No development of land shall be approved by the village without receiving a statement signed by the Village Engineer certifying that the improvements proposed by the subdivider, developer, builder meet the minimum requirements of the village and that they comply with the following:
(A) General underground improvements.
(1) The underground improvements shall be installed in the parkway wherever possible.
(2) The allowable loading on pipes shall be determined from the appropriate tables in the Standard Specifications for Water and Sewer Main Construction of Illinois, May 1986 or latest edition, and "Concrete Pipe Handbook". The pipe shall be designed for a minimum H-15 wheel load.
(3) No sewer may be installed on a curved alignment.
(4) Where the trenches for underground improvements are installed under existing or proposed pavements, driveways and sidewalk, or within two feet of the back of curb, trench backfill, according to Para. 20, "State Standard Specifications", shall be used for backfilling the trenches.
(5) All sewer and water main trenches shall be undercut six inches and the pipe laid on a six inch cushion IEPA/NSSD approved granular material. This requirement may be waived at the discretion of the Village Engineer.
(6) All underground improvements shall be completed prior to any surface improvements.
(B) A complete system of sanitary sewers shall be constructed throughout the development allowing for the extension of the village sewer system to adjacent areas.
(1) Only sanitary sewage shall be connected to the sanitary sewer system.
(2) Sewage flow shall be estimated, based on the following assumptions for domestic uses;
(a) 4.0 persons/house
(b) 100 gal/capita/day (includes infiltration) average daily flow
(c) Average day = 24 hours
(d) Maximum daily flow = Fx average daily flow
F = 4.00 for 8" and 10";
F = 2.50 for 12' and larger
(3) Sanitary sewers shall be designed to flow full with a minimum velocity of two feet per second, and a maximum velocity not to exceed that of critical flow, based on Kutter's Formula using a "n" value of 0.013 for concrete pipe.
(4) The minimum size public sanitary sewer shall be eight inches in diameter.
(5) All sanitary sewers and services shall be constructed in accordance with the Design and Construction Policy.
(6) Minimum cover on sanitary sewers shall be eight feet or as directed by the Village Engineer. Sewers in excess of 20 feet cover may require special bedding and pipe as approved by the Village Engineer. Risers shall be required where sewers are over ten feet deep or more, and shall extend to within eight feet of grade.
(7) All sanitary sewers shall be located in the parkway, on the north or west side of the street.
(8) Maximum allowable infiltration shall be 200 gallons per inch diameter of sewer pipe per mile per day.
(9) A sanitary house service shall be installed at the center of each lot at the time of the sanitary sewer installation and shall extend to the property line. The service shall be a minimum size of six inches in diameter and shall be installed at a minimum grade of one-eighth inch per foot and maximum grade of one inch per foot.
(10) Sanitary sewer manholes are to be a minimum four feet diameter precast concrete as per ASTM designation C 478. Jointing material shall be a mastic joint sealer.
(11) The sewer service shall be connected to the main sewer with a wye. If a wye is not available, the service shall be connected to the sewer by means of a saddle.
(12) Sewage lift stations will not be permitted if gravity connection to any part of an existing or approved sewer is possible.
(C) A complete system of water mains shall be constructed throughout the development sized to permit for future extension of the village water system to adjacent areas. Every lot in the development shall be serviced by means of a house connection within its own frontage.
(1) The water system shall be designed so that it will be circulating or looped whenever possible.
(2) Water mains shall be not less than eight inch internal diameter and constructed of ASA 21.6 Class 150 Cast Iron Pipe or other material as directed by the Village Engineer with single ring push-on joint or mechanical joint. Pipe and fittings shall have a standard cement lining as per ASA 21.4
(3) Valves shall be located so that in the event of a single break not more than 1,000 feet of main will be out of service and require the closing of not more than three valves. All valves shall open to the left. Precast concrete vaults shall be constructed around all valves. Four foot diameter vaults shall be constructed on valves up to eight inches in diameter, with five foot diameter vaults around larger valves.
(4) Fire hydrants shall be installed throughout the entire development, located at intervals not to exceed 400 feet, and no house shall be greater than 200 feet from a hydrant.
(5) Concrete thrust blocks shall be placed behind all fittings and a two foot square precast concrete block shall be placed under all hydrants. Retainer glands shall be used if soil conditions are poor, or as directed by the Village Engineer.
(6) All water mains shall be located in the parkway, on the south or east side of the street.
(7) Connections to the existing water system shall be made by pressure tap unless otherwise authorized by Village Engineer.
(8) A water service shall be installed at the center of each lot at the time of the water main installation and shall extend to the property line. The service shall include a one inch Type "K" copper pipe and a one inch cc thread brass service saddle, Mueller H 13000 or H 16000 Series. A corporation cock and roundway shall be located approximately one foot from the sidewalk. The corporation cock shall be Mueller No. H 15000 and the roundway shall be Mueller No. H 15154. If the sanitary and water services are installed in a common trench, the water service must be placed on a shelf one foot above the top of the sewer service and 18 inches from the edge of the sewer trench.
(D) A complete system of storm sewers shall be constructed to drain the development and any contiguous drainage areas. The developer shall submit to the Village Engineer two copies of the storm drainage computations.
(1) In general, the release rate requirement of .04 cfs/acre for the 2-year event and .15 cfs/acre for the 100 year event should apply to regulated developments that meet one of the following requirements:
(a) Single family detached residential developments with five or more units.
(b) Multi-family, non-residential, and other developments of three acres or more in size, or which will result in an impervious area of 50% or more of the development site.
(c) The public road construction project resulting in more than one and one-half acres of additional impervious surface per mile on linear projects, or more than one acre of additional impervious surface per nonlinear project.
(2) All subdivisions of five acres or larger shall have on-site storm water detention facilities. These shall be designed and constructed in accordance with the latest state, county, or village requirements which best protect the property involved, in order to provide detention for the 100-year frequency storm on the developed site with a maximum release rate as produced by the three-year storm on the undeveloped site.
(3) The rational method shall be employed when computing storm runoff. A ten year storm shall be used for design purposes.
(4) Storm sewer shall be designed to flow full, using Manning's Formula.
(5) Storm sewers shall be designed, when flowing full, to have a minimum velocity of two and one-half feet per second and maximum velocity not to exceed the critical flow.
(6) All inlets shall be located to drain a maximum street length of 300 feet. Where the inlet is located at a low point, additional inlets may be required by the Village Engineer. Depressed street crowns to facilitate drainage will not be allowed.
(7) All inlets shall be located to drain a maximum street length of 400 feet. Where the inlet is located at a low point, additional inlets may be required by the Village Engineer. Depressed street crowns to facilitate drainage will not be allowed.
(a) All water entering inlets shall pass through a catch basin before entering the main sewer at a manhole.
(b) Catch basins shall be required where the length of flow in swale exceeds 400 feet.
(8) Rear yard catch basins shall be required where the length of flow in a swale exceeds 400 feet.
(9) The minimum size storm sewer shall be 12 inches in diameter, and minimum size inlet connection shall be ten inches in diameter.
(10) Minimum cover shall be three feet for all storm sewers unless special precautions are taken to protect the pipe, as approved by the Village Engineer.
(11) All storm sewers shall be located in the parkway, on the north or west side of the street.
(12) All manholes, inlets, and catch basins shall be designed in accordance with the standards of the village, as shown on the detail sheet.
(13) No open ditches will be allowed within the subdivision.
(14) Spillways shall be required whenever a storm sewer enters a main water course above the flow line.
(15) Where the downstream capacity of the sewer system or water course is inadequate, or where the topography of the ground is such that flooding can be expected, the developer shall point this out in the drainage report.
(16) Where the downstream capacity of the sewer system or water course is inadequate, or where the topography of the ground is such that flooding can be expected, the developer shall point this out in the drainage report.
(E) All public utility lines for telephone and electric services shall be placed underground in rear and side lot line easements, or in a dedicated right-of-way. These services shall be placed in manner which will not conflict with other underground services. Transformer boxes shall be located so as not to be unsightly, or hazardous, to the public.
(Ord. 1995-0-25, passed 12-26-95)