Anti-fouling coatings and other discharges from the nation’s 140,000 smaller commercial vessels will remain exempt from federal clean water permitting requirements until December 2013, under an extension just signed by President Obama.
The legislation further extends a two-year moratorium for National Pollutant Discharge Elimination System (NPDES) permits for these vessels under the Clean Water Act.
The moratorium was granted in July 2008 and was set to expire July 31, but both the U.S. House and Senate voted in July to extend it until Dec. 18, 2013. Obama signed the final measure (S. 3372) on July 30.
EPA Tasked with Study
The purpose of the moratorium was to allow time for the U.S. Environmental Protection Agency to study the discharges "incidental to [the] normal operation" of commercial fishing vessels and other non-recreational vessels less than 79 feet. Those discharges include antifouling coatings.
EPA then sampled wastewater discharges and gathered shipboard process information from 61 vessels in nine vessel classes, including fishing vessels, tugboats, water taxis, tour boats, towing/salvage vessels, small research vessels, a fire boat, and a supply boat. Vessels were sampled in 15 separate cities and towns in nine states across multiple geographic regions.
EPA sampled more commercial fishing vessels than any other vessel class due to the large number of fishing vessels subject to the P.L. 110-299 permitting moratorium.
Copper: ‘Greatest Potential Risk’
In a draft report of its findings to Congress this spring, EPA reported that dissolved copper was the analyte detected in the discharges “at concentrations that consistently posed the greatest potential risk for local impacts and for contributing to exceedances of water quality standards in larger water bodies.”
“Concentrations of dissolved copper exceeding the most protective screening benchmark were found in every sampled discharge type, except for outboard engine and generator engine effluents,” the draft report said.
The agency noted that copper is leached “from antifouling hull coatings used on certain vessels to prevent buildup of organisms such as barnacles and algae. Copper can also be released via underwater hull cleaning, hull coating removal operations, and paint application.”
EPA said those results were consistent “with real-world observations that metals are frequently associated with vessel discharges in concentrations of potential environmental concern.”
“Environmental impacts from dissolved copper leaching from antifouling hull coatings have been well documented in low-flushing environments in harbors with large numbers of recreational vessels,” EPA said.
The American Coatings Association’s Antifouling Working Group submitted comments on the draft “to highlight the importance of using effective antifouling coatings to the prevention of spreading invasive species in our national waterways,” according to an association statement.
More Work Ahead
Despite the draft report’s findings, lawmakers said that EPA had more work to do.
“EPA completed this study earlier this year and determined that discharges from these smaller vessels are not benign,” Rep. James L. Oberstar (D-MN), chairman of the Transportation Committee, said in a statement. “Appropriately, EPA plans on bringing these vessels within the scope of the National Pollutant Discharge Elimination System (NPDES) program.
“Currently, however, EPA does not have the framework in place or the resources to expand NPDES coverage to these smaller vessels.”
Oberstar said the extension would “allow EPA time to implement the appropriate Clean Water Act mechanisms for controlling, minimizing, and properly addressing these types of vessel discharges. It will also allow the agency to plan for the inclusion of these smaller vessels when the agency renews its Vessel General Permits program.”