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Density Matters: Review of Approaches to Setting Organism-Based Ballast Water Discharge Standards
Citation:
LEE, H., D. REUSSER, M. R. FRAZIER, AND G. RUIZ. Density Matters: Review of Approaches to Setting Organism-Based Ballast Water Discharge Standards. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/031 (NTIS PB2012-110754), 2010.
Impact/Purpose:
To assist the Office of Water in developing national ballast water discharge standards under NPDES permitting, approaches to generating organism-based standards for ballast water were evaluated. Six existing approaches were identified and each either had conceptual limitations or the required input data were not readily available. Of these, population viability analysis (PVA) models showed the most promise, though the lack of long-term population studies hampers its application. The "zero detectable organism" standard was considered ambiguous until a sampling protocol is developed and was not recommended for use at a national level. A new approach, the per capita invasion probability ("PCIP") approach addresses many of the limitations of the previous methodologies. The PCIP approach allows risk managers to generate quantitative discharge standards using historical invasion rates, ballast water discharge volumes, and ballast water organism concentrations. The statistical power of sampling ballast water for both validation of ballast water treatment systems and ship-board compliance monitoring was also evaluated. With existing methodologies, it will be extremely difficult to obtain a sufficient sample volume of ballast water for compliance monitoring, though it should be possible to obtain sufficient samples during land-base validation of ballast water treatment systems.
Description:
As part of their effort to develop national ballast water discharge standards under NPDES permitting, the Office of Water requested that WED scientists identify and review existing approaches to generating organism-based discharge standards for ballast water. Six potential approaches were identified and the utility and uncertainties of each approach was evaluated. During the process of reviewing the existing approaches, the WED scientists, in conjunction with scientists at the USGS and Smithsonian Institution, developed a new approach (per capita invasion probability or "PCIP") that addresses many of the limitations of the previous methodologies. THE PCIP approach allows risk managers to generate quantitative discharge standards using historical invasion rates, ballast water discharge volumes, and ballast water organism concentrations. The statistical power of sampling ballast water for both the validation of ballast water treatment systems and ship-board compliance monitoring with the existing methods, though it should be possible to obtain sufficient samples during treatment validation. The report will go to a National Academy of Sciences expert panel that will use it in their evaluation of approaches to developing ballast water discharge standards for the Office of Water.