Storm drain and culvert pipe may be corrugated metal pipe, reinforced concrete, or polyethylene storm sewer pipe with a minimum diameter of 15 inches across driveways and 18 inches for road drainage.
A. 
Round corrugated metal pipe and oblate corrugated metal pipe shall conform to NYSDOT specifications, with the following exceptions:
(1) 
All corrugated metal pipe shall be NYSDOT approved polymer coated or Type II aluminized steel pipe having a minimum steel gauge of 16. No other type of metal pipe will be allowed.
(2) 
All collars or connecting bands shall be 12 inches wide and shall be furnished with bolts six inches long.
B. 
Reinforced concrete pipe shall be Class V and shall conform to NYSDOT specifications. All reinforced concrete pipe shall be manufactured with slip joints or bell and spigot joints. Each piece of reinforced concrete pipe shall be marked with the specification number and the date of manufacture.
C. 
Round smooth interior polyethylene storm sewer pipe and fittings shall conform to the physical requirements of Type III, Category 4 or 5, P33 or P34, Class C per ASTM D-1248 with the applicable requirements defined in ASTM D-1248.
The following specifications and drawings show the minimum acceptable construction for typical catch basins and curb inlets.[1] Whenever, in the opinion of the Town Superintendent of Highways or Town Engineer, ground conditions or other circumstances require it, larger or heavier material, additional materials, reinforcing or other modifications and improvements in design and construction shall be made as directed by the Town Superintendent of Highways at any time prior to paving.
[1]
Editor's Note: The drawings are included at the end of this chapter.
Catch basins shall be constructed at all points of change in slope or alignment and at all junction points. At no time shall catch basins be spaced farther apart than 300 feet for slopes less than 3%, 250 feet for slopes from 3% to 6% and 200 feet for slopes over 6% in gradient. Special design conditions may require spacings of less than these distances.
Holes for catch basins shall be excavated to a depth of 35 inches below the designated elevation of the invert of the effluent pipe. Crushed stone or run-of-bank gravel shall be laid in the hole to a uniform depth of 12 inches, leveled and compacted over the entire area under the base. In the case of a field constructed catch basin, the following: On this stone or gravel shall be laid an eight-inch-thick slab of one-to-two-to-four- mix portland cement concrete. The slab shall extend four inches beyond the outside of the walls of the catch basin on every side. The slab shall be smooth and level.
A. 
The catch basin walls shall be constructed of reinforced concrete to a maximum depth of 10 feet below the finished surface. Stretcher blocks shall be minimum of eight inches thick.
B. 
Any concrete blocks forming sections of the catch basin walls shall be laid up with mortar compound of portland cement and mortar sand conforming to New York State Department of Public Works specifications in the proportion of one to two (1:2).
C. 
Inside dimension of the catch basin shall remain constant from top to bottom and shall match the frame opening of the curb inlet to be used.
D. 
Catch basins constructed of precast concrete shall be designed to carry an HS-20 loading plus 25% impact. Shop drawings, if required, shall be submitted for review by the Town Highway Superintendent and the Town Engineer.
A. 
Concrete blocks around all pipes entering or leaving catch basins shall be cut to fit the contours of the pipes as closely as possible. Remaining interstices shall be solidly filled with mortar for the full thickness of the wall. Ends of all pipes shall be cut off flush with the inside surfaces of the catch basin walls. Knockout holes for precast concrete catch basins shall be finished in a like manner.
B. 
When the diameter of the effluent pipe is greater than that of an influent pipe, the elevation of the top of the influent pipe shall be no lower than the elevation of the top of the effluent pipe.
C. 
When the diameter of the effluent pipe is the same as or smaller than that of an influent pipe, the elevation of the invert of the influent pipe shall be no lower than the elevation of the invert of the effluent pipe. In no case shall the top of any influent pipe be more than five feet above the invert of the effluent pipe.
D. 
In general, the road construction and the installation of culverts and catch basins shall comply with the following as may be ordered by the Highway Superintendent or Town Engineer:
(1) 
Remove, haul, and dispose of materials and obstructions encountered. Remove obstructions within the lines of construction, or that would interfere with construction. Obstructions consist of metallic, wooden, concrete or masonry debris, tree roots and similar items.
(2) 
Excavate to levels required for bottoms of culverts, footings, pits, walls, subgrades, pavement, utility lines, and similar items. In all cases of excavation work, excavate to the extent necessary to provide suitable excavation protection. Provide space to permit form placing, inspection work, support systems, waterproofing, excavation protection, and other underground work adjacent to construction. Where nature of soil permits, excavate to the footing, road subgrade, or culvert lines; otherwise, allow for suitable bedding and for form placement and removal.
(3) 
At load-bearing elevations or subgrade, remove unsuitable materials (including weak saturates material such as peat, muck, etc.) disclosed below such elevations. Under footings and foundations, fill the resulting void with concrete; under slabs and paving fill the resulting voids with materials acceptable to the Highway Superintendent or Town Engineer. Footings and foundations shall bear on firm soil capable of supporting the loadings. If satisfactory bearing capacity is not found at the bearing elevations shown, deepen, or enlarge the excavations as directed by the Highway Superintendent or Town Engineer. Such excavations, and fill, beyond the limits shown on the approved plans, when authorized, will be acceptable. However, if excavations are carried beyond the limits shown, without authorization, or unsatisfactory conditions occur due to the contractor's operations, the contractor shall fill the voids with one of the materials specified above, as directed by the Highway Superintendent or Town Engineer.
(4) 
Protect active utilities within excavated areas at all times. Remove, fill or seal utilities as shown on the approved plans. Immediately notify the Highway Superintendent or Town Engineer of any utilities encountered that are not shown on the subdivision (or site plan) construction drawings.
(a) 
Exercise extreme caution when excavation is in the proximity of existing underground utilities so as not to damage or disrupt service. Cautiously hand dig areas noted or directed, and use probes as necessary to locate or expose existing utilities before proceeding with mechanical excavation equipment. Notify the Highway Superintendent or Town Engineer immediately of any existing conditions encountered that may require redesign or relocation of new work to avoid existing utilities, etc. Existing utilities damaged or disrupted by excavation work shall be immediately restored and repaired at the expense of the contractor.
(5) 
Place suitable and approved excavated materials directly into fill areas, if possible. Otherwise stockpile on site.
(6) 
Store on the project site where shown on the approved plans or as directed all excavated material suitable and approved for backfill, fill, and rough grading. Remove unsuitable material from the project site as ordered by the Highway Superintendent or Town Engineer. Provide additional fill material, if required.
(7) 
Trim, level and clean excavations just prior to placement of subsequent work. If bottom of continuous footings are at different elevations, step the bottoms as required, without sloping where nature of the soil permits. Subsequent grading work of any kind shall not be performed until soil bearing capacity conditions have been reviewed and approved, including the ordering of soil bearing tests if deemed necessary, by the Highway Superintendent and Town Engineer.
(8) 
Stockpile excavated project-usable topsoil and earth material for fill and backfill, each in separate piles in areas (within the work area limits) as selected by the contractor, or haul to other locations on the site if directed by the Highway Superintendent or Town Engineer, clear of construction operations of other contractors, and separate for other stockpiled soils to prevent intermixing. Shape pile so that surface water will drain freely and to minimize wind erosion. At the completion of the work, remove all excessive stockpiled materials from the site unless otherwise directed by the Highway Superintendent or Town Engineer.
(9) 
Maintain the entire project site free draining at all times. Arrange site excavations and fill work to avoid obstructing the natural flow of water away from areas of work. If determined necessary by the Highway Superintendent or Town Engineer, provide temporary drainage ditches, filled in when no longer required, or provide temporary pumping.
(10) 
Maintain excavations that are not free-draining free from water until such time that the permanent construction is in place; that backfilling is complete; and that drainage systems are operating in constructed areas below grade. Provide pumps, well point systems, or other systems as required by the conditions. Operate pumps and other water moving systems as necessary to accomplish the above on a twenty-four-hour basis.
(11) 
Excavation protection shall be as required and as determined necessary by the Highway Superintendent or Town Engineer, and shall generally consist of the following:
(a) 
Provide excavation protection as required to support the earth banks of all types of excavations including trenches, existing structures, services and utilities.
(b) 
Excavation protection shall consist of the use of angle of repose of the soils or the providing of a support system, based on site conditions and to include the following factors:
[1] 
Depth of cut and type of soil.
[2] 
Water table and variations in the extent of same while the excavation is open.
[3] 
Anticipated changes in the material due to exposure to air, sun, water or freezing.
[4] 
Load imposed by structures, equipment, overlying material or stored material.
[5] 
Vibration from traffic, equipment, or demolition or construction operations.
[6] 
Space allowed for excavations.
(c) 
Design and provide the support systems of such strength, rigidity and spacing as required to suit site conditions, and in such quantity as required to maintain the project schedule and integrity.
(d) 
The support systems may include, but are not necessarily limited to:
[1] 
Bracing.
[2] 
Cribbing.
[3] 
Sheet piling (new and/or project salvaged).
[4] 
Shoring.
[5] 
Stringers.
[6] 
Tie rods or tie backs.
[7] 
Tight sheeting (new and/or project salvaged).
[8] 
Trench jacking.
[9] 
Trench shield.
[10] 
Underpinning.
[11] 
Uprights.
(e) 
The contractor shall maintain the support systems in place until immediately prior to filling or backfilling operations, and shall remove the support systems in stages as filling or backfilling progresses unless specified otherwise by the Highway Superintendent or Town Engineer. Parts of the support system may be left in place up to two feet below new grades where so directed or approved by the Highway Superintendent or Town Engineer.
(f) 
Place sheet pilings by conventional methods at locations shown on the construction drawings or as required to minimize inflow of groundwater in deep excavations. Sheet piling placed to control groundwater shall remain in place. The interlock between the sheets shall be watertight.
A. 
In through and commercial streets, all catch basin inlet grates shall be NYSDOT standard reticuline grate inlets on a curb-type top slab. Please refer to Figure 6A of the Highway Specifications.[1]
[1]
Editor's Note: Said figure is included at the end of this chapter.
B. 
In rural and suburban roads, all catch basin inlet grates shall be heavy-duty full frame bicycle-type grate inlets. Please refer to Figure 6B of the Highway Specifications.[2]
[2]
Editor's Note: Said figure is included at the end of this chapter.
C. 
The contractor shall submit specification sheets for the catch basin inlet frame and grate to the Town Engineer and the Highway Superintendent for review and acceptance prior to the use of same on the construction site.
D. 
If required, catch basins shall be capped with curb inlets having a minimum frame of 30 inches by 48 inches of a type as designated by the Town Superintendent of Highways.
E. 
Curb inlets shall be installed so that the top of the grading is two inches below the finished grade and the pavement shall be sloped toward the inlet as shown on the drawings which follow.[3]
[3]
Editor's Note: See Figures 6A and 6B at the end of this chapter.
F. 
Curb-front openings on all curb inlets shall have a solid horizontal bar centered in the opening to prevent the ingress of small children. This bar shall be part of the casting or solidly welded in place subsequent to manufacture.
Catch basins having a depth greater than 48 inches from the finished surface to the top of the concrete base shall be provided with steps. Steps shall be of wrought iron having a minimum diameter of 3/4 inch which shall be hot-bent to shape and hot-dipped galvanized after banding. Steps may also be constructed of molded polyethylene reinforced with a three-fourths-inch minimum diameter iron bar. They shall be solidly set in construction and shall extend all the way through the wall. The steps shall extend 4 1/2 inches inside the wall of the catch basin. The top step shall be not more than 18 inches below the finished surface, and thence to the base, steps shall be no more than 18 inches apart.