Verifying BallastWater Treatment Performance A protocol ready for pilot-scale testing should improve knowledge of available technologies. CARLTON D. HUNT DEBOR AH C. TA NIS BATTELLE THOM AS G. STEV ENS NSF INTERNATIONAL R AY M. FREDERICK U.S. EPA RICH ARD A. EV ERETT U.S. COAST GUARD
T
he invasion of nonindigenous species has been cited as the greatest global threat to biodiversity other than habitat loss (1). Conservation biologists recognize these introductions and habitat
destruction as the two most serious threats to endangered species worldwide (2). Nonindigenous aquatic nuisance
species (ANS) that live in coastal areas around the world tems (3–5) and are considered one of the most important environmental issues that the maritime community faces (6). In the U.S., for example, ANS alter important ecological processes and causes serious economic losses (7).
EDWARD LEMIEUX
have had profound negative impacts on aquatic ecosys-
In 2005, a protocol pilot test will be conducted at the Center for Corrosion Science and Engineering, U.S. Naval Research Laboratory in Key West, Fla.
© 2005 American Chemical Society
AUGUST 1, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 321A
A major vector for ANS is ship ballast water, which transports ~5000–7000 species daily (8). Vessels frequently deballast and reballast during cargo loading and unloading to maintain trim and stability (6). Globally, 3–5 billion metric tons (m3) of ballast water are discharged annually, with at least 2 billion gallons (gal; ~8 million m3) from around the world discharged into U.S. waters. With so much at stake, the U.S. EPA, NSF International, Battelle, and the U.S. Coast Guard (USCG) are jointly developing a protocol for verifying the technical performance of commercially available technologies designed to treat ship ballast water for potentially invasive species (16).
What are the ETV Program and the WQP Center? In the Environmental Technology Verification (ETV) Program, the U.S. EPA partners with private testing and research organizations. ETV is composed of one pilot program and six verification centers, including the Water Quality Protection (WQP) Center. ETV provides technically sound, credible, independent data on the actual performance of technologies designed to prevent or control degradation of the environment. Stakeholder input is an important aspect of the program for the direction and development of testing and implementing protocols. In addition, ETV provides information to potential purchasers and regulators on the efficacy, operation, and maintenance of technologies. NSF International, a nonprofit third-party testing and certification organization, is the verification partner working with EPA to manage the WQP Center. This center handles technologies for the protection of groundwater and surface water from contamination. Information on the ETV Program and the WQP Center, as well as a verification report and a summary verification statement, is available at www.epa.gov/ etv. Information about NSF International and its efforts is available at www.nsf.org/etv. As explained in this article, the protocol will be applied under EPA’s Environmental Technology Verification (ETV) Program (see box). ETV will use the procedure to conduct the subsequent technology verification tests. The protocol was developed with extensive input from a ballast-water stakeholder group and a technical panel that included representatives from federal and state agencies, nongovernmental organizations, scientists working on the ballast-water issue, and the developing ballast-water treatment industry.
Understanding the problem This global transport of ballast water has led to problems such as the displacement of native freshwater species and the alteration of the food web by Eurasian zebra mussels (Dreissena polymorpha) in the Great Lakes and the Mississippi and Hudson Rivers (9); the decimation of the anchovy industry in the Black and Azov Seas by the American comb jelly (Mnemiopsis leidy), probably transported from southern New England (10); and the introduction to southern Australia of the North Pacific sea star (Asterias amurensis), which threatens commercial stocks of shellfish species such as oysters and scallops (10). The continuing discovery of new nonindigenous species worldwide demonstrates the urgent need for ballast-water man322A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / AUGUST 1, 2005
agement (BWM) to reduce the risk of future introductions (11). Because of the economic and environmental problems resulting from ANS, the U.S. Congress passed the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (Public Law 101-646, NANPCA) and the National Invasive Species Act of 1996 (Public Law 104-332, NISA). In response to mandates in the legislation, USCG established ballast-water reporting and management regulations for the Great Lakes (per NANPCA) and reporting regulations and voluntary management guidelines for the rest of the U.S. (per NISA) in 2001. In 2004, USCG published a rule that implemented penalties for nonreporting and extended the reporting requirement to all vessels arriving to U.S. ports and places, including coastal traffic (12). Because adherence to the voluntary guidelines was not found to be effective (6), USCG also published a revised rule in 2004 that makes BWM mandatory for all vessels equipped with ballast-water tanks entering U.S. waters from outside the 200-mile exclusive economic zone (EEZ, 13). This last rule includes a provision that allows vessels to “use an ‘environmentally sound’ U.S. Coast Guard-approved alternative ballast water management method before the vessel enters the U.S. EEZ” (13). An alternative, environmentally sound approach to BWM is a method, effort, action, or program that will prevent and control ANS introductions during ballast-water discharge. Methods of BWM under investigation worldwide include treatment technologies, such as filtration, hydrocyclonic separation, UV radiation, ultrasound, deoxygenation, numerous chemical biocides, and thermal treatment. However, the capabilities and limitations of these treatment technologies under the conditions likely to be encountered during ballasting operations and in ballast tanks are poorly understood. The degree to which any technology can be used to treat ballast water depends on several factors, including the biological treatment efficacy (i.e., an organism’s susceptibility to specific treatment), environmental acceptability (i.e., little or no impact on the receiving environment), shipboard practicability (onboard vessels have constraints of space, time, and power), cost-effectiveness, and safety. Unresolved issues include the specifics of approved national and international ballast-water treatment standards and processes for certifying the treatment technologies. Progress on an international standard was made with the February 13, 2004, adoption of the International Convention for the Control and Management of Ships’ Ballast Water & Sediments 2004 (14) by the International Maritime Organization (IMO). The IMO convention will enter into force 12 months after ratification by 30 countries that represent 35% of world merchant shipping tonnage. Prior to this IMO convention, USCG initiated a rule-making effort to define an acceptable ballast-water treatment standard for the U.S. (15). Discharge standards eventually established under this rule are expected to apply to all ballast-water treatment technologies. But before the standards are
put in place, actions must be completed, including formulating technology certification requirements and developing a testing protocol to ensure acceptable treatment-system performance. In anticipation, USCG teamed with EPA’s ETV Program’s Water Quality Protection (WQP) Center to develop a verification protocol with which to evaluate the effectiveness of technologies designed to treat ballast water for invasive species (see box; 16). The ETV-WQP Center began developing ballastwater treatment verification protocols in early 2000. Since then, the program has convened annual stakeholder group meetings and obtained input from a panel of technical experts. These activities helped define key factors necessary for verification and for the experimental design for testing and to ensure that the verification protocol would be a product of scientific, technical, and regulatory collaboration. Protocol development has been particularly demanding because of the lack of commercial-ready treatment technologies, a consensus on the level of treatment that technologies must meet, and a clear definition of the biological measures necessary to verify treatment performance. Subsequently, protocol and treatment technology developments have proceeded in tandem. National and international technology developers, regulators, and policy makers have both gained input and contributed information. The protocol developers have had to address many issues, including what volumes to treat and for how long, various challenging water-quality conditions, which species and what abundances to use for testing, whether to use surrogate or ambient species, what the biological measurements of viability are, which statistical design and sampling methods to use, and how to set test-facility requirements and operations to ensure consistency among tests and across test facilities. Most of these issues have been sufficiently addressed to conduct a pilot test of the verification protocol, which is planned for the end of 2005 at the Naval Research Laboratory in Key West, Fla. International ETV test facilities are also likely to come on-line as a result of a Letter of Intent signed in May 2004 between ETV and the Institute of Environmental Science and Engineering of Singapore’s Nanyang Technological University.
The verification protocol In the draft protocol and verification testing program, ballast-water treatment technologies are defined as “prefabricated, commercial-ready treatment systems designed to remove, kill or inactivate organisms that are potentially harmful to human health and receiving ecosystems from ballast water prior to discharge.” This definition includes both in-line (treating the ballast water on uplift, discharge, or during circulation) and in-tank (treating ballast water during the time that it resides in the ballast tanks) systems, as well as combinations of the two approaches. The protocol includes design flexibility to accommodate systems that may conduct the treatment through single- or multistep processes and can treat source water with a wide range of physical and water-quality characteristics (fresh, estuarine, or marine). A ballast-water
treatment technology must also comply with all existing maritime laws and regulations for operation, discharge, and personnel and vessel safety. As directed by the stakeholders, the protocol will verify six characteristics of treatment systems. First, biological treatment performance is defined as the removal, inactivation, or killing of organisms. Performance is measured against manufacturer and vendor claims, which will likely reflect removal efficiencies (e.g., a removal ratio) or threshold concentrations stipulated in ballast-water discharge standards. Biological treatment performance is evaluated by measuring both the number and the viability of organisms passing through the treatment. Second, operation and maintenance (O&M) of the treatment system includes labor hours, expertise to operate, and the equipment and consumables required to achieve the performance goals and objectives of the system. Third, reliability is defined as the system’s ability to achieve consistent performance over a period of operation. Fourth, cost factors include only quantifiable components, such as chemical use, labor hours, power consumption, and operational considerations. Fifth, environmental acceptability assesses posttreatment water quality for factors that may adversely affect the environment and determines whether the treated water meets federal and state water-quality standards for various characteristics. This would include evaluation of both residuals and byproducts, if any. Sixth, safety factors include any system-related issues that may pose a threat to operator safety or shipboard operations, such as generation or storage of hazardous materials. Designing scientifically credible tests at reasonable costs for fully operational units was a major challenge during the verification protocol development. In addition, tests needed to accommodate flows often >300 m3/h or volumes of water in ballast tanks that ranged from several hundred to several tens of thousands of cubic meters.
Designing scientifically credible tests at reasonable costs for fully operational units was a major challenge during the verification protocol development. Early in the process, stakeholders recommended that the ETV effort should focus on testing at a land-based facility and that onboard testing protocols should be considered later. This guidance arose for several reasons. First, water quality conditions encountered by treatment systems worldwide vary greatly. Second, technology verification with onboard systems would require transit between several different locations to experience a range of AUGUST 1, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 323A
TA B L E 1
Water-quality challenge conditions for verification testing Water type
Water-quality characteristics
Fresh (salinity
