturated subgrades. American States Utility Services Excavation, Trenching and Backfilling

11 B. The Contractor shall reconstruct subgrades damaged by freezing temperatures, frost, rain, accumulated water, or construction activities, as directed by the Utility, without additional compensation. 3.6 STORAGE AND PLACEMENT OF SOIL MATERIALS A. STORAGE OF SOIL MATERIALS 1. The Contractor shall stockpile borrow soil materials and excavated satisfactory soil materials without intermixing. The Contractor shall place, grade, and shape stockpiles to drain surface water and cover the stockpiles to prevent windblown dust and install erosion & sediment control measures as shown on plans and as specified in Division Erosion and Sedimentation Control 2. The Contractor shall stockpile soil materials away from edge of excavations and shall not stockpile soil materials within drip line of trees to remain. 3. All storage and placement of soil materials shall be in accordance with OSHA requirements and Army Corps of Engineers EM 385. B. SOIL FILL 1. The Contractor shall plow, scarify, bench, or break up sloped surfaces steeper than 1 vertical to 4 horizontal so fill material will bond with existing material. 2. The Contractor shall place and compact fill material in layers to required elevations as follows: a. Under grass and planted areas, use satisfactory soil material. b. Under walks and pavements, use satisfactory soil material. c. Under steps and ramps, use engineered fill. d. Under building slabs, use engineered fill. e. Under footings and foundations, use engineered fill. C. SOIL MOISTURE CONTROL 1. The Contractor shall uniformly moisten or aerate subgrade, and each subsequent fill or backfill soil layer, before compaction to within 2 percent of optimum moisture content unless approved by the Utility. 2. The Contractor shall not place backfill or fill soil material on surfaces that are muddy, frozen, or contain frost or ice. American States Utility Services Excavation, Trenching and Backfilling

12 3. The Contractor shall remove and replace, or scarify and air dry, otherwise satisfactory soil material that exceeds optimum moisture content by 2 percent and is too wet to compact to specified dry unit weight. 3.7 UTILITY TRENCH BACKFILL A. The Contractor shall place backfill on subgrades free of debris, mud, frost, snow, or ice. B. The Contractor shall place and compact bedding course on trench bottoms and where indicated. The Contractor shall shape bedding course to provide continuous support for bells, joints, and barrels of pipes and for joints, fittings, and bodies of conduits. C. If backfill and fill material is required within 20 feet of a residential structure or building, the Contractor shall place fill material in horizontal layers not exceeding a loose depth of 6 inches, and compact each layer with the use of light compaction equipment (tampers, walk behind rollers, etc.) to a density as specified below. D. The Contractor shall backfill trenches excavated under footings and within 18- inches of bottom of footings with satisfactory soil or fill with concrete to elevation of bottom of footings. Concrete is specified in specification Miscellaneous Cast-in-Place Concrete. E. For trenches under roadways, the Contractor shall provide 4-inch thick, concretebase slab support for piping or conduit less than 30 inches below surface of roadways. After installing and testing, completely encase piping or conduit in a minimum of 4 inches of concrete before backfilling or placing roadway subbase course. Concrete is specified in specification Miscellaneous Cast-in- Place Concrete. F. The Contractor shall place and compact initial backfill with satisfactory soil, free of particles larger than 1 inch in any dimension, in accordance with backfilling requirements found in this Section and the drawing details. 1. The Contractor shall carefully compact initial backfill under pipe haunches and compact evenly up on both sides and along the full length of piping or conduit to avoid damage or displacement of piping or conduit, and shall coordinate backfilling with utilities testing. 2. Backfill material shall consist of satisfactory material at a moisture content that will facilitate compaction, free from stones as specified above. The backfill shall be brought up evenly on both sides of the pipe for the full length of the pipe. Care shall be taken to insure thorough compaction of the fill under haunches of the pipe and to prevent injuring or moving the pipe. 3. Backfill material in trenches shall be placed in layers and compacted with approved tampers in accordance with the section on Compaction in this specification. Backfill shall be deposited in the trench uniformly for the full American States Utility Services Excavation, Trenching and Backfilling

13 width on each side of the pipe and along the entire length simultaneously. The remainder of the trench shall be backfilled in layers not exceeding 12-inches in loose thickness compacted as specified in the section on Compaction in this specification. Each layer shall be thoroughly compacted by an approved mechanical tamping device. G. The Contractor shall place and compact final backfill of satisfactory soil to final subgrade elevation in accordance with backfilling requirements found in this Section. H. The Contractor shall install warning tape as specified in Water Piping, Structures & Appurtenances and Sanitary Sewer Piping, Structures & Appurtenances. I. Backfill material around structures and appurtenances shall be placed in such a manner that the structure will not be damaged by the shock of falling earth. No backfill shall be placed around manholes, catch basin, inlets or similar structure until the concrete has been allowed to cure for a minimum of three (3) days. The backfill material shall be deposited and compacted as specified and shall be placed in such manner as to prevent eccentric loading and excessive stress on the structure. J. No backfilling will be allowed when in the opinion of the Utility, weather conditions are such that an acceptable job cannot be obtained. Water flooding or jetting methods of compaction will not be permitted. The operation of heavy equipment shall be conducted so that no damage to the pipe may result. 3.8 COMPACTION OF SOIL BACKFILLS AND FILLS A. Percentage of Maximum Density Requirements. 1. Compact each layer or backfill to not less than the following percentages of the maximum dry density as determined by Modified Proctor ASTM D 1557 (AASHTO T-99). Compact soil materials using equipment suitable for materials to be compacted and work area locations. a. Initial or Pipe Zone backfill for all laying conditions shall be compacted to 95 percent. b. Backfill beneath and within 5 feet of buildings and structures, including those shown for future construction shall be compacted to 95 percent. c. Backfill beneath pavements, walks, roadways, and road shoulders, including those shown for future construction or proposed shall be compacted to 95 percent. d. Backfill for all other unpaved areas shall be compacted to 85 percent. American States Utility Services Excavation, Trenching and Backfilling

14 B. The Contractor shall use power-driven hand tampers for compacting materials adjacent to structures and in areas inaccessible to rollers. C. The Contractor shall use equipment capable of adding moisture to the soil material as determined by moisture-density tests. Where required, the Contractor shall uniformly apply water to the surface of the subgrade or layer of soil material in such a manner as to prevent free water appearing on the surface, either during or subsequent to compacting operations. D. The Contractor shall remove and replace, scarify and air dry, or manipulate soil material that is too wet to permit compaction to specified percentage of maximum density at no additional cost to the owner. E. The Contractor shall not place or compact material that is muddy, frozen, or contains frost or ice. 3.9 GRADING A. Generally the Contractor shall uniformly grade areas to a smooth surface, free of irregular surface change, and comply with compaction requirements and grade to cross sections, lines, and elevations indicated. B. The Contractor shall slope grades to direct water away from buildings and to prevent ponding, and shall finish subgrades to required elevations within the following tolerances: 1. Turf or Unpaved Areas: Plus or minus 1 inch. 2. Walks: Plus or minus 1/2 inch 3. Pavements: Plus or minus 1/2 inch. 4. Grading inside Building Lines: Finish subgrade to a tolerance of 1/2 inch when tested with a 10-foot straightedge FIELD QUALITY CONTROL A. The Contractor or the Utility shall engage a qualified geotechnical engineering testing agency to perform tests and inspections. See Scope of Work for the project for requirements. B. The Contractor shall allow the testing agency to inspect and test subgrades and each fill or backfill layer. The Contractor shall proceed with subsequent earth moving only after test results for previously completed work comply with requirements. C. Tests for density of compaction shall be performed at 150-foot intervals along the trench or excavation, and shall be performed for each 2-foot depth of fill material. If the trench crosses a road (paved or unpaved), additional compaction test(s) shall be performed at the road crossing. In the event of failed tests additional American States Utility Services Excavation, Trenching and Backfilling

15 tests may be performed at the Contractor s expense to determine the limit of failed compaction. D. Compaction tests shall generally be completed as the construction progresses. In extenuating circumstances, the Utility may elect to have compaction tests performed after the backfill is complete. The Contractor shall be required to excavate to various elevations for density tests to be performed, backfill and recompact without additional costs to the Owner. E. For every lateral installed on the project, a minimum frequency one out of every three laterals is to be tested for compaction. If a compaction test fails, the Contractor shall re-excavate and re-compact all three laterals in the group. The Utility representative will determine which of the three laterals shall be retested. Instead of re-excavating and re-compacting all three laterals in the group, the Contractor may test all the laterals in the group to confirm the backfill meets the required compaction. F. At footing subgrades, at least one test of each soil stratum will be performed to verify design bearing capacities. Subsequent verification and approval of other footing subgrades may be based on a visual comparison of subgrade with tested subgrade when approved by the Utility. G. When testing agency reports that subgrades, fills, or backfills have not achieved degree of compaction specified, the Contractor shall scarify and moisten or aerate, or remove and replace soil materials to depth required. The Contractor shall then re-compact and retest until specified compaction is obtained PROTECTION A. The Contractor shall protect newly graded areas from traffic, freezing, and erosion, and keep areas free of trash and debris. B. The Contractor shall repair and reestablish grades to specified tolerances where completed or partially completed surfaces become eroded, rutted, settled, or where they lose compaction due to subsequent construction operations or weather conditions. C. Where settling occurs before Project warranty period elapses, the Contractor shall remove finished surfacing, backfill with additional soil material, compact, and reconstruct surfacing. The Contractor shall restore appearance, quality, and condition of finished surfacing to match adjacent work, and eliminate evidence of restoration to greatest extent possible American States Utility Services Excavation, Trenching and Backfilling

16 3.12 DISPOSAL OF SURPLUS AND WASTE MATERIALS A. The Contractor, at their expense, shall dispose of all excess excavated material unless ordered to another area of the project by the Utility. B. The Contractor's obligation to remove and dispose of excess materials shall in no manner convey to him any rights of property in any material taken from any excavation. No extra payment shall be made for hauling excess material from one project area to another within the limits of the Base. All excess excavated material shall be disposed of by the Contractor at his expense, unless ordered to another area of the project by the Utility. C. The Contractor shall remove surplus satisfactory soil and waste materials, including unsatisfactory soil, trash, and debris, and legally dispose of them at Utility's direction. END OF SECTION American States Utility Services Excavation, Trenching and Backfilling