Related Work Specified Elsewhere 1. Structural Earthwork: 02200

2. Protecting Existing Utilities: 02222.

3. Pavement Removal and Replacement: 02578.

4. Concrete: 03300.

C. Submittals

1. Shop drawings shall be submitted showing excavation and shoring, bracing, or sloping for worker protection.

2. Copies of a report from a testing laboratory shall be submitted verifying that backfill material conforms to the specified gradations or characteristics for pea gravel, granular material, imported sand, rock refill for foundation stabilization, and water.

D. Measurement and Payment

1. Payment for the work in this section shall be included within the appropriate pipeline or appurtenance bid item.

2. Payment for over-excavation where the bottom of trench is wet or spongy (Over-Excavation Ordered by Mesa Water) will be paid for at the unit price bid for “Over-Excavation Ordered by Mesa Water”. The refilling of the over-excavation with aggregate bedding will be paid for at the unit price bid for “Imported Aggregate Bedding Ordered by Mesa Water”.

The unit price bid amount will hold for any quantity of over-excavation and/or refill material from 0 to 1,000 cubic yards, based on the trench details shown on the plans.

This item has been included in the bid schedule for work that may possibly be required to complete the project, but which cannot be reasonably predicted, and shall be the basis of payment for over-excavation and refill material for trench foundation stabilization if authorized in writing by Mesa Water.

additional earthwork, disposal of all excess or waste material, and placing of the refill material. The Mesa Water Representative shall be the sole judge as to the necessity, the amount, and depth that may be required in any given situation. No additional payment shall be made for foundation stabilization that is not authorized in writing by Mesa Water.

3. Any over-excavation which may become necessary due to changes in grade of the pipelines to be constructed, where Mesa Water is a party to the contract, in order to avoid existing subsurface structures and utilities, as ordered by Mesa Water Representative, in writing, shall be performed by the contractor at his own expense when such over-excavation is less than six (6) inches below the grade of the bottom of the trench.

4. Any excavation carried below the subgrade, or below the grade shown or ordered, shall be refilled to the required grade with selected material and compacted by mechanical means to 90 percent of maximum density. Such work shall be performed by the contractor at his own expense where Mesa Water is a party to the contract.

5. All costs of drying, blending, transporting, and/or importing backfill material and all costs for the removal and disposal of unsuitable material and excess excavated material shall be included in the prices bid for the various items of work.

6. Full compensation for protection of utilities or replacement of utilities and street improvements including, but not limited, to removal and disposal and reconstruction of existing curb, gutter, spandrels, cross-gutters, sidewalks, driveway aprons, and handicapped ramps shall be included in the contract unit prices for which such work is appurtenant thereto, and no additional allowance or payment will be made therefore, where Mesa Water is a party to the contract. Said various contract unit prices shall include all labor, materials, tools, and equipment necessary or incidental to the replacement work.

7. The same shall apply to all costs incurred in exposing or excavating existing utilities and service lines, and no additional allowance will be made therefore, as they shall be included in the prices bid for the various items of work where Mesa Water is a party to the contract.

E. Protection of Existing Utilities and Facilities

1. General: The contractor shall be responsible for the care and protection of all existing sewer pipelines, water pipelines, gas mains, storm drains, culverts, or other facilities and structures that may be encountered in or near the area of work. Unless otherwise indicated on the drawings, all utilities shall be protected in place and service shall be continuously maintained.

The contractor shall be responsible for the location of and protection in place, of all service connections whether or not shown on the drawings.

TRENCHING, BACKFILLING, AND COMPACTING 02223 - 2

MESA WATER DISTRICT

from the respective utility’s owner or from available pothole information. The accuracy of the utilities is not guaranteed. Actual locations (not depth) will be provided by utilities through the Underground Service Alert (USA) process.

It shall be the contractor’s responsibility to make exploratory excavations (by “hand”

where prudent) to determine the true location and depth of all utilities shown on the drawings. The contractor shall also determine the type of material and condition of any utility which may be affected by or affect the work. The contractor shall conduct the exploratory excavations at least 1,500 feet ahead of a pipe trench heading (or a minimum of ten (10) working days in advance of the planned construction, whichever is greater) to provide sufficient lead-time to resolve utility conflicts. For portions of the pipeline where steel pipe is proposed to be used, the potholing shall be completed prior to submittal of the actual pipe laying diagrams. The contractor shall submit a set of potholing plans to Mesa Water or the design engineer prior to submitting the actual line lay diagrams.

2. Notification: It shall be the duty of the contractor to notify each agency of jurisdiction and make arrangements for locating each agency's facilities prior to beginning construction. The contractor shall notify Underground Services Alert (Dig Alert) at least two working days prior to construction at 1-800-422-4133.

3. Damage: In the event of damage to any existing facilities during the progress of the work due to the failure of the contractor to exercise the proper precautions, the contractor shall be responsible for the cost of all repairs and protection to said facilities. The Contractor's work may be stopped until repair operations are complete.

F. Protection of Landscaping

1. General: The contractor shall be responsible for the protection of all the trees, shrubs, fences, and other landscape items adjacent to or within the work area, unless directed otherwise on the drawings. In the event of damage to landscape items, the contractor shall replace the damaged items in a manner satisfactory to owner, the jurisdictional agency and/or Mesa Water.

The contractor shall verify that any damaged landscaping shall be replaced with landscaping that meets the current and applicable local landscape standards, codes, and ordinances, including but not limited to AB 1881 (Water Efficient Landscape Ordinance).

2. Restoration: After the completion of work in planted or improved areas within public or private easements, the contractor shall restore such areas to original condition.

Restoration shall include regrading, placement of 5-inches of topsoil, reseeding, and replacement of landscaping. All irrigation facilities shall be restored/replaced to a condition equal to or better than existing per the manufacturer’s recommendations and/or industry standards.

1. Pavement Zone: The pavement zone shall include the asphaltic concrete and aggregate base pavement section placed over the street zone. This zone is often referred to as the “structural section” of the street or highway.

2. Trench Zone: The trench zone shall include the portion of the trench from the top of the pipe zone to the bottom of the pavement zone in paved areas or to the existing surface in unpaved areas.

3. Street Zone: The street zone is the top 12 inches of the trench zone and is immediately below the pavement zone in paved areas or areas to be paved.

4. Pipe Zone: The pipe zone shall include the full width of trench from the bottom of the pipe or conduit to a horizontal level 12-inches above the top of the pipe. Where multiple pipes or conduits are placed in the same trench, the pipe zone shall extend from the bottom of the lowest pipes to a horizontal level above the top of the highest or topmost pipe.

5. Pipe Base: The pipe base shall be defined as a 4 or 6-inch layer of material immediately below the pipe zone and extending over the full trench width.

PART 2 - MATERIALS