A. General Requirements:
1. No plat of any subdivision shall be approved by the village board unless the subdivider provides for construction of a sanitary sewer system adequate to serve the needs of the entire subdivision when the same is fully developed. The location and design of said sanitary sewer system shall be reviewed by the village engineer and approved by the Illinois environmental protection agency (IEPA). This requirement shall not apply to any new subdivision which cannot be provided with sanitary sewer service.
2. The adequacy of the existing sanitary sewers to which the proposed development is to outlet into must first be determined by the subdivider. If the existing sewers are not adequate, it shall be the subdivider's responsibility to find an outlet for the sanitary sewers. This work shall be done in cooperation within the village engineer and the village water and sewer system committee. Capacity of sanitary sewers shall be determined utilizing IEPA regulatory requirements.
3. All design calculations must be submitted to the village engineer for review.
4. All permits required must be obtained by the subdivider (i.e., an IEPA construction and operation permit). Permit application forms shall be reviewed by the village engineer before being submitted to the IEPA.
5. All sanitary sewer work shall be done in accordance with the regulations and standards of the IEPA and the village water and sewer use ordinances 1 , unless more stringent requirements are stated herein.
B. Design:
1. Mainline sanitary sewers shall be a minimum of eight inches (8") in diameter.
2. Maximum distance between manholes shall be four hundred feet (400').
3. Manholes shall be installed to provide access to continuous underground sanitary sewers for the purpose of inspection and maintenance. Manholes shall be provided at the following locations:
a. Where two (2) or more storm sewers converge.
b. Where pipe size changes.
c. Where a change in alignment occurs.
d. Where a change in pipe slope occurs.
4. Manholes shall be at least four feet (4') in diameter, constructed of precast reinforced concrete units in accordance with the standard details in section 12-7-6 of this title, and shall have gasketed joints.
5. All main sanitary sewer lines shall be terminated with a manhole. This requirement may be waived for sewer lines less than one hundred fifty feet (150') in length upon authorization by the village engineer and when a cleanout is constructed at the end of the sewer line.
6. Each lot shall be provided with a tee or wye connection located near the center of the lot (with pancake plug). All service lines and tees/wyes shall be constructed watertight.
7. No service lines shall be connected to mainline manholes, except at the last upstream manhole of an individual sewer.
8. Any service line stub which is nine feet (9') or greater from the finished surface shall be provided with a riser to bring the service within nine feet (9') of the surface. All such service tees/wyes shall be encased with six inches (6") of concrete (with pancake plug).
9. Drop connections for service lines at manholes will not be allowed.
10. Back lot line sanitary sewer services shall be provided with manholes at all street crossings.
11. Minimum and maximum pipe slopes shall conform with the Illinois administrative code, title 35, subtitle C, chapter 11, part 370, section 320, and with the following requirements:
a. The minimum allowable velocity shall be two feet (2') per second. However, the preferred minimum velocity shall be two and one-half feet (21/2') per second.
b. Precautions shall be taken by the contractor to prevent scouring or displacement of the pipe if velocities exceed ten feet (10') per second.
12. Sanitary sewer service lines shall have a minimum diameter of six inches (6") and a minimum slope of one-eighth inch (1/8") per foot, and shall be extended from the mainline sewer to at least five feet (5') beyond the property line. Building sewers (6 inch diameter minimum) from the buildings to the service sewer connection shall be laid at a minimum slope of one-fourth inch (1/4") per foot.
13. The openings through which pipes enter the manhole structure shall be gasketed and shall be completely and firmly filled with nonshrink grout.
C. Materials:
1. Mainline Sewers: Materials for mainline sewers shall be:
a. Polyvinyl chloride (PVC) pipe (for mainline sewers up to 15 inches in diameter) generally conforming to ASTM standard D-3034, type PSM, with minimum wall thickness standard dimension ratio (SDR) of 26 and push on flexible elastomeric seal joints conforming to ASTM standard D-3212; polyvinyl chloride (PVC) pipe (for mainline sewers 18 through 36 inches in diameter) generally conforming to ASTM standard F-679.
b. If permission is granted by the village public works superintendent, ductile iron pipe may be used in lieu of PVC (see the requirements of subsection 12-5-8B2b of this chapter).
2. Service Sewers: Materials for service sewers (6 inch diameter) and building sewers (6 inch diameter) shall be polyvinyl chloride (PVC) pipe (4 through 15 inch diameter) generally conforming to ASTM standard D-3034, type PSM, with minimum wall thickness standard dimension ratio (SDR) of 26 and push on flexible elastomeric seal joints conforming to ASTM standard D-3212.
3. Force Main Pipe: All force main pipe shall be constructed of pressure class plastic pipe as defined in subsection C1a of this section.
4. Manholes: Materials for manholes shall be:
a. Leaktight (including pipe entries) and shall be constructed according to the standard details in section 12-7-6 of this title. All manholes shall have an inside diameter as shown in section 12-7-6 of this title. Brick manholes will not be allowed. Manholes shall be constructed of precast reinforced concrete manhole components in general conformance to ASTM standard C-478. The use of concrete masonry units, complying with ASTM standard C-139, for manhole barrel sections shall be subject to the authorization of the village engineer on an individual basis. No bitumastic materials shall be used in the construction of the manholes.
b. The base shall be an eight inch (8") thick monolithic unit with welded wire fabric reinforcement.
c. Precast barrel and cone components: Manhole joints shall be compression type utilizing rubber "O" ring gaskets. The barrel thickness for four foot (4') diameter manholes shall be 5.75 inches (wall C); for five foot (5') diameter manholes, 6.75 inches (wall C); for six foot (6') diameter manholes, seven inches (7") (wall B). No bitumastic materials will be used to seal manhole joints. Cones shall be eccentric. Pipe entry holes shall be precast in the barrel sections. Sanitary manhole pipe entries shall be watertight compression joints utilizing rubber gaskets compatible with the pipe being used.
d. Precast concrete flat tops required for manholes shall be manufactured according to the standard details of the IDOT.
e. Concrete masonry units may be used for manhole construction if authorized by the village engineer. Masonry unit manholes shall be built with mortared joints, upon a flat base component.
f. Steps shall be set into the manhole walls at the time when the manhole walls are cast. Steps shall be set at sixteen inches (16") on centers. The manhole steps shall consist of fiber reinforced plastic (FRP). Cast iron steps are not allowed.
g. Each manhole shall have the frame, lid, or grate as specified in this title or shown in the standard drawings in section 12-7-6 of this title. All closed lids shall have concealed pickholes and shall be self-sealing with rubber gasketed lids. Castings for sanitary manholes installed in streets or traveled surfaces shall be Neenah model R-1713 or equivalent. Castings for sanitary manholes installed in yard areas (areas not expecting heavy loads) shall be Neenah model R-1772A or equivalent.
h. All pipes connected to manholes and inlets shall be cut to fit with a concrete saw or similar saw. Breaking off pipe sections with hammers, chisels, or chains will not be allowed.
5. Cleanouts: Cleanouts shall be constructed as shown on the standard drawings in section 12-7-6 of this title, and shall include a wye fitting, piping, plug, concrete encasement, a concrete pad, and a cast iron cleanout ferrule and brass plug.
6. Fittings: Fittings shall be the same type of material as the pipe. All joints shall be watertight and gastight. Connections between different pipe materials shall be made with a manufactured coupling.
7. Taps: Sewer taps to existing sewer lines shall be constructed as required by the village engineer utilizing manufactured fittings and couplings, and shall be made watertight. Sewer taps to existing sewer lines shall be inspected by the village superintendent of public works before they are encased or backfilled.
D. Wastewater Pump Stations:
1. The type and design of wastewater pump stations must be approved by the village engineer.
2. All design calculations must be submitted to the village engineer for review.
3. All construction shop drawings must be submitted to the village engineer for review. Operation and maintenance manuals shall be provided for all equipment and materials provided for the pump stations.
E. Construction: All construction shall be in accordance with this section and section 12-5-7 of this chapter, the IEPA regulations, and the following additional requirements:
1. All gravity sewer pipe shall be laid to conform to the prescribed line and grade shown on the drawings by using a laser. The subdivider shall constantly check the line and grade of the laser beam and the pipe, and in the event they do not meet the elevations and grades shown on the drawings, the subdivider shall stop the work and notify the developer's engineer, remedy the cause, and relay any pipe installed at improper grade or elevations. Minimum cover shall be four feet (4') from finished grade to the top of the pipe for gravity sewers or force main. Special structural protection shall be provided for cases where there is less than minimum cover.
2. Laying of pipe shall be accomplished to line and grade in the trench only after it has been dewatered and the foundation and/or bedding has been prepared. Mud, silt, gravel and other foreign material shall be kept out of the pipe and off the jointing surfaces. Dewatering sufficient to maintain the water level at or below the surface of trench bottom or base of the bedding course shall be accomplished prior to pipe laying and jointing, if not prior to excavation and placing of the bedding. The dewatering operation, however accomplished, shall be carried out so that it does not destroy or weaken the strength of the soil under or alongside the trench. The normal water table shall be restored to its natural level in such a manner as to not disturb the pipe and its foundation.
3. All pipe laid shall be retained in position so as to maintain alignment and joint closure until sufficient backfill has been completed to adequately hold the pipe in place. The pipe shall be laid up grade from point of connection on the existing pipe or from a designated starting point. The pipe shall be installed with the "female" end upgrade, unless authorized otherwise. When pipe laying is not in progress, the forward end of the pipe shall be kept tightly closed with a temporary plug.
4. Pipe bedding shall be placed so that the entire length of the pipe will have full bearing, six inches (6") over the top.
5. Plugs for pipe branches, stubs or other open ends which are not to be immediately connected shall be made of an authorized material and shall be secured in place with a joint comparable to the mainline joint. Stoppers may be of an integrally cast breakout design.
6. No existing pipe shall be connected to a new pipe unless specifically authorized in each instance by the village engineer. Storm drains and drain tiles shall not be connected to a wastewater sewer.
7. The subdivider shall install service sewers (laterals) as shown in section 12-7-6 of this title. Excavation, backfill, restoration of surfaces, and the laying of service sewers (laterals) shall be the same as for the mainline gravity sewers. The subdivider shall connect the service sewers (laterals) to the mainline gravity sewer by either a service riser and service wye, only a service wye, or at a manhole stub. If required, the subdivider shall also make the four inch (4") diameter building sewer connections to the six inch (6") diameter service sewers (laterals).
8. Existing sewers severed during any excavation shall be repaired by replacing them with ductile iron pipe of the same inside diameter. The ends of the ductile iron pipe shall be joined to the existing pipe on each side of the trench by the method illustrated on the drawings in section 12-7-6 of this title.
9. Pipes shall be jointed as recommended by the pipe manufacturer. Dissimilar pipes shall be jointed with suitable adapter couplings and concrete encasement, unless otherwise authorized by the developer's engineer.
10. The following shall apply to wastewater sewer service risers and laterals:
a. Where the depth of the sewer invert is greater than nine feet (9') below the surface of the ground, a service riser shall be constructed to an elevation of nine feet (9') below the ground elevation. In some locations, nine feet (9') of depth may be too shallow to serve basements. At other locations, wyes may have to be installed so that the spur is at a right angle to the vertical plane through the centerline of the sewer.
b. The subdivider shall be responsible for closely checking the basement elevations along with the distance from the new mainline sewer to the building to be served and shall install the spur of the tee/wye, or the top of the riser, or the end of the lateral (whichever applies) at a low enough elevation to permit the six inch (6") diameter service sewer to be installed at a one-eighth inch (1/8") per foot grade and still have the flow line of the upstream end of the building sewer at least one foot (1') below the basement elevation. In no case shall the top of the riser be less than nine feet (9') below the ground surface.
c. The service riser shall be constructed with a six inch (6") tee/wye placed to receive the six inch (6") riser or lateral. The riser pipe shall extend to the elevation as above determined. The tee/wye or tee/wye and riser combination shall be installed and bedded as shown on the drawings in section 12-7-6 of this title.
d. Six inch (6") laterals shall be constructed from the tee/wye branch and riser to five feet (5') beyond the property line of the lot to be served, or to the location shown in section 12-7-6 of this title, and shall terminate with a manufactured temporary plug. In many cases, these laterals will have to be constructed across streets, alleys, sidewalks and easements to reach the property line.
e. Prior to backfilling, the subdivider shall place a two inch by eight inch (2" x 8") stake at the end of the riser or lateral, perpendicular to the horizontal plane through the centerline of the pipe to serve as a visual indicator of the location of the service. The stake shall extend at least three feet (3') above finished grade and shall be painted with orange and red fluorescent paint. Care shall be taken while backfilling to ensure the stake remains vertical.
11. The subdivider shall connect service sewers and risers (6 inch diameter) to the new mainline sewers by core drilling a six inch (6") diameter hole in the pipe wall, installing a cast iron tee saddle on the sanitary sewer and connecting the service sewer to the tee. Care must be taken in ordering tee saddles so they are compatible with both the mainline sewer pipe type and the brand of service sewer pipe being used.
12. Manhole construction shall be as follows:
a. The base section shall be placed on a compacted granular bedding not less than six inches (6") thick and extending to the limits of the excavation. The bedding shall be smooth and level to assure uniform contact and support of the manhole base. The manhole base and fillet may be cast monolithically with the bottom barrel section of the manhole.
b. All lift holes shall be completely filled with nonshrink grout and the exterior coated with a layer of waterproofing paint prior to backfilling. All void spaces on the inside and outside of manhole joints shall be filled with nonshrink grout.
c. For manhole joints that will be subject to a constant hydrostatic pressure, an external rubber seal with metal bands shall be placed around the joints in the barrel section.
d. Blockouts (within the manholes at the fillets) used to install the rubber pipe gaskets shall be filled with concrete to the centerline of the influent and/or effluent piping.
e. After all sewers have been connected to the manhole, a concrete fillet shall be constructed in the bottom of the manhole as shown in section 12-7-6 of this title. Placement of the fillets shall be prior to placement of the manhole flat tops and/or frames and grates.
f. Castings placed on concrete or masonry surfaces shall be set in full mortar beds. Castings shall be set accurately to the finished elevation so that no subsequent adjustment will be necessary.
g. Manholes shall be furnished with a one-half inch (1/2") diameter pipe nipple ten inches (10") long with a cap extending through the manhole wall and located at the top of the sewer pipe or by an alternative method authorized by the village engineer to assist in determining the level of the ambient water table.
F. Testing:
1. All wastewater sewers shall be tested for leakage using the infiltration test if the water table is twenty four inches (24") or higher above the crown of the pipe, and the exfiltration by water test will be used if the water table is less than twenty four inches (24") above the crown of the pipe. If authorized by the developer's engineer, pressure air testing of the sewers may be used only if conditions do not permit testing by infiltration or exfiltration by water. PVC sewer pipe shall also be tested for deflection.
2. All sewers shall be lamped, and shall show at least three- fourths (3/4) of the cross sectional area of the pipe between adjacent manholes. All sewers not passing the lamping test shall be considered unsatisfactory and shall be repaired by the subdivider.
3. Any sewer not passing the tests required in subsections F1 and F2 of this section shall be deemed unacceptable and shall be properly repaired by the subdivider and retested until such time as the sewer passes these required tests.
4. The maximum section to be tested shall be between adjacent manholes. The developer's engineer shall determine what the testing section lengths shall be. The subdivider will be advised of the results of all tests performed as a guide to his operation.
5. The subdivider shall flush all sewers with water sufficient in volume to obtain free flow through each line. Flushing water and debris shall not enter any pump station wet well. Water will be pumped from the sewer system during flushing to a discharge location authorized by the developer's engineer. A visual inspection shall be made and all obstructions removed and defects corrected. The subdivider shall cooperate with the village engineer in the performance of leakage and exfiltration tests on all sections of sewer after backfilling. The subdivider shall supply all materials, equipment, and labor necessary to complete the testing requirements. The subdivider is also responsible for the disposal of flow from the pipe, or trench upstream from the pipe, or trench upstream from the section being tested, for a period of not more than eight (8) hours for each test performed. Tests will be performed in such manner and at such times as to cause the least possible hindrance to the progress of work.
6. Test methods are as follows:
a. Infiltration Method: The section of sewer to be tested shall have been backfilled and a check made to ensure the water level in the trench is a minimum of twenty four inches (24") over the crown of the sewer pipe. Infiltration flow shall be measured by a ninety degree (90°) V-notch weir with free fall discharge or other means acceptable to the village engineer. Infiltration leakage shall not exceed two hundred (200) gallons per inch of pipe diameter per mile per day of sewer pipe, including manholes in the test section.
b. Exfiltration Method: The section of sewer to be tested shall be sealed by inserting inflatable rubber bags in the pipes or by other means, and then water shall be introduced into a manhole until the section is completely filled. The subdivider shall fill the pipe to the test level eight (8) hours prior to the time of exfiltration testing to permit normal absorption into the pipe walls. Throughout the test period of at least one hour, the water level in the upper manhole shall be maintained at least twenty four inches (24") above the crown at the upper end of the pipe or at least twenty four inches (24") above the groundwater table, whichever is higher. The length of pipe tested shall be limited so that the pressure on the centerline of the lower end of the section tested shall not exceed six feet (6') of water column. Exfiltration leakage shall not exceed two hundred forty (240) gallons per inch of pipe diameter per mile per day of sewer pipe, including manholes in the test section.
c. Air Testing: Air testing shall be done in accordance with ASTM standard C-828, "Recommended Practice For Low-Pressure Air Test Of Vitrified Clay Pipe Sewer Lines (4 To 12 Inches)".
d. Deflection Testing: Following their construction, all PVC wastewater sewers shall be tested for deflection per the requirements of sections 31-1.11B(4) and 31.11C(4) of the "Standard Specifications For Water And Sewer Main Construction In Illinois".
7. Prior to putting any service connection from a house or other user to a mainline sewer into use, the subdivider's engineer shall file a certificate with the village stating that the required improvements were constructed in accordance with the approved engineering drawings and specifications. Such certificate shall include the following:
a. The elevation of the groundwater line and the elevations of the upper and lower pipe inverts for each portion tested.
b. The infiltration, exfiltration, or one pound air pressure drop rates of each portion tested and the allowable rates based upon the test method utilized.
c. A statement that all reaches between manholes have passed the required leakage tests.
d. A statement that all reaches between manholes have passed all deflection tests and a compilation of deflection test results (if applicable).
e. A statement that all reaches between manholes have passed all lamping tests and that all reaches are clean and straight and free of all obstructions or debris. (Ord. 2007-19, 5-21-2007)
Notes
| 1 | 1. See title 9 of this code. |