Expose all underground utilities which may be in conflict with proposed sanitary sewer lines prior to installing new lines. If faults, caverns or subsidence are discovered during construction, halt work to allow features to be inspected by the Engineer or the designated representative of the Engineer. Construction may only be resumed with approval of Engineer or the designated representative of the Engineer.
(Ordinance 2007-106, App. B, adopted 3/20/07)
A. 
Pipe Laying and Jointing.
Once the foundation has been prepared, pipe shall be laid with the spigot ends in the direction of the outlet or low end of the pipeline. The interior of the pipe shall be free from all dirt, joint material and foreign material as the work progresses and shall be clean upon its completion. Inside surfaces of adjacent sections of pipe shall be constructed in such a manner to provide the best possible flow conditions. Tight fitting stoppers or bulkheads shall be placed in the ends of all pipelines when the work has stopped, to prevent dirt or trash from entering the pipe.
B. 
PVC Pipe.
Bedding of the pipe shall be as detailed on the plans for the laying conditions.
1. 
Solvent Weld Joints.
When joints are made, the pipe fittings and couplings shall be at the same temperature. All joints shall be tested for a snug dry fit before solvent is applied. If the dry fit is such that the couplings are loose or if force is required to test dry fit, the pipe shall be rejected. A nonsynthetic brush shall be used to apply solvent cement in accordance with the manufacturer’s recommendations. Lightly apply cement to the inside of the fitting and more generously to the outside of the pipe. The joint shall then be stabbed into the fitting and given a quarter turn. If sufficient cement has been used, a small bead will form between the pipe and the shoulder of the fitting. Remove this excess solvent. The joint shall not be moved until the cement weld has set. Fittings for service lines or laterals shall be assembled so that no strain is placed on the pipe during or after the backfill operation.
2. 
Push-On Joints.
Before jointing, both bell and spigot ends shall be thoroughly cleaned and a lubricant supplied by the pipe manufacturer shall be applied according to the manufacturer’s recommendations. Spigot end shall be beveled so it will not dislodge or damage gasket. To insure proper sealing of the joint, sufficient pressure shall be applied until reference mark on spigot is flush with end of bell.
3. 
Cutting Pipe.
If it is necessary to cut the pipe, a fine tooth hacksaw shall be used and the burrs removed with a file. The outer surface of the pipe and the inner surface of the fittings shall be wiped with a clean cloth to remove all foreign matter and moisture before application of the solvent cement, for solvent weld joints. Bevel end of pipe per manufacturer’s recommendations for push-on joints.
C. 
Ductile Iron Pipe.
Bedding of the pipe shall be as detailed on the plans for the laying conditions.
1. 
Before jointing, both bell and spigot ends shall be thoroughly cleaned and a lubricant supplied by the pipe manufacturer shall be applied according to the manufacturer’s recommendations. Spigot end shall be beveled so it will not dislodge or damage gasket. To insure proper sealing of the joint, sufficient pressure shall be applied until reference mark on spigot is flush with end of bell.
2. 
Mechanical Joints. Joints shall be made in a workmanlike manner, using rubber gasket seals, follower glands, and standard bolts. Overstressing of bolts to stop leaks resulting from poor installation practice will not be permitted.
3. 
Wall Sleeves. At all points where the pipe must pass through a wall of a structure, the Contractor shall furnish and install suitable sleeves and wall castings, unless otherwise shown on the plans. The wall sleeve or wall casting shall be a mechanical joint and/or flange fitting flush with the wall, with flanges tapped for studs.
D. 
Conductive Trace Wire.
Install conductive trace wire in compliance with Section 2605 - Conductive Trace Wire for Underground Pipe Installation with all force mains and gravity lines. Cad-weld trace wire to manhole frames.
E. 
Curved Alignment.
For curved sewer lines, the Contractor shall not exceed the pipe manufacturer’s recommended maximum deflection at each joint. Each joint shall be pushed “home” prior to deflecting the pipe and pipe shall not be stressed or bent to achieve curvature. The Contractor shall reduce the pipe lengths according to the manufacturer’s recommendations, if the radius of curvature cannot be achieved without exceeding the maximum deflection using standard length joints of pipe.
F. 
Valve Boxes and Operator Extensions.
Valves buried in the ground shall be provided with cast iron valve boxes of proper dimensions to fit over the valve, and to extend to such elevation, at slightly above the finished ground line. Valve boxes shall be set vertical and centered with the valve stem. Provide and install a valve operator extension on any buried valve that is installed with the nut operator more than 30-inches below surrounding finished grade.
G. 
Thrust Blocking.
Thrust blocking for pressure sewers (force mains) shall be in accordance with the pipe manufacturer’s recommendation.
H. 
Embedment and Encasement.
Embedment and encasement shall be placed at the locations shown on the plans and in conformance with Section 02222 Excavation, Trenching and Backfilling for Utilities. If the maximum width is exceeded at any point, the Contractor shall use the next number of embedment higher than that designated on the plans. The additional cost for using the higher type of embedment required because of over cutting will be at the expense of the Contractor.
1. 
Typical DIP Embedment.
Unless otherwise shown on plans use Type 2 embedment in accordance with ASTM A746.
2. 
Typical PVC Embedment.
Pipe shall be imbedded in sand or gravel with fines meeting the designation of Class I or II Soil per ASTM D-2321 compacted to a minimum of eighty-five (85) percent Standard Proctor. The embedment shall extend from four (4) inches below the pipe to a point twelve (12) inches above the top of the pipe.
I. 
Fiberglass Manhole Construction.
1. 
The manhole shall be constructed on a concrete foundation of the size and shape shown on the plans. The foundation shall be placed against undisturbed earth and the thickness shall be a minimum of eight (8) inches below the bottom of the outside diameter of the sewer pipe or bottom edge of manhole section. If the manhole is over twelve (12) feet deep, then the foundation thickness shall be a minimum of twelve (12) inches below the bottom of the sewer pipe’s outside diameter or bottom edge of manhole section.
2. 
The base of the reinforced fiberglass manhole shall be cut to accommodate the size of the sewer pipe indicated on the plans. The maximum tolerance for the cutout is one-half (1/2) inch greater than the required opening. The base shall be embedded in a concrete foundation to a minimum depth of six (6) inches. The base and foundation shall be placed as soon as practicable after the sewer line is completed through the manhole location. To get the proper seal where the manhole cutout fits over the pipe, fresh concrete which is monolithic with slab concrete must be used as shown on the outside of the manhole and waterstop gaskets shall be installed on all pipes penetrating the manhole. Manholes will be rejected if this seal is not made when the slab is poured and the manhole is placed. Grout with a cold joint between grout and the concrete slab is not acceptable.
3. 
Where sewer pipe for a drop connection enters a manhole other than at bottom cut out, a saddle type connection to the manhole for the pipe size will be provided as shown. Connections depending upon grout for sealing will not be allowed.
4. 
Manholes shall be installed as one basic unit. The Contractor is responsible for verifying the correct manhole depth before construction. Top of fiberglass portion of manhole shall not be less than twelve (12) inches nor greater than eighteen (18) inches from final grade. The Contractor is responsible for the correct depth of manholes relocated in the field because of unforeseen conflicts. Manhole tops shall be adjusted with precast concrete rings and be set as follows:
a. 
Developed Areas.
Manhole tops shall be set one (1) inch higher than the existing elevation of natural ground or other final grade, unless shown otherwise on the plans.
b. 
Undeveloped Areas.
Manhole tops shall be set flush with paved surfaces and one (1) inch higher than shoulder and/or proposed final grade elevations in easement or other unpaved areas. Where manholes are located in a ditch bottom, set manhole top a minimum of twelve (12) inches above the ditch bottom and reshape the ditch around the manhole.
5. 
Backfill around manholes and drop connections immediately after mortar and concrete have set. Place backfill around the manhole evenly in six (6) inch layers and in such a manner that no torque is applied to the manhole. For manholes in paved areas backfill around manholes shall be of same material and compaction as specified for sewer line in paved areas. Where a proposed sewer line connects to an existing manhole at or near a manhole invert, reshape the invert of the existing manhole so that no turbulence is created in the manhole as a result of the connection.
6. 
Precast concrete rings shall be used to adjust the top of the manhole to the proposed grade if necessary.
J. 
Precast Manholes.
Construction of precast concrete manholes shall follow the general procedures for fiberglass manholes except that precast manhole bottoms may be used if cast as an integral part of the bottom ring.
K. 
Cast-in-Place Manholes.
Manholes shall be constructed of concrete conforming to Section 03300, Cast-in-Place Concrete. Manholes shall be poured in place as shown on the plan sanitary sewer detail sheet. The foundation shall be placed against undisturbed earth and shall be a minimum of eight (8) inches thick below the bottom of the sewer outside diameter, except if the manhole is over twelve (12) feet deep make the foundation twelve (12) inches thick below the bottom of the sewer pipe outside diameter. The manhole foundation, walls and cone section shall be constructed in a single continuous monolithic concrete pour.
L. 
Construction Methods For All Manholes.
1. 
Manhole Connections.
Watertight, size-on-size resilient connectors allowing for differential settlement shall be used to connect pipe to manholes. Pipe to manhole connectors shall conform to ASTM C-923. Water stop gaskets shall be installed on the pipe for connection to existing manholes and shall be grouted in place with non-shrink grout having a minimum thickness of one (1) inch around the gasket.
2. 
Manhole Inverts.
The bottom of the manhole shall be provided with a “U” shaped channel that is as much as possible a smooth continuation of the inlet and outlet pipes. For manholes connected to pipes less than fifteen (15) inches in diameter the channel depth shall be at least half the largest pipe diameter. For manholes connected to pipes greater than twenty-four (24) inches in diameter the channel depth shall be at least equal to the largest pipe diameter. Invert flow channels shall be on an even slope from pipe to pipe. The bench provided above the channel shall be sloped at a minimum of 0.5 inch per foot. Where sewer lines enter the manhole higher than twenty-four (24) inches above the manhole invert, the invert shall be filleted to prevent solids deposition. Where the main sewer (lowest line) passes straight through the manhole and the degree of deflection of the main sewer is less than five (5) degrees, and no other line or stub out is shown entering the manhole below the center line of the main sewer, lay the sewer continuously through the manhole. After the manhole walls have been completed, cut out and remove the top half of the barrel of the sewer pipe that was previously laid through the manhole. Use concrete with one (1) inch mortar topping and construct the remainder of invert as shown on plans. Where the main sewer (lowest line) alignment deflects greater than five (5) degrees at the manhole or where another sewer or stub out enters at or below the center line of the main sewer, terminate the main sewer pipe laying in such a manner that the ends of pipe protrude inside of the manhole. The invert shall be constructed with concrete and topped with one (1) inch of mortar. The invert shall be shaped to allow for a smooth flow across the floor of the manhole and slope the side as required to prevent deposition of solids.
3. 
Stubs Outs.
Stub outs shall be installed to line and grade where shown. One (1) full joint of pipe, of the size indicated, will be used for the stub out. Seal the stub out with a plug. The plug shall be installed in such a manner as to prevent seepage or leakage through stub outs. The plug shall be installed such that it may easily be removed in the future without damaging the bell or groove end of the stub out.
4. 
Contractor shall meet all OSHA requirements relating to entry into confined spaces prior to personnel entering manhole for any reason.
M. 
Cleanout Structures.
Cleanout structures shall be constructed where shown on the plans and as specified. Cleanouts shall consist of six (6) inch riser pipe laid on an angle on undisturbed natural ground. Machine tamp all backfill around and above the pipe in layers six (6) inches or less in depth so that no settlement shall occur after the cleanout is constructed. Other construction details shall conform to the cleanout detail shown on the plans.
N. 
Connections.
1. 
Drop Connections.
Drop connections on manholes shall be constructed according to the plans and these specifications. The connection shall include the indicated fittings and necessary backfill material.
2. 
Service Connections.
Standard service connections shall consist of a wye and forty-five (45) degree bend and the necessary four (4) inch diameter PVC sewer pipe to reach the property line, or be plugged and sealed at the end. The plans may require a larger service line. Install a larger service line when shown on the plans. If required, the Contractor shall raise the lateral by means of a steeper grade from the main. Locations of the service outlets and the depth to the top of the lateral pipe, if depth is not shown on the plans, will be designated at the time of construction. Minimum depth of cover over the end of the lateral pipe shall be five (5) feet.
O. 
Separation Distances.
The following are separation distances that shall apply between potable water and wastewater treatment plants, and water lines and sanitary sewers.
1. 
Potable Water Treatment Plant Separation.
Sanitary sewers located within 50 feet of any underground treatment plant units shall be constructed of ductile iron or PVC with a minimum pressure rating of 150 pounds per square inch and watertight joints.
2. 
Water Line/New Sewer Line Separation.
Sanitary sewers shall not be installed within nine (9) feet, in all directions, to existing water lines. Sewer lines parallel to water lines must be installed in separate trenches. If the nine (9) feet separation distance cannot be achieved, the following guidelines apply.
a. 
Where a sanitary sewer parallels a water line, the sewer shall be constructed of cast iron, ductile iron or PVC meeting ASTM specifications with a pressure rating of 150 psi for both the pipe and joints. A minimum vertical distance of two (2) feet and a minimum horizontal distance of four (4) feet between the outside diameters of the pipes is required. The sewer shall be located below the water line.
b. 
Where a sanitary sewer crosses a water line, and the sewer is constructed of cast iron, ductile iron or PVC with a minimum pressure rating of 150 psi, an absolute minimum distance of six (6) inches between the outside diameters shall be maintained. The sewer line shall be placed below the water line if possible, and one length of the sewer pipe must be centered on the water line.
c. 
Where a sewer line crosses under a water line and the sewer line is constructed of ABS truss pipe, similar semi-rigid plastic composite pipe, or concrete pipe with gasketed joints, a minimum separation distance of two (2) feet must be maintained. The initial backfill shall be cement stabilized sand (two and one-half bags of cement per cubic yard of sand) for all sections of sewer within nine feet of the water line. This initial backfill shall be from one quarter diameter below the centerline of the pipe to one pipe diameter (but not less than twelve (12) inches) above the top of the pipe.
d. 
Where a sewer crosses over a water line all portions of the sewer within nine (9) feet of the water line shall be constructed of cast iron, ductile iron, or PVC pipe with a pressure rating of at least 150 psi using appropriate adapters. In lieu of this procedure the new conveyance may be encased in a joint of 150 psi pressure class pipe at least eighteen (18) feet long and two (2) nominal sizes larger than the new conveyance. The space around the carrier pipe shall be supported at five (5) foot intervals with spacers or be filled to the springline with washed sand. The encasement pipe should be centered on the crossing and both ends sealed with cement grout or manufactured seal.
3. 
Water Line/Manhole Separation.
If the sanitary sewer manholes and the connecting sewer cannot be made watertight and tested for no leakage, then a minimum horizontal separation distance of nine (9) feet must be provided between the manhole and the water line. If the minimum distance of nine (9) feet cannot be achieved, then a carrier pipe as specified in the preceding subsection shall be used.
P. 
Casing Spacers:
Casing spacers shall be installed on all carrier pipe which is installed inside a casing. Casing spacers shall be installed such that the distance between spacers does not exceed the maximum distance recommended by the spacer manufacturer dependent on potential weight of the carrier pipe and casing, both full of water, except the distance between spacers shall not exceed seven (7) feet. A casing spacer shall be installed within one (1) foot of the end of each joint of nonwelded carrier pipe, and two adjacent spacers shall be installed on the carrier pipe at each end of the casing such that the last spacer is within one (1) foot of the end of the casing.
A. 
Test For Deflection of PVC Pipe.
All PVC pipe installed for gravity sewers will be tested for deflection according to this specification after the pipe segment has been in place for a minimum of thirty (30) days. Maximum allowable deflection shall not exceed five percent (5%) of the inside diameter of the pipe. The inside diameter shall be the average outside diameter minus two (2) minimum wall thicknesses for outside diameter controlled pipe or the average inside diameter for inside diameter controlled pipe. A “go, no-go” mandrel will be used to check the deflection of an installed section of PVC pipe. The mandrel will be sized so that it will not “go” when encountering a deflection that is greater than permissible. The mandrel must be of such design as to minimize the possibility of it being hung up in the pipe by silt or other residues. A design sized to permit up to five percent (5%) deflection in pipe is shown in Figures 3.03A & 3.03B. Table 3.03A showing the required dimensions of mandrels for various pipes is attached. Suggested instructions for its use are as follows:
1. 
Completely flush the line making sure the pipe is clean of any mud or debris that would hinder the passage of the mandrel.
2. 
During the final flushing of the line, attach a floating block or ball to the end of the mandrel pull rope and float the rope through the line.
3. 
Once the rope is threaded through the line, connect the pull rope to the mandrel and place the mandrel in the entrance of the pipe.
4. 
Connect a retrieval rope to the back of the mandrel to pull it back, if necessary.
5. 
Remove all slack in the pull rope and place a tape marker on the rope at the ends of the pipe where the mandrel will exit, determining the location of the mandrel in the line.
6. 
Draw the mandrel through the sewer line by hand pulling only. If any irregularities or obstructions are encountered in the line, the Engineer or designated representative of the Engineer should establish the corrective action, if required.
7. 
If a section with excessive deflection is found, locate it; dig down and uncover the pipe; inspect the pipe, if any damaged pipe is found, replace it; if pipe is not damaged, replace and thoroughly tamp the haunching and initial backfill; replace remainder of backfill.
8. 
Retest this section for deflection a minimum of thirty (30) days after completing the repair.
-Image-5.tif
B. 
Testing Pressure Sewers For Leakage.
All pressure sewers shall be tested for leakage with a hydrostatic test to be completed in the presence of the Engineer or designated representative of the Engineer. Leaks demonstrated by the tests are to be repaired at the expense of the Contractor.
1. 
Performance.
Newly laid pipe or any valved section of piping shall be subjected for one (1) hour to a hydrostatic pressure test of twenty-five (25) pounds per square inch gauge or 1.5 times the maximum force main design pressure, whichever is larger. The following formula shall be used to determine the permissible leakage that shall not be exceeded:
L = (S)(D)(P 0.5)/133,200
Where, L = leakage in gallons per hour
S
=
length of pipe in feet
D
=
inside diameter of pipe in inches
P
=
pressure in pounds per square inch
2. 
Execution.
Fill test section of pipe with water and expel the air from the pipe. Apply the specified test pressure by means of a pump connected to the pipe. The Contractor shall furnish the necessary pump, pipe connections, gauge and meter and shall conduct the test. If force main is tapped to perform test, plug taps with brass fittings upon completion of test.
a. 
Inspect the route of the pipe during the test period to locate any leaks or breaks. The Contractor shall replace any cracked or defective pipe, fittings or valves disclosed in the pressure test.
b. 
When the one (1) hour test period is completed, bring the pressure in the pipe up to the specified test pressure and determine the amount of water lost during the test. No piping installation shall be accepted until the leakage amount is less than that specified. Should any test of combined sections or individual sections of pipe show leakage greater than the specified limit, the Contractor shall locate and repair the defective joints or defective pipe until the test proves that the leakage is within the specified allowance.
c. 
Testing Gravity Sanitary Sewers For Leakage.
The Contractor shall test all gravity sewer lines using either the infiltration method, exfiltration method, or the low pressure air test, in the presence of the Engineer or designated representative of the Engineer or his representative. Additionally, all new manholes shall be tested. The Engineer or designated representative of the Engineer shall be notified no later than the preceding day, of the date and approximate time the tests will be made. Sewers shall not show leakage of more than fifty (50) gallons per inch diameter per mile of pipe per twenty-four (24) hours at a minimum test head of two (2) feet above the crown of pipes at the upstream manhole using the infiltration or exfiltration test except for pipes installed in the 25 year flood plain, which shall show leakage less than 10 gallons per inch diameter per mile of pipe per twenty four (24) hours. For the air test, leakage shall not exceed the amount specified herein for the length and diameter of the pipe tested. The Engineer or designated representative of the Engineer may vary the procedures for “Infiltration Test,” “Exfiltration Test,” and “Air Test” provided the methods used give an accurate measurement of the leakage.
1. 
Preparation for Testing.
The Contractor shall supply all water for the tests, all equipment and labor necessary to convey the water into the sewer, and all labor and equipment to install test plugs, and other incidental work in conducting the tests and the cost thereof shall be included in the price for constructing the sewer. The Contractor shall supply the test plugs and the risers for the tests and will conduct the tests.
a. 
Before testing is observed by the Engineer or designated representative of the Engineer, sewers shall be completely backfilled, except for the stacks, but not necessarily water tamped.
The Contractor may make preliminary tests with a minimum of eighteen (18) inches of backfill over the pipe to determine if any repairs are necessary. These tests are for the Contractor’s information and shall not be performed in lieu of the tests to be observed by the Engineer or designated representative of the Engineer. These line tests will be made between the inlet side of the downstream manhole and the outlet side of the next upstream manhole.
b. 
Unless the Contractor has been notified that the tests will be made by the infiltration method, he shall leave the tops of stacks exposed and unplugged until after the leak test has been made. If a stack terminates below the test level, they shall be temporarily extended upward by installing an additional length of pipe in the top.
c. 
The Contractor shall provide suitable means to determine the groundwater level at any time until the testing is completed. As an example, a pipe not less than three (3) inches in diameter, such as a downspout pipe, closed at the bottom and perforated for at least the lower three (3) feet, with the perforations wrapped with at least two (2) thicknesses of filter fabric, set in the trench prior to backfilling. These pipes shall than be removed or cut off at least two (2) feet below the ground after testing has been completed. Prior to removal, the pipes shall be protected against damage and earth or other material excluded therefrom. Generally one pipe shall be installed in each run of pipeline between manholes.
d. 
Stubs or house connections connected to the section being tested for leakage which are below the test water level, will be considered in computing the allowable leakage but the Contractor will not be held responsible for excess leakage in sewers not laid by him which have been connected to the lines being tested. The Engineer or designated representative of the Engineer may request individual stubs or house connections in the system that were constructed under this contract to be tested. Prior arrangements for access to the ends of the pipe will be made for these tests.
2. 
Infiltration Test.
For the Infiltration Test, all pumps must be stopped and the groundwater allowed to return to its normal level and to remain so for at least 24 hours. Before the test is started, the pipe will be filled with water to a depth that will cause leakage to flow at a uniform rate through an opening in the plug in the downstream end of the section of sewer being tested. Leakage will be determined by measuring the flow through the opening in the downstream plug during a given time. Five measurements will be taken. The average of the measurements will be used. If one of the five measurements varies by more than fifty percent (50%) of the other four, then that measurement will be discarded, except for the last measurement taken. If the results of the tests are satisfactory, but the last of the five measurements shows leakage in excess of that permitted, tests shall be continued to determine if additional leaks may have developed during testing.
Size of Pipe
Allowable Leakage*, Gallon Per Minute Per 100 Ft.
6"
0.0039
8"
0.0053
10"
0.0066
12"
0.0079
15"
0.0099
18"
0.0118
21"
0.0138
24"
0.0158
27"
0.0178
30"
0.0197
36"
0.0237
*Equivalent to 50 gal. per inch diameter per mile per 24 hours
For other diameters, multiply square of diameter by value for 1" diameter.
3. 
Exfiltration Test.
In order to permit absorption by the pipe, the Contractor may keep the pipe full of water for 24 hours prior to the test. The Engineer or designated representative of the Engineer shall be notified by the Contractor before backfilling is completed that the pipe will be filled and will be given 48 hours before the test to allow time for filling and soaking the pipe. At least two (2) hours before the tests start, the water will be bled off below the level of the top of the pipe at its lower end and allowed to remain so until the water level remains static at this level or continues to fall. The test shall be made in the following manner.
a. 
A watertight plug, equipped with a pipe riser will be inserted and braced in the inlet opening in the downstream manhole and a similar plug equipped with a suitable vent pipe that will permit the escape of air in the pipe at its upper end, will be inserted and braced in the outlet in the upstream manhole. Fill the sewer and riser with water up to a level either four (4) feet above the crown of the sewer pipe at its lower end or two (2) foot above the crown of the sewer pipe at its upper end, whichever is higher, plus the vertical distance from the invert of the sewer at its lower end up to the level of the groundwater where such groundwater exists above the invert of the sewer.
b. 
The sewer will be filled with water as a continuous operation, as rapidly as the supply will permit, and the test measurement will be started as soon as the water is at the required level. This will be completed in not less than two (2) hours for sewers twelve (12) inches or smaller, not less than three (3) hours for sewers fifteen (15) inches through twenty-four (24) inches and not less than four (4) hours for larger sewers. A measurement of the water level will be recorded at each minute for five (5) minutes or until the level has dropped twelve (12) inches, whichever occurs first. The water will then be brought back to the required level and the test shall be repeated until five (5) such tests have been performed. Use the average of these results, discarding any of the five (5) observations that varies by more than fifty percent (50%) form the average of the other four (4) except for the last one. If the results of the tests are otherwise satisfactory, but the last of the five (5) measurements shows leakage in excess of that permitted, the tests will be continued to determine if additional leaks may have developed during testing.
c. 
The total leakage in cubic inches shall be the total cross-sectional area in square inches of the inside of the two (2) risers and of any stacks in the sewer multiplied by the drop in water level in inches.
Table For Measuring Leakage in Sewers
Diameter of Riser or Stack
Volume Per Inch of Depth
Cu. Inch
Gallons
1"
0.7854
0.0034
2"
3.1416
0.0136
2-1/2"
4.9087
0.0212
3"
7.0686
0.0306
4"
12.5664
0.0544
5"
19.6350
0.0850
6"
28.2743
0.1224
8"
50.2655
0.2176
4. 
Air Test.
The air test shall be performed as follows.
a. 
To perform the air test, all the water should be flushed and drained from the line being tested prior to beginning the test. All pipe outlets, especially laterals and services, shall be plugged. Air shall be added until the internal air pressure of the sewer line is 4.0 psi greater than the pressure exerted on the pipe by the groundwater above the pipe. Allow the air pressure to stabilize after it has reached 4 psig. As the air temperature stabilizes, the air pressure will normally drop. When the pressure has stabilized at 3.5 psig, allow the pressure to drop to 2.5 psig. The time it takes the pressure to drop from 3.5 psig to 2.5 psig shall be recorded. If the time it takes the pressure to drop exceeds the time permitted, the line has passed. If the time is less then allowable, the line has failed.
b. 
The air pressure test should not be used when the pipe is submerged in groundwater, because the static water pressure will greatly affect the results. The water infiltration test will be used in this case.
c. 
For sections of pipe less than 36-inch average inside diameter, the minimum time allowable for the pressure to drop from 3.5 pounds per square inch gauge to 2.5 pounds per square inch gauge shall be computed from the following equation:
T = 0.085(D)(K)/(Q)
where,
T
=
time for pressure to drop 1.0 pound per square inch gauge in seconds
K
=
0.000419(D)(L), but not less than 1.0
D
=
average inside diameter in inches
L
=
length of line in feet of same pipe size being tested
Q
=
rate of loss, 0.0015 cubic feet per minute per square foot internal surface shall be used
d. 
Since a K value of less than 1.0 shall not be used, there are minimum testing times for each pipe diameter as follows:
Air Test Table
Pipe Diameter
(inches)
Minimum Time
(seconds)
Length Time for Minimum Time
(feet)
for Longer Length
(seconds)
6
340
398
0.855(L)
8
454
298
1.520(L)
10
567
239
2.374(L)
12
680
199
3.419(L)
15
850
159
5.342(L)
18
1020
133
7.693(L)
21
1190
114
10.471(L)
24
1360
100
13.676(L)
27
1530
88
17.309(L)
30
1700
80
21.369(L)
33
1870
72
25.856(L)
e. 
For sections of pipe with an average inside diameter less than thirty-six (36) inches, the test may be stopped if no pressure loss has occurred during the first twenty-five percent (25%) of the calculated testing time. If any pressure loss has occurred during the first twenty-five percent (25%) of the testing period, then the test shall be continued for the entire required time.
f. 
Lines with an average inside diameter of twenty-seven (27) inches or larger may be air tested at each joint. Pipe with an inside diameter greater than thirty-six (36) inches shall be tested for leakage at each joint. A visual inspection of the line between the joints shall be performed immediately after an air test. Regardless of pipe size there shall be a minimum of ten (10) seconds allowable for the pressure to drop from 3.5 psig to 2.5 psig during a joint test.
5. 
Retests.
Sewers which fail to meet the requirements of the leak test will be tested again for leakage, after repairs have been completed by the Contractor. If a sewer fails to pass the requirements of the leak test a second time, and additional repairs and retests are performed, then the sum of fifty dollars ($50.00) will be deducted from the amounts due the Contractor to compensate the Owner for the costs of making additional retests.
6. 
Manhole Test.
All manholes shall be tested for leakage by plugging the lines entering the manhole and completely filling the manhole with water. If leakage exceeds 0.025 gallons per foot of diameter per foot of head per hour, repairs shall be made to make the manhole water tight, and a retest shall be performed. Concrete manholes may be filled for 24 hours before the test.
(Ordinance 2007-106, App. B, adopted 3/20/07)