ilkti ...:- WOC LP Standards Section E005 - Excavation kj/0i DOCUMENT NO: WOC-HSE-ST-0001 & EP Department 44, 4R 11. C

Transcription

1 ...:- 44, 4R 11. C WOC LP & EP Department WOC HSE Standards Manual DOCUMENT NO: WOC-HSE-ST-0001 Section E005 - Excavation REV ISSUE PREPARED BY REVIEWED BY APPROVED BY ISSUE DATE 0 Issued for Use kj/0i W. McIntosh s/z / - ksvxkj,75 LP & EP Manager ilkti WO Executive Vice President Operations June 2009

2 .._ A. ''.., oi, col Excavation WOC-HSE-ST June of 5 PURPOSE To provide guidelines for excavation activities and protective measures to remove hazards to employees APPLICATION All WAHA employees, contractors and others working in open excavations including trenches. 3. POTENTIAL HAZARDS Death by Asphyxiation Serious crush injuries Electric shock Pipeline damage Drowning Slips, Trips & Falls Toxic and/or flammable atmosphere 4. PROCEDURES 4.1. Approvals and Permits: All permits and approvals must be obtained prior to the commencement of any work on an existing plan site, well site, or pipeline right-of-way. All pipelines, underground piping, cables, or other underground facilities, must be located and identified in the proposed work area prior to commencing any excavation or construction work which penetrates deeper than 30 centimeters from the surface. A safe work permit should be issued for all work within 30 meters of an existing underground facility. A Waha Permit to Work (complete with Ground disturbance checklist see Appendix 1) must be issued for all excavation work within 2.5 meters of an existing underground facility. [See: Waha Permit to Work process] 4.2. Pre-Job Safety Meeting Prior to performing any work, a pre-job meeting must be conducted, covering all safety and procedural aspects. Where the excavation is complex or involves multiple lines, a sitespecific procedure must be prepared.

3 1 C ap+ o - Excavation WOC-HSE-ST June of Identifications The owner must ensure that all underground facilities are properly identified and located prior to any excavation. A written record must be kept of this identification. A Waha representative must inspect and document the location and marking. Open excavation shall be barricaded for identification and to protect people from falling Location of Underground Pipelines and Utilities No mechanical excavation shall be undertaken on a Pipeline Right-of-way or within 2.5 metres of the outside of a pipe, cable or conduit before hand exposure. After hand exposure, the operation may progress only under the direct on-site supervision of an owner's representative During mechanical excavation, where existing underground pipe, cable, conduit or facilities are involved, an observer is required at all times. The observer and/or operator must be provided with a copy of drawings, permits and agreements, locating all existing underground installations If excavating in a suspected atmospheric hazardous area, the atmospheres shall be tested before employees enter excavations greater than 1.25 metres in depth Daily inspections of excavations, the adjacent areas, and protective systems shall be made by a Waha representative for evidence of a situation that could result in possible cave-ins or other hazardous conditions Protective Measures Before a worker begins working in an excavation greater than 1.25 meters in depth and narrower than its depth, the employer must ensure that the worker is protected from cave-ins and sliding material by the following: Cutting back the walls to reduce the remaining vertical height to less than 1.25 meters, or Installing temporary protective structures.

4 .._ 40" ' Npt iltif -,- ok CO Excavation WOC-HSE-ST June of 5 Protected by means of water removal equipment or drainage systems and special wall support if it subject to water accumulation Where cutback method is used, the walls must be cut back, in hard and compact soils, to not less than 30 degrees from the vertical. In all other soils, 45 degrees from the vertical will be the minimum In shored excavations of over 3 meters, the shoring (design) must be approved by a competent professional engineer Spoil piles must be at least 1 meter from the side of the excavation and have a slope of less than 45 degrees Access ladder should be provided for worker entrance and egress for excavation greater than 1.25 metres. Safe access/egress by means of stairways, ladders, etc. shall be provided for every 7.5 meter travel distance If the excavation is to be left unattended, it must be barricaded at distance greater than 1 meter from the side of excavation complete with warning signs 5.0 PRECAUTIONS No employee shall be permitted underneath loads handled by lifting or digging equipment. Employees shall not work in excavations in which there is accumulated water unless special supports are installed to protect cave-ins and control water level. 6.0 REFERENCES OSHA CFR 1926 Subpart P

5 .._ It *. -7'9 0/L C '? Excavation WOC-HSE-ST June of 5 Appendix 1 Excavation Checklist Work order No Descnption and location of proposed Ground Disturbance 1 Permit to Work No., Ground Disturbance Checklist Referenced drawings Facilities Plot Plan attached? Y N R&D and or PFD drawings attached? Y N Underground Civil Drawings attached? Y N Project or as built piping layout or isometric drawings attached? Y N Electrical. single line and loop drawings attached? `I N Identify documented buried services within 3 meters of the proposed ground disturbance work area. Specify below. Electrical cables. Y N Cathodic Protection. Provide detailed description, depth, srze number etc. Telephone / Fiber Optics. V N Instrumentation. Y N Process piping. Y N Any Buried Services marked Yes must be located and the Underground Sumps. V N physical location flagged with survey marker flags Potable water piping Fire water piping. Y N Utility water piping Y N Septic or sewer piping. Y N Are special safety precautions or equipment required? Specify befow. Electrical isolation Y N Continuous gas monitors. Y N Personal protective gear. Y N Piping or mechanical isolation Y N Explosion proof equipment Y N Hand exposure only (No Mattock) Y N Depressuraaeon or draining Y N Barriers and waming signs Y N Purging or ventilation. N Safety harness I lifeline. `I N Ladders (Every 25 feet distance) Y N Task analysis and procedure Y N Trenching Refer to SSPM Y N Use wooden tools at near cable Y N Other Y N Protective measures (excavation greet* than 1.5 meter in depth). 1 Cutback method (minimum 30 for hard/compacted soils or 45 for all other soils). Y N 2 Shoring method (for more than 3 meters depth must be approved by professional engineers). Y N 3 Soil piles more than 1 meter from die side of excavation and sloped less than 45 Y N 4 Barricaded at distance of I meter from the side of excavation complete with warning signs Y N 5 Safe access/egress by means of sta ovays. ladders, ramps. etc provided for every 25 feet travel distance V N 6 Excavations subject to water accumulaton shall be protected by means of ate removal equipment o f drainage systems. Y N 7 Develop task analysis and procedure Y N Additional job specific comments. Area scanned by and witnessed by signatures. I have scanned the area within 3 meters of the proposed Ground Disturbance for buried services with an electronic locator Approval signatures. This Ground Disturbance Checklist has been reviewed and found to be completed fully to my satisfaction. This Ground Disturbance Checklist has been reviewed and found to be completed fully to my sabsfaction Name & Signature Dept Data of Scan IIE SupervisorfInspector (Responsible Person) Date Mechanical Supervisor/Inspector (Responsible Person) Data I have checked the above conditions and consider it safe to carry out this work. I have also reviewed this Ground Disturbance Checklist and have found it to be fully completed to my satisfaction. Ops/Field Supt or Supv, or Dept. Supt Date A Safe Work Permit must be obtained and a copy of this "Approved' Ground Disturbance Checklist must be attached to the Safe Work Permit before any work is allowed Any noted discrepancies in facilities drawings, and/or if any modifications are made to any underground service they must be fully documented and immediately forwarded to the Engineering Department for the necessary corrections to be made