There are millions and millions of feet of vintage pipelines in use throughout the United Stateswith an exterior coating that contains asbestos. There is probably an equal amount of footage existing in out-of-use, idled, or abandoned pipelines.All of these pipelines were installed prior to 1980. In almost every instance when it comes to older or vintage pipelines, we are referring to lines that are over 40 years of age.Most pipelines today are built and designed to have a life span of 25-40 years, but many will stay in service much longer. Their heavier walled predecessor pipelines (the subject of this article) might be 50-80 years of age. These predecessor pipelines built prior to 1980 have a 90% chance of having 10%-50% chrysotile asbestos in their coal tar or felt type coating.
The asbestos in the coating is an excellent insulator and protector of line pipe and serves the industry well as seen in the hundreds of thousands of miles of pipeline that are still in operation with good bonded coating in tact and serviceable. Wear and tear eventually takes a toll, and disbonded coal tar coatings often reveal anomalies such as stress cracking or corrosion that lead to leaks, eruptions, and explosions.
Shutting down or partially shutting down a pipeline for the purpose of inspection is an expensive and time-consuming prospect. The repairs needed and executed when anomalies are found compound the expense and time consumed, but they are entirely necessary to maintain the integrity of the pipeline.
Often pipeline owners/operators are lacking in information when it comes to doing repair work and dealing with potential asbestos problems. This article will introduce guidelines for a correct, safe, and informed way of dealing with asbestos containing material (ACM) when preparing for and making routine repairs on pipeline segments.
The problem is fixed either by replacing that section where the anomaly occurs (dent, exterior wear, disbonding of coating, cracking, etc.) or by repairing the same section by reinforcement by clamping or other means of strengthening the worn or damaged area.
Inline inspections are usually the first step in determining whether repairs are needed. Interior smart pigs (ILI) running the length of the pipeline or segments can identify the location of the anomaly or possible problem areas depending on the type of test or inspection administered. Surveying teams can then mark the surface area with stakes where a dig might take place for repair or for further assessment, e.g., open inspection or x-ray scan.
Unforeseen Surface Problems
Problems can occur when too much time elapses between the time the inline inspection stakes are inserted and the actual dig to repair the pipe takes or additional subsequent inspection.Stakes that initially marked areas of concern can be inadvertently moved by mowers, landowners, kids playing, animals, weather, and various other types of incidents.Once these stakes are moved, it can cause additional expense and time consumed as repeat inspection and identification efforts will be needed to locate the actual problem that might be only a few inches or a few feet away.Therefore, inspection and pipeline repair digs should be closely coordinated so that as little time as possible passes between inspection and repair.
Steps to take
Internal inspections to that locate the areas in need of repair and the contractors to make the necessary digs and repairs are costly to a pipeline company. The disruptions and interruptions to throughput revenue are sizable. No company wants to interrupt a basic revenue flow or source. So,pipeline repairs are serious undertakings as they can be costly, time consuming, and disruptive to a pipeline operating company;however, needed repairs must be addressed.
After the process of finding the anomaly or problem through inline inspections or other diagnostics and locating the position on the pipeline through above ground surveys, a dig occurs. It is at this point asbestos workers and supervisors are on the scene to safely prepare for the repair work to be done. Plywood is laid in the ditch, plastic liner is set down and the work begins. Certified contractors wrap the exterior with plastic wrap, loosen the ACM exterior coating, and then remove the plastic liner along with the fallen ACM coating residue. All ACM waste including gloves and Tyvek suits worn in the removal process by workers are double-bagged and labeled. Labeled bags of ACM waste are removed to a designated licensed landfill. The following work plan gives an overview of the ACM removal process. A complete set of guidelines including references to state, federal, and professional association requirements can be obtained by emailing a request for “Pipeline Asbestos Procedures” to email@example.com.
Asbestos Pipeline Insulation Removal Work Plan
Asbestos training schools for workers and supervisors
Natec of Texas is a Houston-based company offering training certifications in asbestos abatement for pipeline personnel and others who work with this material. Natec of Texas offers in-house training programs for workers who will be working directly with asbestos containing material (eight-hour course at their facility or at your facility with ten to twelve personnel). Natec also offers a one-week supervisor and contractor comprehensive certification course at their facility in Houston for asbestos abatement. A certified contractor/supervisor is required to be on the job when this asbestos removal work is performed.State and federal guidelines in many states are the same and require basic guidelines to be followed. If you don’t have time or personnel to send for certification, Pipeline Equities can provide certified contractor/supervisors on a per diem basis for pipeline asbestos abatement projects.
I wrote an article for this publication called Land Developers and Alien Pipelines for Underground Construction magazine (March 2018) about surprise pipeline discoveries in expanding and developing urban locations where oilfields once existed and are now depleted. Usually, the gathering lines for these old crude or gas fields are left in place. Many times they are lease lines and reside on large tracts that do not require recorded easements. Recently, I supervised a job where a highway was being built around Houston and gathering lines connecting wells and tank batteries were found that were almost 100 years old. No one knew about them until the construction repair crew started digging for another known line and found the other two alien gathering lines. The biggest surprise comes in tapping these old lines to determine what they might contain. What if unpigged crude or diesel fuel is found, and the prior owner has not been in business for 30 years? What then? Trained personnel are needed to use proper procedures to tap and drain the line to make sure the urban surroundings are not disturbed and contaminated by repair efforts.
A line might go across a housing development in the back or in front of homes in a neighborhood. Landowners can’t see a buried pipeline, and signage is never permanent.Homeowners plant flowerbeds and build sidewalks and driveways over them.
Sometimes the line might be pigged, and a surveyor stake is placed where an anomaly exists in the line. Recently, I have supervised projects where the landowner inadvertently and innocently moved the surveyor stake to mow the grass. He put the stake back approximately in the same place, but a few feet off. An expensive day was lost as the crew brought back the excavator, obtained permission, and dug up more grass and flowerbeds at the landowner’s home to make the necessary pipeline repairs.
With the extensive number of old or vintage pipelines in service with ACMin the coating, there will be more and more repair jobs coming. When the pipelines are not repaired, but retired instead, the lines are for the most part abandoned or retired in place. When this happens maintenance and signage maintenance stops or changes oftentimes. This leaves the probability open that a landowner or other uninformed excavator will uncover old pipe and have the same asbestos problems with little knowledge or training in how to proceed.
David Howell is managing partner of Pipeline Equities, a Houston based pipeline environmental, recovery and appraisal company with trained and certified contractor/supervisor personnel available for pipeline and asbestos repair projects. Contact David Howell at 713-623-0690 or firstname.lastname@example.org.
As soon as site is uncovered, post hazard signs and asbestos warning signs around the perimeter of the excavation site.
Sometimes it is good to erect shelters for rain and sun protection over the work area particularly when x-rays are being conducted or additional diagnostics are taking place.
Keeping the asbestos coated material (ACM) wet with treated surfactant water maintains the non-friable state of asbestos fibers. Note warning barriers are in place, plastic sheeting is placed below area of pipe to be worked or examined. In addition, plywood is placed below to maintain stability.
After wetting exterior, plastic wrap is applied to designated problem area to be examined or repaired.
In some cases, depending on depth, soil conditions, and trenching methods, more protection for workers may be in order. Shown above is instructor properly applying protective plastic wrap after wetting of coating. Note tape on each side of area to be wrapped will be applied.
When area of investigation is wrapped and taped at each end, bronze hammers are used to loosen the coal tar coating bonded to the pipe exterior. In some cases of stress corrosion, cracking, or SCC, the bonding will be poor and loosening is not required.
Continuing to use surfactant water to keep any particle from becoming friable and special slicing tools are effective in allowing the loose coal tar coating to into the plastic liner laid under the repair area.
In this case, the plastic liner was rolled up with the coating and prepared for double bagging.
Gloves, Tyvek suits are disposed of in the second bag of the double bagging process.
Powered By Glorious Media