411-31. Regulations Regarding Construction, Laying or Maintaining or Water or Sewer Pipe Lines, Storm Drains, Conduits or Other Underground Utilities.
(a) Excavation. The excavation of all trenches running parallel to the existing pavement shall be conducted only one (1) side of the pavement at a time and shall not exceed 800 feet in length at any one time, and no excavation shall be started on the opposite side until the trench first excavated has been filled, compacted, and surfaced as required herein or as specified in the permit.
This restriction is not intended to prohibit such excavations as may be required for boring a pipe, conduit or other object underneath a County highway or right of way. (Ord. 896, § 320, 12/21/1972)
(b) Backfill. Backfill in all trenches shall be made by mechanical tamping unless otherwise provided by permit conditions. Backfill material shall be free from stones or lumps exceeding three inches (3") in greatest diameter, vegetable matter or other unsatisfactory material. Backfill material shall be placed to the subgrade of the pavement in lifts consistent with the type of soil involved and the degree of consolidation specified by the Department of Public Works. Such backfill shall be done in a manner that will permit the restoration of the surface to a density condition not less than that existing prior to excavation unless otherwise specified. Director may require soil tests to be furnished to the Department by a recognized soils testing laboratory or registered professional engineer specializing in soil mechanics, when, in the Director’s opinion, backfill for any excavation is not being adequately compacted. In such cases resurfacing will not be permitted unless such tests show that the upper two feet (2') of backfill material has been compacted to a relative compaction of not less than ninety percent (90%). All expense of such tests shall be borne by the permittee. It shall be the responsibility of the permittee to properly maintain refilled trenches in perpetuity. (Ord. 896, § 321, 12/21/1972)
(c) Failures, Settlements. In determining proper maintenance, the following criteria shall be used to define a failure:
(1) In the traveled way, a depression of one-fourth inch (1/4") per two feet (2') of trench width below the average of the sides of the uncut portion.
(2) Along the outside edge of the shoulder section, a minimum of four feet (4') from edge of traveled way of an unsurfaced road, a depression of three-fourths of an inch (3/4") below the average of the side of the uncut portion.
Whenever failures are detected and the Director of Public Works notifies the permittee of the failure, said permittee shall correct all such failures within ten (10) calendar days from the date that written notice is received from the Director unless otherwise authorized in writing by the Director. If permittee does not correct any or all failures, the Director shall take whatever steps he deems necessary to correct the failures. The permittee shall reimburse the County for all costs concerned based upon Associated General Contractors’ rates prevailing when the work is undertaken by the County. Reimbursement shall be made within thirty (30) calendar days of the mailing of the itemized statement. (Ord. 896, § 322, 12/21/1972)
(d) Repavement of Trenches. Minimum restoration of the traveled way shall consist of placing ten inches (10") of Class 2 aggregate base material and three inches (3") of asphalt concrete pavement over all excavations. Restoration shall begin after approval of the backfill compaction by the authorized County representative. All materials and methods employed shall conform to the most current issue of the standard CALTRANS specifications. Prior to placing asphalt concrete surfacing, the existing pavement longitudinally along both sides of the trench shall be cut in a neat line six inches (6") back from the outside edges of the trench and removed, in order to provide a key. The top three inches (3") of the trench shall consist of asphalt concrete pavement.
Paved restoration surfacing for the trench higher than one-fourth of an inch (1/4") per two feet (2') of trench width above the edge of the existing surfacing shall be deemed improper backfilling and shall be reconstructed to the tolerance specified above.
The above-mentioned tolerance need not be adhered to for temporary work which will have a duration of less than thirty (30) calendar days, provided that at no time shall the temporary surfacing exceed twice the above-mentioned tolerances.
Where the existing traveled way does not have an oiled surface, asphalt concrete surfacing may not be required. (Ord. 896, § 323, 12/21/1972)
(e) Temporary Surfacing. When the Director determines that a satisfactory permanent repavement of an excavation area or trench cannot be made within thirty (30) calendar days, he may require a temporary pavement consisting of two inches (2") of cold plant mix surfacing over the excavation area or trench. The temporary cold mix surfacing shall not exceed twice the tolerances as set forth in subsection (d) for determining improper backfill. The permittee shall be responsible for placing, maintaining, and removing temporary pavement. (Ord. 896, § 324, 12/21/1972)