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92f71'I0f1 71 INSTALLATION xcavE� atlon and backfill shall conform to the provisions in Section 19 Alternate C, "Earthwork (Structure Excavation and Backfill)," of these special provisions. The pipe shall be laid in a trench excavated to the lines andgrades designated by the Engineer. The bottom of the trench shall be graded and prepared to provide a firm and uniform bearing throughout the entire length of the pipe barrel. Suitable excavation shall be made to receive the bell of the the and e i j p p joint shall not bear upon the bottom of the trench. All adjustment to line and grade shall be made by scraping away or filing in with sand, gravel, or granular material under the body of the pipe, and not by wedging or blocking. Trenches shall not be left open farther tLan 300 feet in advance of pipe laying operations or 200 feet to the rear thereof, unless othherwise permitted by the Director. The excavation shall be supported so that it will be safe and that the ground alongside the excavation will not slide or settle, and all exist ingg improvements, either on public or private property, will be fully protected from damage. All supports shall be removed after construction is completed, unless otherwise directed by the Engineer, and shall be withdrawn in a manner that will prevent the caving of the sides of the excavation. All openings caused by the removal of supports shall be filled with suitable material properly compacted. Backfill of pipe trenches may be placed while the joint mortar is still plastic. Should he joint mortar become set before the backfill is placed, backfilling the pipe trenches shall not be commenced within 16 hours of jointing the pipe sections. Pipe shall be protected during handling against impact shocks and free fall. When the new facilities interfere with the existing flow of sewage, the Contractor shall provide satisfactory bypass facilities at his expense. The pipe shall be laid without break upgrade from structure to structure, with bell end up rade for bell and spigot pipe, unless otherwise permitted by Ehe Director. Sewer pipe shall be connected to existing facilities as shown on the plans and as directed by the Engineer. Whenever the work ceases for any reason, the end of the pipe shall be securely closed with a tight fitting plug or cover. Whenever existing pippes are to be cut or abandoned, the open ends of said pipes shall be securely closed by a tight fitting plug or wall of concrete not less than 0.5 toot: thick. All joints shall be carefully cleaned on the inside. Stoppers for pipes and branches left unconnected shall be made of the same material as the pipe, or of resilient joint material conforming to the requirements of ASTM Designation: C 425. After placing the sto per, it shall be covered with a layer of sealant. The sealan shall be sufficiently fluid to ensure free flow around the stopper. Where shown on the plans or directed by tha Engineer, sewer pipe shall be encased in concrete, reinforced with concrete, or backfilled with concrete, in accordance with the details shown on the plans. Concrete for pipe encasement, pipe reinforcement, and backfill shall conform to the provisions in Section 90-10, "Minor Concrete," of the Standard Specifications, except that the minor concrete shall contain not less than 470 pounds of cement per cubic yard. All concrete shall be cured for a period of not less than 10 days after being placed and shall be protected from damage. New manholes, drop inlet connections, larripholes, service laterals, service cleanouts, terminal cleanout structures, and ipe chimneys for sewers shall be constructed in accordance with he details shown on theplans, as specified in these special provisions and as directed by the Engineer. Precast concrete ppipe manholes shall conform to the provisions in Section 70, "Miscellaneous Facilities," of the Standard Specifications, except for measurement and payment. When the manhole is located in the pavement area, it shall not be constructed to final grade until the pavement has been completed. The inside bottoms of existing manholes, where new connections are made, and of new manholes shall be shaped to provide channels conforming to the size and shape of the lower portion of the inlets and outlets of the manholes. The channels shall vary uniformly in size and shape from inlet to outlet. No pipe shall project more than 0.17 foot into a manhole and in no case shall the bell of a pipe be built into the wall of a manhole or structure. MANHOLE COATING All new manholes, as defined below, downstream from hydrogen sulfide producing structures, to the point of connection into the existing system, shall receive a protective coating. In addition, any existing manholes downstream from new hydrogen sulfide producing sewer systems that the Engineer determines may be affected by new sewer systems shall be coated. At a minimum, all sanitary sewer manholes downstream from all pump stations, drop manholes, and manhole pumping stations shall be coated. All manholes used for manhole pumping stations shall be coated. All manholes constructed on sewer lines 24 -inches and larger, and any other structure where the Engineer determines that hydrogen sulfide gas may be a problem, shall be coated. The coating material shall have a minimum pot life of 35 minutes at 70•F and a drying time (ASTM D-1690) of 4 hours. The flash point of the individual components and the fluid mixture shall be a minimum of 220'F (COC). The coating material shall have a low temperature total cure capability of 40'F, minimum. The cured coating material shall have sufficient abrasion resistance to exhibit a weight loss of less than 92 mg when measured in accordance with ASTM D-4060. Adhesion (ASTM D-4541) shall be 400 psi, minimum, with a direct impact resistance (ASTM D-2794) of 18 inch -pounds. The cured coating shall be capable of repair at any time during its life. The coating shall be resistant to attack from the following: Oxidizing agents such as bleaches, sulfuric, acetic, hydrochloric, phosphoric, nitric, chromic, oleic, and stearic acids; sodium and calcium hydroxidies, ammonium, sodium, calcium, magnesium, and ferric chlorides; ferric sulfate, petroleum oils and greases, vegetable and animal oils, fats, greases, soaps, and detergents. The coating shall be impermeable to sewage gases and liquids and shall not be conducive to bacterial or fungal growth. Surfaces to be coated shall be cleaned of all dirt, dust, corrosion, loose concrete, grease, oils and foreign matter. Surface shall be abrasive treated to achieve a finish conforming to ASTM D-4259. Surfaces shall be dry prior to receiving coatings. Pre -cast concrete pipe sections shall be cored for the installation of pi e and other penetrations prior to being coated. Coating shall extend to the outside edge of all holes and joints. The epoxy material shall be applied by high pressure airless spray equipment. The coating shall be app ied using cross spray methods to eliminate pinholing and shadow.inc(. The epoxy primer shall be applied to achieve an initial thickness of 3 to 6 mil. The epoxy coating material shall be applied in a single coat multiple pass application to achieve a dry film thickness of 60 mil, minimum. All coating operations shall be performed in the presence of the Engineer. All coating work done in the absence of the Engineer is subject to refection unless specifically approved, in writing, by the Engineer prior to the work being performed. The Engineer shall have access to the construction site and those areas involved with the performance of the coating work. All applicable safety equipment and suitable respirators shall be used during coating operations as recommended by the manufacturer and the material safety data sheets. The coating shall be free of all blisters, pinholes, holidays and discontinuities. The finished coating shall be tested for pinholes and discontinuities using a high-voltage spark tester. All testing shall be performed by the Contractor in the presence of the Engineer. The testing shall be performed at a minimurn voltage of 125 volts per mil of dry film thickness. The Contractor shall verify the proper operation of the testing equipment as per the manufacturer's written instructions prior to spark testing. Spark tester shall be Tinker-Rasor AP -W, or approved equal. All areas required to be repaired as determined by testing and inspection, shall be first spot scarified and then spot recoated as per manufacturer's recommendations. TESTING AND INSPECTION Prior to performing tests, the pipe installation shall be thoroughly cleaned. Cleaning shall be performed by the Contractor by means of an inflatable rubber ball. The ball shall be of a size that will inflate to fitinto the pipe to be tested. The ball shall be controlled wit a tag line. The ball shall be placed in the last lamphole or maintenance hole on the pipe to be cleaned, and water shall be introduced behind it. The all shall pass through the pipe with only the pressure of the water impelling it. All debris flushed out ahead of the ball shall be removed at the first maintenance hole where its presence is noted. In the event cement or wedged debris or a damaged pipe shall stop the ball, the Contractor shall remove the obstruction. Following the placernent and compaction of backfill and prior to placement of permanent pavement, the Contractors shall perform a deflection test on the pipe. If the pipe should fail the deflection test, the Contractor shall uncover the pipe and make adjustments in the bedding and/or backfill conditions that will be necessary to achieve a passing test. The trench shall be backfilled and street subgrade shall be recompacted and the pipe retested. Any corrective measures found necessary to meet the deflection requirements, including recompaction and regrading of the street subgrade, shall be included in the unit price bid for the sanitary sewer pipe. The Contractor shall furnish all equipment deeded to complete this test. The cost for the deflection test shall be included in the unit price bid for the sanitary sewer pipe. Deflection test shall be conducted after the placement and densification of backfill. The Contractor shall furnish properly sized mandrels for size and type of pipe installed. Certification of proper size shall be required and mandrel identified in a manner to identify with certification. For ABS Pipe--r_fl mainline pipe shall be cleaned and then mandrelled to measure for obstructions (deflection, joint offsets, lateral intrusions, etc.). A rigid mandrel with a circular cross-section having a diameter at least abs of the specified average inside diameter shall be pulled through the pipe. The method of measuring the deflection shall be approved by the Engineer. Any pipe through which the mandrel will not pass shall be said to have failed and will be s;_piired by the Contractor at his expense. For HDPE Pipe --Maximum long-term deflection for HDPE pipe shall be no more than 5%. Lorig-term deflection shall be calculated as the short-term deflection multiplied by a deflection lag factor based upon the average inside diameter of the pipe. In no case shall a deflection lag factor of less than 1.5 be accepted. Short-term deflection shall be measured with a mandrel no sooner than 30 days following installation. Mandrel deflection tests may be required during installation to have an odd number of legs totaling no less than nine. Pipe sections not meeting the deflection requirements shall be excavated, reinstalled, and subject to an additional 30 --day deflection test. For PVC Pipe --The following table lists minimum pipe I.D. deflections: i.e., O.D. of mandrel: Table of Allowable Deflections for PVC Pine G, a iv e Ouse r.L,. 4, n_ A,iowaole i.u. 4" PVC 3.966 3.66 6" PVC 5.742 5.36 8" PVC 7.665 7.18 10" PVC 9.563 8.98 12" PVC 11.361 10.69 15" PVC 13.898 13.08 At his option, the Engineer may re tire a sample of ten percent (10%) of the laterals randomly selected by the inspectors shall also be tested for deflection. If difficulty is encountered in passing the mandrel test, the inspector may direct that a larger sample of laterals be tested up to including one - hundred percent (100%) of all laterals. At the Contractor's expense, all locations with deflection greater than allowable shall be excavated, repaired or replaced, backfilled and retested. tiny corrective work proposed shall be approved b the Engineer. No vibrating re -rounded devices shall be aflowed to correct pipe deflections. In addition to the deflection requirements, the Contractor shall furnish all equipment, materials and labor necessary to provide video inspection of all main line sewer pipes. The video log shall be recorded using VHS format and shall include an on-screen counter indicating theosition of the camera, in feet, with respect to the length or stationing of the sewer main being televised_ The County shall be provided with two copies of the completed video log. The video shall be performed following the placement and densification of backfill, but prior to the placement of paving. Any defective pipe or conditions discovered by televising shall be corrected by the Contractor at his expense. Any corrective work proposed shall first be approved by the Engineer. Defective work shall consist of the following: cracks or breaks in the pipe; joints offset by more than 3/8 inch or 1 percent of the inside diameter, whichever is greater; protruding, deformed or folded gaskets; ets• standing water at a depth greater than 0.01 foot per inch of diameter (based on a loss of pipe area of 6.8 percent). The County may also televise the sewer mains prior to the expiration of the one year warranty period. If a defective condition is unaccountably found, it shall be presumed to be caused by defective workmanship or materials. The Contractor shall be notified and shall correct the work in a manner approved by the Engineer. Full compensation for furnishing all labor, materials, tools, equipment and incidentals for providing video inspection of the sewer pipes shall be considered as being included in the runit- contact a 't Y _ costs bid for the various sizes of sewer pipe installed and no additional compensation shall be made therefor_ when designated on the plans, sewers shall be tested by the Contractor for watertightness. Each section of sewer shall be tested between successive maintenance holes by closing the lower end of the sewer to be tested and inlet sewer of the upper maintenance hole with stoppers. The pipe and maintenance hole shall_ be filled with water to a point 4 feet (1.22m) above the invert of the sewer at the center of the upper maintenance hole; or if ground water is present, 4 feet (1.22m) above the average adjacent ground water level. Thc:.,allowable leakage will be computed by the formulae: E 0.0001 LDfH for mortared joints. E _ 0.00002 LDrH for all other joints. LJhere: L is length of sewer and house connections tested, in feet. E is the allowable leakage in gallons per minute of sewer tested. D is the internal diameter of the pipe, in inches. H is the difference in elevation, in feet, between the water surface in the upper maintenance hole and the invert of the pipe at the lower maintenance hole; or if groundwater is present above the invert of the pipe in the lower maintenance hole, the difference in elevation between the water surface in the upper maintenance hole and the groundwater at the lower maintenance hole. di wever, the maximum shall not exceed 200 gallons per inch of 11,1-ernal diameter per mile per day. 'Phe Conti actor shall, at his expense, furnish all water, matarials and labor for making the required test. All tests shall be made in the presence of the Engineer. where the leakage of the sewer exceeds the above amount, it shall be corrected immediately and the amount of leakage reduced to a quantity within the specified amount. In any case, the Cont actor shall stop any individual leaks which may be observed. AiR PRESSURE TEST The Contractor shall furnish all materials, equipment and aboi for making an air test. Air test equipment shall be approved by the Director prior to the beginning of the test. ac:h section of sewer shall be tested between successive m.,;_r,tF-nance holes by plugging and bracing all openings in the main ,ewer :line and the upper ends of all sewer connections. Prior to any air pressure testing, all pipe plugs shall be checked with a .soap solution to detect any air leakage. If any leaks are found, the air pressure shall. be released, the leaks eliminated and the test procedure started over again. Phe final leakage test of the sewer main line and branching sewer connections Shall be conducted in the presence of the Director or his representative in the following manner: I. Clean pipe to be tested by propelling snug fitting inflated rubber ball through the pipe with water. Plug all pipe outlets with suitable test plugs, brace each plug securely. 3. If the pipe to be tested is submerged in ground water, insert a pipe probe by boring, or letting, into the backfill material adjacent to the center of the pipe and determine the pressure in the probe when air passes slowly through it. This is the back pressure due to ground water submergence over the end of the probe. All gauge pressures in the test should be increased by this amount. Add air slowly to the Fortiori of the pipe installation under test until the internal air pressure is raised to 4.0 psig. After an internal pressure of 4.0 psig is obtained, allow at least two minutes for air temperature to stabilize, adding only the amount of air required to maintain pressure. When pressure decreases to 3.5 psig, ;tart stop watch. The following applies to all pipes other than PVC and ABS (see 6b): Determine the time in seconds that i.s required for the internal air pressure to reach 2.5 psig. Minimum permissible pressure holding times are indicated by the following formula and table in seconds: c = k (d) 4 ,There t = minimum required time in seconds k = constant 0.022 d = nominal pipe diameter in inches q = allowable air loss rate per unit area, 0.003 cu. ft./min./sq. ft. of internal/surface area L E N G T H O L L N E N F E E T MINIMUM HOLDING TIME IN SECONDS REQUIRED FOR PRESSURE TO DROP FROM 3 1/2 TO 2 1/2 PSIG PIPE DIAMETER NOTES: (1) TO BE USED WHEN TESTING ONE DIAMETER ONLY. (2) THE ABOVE AIR PRESSURE TEST PROCEDURE IS BASED ON ASTM C828. ANY SPECIAL SITUATIONS OR CONDITIONS SHALL CONFORM TO THIS ASTM STANDARD. 6b. For PVC and ABS lines, the following table lists the minimum times allowed for a pressure drop from 3.5 psi to 3.0 psi in excess of the ground water pressure at the top of the pipe. 1 Pipe Die (in) 4" 6" 8" 10" 12" 15" 18" 21" 24" 27" 30" 33" 36" 39" 25 4 10 16 28 40 62 89 121 158 200 248 299 356 418 50 9 20 35 55 79 124 178 243 317 401 495 599 713 837 75 13 30 53 83 119 186 267 364 475 601 743 898 1020 1105 100 18 40 70 110 158 248 256 485 634 765 851 935 10 4:43 125 22 50 86 138 198 309 996 595 680 12 5:40 199 1.709L 5:90 150 26 59 106 165 238 371 510 I 7:05 1 159 1 2.671E 7:05 7:05 7:05 11:06 175 31 69 123 193 277 425 200 35 79 141 220 317 225 40 69 158 248 340 250 44 99 176 275 275 48 109 194 283 300 53 119 211 350 62 139 227 400 70 158 950 79 170 500 88 550 97 600 106 650 1 113 170 1 227 1 283 1 340 1 425 1 51U 595 680 765 1 851 935 1020 1105 NOTES: (1) TO BE USED WHEN TESTING ONE DIAMETER ONLY. (2) THE ABOVE AIR PRESSURE TEST PROCEDURE IS BASED ON ASTM C828. ANY SPECIAL SITUATIONS OR CONDITIONS SHALL CONFORM TO THIS ASTM STANDARD. 6b. For PVC and ABS lines, the following table lists the minimum times allowed for a pressure drop from 3.5 psi to 3.0 psi in excess of the ground water pressure at the top of the pipe. 1 Pipe Die (in) 2 Pun Time {,nin 3 Lgth for Min 4 Time for Lngr specification time for Length (L) shown (min: sec) a i $ a 96 e = sec) Time Lg ch 100 ft 150 ft 200 ft 250 ft 300 ft 350 ft 400 ft 450 ft 4 1:53 597 .190L 1:53 1:53 1:53 1:53 1:53 1:53 1:53 1:53 6 2:50 396 .427L 2:50 2:50 2:50 2:50 2:50 2:50 2:51 3:12 8 3:47 296 .760L 3: 97 3:97 3:97 3:47 3:48 4:26 5:04 5:42 10 4:43 239 1.167L 9:93 4:43 4:43 4:57 5:56 6:55 7:54 859 12 5:40 199 1.709L 5:90 5:40 5:42 7:08 8:33 9:58 11:24 1250 15 I 7:05 1 159 1 2.671E 7:05 7:05 7:05 11:06 13:21 15:35 17:98 2002 SAFETY NOTE: The air test may be dangerous if, because of ignorance or carelessness, a :Line is improperly prepared. It is extremely important that the various plugs be installed and braced in such a way as to prevent blow outs. Inasmuch as a force of 250 lbs. is exerted on an 8" plug by an internal pipe pressure of 5 psi, it should be realized that sudden expulsion of a poorly installed plug or of a plug that is partially deflated before the pipe pressure is released can be dangerous. As a safety precaution, pressurizing equipment should include a regulator set at perhaps 10 psi to avoid over -pressurizing and damaging an otherwise acceptable line. No one shall be allowed If the time lapse is less than that shown in the table, the contractor shall make the necessary corrections to reduce the leakage to acceptable limits. 1 i i 0 g 0 W a i $ a 96 e = 1 i i SHEET 4 OF 15 S g o w o r SHEET 4 OF 15 S