Best practices for managing contaminated-water diving operations
BY NICK FORTUNA
The tank barge Argo had rested at the bottom of Lake Erie for more than three-quarters of a century, making nary a peep, until its cargo, long known to be dangerous, officially became an emergency in October 2015.
The barge had gone down during a storm in 1937 while carrying approximately 4,762 barrels of crude oil, according to news reports at the time. That meant that the Argo was the sunken vessel posing the greatest environmental risk to the Great Lakes, according to a 2013 study by the National Oceanic and Atmospheric Administration.
In 2015, when Cleveland Underwater Explorers located the wreck about 50 feet below the surface, T&T Salvage was contracted by the U.S. Coast Guard to conduct an assessment. What divers found was an environmental disaster waiting to happen – a small leak from a rivet hole that was releasing benzene into the water from one of the barge’s eight cargo tanks.
A 2017 study by the National Center for Biotechnology Information found that most of the incidents with responder injuries were caused by human error and equipment failure.
For Jim Elliott, chief operating officer of the Teichman Group, the Galveston, Texas-based parent company of T&T Salvage, the Argo represented another high-profile salvage project in a long, distinguished career. Elliott, a member of the ADCI Commercial Diving Hall of Fame, had served as a decorated commanding officer in the Coast Guard and had responded to more than 250 marine salvage and pollution incidents.
“The Argo project was unique given the toxicity of the cargo,” said Elliott, a past president of the American Salvage Association. “Air monitoring on the surface detected what is referred to as ‘IDLH,’ or ‘immediately dangerous to life or health,’ conditions. This meant that not only was there a risk to the diver but also to the surface-support team and the public.
“The toxicity of the cargo required on-site oversight of the Coast Guard’s specialized National Strike Force to include the development of a comprehensive safety plan and detailed procedures to mitigate risks. Federal, state and local agencies managed the project within a Unified Command that also included Canadian governmental representatives concerned about the potential cross-border public-safety and pollution threats.”
The plan was for commercial divers to install valves atop the tanks to connect hoses and hydraulic pumps, and to install a separate standpipe with an internal pressure-monitoring device on each tank. T&T Salvage would be conducting around-the-clock diving operations in cold, contaminated water, with underwater visibility of less than a foot, to complete the project before the pending ice season.
Once the cargo tanks had been hot-tapped, the salvage crew would pump the remaining cargo into receiving tanks on the surface for safe disposal.
Just a few months earlier, in September 2015, T&T Salvage had responded to a tank-barge collision in the Mississippi River, salvaging and lightering a damaged barge and managing a spill of 2,800 barrels of heavy clarified slurry oil. The slurry quickly sank to the river bottom, and T&T designed a recovery system that included an environmental clamshell.
Comprehensive Safety Checklist
To help diving contractors manage difficult contaminated-water projects, Elliott developed this comprehensive safety checklist. The guidelines come from his experience as well as guidance published by the ADCI, International Marine Contractors Association, Environmental Protection Agency, Navy and NOAA.
1) Conduct a hazard evaluation.
If the contaminant is unknown, conduct a sampling study before diving. Diving operations shouldn’t begin until the pollutant has been identified and a hazard evaluation completed.
The sampling study should determine the degree and extent of contamination and take into account environmental factors such as geographic location, thermal conditions, water depth, speed of the current and the weather forecast. Based on the sampling study, contractors should establish three separate zones: a support zone, sometimes called a cold zone or clean zone; a contamination-reduction zone; and an exclusion zone, or a high-contamination zone or hot zone.
At the Argo, testing revealed the cargo to be about 70% benzene, a known carcinogen, so surface workers on support vessels would need to wear self-contained breathing apparatus, with continuous air monitoring, along with splash-resistant Tyvek suits and chemically resistant gloves.
For divers, it’s important to note that standard scuba gear doesn’t provide adequate protection in contaminated water, according to NOAA’s Diving Standards and Safety Manual. With scuba gear, there is substantial risk that the diver could ingest or be exposed to toxic chemicals.
Elliott said that in the past, scuba divers often were used in salvage and sunken-oil response operations, including on the Morris J. Berman barge, which sunk in 1994 after hitting a coral reef near San Juan, Puerto Rico, and the Erika tanker, which broke in two amid a heavy storm as it entered the Bay of Biscay, west of France, in 1999. But now, NOAA, the Navy, ADCI and IMCA all recognize the inadequacy of scuba gear in such environments and recommend complete protection of the diver.
Specifically, the ADCI recommends a “helmeted surface-supplied diver with mated nonporous dry suit with attached boots, gloves and a return-line exhaust or double-exhaust valve system.” The bottom line: Diving equipment designed to eliminate any exposure to contaminants, both for divers and support crew, should be considered when diving in contaminated water, Elliott said.
Diving operations should cease if there is any suspected breach in the watertight integrity of the surface-supplied diving system.
In addition, divers and topside personnel who could be exposed to the contaminant should be placed on a medical monitoring program.
Contractors should assign a site safety officer to the project and prepare a site-specific safety plan, Elliott said. A best practice is to consider contracting an experienced third-party safety professional to review the requirements and checklists with the diving supervisor and designated person in charge before commencing diving operations.
As an example, Elliott said that when he was in the Coast Guard during the 2004 Athos I sunken-oil response in the Delaware River, he sought out Don Dryden, now an ADCI board member and East Coast Chapter president, to serve as a safety officer dedicated exclusively to the contaminated-water diving operations.
2) Select and test commercial diving equipment to prevent exposure.
Every piece of diving equipment, including umbilical and connectors, must be compatible with the contaminants, meaning that those contaminants won’t degrade the equipment and endanger divers. Diving-system materials must be of matching durability to ensure that some components haven’t exceeded their useful life spans.
Exposure to contaminants takes its toll on diving equipment, which must be maintained, repaired and replaced more frequently than equipment used in unpolluted environments.
At the Argo, for example, after the crew patched the small leak they had detected, divers discovered the following morning that the toxic cargo had deteriorated the rubber valves on their dry suits and etched the faceplates on their helmets. As a result, the response team reviewed and improved its contaminated-water diving equipment, processes and plans before moving forward.
Before diving, contractors should conduct a diving-system leak test and consider using a positive-pressure diving system to limit exposure. Review equipment durability, material permeation rates and potential breakthrough times.
Personal protective equipment is only as strong as its weakest link, Elliott said, so it’s important to inspect and test diving-suit seam construction and potential breach points before and after each dive.
Air-compressor intakes must be kept in a safe atmosphere, or divers should use bottled air compressed in a clean atmosphere.
Contractors may refer to the National Fire Protection Association’s Standard for Vapor Protective Suits for Hazardous Chemical Emergencies, or the Standard Guide for Chemicals to Evaluate Protective Clothing Materials from the American Society for Testing and Materials, to develop test formats. However, contractors should also consult with manufacturers regarding the compatibility of equipment to the specific contaminant prior to conducting operations.
Commercial divers may use mixed-gas, saturation and one-atmosphere diving systems to extend bottom times at depth. Comprehensive standards for these operations have been published by the ADCI, IMCA and Navy. As with surface-supplied diving procedures, contaminated-water diving plans must consider the compatibility of materials, procedures to prevent cross-contamination of pressure vessels for human occupancy, and personnel and equipment decontamination methods.
3) Ensure divers and topside personnel are trained for contaminated-water diving.
Diving personnel should have training or experience in decontamination procedures; dry-suit diving (donning, doffing and emergency procedures); leak-testing procedures; maintenance, repair and proper use of contaminated-water diving systems; sampling procedures; emergency procedures; and OSHA’s Hazardous Waste Operations and Emergency Response (HAZWOPER) standards. Annual refresher courses should be required and documented.
Training should be based on the duties and functions to be performed by each member of the diving team, decontamination team and surface-support personnel.
A backup team, or standby divers, must be equipped and trained to the same standard as the entry team. If the diving mode is surface-supplied, the standby diver’s umbilical must be at least 50 feet longer than that of the diver in the water as an additional safety factor, Elliott said, citing Steven Barsky’s “Diving in High-Risk Environments.”
A decontamination system must be set up and manned by trained responders. Procedures must be put in place to remove the specific contaminant from the surface of the diver, diving system, equipment, the environment and property. In addition, there should be a system in place to measure the effectiveness of decontamination procedures.
A 2017 study by the National Center for Biotechnology Information found that most of the incidents with responder injuries were caused by human error and equipment failure, Elliott said. Additionally, the study found that most first responders hadn’t received even basic hazardous-materials training.
Elliott said that even prior to mobilization, contractors must ensure that their divers have the proper training and equipment for contaminated-water diving. Additional site-specific training with detailed equipment inspections and tests should be completed before entering the water.
Diving contractors also should develop a disposal plan for contaminated equipment and decontamination waste, in accordance with federal, state and local regulations.
Often forgotten, contractors should maintain comprehensive records of projects involving contaminated-water diving, including medical surveillance records, detailed descriptions of exposures to hazardous substances, complaints from workers following exposure, training records, a complete log of response actions and equipment maintenance records. Recordkeeping is mandated by various federal regulations, including OSHA standard 29 CFR 1910.1020, which requires all employee exposure records to be maintained for at least 30 years.
Overall, the safety of responders and the public must be the highest priority during every response operation, Elliott said.
“Companies planning to conduct contaminated-water diving should ensure that operations are conducted with trained, experienced and equipped divers and with the safety of everyone involved – the diver, topside support personnel and the public – always in mind,” he said.
“While this summary checklist provides a good overview, site-specific dive and safety plans must be prepared in close coordination with the federal, state and local agencies managing the response. In the end, a wise decision may be simply not to dive in a particular contaminant since personal protective equipment is the last line of defense in managing a hazardous-materials incident.”