Charlottetown Marine Terminal Pipeline Decommissioning Project Description 69 Marr Road Unit B Rothesay NB, E2E 3J9 Tel (506) 848-1920 Fax (506) 848-1929
Charlottetown Marine Terminal Pipeline Decommissioning Table of Contents 1 Introduction 1 2 Background Information 1 3 Site Conditions 2 4 Decommissioning Plan 3 4.1 Pipeline Flushing 4.2 Aboveground Piping on Causeway 4.3 Underground Piping into Tank Farm 4.4 Sub-sea Pipeline & Caisson Piping 4.5 Caisson Appendix A Appendix B Appendix C Figures Pipeline Inspection Report, Photos Irving Oil Pipeline Flush Data Appendix D US Federal Code 30 CFR Chapter 11
Charlottetown Marine Terminal Pipeline Decommissioning 1 Introduction The Irving Oil Marine Terminal tank farm in Charlottetown, PE is located on 10 Riverside Drive at the mouth of the Hillsborough River (see Figure 1.0, Appendix A). The tanks are primarily filled via ship and up until January 2008, ship discharges were done from a 40 diameter sheet pile caisson (the rock ) and three 3-10 diameter steel pipelines. New marine lines were commissioned on the government dock, which is operated by the Charlottetown Harbour Authority, and Irving currently fills the tanks from this ship unloading point. Irving will not require the use of the 3 existing lines in the future and plans to decommission them. Several options were considered before determining the preferred approach: Flush the pipeline; abandon the subsea section of the pipeline in place; remove the aboveground portion that runs alongside the causeway; and grout the section that runs under the causeway to the tank farm. The following sections provide background information, a detailed description of existing site conditions and the proposed method of decommissioning. 2 Background Information The installation of the three 10 dock lines on the harbour floor is not a typical installation for an onshore facility. Normally the piping would be routed on or under a dock the entire length from the discharge manifold to the tank farm. In this instance the discharge manifold is installed on a 40 diameter caisson and the piping is routed along the floor of the harbour to the shoreline. Consequently, there are no historical decommissioning examples for this type of installation to refer to. It was decided to look for examples of how decommissioning of subsea piping is completed by the offshore industry. The prevailing method used by the offshore industry along with site specific conditions led to the conclusion that abandonment in place is the preferred method, in this case, to permanently decommission the subsea pipelines and the caisson. The following items present the rationale that led to the recommended approach: 1. A 2001 report prepared by Irving Oil Engineering outlining the findings of an underwater inspection completed by an independent company (Diversified Divers Inc.) indicated that the pipelines were completely covered by mud for about 70% of the length of the subsea section. As the lines have been in place over 40 years, the disturbance caused by removal may have a negative impact on the surrounding environment and fish habitat. A copy of the report can be found in Appendix B. Photos extracted from subsea video are also included in Appendix B. 1
Charlottetown Marine Terminal Pipeline Decommissioning 2. The current method of anchoring the pipeline to the harbour floor is unknown due to the amount of mud/sediment that has built up around the piping (see photos in Appendix B). 3. The pipelines were flushed after final discharge; the reports are included in Appendix C. 4. Abandonment in place is pursued as long as it does not negatively impact on marine activities (fish habitat, navigation). The Charlottetown Harbour Authority has stated that the continued presence of the caisson and piping will not obstruct marine navigation in the harbour. These structures have been in place for over 40 years. Irving intends to maintain their water lot lease for the foreseeable future. 5. Removal of the subsea piping and caisson may involve increased environmental and safety concerns. The planned approach, for the subsea section of the pipeline, would be to flush the pipelines, fill them with seawater, cap off each end and anchor the ends of the pipeline. This method was established based on the requirements of US Federal Code 30 CFR Ch. 11 Section 250.1750-17 (See Appendix D). The section along the causeway will be removed; and the section running underneath the causeway to the tank farm will be grouted and capped in place. A detailed description is provided in Section 4.0. 3 Site Conditions The existing caisson was installed in 1981 to replace an existing structure used to off-load ships. The piping was installed circa 1970. Both the piping and the caisson are protected by cathodic protection systems. The deck of the 40 diameter caisson is about 15 above the low water level and 5 above the high water level. The area behind the sheet piling is filled with 2 minus gravel and the top was capped with a concrete reinforced deck. The sheet piling is driven 30 below the harbor bottom and the low water depth is about 40, making the total structure about 85 from base to deck. The caisson is located 1800 off the shore and 1100 away from the causeway that forms part of the Trans Canada Highway. The length of the subsea piping run is about 1300 and runs along the Irving Oil water lot after it transitions from aboveground part way out the Trans Canada Highway causeway. Three lines run to this point from the caisson (1) 10 gasoline, (1) 10 Distillate and (1) 10 ballast line which has not been in use for years. The subsea piping was installed with a protective coating to prevent exterior corrosion. 2
Charlottetown Marine Terminal Pipeline Decommissioning 4 Decommissioning Plan 4.1 Pipeline Flushing The entire length of gasoline and distillate pipelines from the caisson to the tank farm were flushed with harbour water in 2008. The ballast line has been out of use for several years. The lines are currently filled with water from the caisson to a location inside the tank farm. The log sheets from the pipeline flushing are included in Appendix D. The lines will be pigged utilizing a pump mounted on the caisson and seawater from the harbour. The water displaced and the water used for pigging will be contained inside the tank farm, treated and disposed of as required. 4.2 Aboveground Piping on Causeway The aboveground pipeline section along the causeway will be flushed as indicated above and will be disconnected from the sub-sea portion at the existing set of flanges. The piping will then be cut into sections. The pipe sections will be removed by a boom truck and loaded onto a flat bed truck for transport and disposal/recycling. The existing steel supports will also be removed. The concrete foundations will be left in place. 4.3 Underground Piping into Tank Farm The underground section of piping under the causeway and into the tank farm will be filled with grout and capped at each end. Removal of this piping section would require trenching across the Trans Canada Highway; this has been deemed not feasible. 4.4 Sub-sea Pipeline & Caisson Piping All of the piping on the caisson will be removed from the flanges located just above the high water mark by a barge mounted crane. The piping down the side of the caisson will be removed down to the bottom of the harbour where caps will be welded to the ends of the horizontal piping sections. The old ballast line not will be capped. The remaining valves and flanges will be removed at the shore and the pipelines will be capped. Both ends of the piping will be covered with concrete mats. The concrete mats will be pre-cast concrete with lifting lugs that would allow them to be lowered into place from a barge mounted crane. 4.5 Caisson The caisson will be left in place. The caisson sheet piling is protected by a sacrificial anode system. Continued inspection and upgrading of this system will be done as required. The Charlottetown Harbour Authority does not require the caisson to be removed. 3
The following photos are still photos selected from the Diversified Divers Inc. Pipeline Inspection video (2003). Due to the age of the video and the extraction process, photo quality is low. However, the pictures do show the sediment coverage of the pipeline and that it is providing habitat for marine life.
250.1750 (1) A letter signed by an authorized company official certifying that the platform or other facility site area is cleared of all obstructions and that a company representative witnessed the verification activities; (2) A letter signed by an authorized official of the company that performed the verification work for you certifying that they cleared the platform or other facility site area of all obstructions; (3) The date the verification work was performed and the vessel used; (4) The extent of the area surveyed; (5) The survey method used; (6) The results of the survey, including a list of any debris removed or a statement from the trawling contractor that no objects were recovered; and (7) A post-trawling job plot or map showing the trawled area. [67 FR 35406, May 17, 2002; 67 FR 66049, Oct. 30, 2002] PIPELINE DECOMMISSIONING 250.1750 When may I decommission a pipeline in place? You may decommission a pipeline in place when the Regional Supervisor determines that the pipeline does not constitute a hazard (obstruction) to navigation and commercial fishing operations, unduly interfere with other uses of the OCS, or have adverse environmental effects. 250.1751 How do I decommission a pipeline in place? You must do the following to decommission a pipeline in place: (a) Submit a pipeline decommissioning application in triplicate to the Regional Supervisor for approval that includes the following information: (1) Reason for the operation; (2) Proposed decommissioning procedures; (3) Length (feet) of segment to be decommissioned; and (4) Length (feet) of segment remaining. (b) Pig the pipeline, unless the Regional Supervisor determines that pigging is not practical; (c) Flush the pipeline; (d) Fill the pipeline with seawater; 30 CFR Ch. II (7 1 04 Edition) (e) Cut and plug each end of the pipeline; (f) Bury each end of the pipeline at least 3 feet below the seafloor or cover each end with protective concrete mats, if required by the Regional Supervisor; and (g) Remove all pipeline valves and other fittings that could unduly interfere with other uses of the OCS. 250.1752 How do I remove a pipeline? Before removing a pipeline, you must: (a) Submit a pipeline removal application in triplicate to the Regional Supervisor for approval that includes the following information: (1) Proposed removal procedures; (2) If the Regional Supervisor requires it, a description, including anchor pattern(s), of the vessel(s) you will use to remove the pipeline; (3) Length (feet) to be removed; (4) Length (feet) of the segment that will remain in place; (5) Plans for transportation of the removed pipe for disposal or salvage; (6) Plans to protect archaeological and sensitive biological features during removal operations, including a brief assessment of the environmental impacts of the removal operations and procedures and mitigation measures that you will take to minimize such impacts; and (7) Projected removal schedule and duration. (b) Pig the pipeline, unless the Regional Supervisor determines that pigging is not practical; and (c) Flush the pipeline. 250.1753 After I decommission a pipeline, what information must I submit? Within 30 days after you decommission a pipeline, you must submit a written report to the Regional Supervisor that includes the following: (a) A summary of the decommissioning operation including the date it was completed; (b) A description of any mitigation measures you took; and (c) A statement signed by your authorized representative that certifies that the pipeline was decommissioned according to the approved application. 442 VerDate May<21>2004 14:25 Jul 17, 2004 Jkt 203116 PO 00000 Frm 00442 Fmt 8010 Sfmt 8010 Y:\SGML\203116T.XXX 203116T