(a) Backfill Requirements.
(1) The following backfilling specification is required in connection with any work performed within road rights-of-way: After conduit pipe or other underground facility is installed, it is to be backfilled as indicated in Figure 3. All backfill material shall be free from particles larger than 6 inches and free from cinders, ashes, refuse, vegetable or other organic material. The backfill material shall be deposited in the trench for its full width, in lifts appropriate to the type of compaction equipment used. In all cases, contractor must achieve 95% compaction (Standard Proctor) for the entire length, depth, and width of the installation. This method shall be followed until the top of the trench is reached. Backfilling shall be compacted to a minimum of 95% of the maximum density. In areas outside the construction and maintenance limits of the roadway, but within County right-of-way, compaction to the density of 90% of maximum density is sufficient. Care shall be taken to compact the material under the haunches of the conduit pipe or other facility, to place the backfill evenly on each side, and to avoid displacement of conduit. All material and compaction requirements shall be in accordance with Division Specifications and subject to Division approval. No jetting or puddling will be permitted.
(2) In all cases, utilities should be placed at the back of the ditch line. Where utilities must be placed in the roadway for over 500 feet, the utility/contractor must provide compaction reports from a third party geo-technical firm, or provide proof of filling the trench with either SC#57 stone or Flowable Fill. Where utilities must be placed in the ditch or shoulder for over 500 feet, it will be the responsibility of the utility/contractor to provide compaction reports from a third party geo-technical firm when 3 or more repetitive failures occur without mitigating factors within 1 year.
(3) Aggregate base course and/or aggregate shoulder stone is to be replaced on the shoulder at a thickness equal to 6 inches or its original thickness, whichever is greater. Paved shoulders shall be re-paved in kind.
(4) Backfilling shall not be performed in freezing or wet weather except by permission of the Engineer and backfilling with frozen material will not be permitted. No backfilling shall be made where the material already in the trench is frozen.
(b) Blasting. Blasting will not be permitted within road right-of-way unless there is no feasible alternate. Provisions must be made for adequate protection of the roadway facility, the safety of the traveling public and nearby residents. Notification of each case must be forwarded to the division upon receiving blasting approval from the State Fire Marshal’s Office.
(c) Longitudinal Installations.
(1) To the greatest extent possible, longitudinal installations will not be permitted. Where necessary to connect to existing structures, conduits or appurtenances located within a traveled way, longitudinal installations will be permitted to the maximum lengths necessary to remove additions or extensions of existing services from within the traveled way.
(2) Only public utility companies may occupy the County’s right-of-way longitudinally along the roadway. Perpendicular crossings may be permitted to private companies or individuals. No private individuals or companies shall be allowed to place any utility parallel with the roadway. All installations that run parallel with the pavement shall be the direct responsibility of the utility. On longitudinal installations, other than in municipal pavement sections, pipelines should be parallel to the pavement preferable at or adjacent to the right-of-way line.
(3) The nearest edge of trench should be a minimum of 2 feet or more beyond the slope, ditch or curb line, when practical. Where possible to do so for any length of 500 feet, or more, a greater distance will be expected. The minimum required depth of cover on all longitudinal lines shall be 24 inches. The trench should not be deeper than the distance from the edge of the pavement, curb, paved shoulder, toe of slope, or ditch, as may govern, to the nearest edge of the trench without using a bulkhead. (See Figure 2.) Material excavated or plowed from the trench shall not be stockpiled or stored within 2 feet of the pavement edge or in a highway ditch line.
(4) Municipal pavement sections will be handled on an individual basis in a manner consistent with the prevailing limitations and conditions. Whenever practical, pipelines should be placed under the sidewalk. If the sidewalk location is not practical, pipelines should be placed under the parking lane. Placing of pipelines under the traveled lanes is discouraged and will only be considered as a last resort.
(5) Where longitudinal installations cannot be avoided within a paved roadway, the appropriate methods of pavement repair as detailed in the Appendix will be required. Where the length of a longitudinal installation exceeds 50 lineal feet, as measured along the centerline of the disturbance, the surface restoration of the roadway in whole or in part as defined hereinafter shall be required to a point not less than 25 feet beyond each end of the disturbed pavement. If the longitudinal installation lies within the outer 25% of the paved roadway width on either side of the centerline, the surface restoration of the roadway to 1/2 width shall be required. Care should be taken not to create uneven pavement situations that can be detrimental to traffic. If the longitudinal disturbance occurs within the center 50% of the roadway width, full width surface restoration will be required to the limits herein before specified.
(6) Where the trench patch is within the roadway, the County Engineer may require partial or full width resurfacing of the roadway for a distance up to 50 feet beyond each end of the trench patch. The application rate for the hot laid asphalt surface course shall be not less that 195 lbs./sy.
(d) Crossings.
(1) All crossings should be located as near to a right angle to the road centerline as practical, based on economic consideration of alternates. Locations which are generally unsuitable for pipeline crossings include deep cuts; near footings of bridges and retaining walls; at cross drains where flow of water or stream bed may be obstructed; or within basins of an underpass drained by a pump if pipeline carries a liquid.
(2) No pipe, conduit or other facility shall be placed inside any drainage pipe or culvert. No pipe, conduit, or other facility shall be placed across the ends of any drainage pipe or culvert in a manner that will obstruct the free flow of water. All existing pipes, conduits or other facilities located within existing drainage pipes or culverts shall be allowed to remain in place. Any change in the drainage characteristics of the area which may occur in the future and cause existing pipes, conduits, etc. within existing drainage pipes or culverts to create an obstruction to the free flow of water shall be removed at the expense of the owner of such pipes, conduits or other facilities.
(3) Open trenching will not be employed, except when approved by the County Engineer or his/ her representative. The County reserves the right to require all utility lines and service lines to be bored, to preserve the integrity of the existing pavement and to prevent the disruption to traffic or protection of pedestrians on heavily congested road ways. Where crossings have to be made by open trench, pavement cuts and replacements shall be made in accordance with “Repaving Pipe Trenches” (See Figure 3A and 3B).
(4) The minimum required depth of cover for a crossing is 24 inches. For cover over pipes, commonly specified surfaces are the top of pavement, natural ground, or the flow line of drainage ditches. A protective coating is considered part of the pipe. When the carrier is encased, cover is measured from top of the casing. The critical control for cover on a pipeline crossing is the low point in the highway cross-section, usually the bottom of the longitudinal ditch.
(5) Markers, vents, drains, and shut-offs are appurtenances to pipeline installation. Major pipeline crossings shall be identified by permanent markers. These markers shall furnish sufficient information to enable identification and contact of the owner. Casing pipe over 4 inches in diameter shall be sealed and, if carrying combustibles, provided with a screened vent on each end. Vent standpipes and location markers should be located and constructed outside the clear zone, so as not to interfere with maintenance of the highway nor to be concealed by vegetation; preferably they should stand on a fence or right-of-way line, or in a protected location such as behind guardrail.
(Ord. 3673, § 2, passed 4-1-2003; Ord. 3806, § 1, passed 8-17-04)