A. Roadway Grading.
1. Roadway Grading. Roadway grading shall consist of performing all operations necessary to excavate earth, rock and all other materials upon which the imported borrow, selected fill, aggregate base, cement treated base or other material is to be constructed; to build embankment in the location and to the elevation and form required; to backfill ditches and depressions caused by the removal of obstructions; to furnish all equipment necessary for these operations, and the performance of all incidental work of whatsoever nature may be required to build the grade and maintain it in the form specified.
2. Roadway Earthwork. All roadway earthwork shall be constructed and maintained as specified in Section 19 of the standard specifications.
3. Surplus Excavation. Surplus material from excavation shall be disposed of by the contractor, unless special instructions for such disposal are shown on the plans or in the special provisions.
B. Aggregate Base - Class No. 2. Aggregate Base - Class No. 2, shall be constructed as provided in Section 26 of the standard specifications. The thickness shall be of the dimensions indicated on the plans and shall conform to the grading specifications set forth in the standard specifications. The size of aggregate shall be three-quarter (3/4) inch (maximum) as set forth in Section 26, or as specified by the engineer.
C. Asphalt Concrete.
1. Asphalt Concrete. Asphalt concrete shall be constructed according to the shape and thickness between curbs and gutters as shown on the plans and as herein specified, and otherwise shall conform to the requirements of Section 39 of the standard specifications. Asphalt concrete shall be Type “B.” Paving asphalt shall be of the penetration range specified by the engineer.
2. Prime Coat and Paint Binder. A prime coat of liquid asphalt or a paint binder of asphaltic emulsion shall be applied to the areas to be surfaced in accordance with Section 39-4 of the standard specifications. Prime coat will be required on all base rock.
3. Leveling Course. Leveling course shall consist of surface course material and shall be placed as specified in Section 39-6 of the standard specifications.
4. Base Course. The base course shall be of the thickness as shown on the plans and shall conform to the requirements of the standard specifications.
5. Surface Course. The surface course shall be of the thickness as shown on the plans and shall conform to the requirements of the standard specifications. The aggregate for the surface course shall conform to the grading specified for ½-inch maximum (medium) grading.
D. Seal Coat. Seal coat shall consist of the material and shall be placed as specified in Section 37 of the standard specifications. The bituminous binder shall be 200-300 grade paving asphalt or emulsion spread at the rate as set forth in the standard specifications and as specified by the engineer. The preparation of surface prior to seal coating shall be as specified in Section 37 of the standard specifications.
E. Pavement Replacement. Pavement replacement shall consist of Type “A” Alternate 1, Type “A” Alternate 2, Type “B,” Type “C” or Type “D” as shown on the city of Chico Standard Plan No. S-17. The specific type of pavement replacement shall be as shown on the plans.
All work necessary to complete the pavement replacement, as shown on said Standard Plan, shall be done in accordance with the applicable sections of the standard specifications.
F. Tapering Into Adjacent Streets. The contractor shall construct smooth tapers into all adjacent streets. The exact length of taper and the grade of the taper shall be under the direction of the engineer. The contractor shall butt all pavement tapers as directed by the engineer. The tapers shall consist of a minimum of six (6) inches aggregate base and two (2) inches asphalt concrete.
G. Portland Cement Concrete Curbs, Gutters, Sidewalks, Driveways, Accessible Ramps, and Alleys.
1. General. Portland cement concrete curbs, gutters, sidewalks, driveways, handicapped ramps, and alleys shall be constructed at the location shown on the plans, or as directed by the engineer, and shall conform to the details and dimensions as shown on the following city of Chico, standard plans:
a. Standard Plan No. S-1, “P.C.C. Sidewalk Details”;
b. Standard Plan No. S-2, “P.C.C. Curb and Gutter”;
c. Standard Plan No. S-2A, “Curb, Gutter & Sidewalk Installation at Trees”;
d. Standard Plan No. S-3, “Existing Curb and/or Gutter - Replacement Details”;
e. Standard Plan No. S-5, “Residential Driveway Approach”;
f. Standard Plan No. S-5A, “Commercial Driveway Approach”;
g. Standard Plan No. S-5B, “Curb, Gutter, & Driveway Details”;
h. Standard Plan No. S-5C, “Curbed Driveway Entrance”;
i. Standard Plan No. S-9, “Alley Pavement”;
j. Standard Plan No. S-27, “P.C.C. Accessible Ramp”;
k. Standard Plan No. S-27-A, “P.C.C. Accessible Ramp.”
2. Materials.
a. Concrete. Construction of all curbs, gutters, sidewalks, driveways, accessible ramps, and alleys shall be of class “A” Portland cement concrete as specified in Section 90, “Portland Cement Concrete” of the standard specifications, and shall conform to the provisions of Section 90-10, “Minor Concrete” of the standard specifications.
b. Adhesives. Adhesives or bonding agents used to join new concrete to existing concrete shall be approved by the engineer prior to use in the work.
c. Lampblack. Lampblack of approved quality shall be mixed with all of one pound per cubic yard of concrete.
d. Joint Filler. Premolded expansion joint filler shall conform to the provisions of Section 51-1.12C of the standard specifications.
e. Dowels. Steel dowels, where specified, shall conform to the provisions of Section 51-1.13 and 52-1.02A of the standard specifications.
f. Curing. The curing method for Portland cement concrete shall conform to Section 90-7.01B of the standard specifications. The curing compound shall consist of the compound specified in Section 90-7.01B(4) of the standard specifications.
3. Construction.
a. Construction of all curbs, gutters, sidewalks, driveways, and accessible ramps shall conform to the provisions of Section 73, “Concrete Curbs and Sidewalks” of the standard specifications.
b. Construction of all alleys shall conform to the provisions of Section 90-10, “Minor Concrete” of the standard specifications.
c. Subgrade preparation shall conform to the provisions of Section 73-1.02 of the standard specifications. Where subgrade occurs in a fill section, the base material shall be compacted to a relative density of 95 percent in conformance with California Test Method No. 216.
d. No concrete shall be placed until the subgrade and forms have been reviewed for satisfactory compaction, alignment, and grade and approved by the engineer.
e. Premolded expansion joints, 1/4 inch wide, shall be installed in all curbs, gutters, driveways and sidewalks as follows:
(1) As shown on city of Chico Standard Plans S-1, S-2, S-2A, S-3, S-5, S-5A, S-5C, S-7, S-27 and S-27A;
(2) At maximum 48-foot intervals in all new curb and gutter constructions;
(3) At locations of expansion joints in existing sidewalks, curbs or gutters.
f. Control joints, 1/8-inch wide, scored at least 1/10 the depth of concrete being placed, shall be constructed at maximum 12-foot intervals in all new curbs, gutters and sidewalks.
g. Extruded curb construction shall not be used without a prior test demonstration of proposed equipment and procedures, off the side of work, and shall not be used without prior approval by the engineer.
H. Standard Fence. Standard fence shall conform to the requirements of Section 80-2 of the standard specifications except as provided herein.
New fence shall be 32-inch wire mesh fabric, as specified in Section 80-2.01E, with 3-strand barbed wire on top, with steel posts at 12 feet center to center, set a minimum of 2.5 feet into the ground.
All fencing removed shall become the property of the contractor and shall be removed from the premises.
I. Bore and Jack Pipe. Bore and jack pipe shall consist of boring and jacking casing and installing pipe inside the casing at locations shown on the plans. Casing and pipe shall be of the types and sizes shown on the plans.
The casing designated in the contract item will be determined for vertical load only. Additional reinforcement or strength of casing required to withstand jacking pressure shall be determined and furnished at the contractor’s expense.
Variations from theoretical grade at the time of completion of placing shall not exceed 0.1 foot for each 30 feet of casing placed.
The excavated hole shall not be more than 0.1 feet greater than the outside limits of the casing. Sluicing and jetting with water will not be permitted. When material tends to cave in from outside these limits, a metal shield shall be used ahead of the first section of casing.
Areas resulting from caving or excavation outside the above limits and the area between the casing and the pipe shall be backfed with sand or grout by a method which will fill the voids.
J. Cast Iron Pipe. Cast iron pipe shall be heavy duty cast iron soil pipe. Pipe joints shall be in accordance with applicable provisions of the Uniform Plumbing Code.
The pipe shall be installed in strict accordance with the manufacturer's instructions.
K. Reinforced Concrete Pipe. Reinforced concrete pipe shall conform to the requirements for materials and methods of installation as set forth in Section 65 of the standard specifications. Reinforced concrete pipe shall be of the class shown on the plans. Backfill shall be in accordance with subsection L below.
L. Trench Backfill. Trench backfill for storm drainage, sanitary sewers, or any other underground utility installation shall conform to, and be constructed in conformance with the requirements as set forth below:
1. New Street Constructions.
a. For any portion of the street right-of-way upon which aggregate sub-base, aggregate base, asphalt concrete or P.C.C. curb and gutter will be constructed, the following materials and installation procedures shall be used:
(1) Backfill material, from the bottom of the trench to a plane two (2) feet below subgrade may consist of trench excavation free from stones and lumps exceeding three (3) inches in greatest dimension, vegetable matter, or other unsatisfactory material. The material shall be compacted to a relative compaction of 90% and shall be placed in conformance with the requirements of Section 19-3.06 of the standard specifications.
(2) Backfill material from two (2) feet below subgrade to subgrade shall conform to the requirements of Section 19-3.06 of the standard specifications.
b. For remaining portions of a new street right-of-way, the following materials and installation procedures shall be used: Backfill material, from the bottom of the trench to finished grade, and installation, shall conform to the requirements of paragraph 1a(1) of this subsection.
2. Existing Street, Alley, Easement Construction.
a. For any portion of a public right-of-way which has any existing improvements for vehicular traffic, the following materials and installation procedures shall be used:
(1) Backfill material, from the bottom of the trench to bottom of the section depicted in Standard S-17, Pavement Replacement, as noted on the plans, shall conform to the requirements of paragraph la(1) of this subsection.
(2) Compaction of backfill material by ponding or jetting will not be allowed unless specifically authorized by the engineer.
3. State Highways.
a. For any existing state highways, any future state highways or freeways, the following materials and installation procedures shall be used: Backfill material shall conform to and be placed in accordance with the requirements of Section 19-3.06 of the standard specifications.
M. Standard Precast Concrete Manholes.
1. Manholes.
a. The contractor shall furnish all materials for the construction, complete, of all standard and other manholes shown on the plans and specifications and all manholes shall be constructed either of precast concrete sections or reinforced concrete. The contractor shall furnish all materials, labor, tools, equipment, and do all the work involved and necessary to complete the manholes as shown on city of Chico Plans S-10 and S-11.
b. Frames and Covers. All manhole frames and covers shall be of the dimensions and weights shown on city of Chico Standard Plans S-14 and S-14A. Each frame and cover shall have its weight indicated on the bottom outside rim of the cover. The seat of the frame shall in each case be machined sufficiently so that the cover will sit evenly and firmly in place without rocking.
2. Portland Cement Concrete Precast.
a. Manholes shall be constructed along the sewer line at such places as shown on the plans.
Manholes shall consist of precast concrete sections set on a concrete base, with cast iron cover as shown on the Standard Plans.
“Kent Seal,” “Ram Neck” or an approved equal, shall be installed at all manhole joints.
Manufacture of these sections shall be governed by specifications for reinforced concrete sewer pipe, ASTM Designation C-76.
b. Portland Cement. Portland cement shall be of standard accepted brand and shall fully meet the requirements of the ASTM specifications for Portland cement, Designation C-150.
c. Coarse Aggregate. Coarse aggregate shall consist of clean, hard, durable screened and washed gravel, or crushed rock, free from organic matter. Aggregate shall be properly graded in conformity with the class of concrete specified, and to secure concrete of not less than twenty-five hundred (2500) pounds per square inch at twenty-eight (28) days.
d. Fine Aggregate. Fine aggregate shall consist of well-graded, hard, durable, clean, natural sand free from all deleterious matter. Use of bank sand, fine river sand, or any other uniformly fine sand, shall not be permitted.
e. Mixing. All concrete mixing shall be done in machine batch mixers of approved type, having a capacity of not less than a full one-sack batch. Each batch shall be run long enough for the conglomerate to become a homogenous mixture, continuing a minimum time of one and one-half (1½) minutes after the last aggregate has been placed in the mixer.
Placing of concrete shall be done immediately after mixing. No concrete shall be placed or used after it has begun to set and no retempering will be allowed.
The ratio of water to cement shall not exceed seven and one-half (7½) gallons of water per sack of cement used, including the water in the aggregates, in order to obtain a concrete having an ultimate strength not less than 2500 pounds per square inch at twenty-eight (28) days.
N. Tree Removal. Tree removal shall consist of removing all trees as shown on the plans and as designated by the engineer. Tree removal shall be performed as herein specified.
All roots of trees to be removed shall be cleared to a point not less than two (2) feet below the surface of the parkway between the back of existing curb and existing sidewalk. Root void shall be backfilled to surface of parkway with native material and shall be jetted into place.
All portions of trees shall be removed from the public right-of-way. The sidewalk, parkway and street areas shall be left in a condition equal to or better than prior to start of work.
O. Portland Cement Concrete Drop Inlets. Portland cement concrete drop inlets shall be of Class “A” Portland cement concrete as per Section 90 and shall be mixed and placed as specified in Section 51 of the standard specifications.
Portland cement concrete drop inlets shall be of the dimensions as shown on the city of Chico, public works department, Standard Plans S-7, S-7A and S-26.
P. Materials for Sewer Lines and Sewer Line Construction.
1. Work to be Done. The work to be done under this section comprises the furnishings of all materials, labor, tools, implements and equipment necessary for construction of the sewer lines, complete and ready for operation. All work shall be in accordance with the details shown on the plans and the provisions of these improvement standards and in conformity with the highest standards of workmanship of this type of construction.
The work shall include the following items and related construction:
a. The construction of all portions of the intercepting and main sewer lines under this contract;
b. Cutting of pavement over trenches;
c. Excavating and dewatering of all trenches;
d. Bracing and shoring of trenches;
e. Bedding, laying and jointing of pipe;
f. Backfill and compaction of backfill;
g. Disposal of excess materials.
2. Excavation for Sewers. The excavation for sewer pipe shall not be made further in advance of laying the pipe than is practical to complete the pipe laying and backfill operation each day.
a. Excavation for Laying Pipe. Pipe shall, unless otherwise directed, be laid in open cut. All trenches shall have vertical sides from the bottom to a point at least six (6) inches above the top of the pipe. Above this point in unstable ground, with the written consent of the engineer, the trench may be sloped as directed. Trenches shall be six (6) inches wider on each side, or a total of twelve (12) inches wider than the exterior diameter of the pipe, exclusive of sockets. In the event that sheeting is required, the width of the trench shall be increased sufficiently to accommodate the sheeting. Sheeting shall not be driven below the invert grade of the pipe unless absolutely necessary due to ground conditions, as sheeting is to be removed in conjunction with the backfilling. If sheeting is driven below the invert grade as required above, it shall remain in place, except that portion two (2) feet above the top of pipe, which shall be cut off and removed as the backfilling is completed.
When using movable trench support, care shall be exercised not to disturb the pipe locations, jointing or embedment. Any voids left in the embedment material by support removal shall be carefully fitted with compacted granular material. Removal of any bracing between sheeting, trench boxes or shields shall only be done where backfilling procedures permit removal without loss of trench support. Any longitudinal movement or disjointing of pipe which results from movement of trench boxes or shields shall be corrected before additional pipe is placed.
b. Trenches in Rock. Every trench in rock shall be fully opened to a final depth at least thirty (30) feet in advance of any place where pipe is being laid. In rock the trench shall be carried six (6) inches below the external diameter of the pipe. Gravel, as herein specified, shall be placed, spread and compacted to provide a firm uniform bed for supporting the pipe.
c. Soil Testing. Should soil conditions such as running water or unstable soils be encountered during trench excavation, the director may require testing in advance of excavation to determine the nature and extent of the conditions. After such determination is made, the director may require modified trenching and embedment procedures, as required by soil conditions.
d. Preparation of Subgrade. Rough excavation in trenches shall not be carried lower than a distance equal to one-tenth (1/10) of the internal diameter of the pipe above the specified grade elevation, and the remainder of the excavation shall be done as the pipe subgrade is prepared and immediately prior to installing the pipe. As an alternate method, the trench may be excavated to depth four (4) inches below the elevation of the outside of the pipe barrel, and embedment material placed and compacted the full width of the trench to the elevation of the outside of the pipe barrel. The subgrade for pipe shall be so prepared that the entire length of each section of pipe shall have a firm and uniform bearing except for such distance as is necessary for bell holes and the proper seating of the pipe joints. Bell holes of below the elevations of the pipe subgrade shall not be larger than one-fourth (1/4) of the distance between pipe joints.
3. Overcut. Excavations shall be carried to the exact depth indicated on the plans or as specified. Should the contractor, through the contractor’s negligence or other fault, excavate below the designated lines, the contractor shall replace such excavation with approved materials at the contractor’s own expense.
4. Protection of Excavation. The contractor shall, where necessary, protect excavations from caving by installing suitable shoring. Any damage resulting from failure to provide shoring shall be repaired at the contractor’s own expense. All shoring shall be removed unless otherwise specifically authorized.
5. Approval of Excavations. The contractor shall notify the engineer where excavations for structure or pipes are completed, and no concrete shall be deposited or pipes laid until the excavations are approved.
6. Vitrified Clay Pipe. All vitrified clay pipe for sanitary sewers shall comply with ASTM Specification 200-69 requirements for absorption, straightness and permissible cracks, chips, fractures and blisters and will also comply with the chemical resistance tests.
All vitrified clay pipe shall be extra strength unglazed vitrified clay pipe meeting the requirements of extra strength pipe for crushing strength, barrel thickness, and other measurements as set forth in the “Clay Pipe Engineering Manual,” issued by the National Clay Pipe Institute.
7. Polyvinyl Chloride (PVC) Pipe. All polyvinyl chloride sewer pipe, sizes 4-inch through 15-inch, shall be DR 35 maximum and shall conform to the requirements of ASTM D 3034.
All joints shall be made with flexible elastomeric seals meeting the requirements of ASTM D 3212, and shall be capable of passing all tests specified in said standards and in these specifications. A factory applied reference mark shall be provided on the spigot end of each pipe to insure proper positioning in the receiving bell.
8. Quality Control Tests and Certification. Written certification by the manufacturer shall be submitted for all sewer pipe stating that the pipe conforms to all specifications referenced herein.
The director may select pipe specimens at random at the point of delivery or at the job site for testing. Tests on these specimens shall be made at a testing facility approved by the director. Tests shall be in accordance with applicable ASTM designations. The cost of all failing tests shall be borne by the contractor.
9. Handling and Storage. Care shall be taken during transporting of the pipe to insure that the binding and tiedown methods do not cut or crack the pipe. Pipe bowed, deformed, cracked or otherwise damaged during shipping or storage shall be rejected. Polyvinyl chloride pipe which shows any change in color or surface finish due to exposure to ultraviolet light shall not be used without the approval of the director.
10. Inspection of Sewer Pipe. Wherever possible, the contractor shall avoid distribution of pipe to the job site too far in advance of laying operations. The contractor shall also supply experienced help for the unloading of the pipe so as to avoid damage caused by unloading operations. Immediately preceding placing and laying of the sewer pipe, it shall be checked for defects in accordance with these improvement standards.
11. Laying Sewer Pipe. Each sewer pipe shall be laid uphill in perfect conformity with the lines and grades as given by the engineer from stakes which the engineer has previously set for the purpose.
The grade line of the pipe shall be obtained by use of batter boards and a “top” line stretched tight and supported every 25 feet, and the contractor will be required at all times to maintain the top lines for a distance covering at least three grade stakes. The contractor shall at all times have available one competent person, whose duty it shall be to set and maintain the top line and to give the line and grade for the pipe.
With the approval of the director, the grade line may be set by use of a construction laser, installed in the trench.
After the trench for pipe sewers has been brought to the proper line and grade in the manner above specified, the pipe shall be laid therein in the following manner:
a. Before any pipe is put in place, the trench bottom shall be prepared so that each pipe shall have a firm and uniform bearing over its entire length. All adjustment to line and grade must be made by scraping away the earth or rock under the body of the pipe as herein specified, and not by wedging or blocking up any portion of the pipe.
b. Bell holes shall be excavated in subgrade and made as small as possible still permitting un-obstructed placing of the jointing material and joint runner and not allowing foreign material to enter the joint. The length of the bell hole shall not exceed one-fourth (1/4) the length of the pipe.
c. The pipe shall be lowered into place in a manner that will insure that the pipe remains clean, care being exercised not to disturb the top line. The pipe shall not be lowered by sliding it down the side of the trench.
d. All pipe shall be fitted together and matched while being laid so that when joined, the inverted forms a true straight grade line. The ends of the pipe shall be brought in contact with each other.
e. If water is encountered in the trench, it shall be kept below the bottom of the bell of the unjoined pipe, and not allowed to come in contact with any part of the pipe forming the joint until after the joint is completely filled with the specified jointing compounds. Should the water, through neglect or otherwise, raise in the trench and enter the annular space in the pipe before the joining operation is completed, the annular space in all pipe so affected shall be freed of all water and foreign matter and thoroughly cleaned, before completing the jointing operation.
f. The pipe shall be checked for position in the trench by using a plumb bob below the “top” line for alignment and the grade shall be obtained by means of a “grade pole” held vertically with one side touching the “top” line and a right angle bracket at the bottom extending and resting on the invert of the pipe in its final position. The vertical distance from the "top" line to the pipe invert grade shall be a multiple of one (1) foot, at a distance above the invert as approved by the engineer.
If the use of a construction laser has been approved, line and grade shall be checked by means of the laser beam.
12. Sewer Pipe Jointing. Unless otherwise approved by the engineer in writing, the jointing material for all sewer pipe, under all conditions of laying, shall be as hereinafter described.
13. Plastisol Joints. Mechanical compression joints shall be an approved type of interlocking, self-centering, resilient, push-type mechanical compression joint, formed or fused on the pipe at the factory, made of plastisol (polyvinyl chloride) to specifications established by the National Clay Pipe Research Corporation.
The annular space shall be controlled either by precision grinding the bell and spigot, or by casting an approved material onto the outside of the spigot and on the inside of the bell, or by a combination of these methods.
The seal shall be obtained by compressing a rubber, plastisol (polyvinyl chloride) or other approved resilient element as the joint is assembled.
Vitrified clay pipe utilizing mechanical compression joints shall be “Wedge- Lock” as manufactured by Pacific Coast Clay Products, or “Speed-Seal Mainline” as manufactured by Gladding McBean Company. No other make of plastisol joint pipe will be permitted except as approved in writing by the engineer.
Pipe shall be installed in strict accordance with the manufacturer's instructions.
14. Elastomeric Joints. Elastomeric joints shall conform to ASTM D 3212 and shall utilize a single gasket for sealing. All joints shall be made in conformance with the manufacturer's recommendations and shall be closed to align the reference mark with the pipe bell.
15. Embedment Materials. Embedment material shall be one of the following types:
a. Clean washed sand, with a maximum particle size of l/4 inch, and with a minimum of 70 percent passing a No. 20 screen.
b. Graded sand and gravel, with a maximum particle size of 3/4 inch, conforming to the gradation requirements for Class 2 aggregate base contained in Section 26 of the state standard specifications.
16. Embedment Procedure.
a. After excavating the trench to a grade at least 4 inches below the pipe barrel elevation, carefully place bedding material the full width of the trench to provide uniform support along the entire length of pipe to be installed.
b. After installing the pipe, place and compact embedment material to the spring line of the pipe, taking care to work the material under the haunches of the pipe and to avoid displacement of the pipe.
c. Place and compact embedment material to the top of the pipe.
d. Place and compact embedment material to a minimum depth of 6 inches over the top of the pipe.
17. Alternate Embedment Procedure. With the approval of the engineer, the following alternate embedment procedure may be used, at the option of the contractor:
a. Excavate the trench and place bedding material as described in subsection P16a of this section;
b. After installing the pipe, place embedment material to a depth at least 8 inches above the top of the pipe;
c. Flood the embedment zone with water by either puddling or jetting. Adequate water must be applied to insure that the entire embedment zone is saturated;
d. Consolidate the embedment material with internal vibrators, applied at sufficiently close intervals that the visible effects of the vibration overlap. Care shall be exercised to avoid disturbance of the pipe during vibration, or contacting the pipe with the vibrator;
e. Allow sufficient drying time that the embedment material will support a man's weight before placing backfill.
18. Straightness. The full diameter of the pipe shall be visible when viewed between consecutive manholes, unless curved alignment is specified. Testing may be by photography or by lamping with lights or mirrors.
19. Manhole Connections. Sewer pipe shall be connected to manhole bases in a manner which will provide a watertight seal. With polyvinyl chloride sewers, special adaptors with resilient seals or waterstops shall be installed in manhole bases to provide a flexible, watertight connection.
20. Test for Leakage. On the completion of each section of the sewer between structures, where the soil is wet due to ground water, the end of the sewer at the upper manhole or structure shall be closed sufficiently to prevent the entrance of water, and the sewer treated for leakage, which if found to occur, shall be located, uncovered, and stopped. Where such leaks are discovered before the completion of the sewer, the sewer shall be immediately uncovered and the leaks stopped. Leakage shall be tested with an air pressure test. The pipeline to be tested shall be suitably plugged at all openings.
Test procedures and allowable pressure loss for vitrified clay sewers shall be as specified by the pamphlet entitled “Low Pressure Air Test for Sanitary Sewers,” published by the National Clay Pipe Institute. Polyvinyl chloride sewers shall be pressurized to 4.0 PSI greater than the average pressure of any groundwater which may submerge the pipe. At least 2 minutes shall be allowed for pressure stabilization. The rate of air loss shall then be determined by measuring the time interval required for the internal pressure to decrease from 3.0 to 2.5 PSI above the average pressure of any groundwater submerging the pipe. The pipeline shall be considered acceptable when the pressure drop described above occurs over a time period of at least (36.3 seconds) x (pipe diameter in inches).
If air pressure testing equipment is not available, water testing may be substituted. Permissible leakage for vitrified clay and polyvinyl chloride sewers will not exceed that allowed by the National Clay Pipe Institute's pamphlet listed above.
Final tests of sewers shall be made by the contractor under the direction of the engineer.
All tools, materials and appurtenances required for testing the sewers as specified shall be furnished by the contractor.
Unsatisfactory conditions shall be required to be corrected prior to acceptance of the project by the Engineer.
Noncompliance with plans and specifications, excessive leakage by infiltration or exfiltration, or similar causes shall be basis of nonacceptance.
21. Backfilling. Backfilling shall be done in accordance with subsection L of this section. Compaction of backfill material by ponding or jetting will not be allowed unless specifically approved by the engineer.
Where the sewer crosses streets or highways, ponding or jetting will not be permitted.
If, at any time during the continuance of the contractor's responsibility, there shall be any settlement of the trenches requiring that repairs be made in any street or highway, or should any defect appear in the system due to negligence or carelessness on the part of the contractor, the engineer may notify the contractor to make such repairs as may be necessary, and should the nature of such defect be such as to require immediate attention, the engineer shall make such repairs as may be necessary and submit a statement of the actual cost of such repairs to the contractor, who shall reimburse the city by cash payment.
22. Test for Deflection. Polyvinyl chloride (PVC) sewers shall be tested for deflection after final backfill and compaction has been completed, but before paving is placed. A rigid mandrel having an outside diameter of 95% of the “average inside diameter” of the pipe, as defined in ASTM D 3034, shall be pulled through the pipeline. The minimum length of the circular portion of the mandrel shall be equal to the nominal diameter of the pipe.
If the mandrel does not pass freely through the pipe, the pipe shall be reexcavated, bedded and backfilled to adequately support the pipe and reduce the deflection to 5% or less of the average inside diameter of the pipe. The pipeline shall then be retested for both leakage and deflection.
Should tests performed by the city, within one year of the original testing and acceptance, show deflection in excess of 7.5% of the average inside diameter of the pipe, the contractor shall reexcavate, bed and backfill the pipe to provide adequate support and reduce the deflection to 5% or less. The pipeline shall be retested for deflection. The contractor shall reimburse the city's cost of testing for all lines which require repair.
23. Disposal of Excess Material. Excess materials which have been excavated from trenches, and which cannot be utilized for backfill, or spread adjacent to the work, shall be removed by the contractor.
24. Protection of Work. The maintaining of a clean and dry joint during construction is essential in order that leakage may be eliminated in the completed sewer. Toward that end, the provisions of these improvement standards shall be rigidly adhered to in order to secure sewers free from leakage.
Whenever the work ceases for any reason, the unfinished end of the sewer shall be sufficiently closed to prevent the entry of dirt or trash, but under no circumstances made watertight.
The interior of the sewer shall be kept free from all dirt and foreign material as the work progresses, and left clean at its completion.
Upon completion of the sewers and prior to the final inspection and before acceptance, when ordered by the engineer, the contractor shall, at the contractor’s own expense, flush and cleanse the sewers of all dirt clods, small rocks, sand or silt deposits and any other materials that may be detrimental to the proper flow and operation of the sewer. The outlet end of the lowest manhole in the system shall be tightly plugged and a pump suction line placed in the manhole ready for use.
A fire hose shall be connected to a fire hydrant nearest to the last structure in the upper end of the system and the fire hose inserted in the sewer pipe as a jet.
The volumes and velocity obtained from the water system should be sufficient to flush any materials in the pipe to the lowest manhole where the pumps will be put into operation to remove the wash water and suspended solids. Disposal of this wash water shall be into the nearest storm drain.
When, in the opinion of the engineer, the wash water is sufficiently clear to indicate that the sewer is clean, the water shall be shut off and the sewer line allowed to drain down. When the lower manhole has been pumped and/ or bailed dry, the remaining residue shall be removed and the manhole left clean.
Q. Trench Sheeting, Shoring and Bracing.
1. Trench sheeting, shoring and bracing shall be installed for any trench or boring and jacking pit five feet or more in depth. Shoring system shall conform to the latest edition of the State Division of Industrial Safety Construction Safety Orders, Sections 1539, 1540, 1541 and 1542 pursuant to State Assembly Bill No. 150 dated October 2, 1973.
2. Permits. The contractor is required to obtain a permit from the State Division of Industrial Safety prior to the excavation of any trench or boring and jacking pit five feet or more in depth.
3. Shoring and Bracing Plans. The contractor shall be required to submit to the public works department, prior to excavation, a detailed plan showing the design of shoring, bracing, sloping, or other provisions to be made for worker protection from hazard of caving ground during the excavation of trench or trenches. If such plan varies from the shoring system standards of the State Division of Industrial Safety Construction Safety Orders, the plan shall be prepared by a registered civil or structural engineer.
R. Maintenance of Trees. Any excavation within the drip line of any trees shall conform to the following requirements:
1. No trees shall be removed unless specifically so designated on the plans or in the special provisions.
2. No roots over two (2) inches in diameter shall be cut.
3. Hand trenching and tunneling will be required when excavation exposes roots two (2) inches in diameter or larger.
4. Roots two (2) inches in diameter or larger which are exposed to the air shall be kept moist.
5. Roots two (2) inches in diameter or larger which are accidentally damaged shall be treated with material approved by the city of Chico park superintendent.
6. If roots two (2) inches in diameter or larger are accidentally cut or broken, the tree shall be trimmed to compensate for the decreased root system. Such trimming shall be done to the satisfaction of the park superintendent.
7. Boring pits shall not be installed within twenty (20) feet of any tree trunk.
8. All work shall be done to the satisfaction of the engineer.
(Res. No. 9 77-78 (part), Res. No. 87 86-87 §2, Res. No. 92 89-90, Res. No. 59 90-91 §§13-17, Res. No. 11 95-96 §§2-3, Res. No. 48 97-98 §§5-6, Res. No. 02 03-04, Res. No. 113-07, Res. No. 19-13)