RCSA § 16-280b-B31
Protection of cast-Iron Pipe
(a)For purposes of this section:#
(1)"Angle Of Influence" means a 45° angle above the horizontal plane starting from the bottom edge of the trench nearest to the Main.#
(2)"Deep Trench" means an excavation more than 5 feet in depth.#
(3)"Shallow Trench" means an excavation 5 feet or less in depth.#
(4)"Sheeting" means a bracing or shoring used to support the sides of an excavation to prevent its collapse during an excavation project.#
(5)"Soft Clay" means earth easily molded by hand, or that has an unconfined compressive strength of 500 to 1000 pounds per square foot.#
(b)Annually, each Operator shall provide a list or map of the Streets that contain cast- iron Pipe to each Authority Having Jurisdiction over any Street and each entity that owns or operates facilities where the Operator's cast-iron Pipe could be affected by excavation. The transmission of such a list or map shall include a request that the Operator receive notice of any planned excavation projects on these Streets not less than 6 months prior to commencing such project.#
(c)Remediation of cast-iron Pipe at trench crossings shall be as follows:#
(1)cast-iron Pipe, 8 inches or less in nominal diameter, shall be replaced as soon as practicable when exposed and undermined by a trench and when there is:#
(A)less than 24 inches of cover; or#
(B)24 inches or more of cover and the trench widths set forth in Table B31-1 are exceeded; Table B31-1 - Maximum Allowable Trench Width Nominal Pipe Diameter Depth of Cover 39 2 to not more than 4 feet More than 4 feet 4 inches or less 3 feet 4 feet 6 inches 4 feet 6 feet 8 inches 5.5 feet 8 feet The trench width shall be determined by the distance along the centerline of the exposed Pipe.#
(2)the minimum length of the replacement of cast-iron Pipe shall be equal to the trench width plus twice the distance from the top of the Pipe to the bottom of the crossing trench, extending equally on both sides of the crossing trench;#
(3)the cast-iron Pipe shall be patrolled and leakage surveyed daily until the Pipe is replaced; and#
(4)cast-iron Pipe does not have to be replaced in accordance with subsection (c)(1)(B) of this section when a Pipe segment is exposed and undermined in a Shallow Trench crossing, provided that:#
(A)the backfill supporting and surrounding the Pipe is thoroughly compacted for the full trench width and for a distance equal to ½ of the trench width on both sides of the centerline of the Pipe; and#
(B)the backfill is free of objectionable material or debris, such as pavement, frozen soil, trash and rocks.#
(d)Remediation of cast-iron Pipe adjacent to parallel excavations shall be as follows:#
(1)cast-iron Pipe, 8 inches or less in nominal diameter, adjacent to parallel excavation, shall be replaced as soon as practicable, provided that the excavation exceeds 8 feet in length and a condition exists as set forth in subsections (d)(2), (d)(3), or (d)(4) of this section;#
(2)a Low Pressure cast-iron Pipe parallel to a Shallow Trench excavation shall be replaced if:#
(A)the Pipe is exposed and undermined; or#
(B)at least ½ of the Pipe diameter lies within the Angle Of Influence, and the bottom of the excavation is below the water table, or the excavation is in Soft Clay;#
(3)a Low Pressure cast-iron Pipe parallel to a Deep Trench excavation and that lies within the Angle Of Influence shall be replaced if:#
(A)the Pipe is exposed and undermined; or#
(B)any portion of the Pipe is within 3 feet of the edge of the trench and Sheeting that may have been used is not left in place;#
(4)a High Pressure cast-iron Pipe parallel to a Shallow Trench or Deep Trench excavation shall be replaced if:#
(A)the Pipe is exposed and undermined; or#
(B)at least ½ of the Pipe diameter lies within the Angle Of Influence and Sheeting that may have been used is not left in place;#
(5)any Pipe that replaces cast-iron Pipe shall extend a safe distance beyond the point where parallel excavation terminates, but at least 10 feet past the end of the affected area; and#
(6)the cast-iron Pipe shall be patrolled and leakage surveyed daily until the Pipe is replaced. 40#
(e)Any segment of cast-iron Pipe that becomes undermined by a water main or sewer main break shall be evaluated and replaced by the Operator pursuant to the provisions of subsection (d) of this section.#