Table of Contents
Fish advisories have become an issue of concern for both anglers and those government agencies charged with safeguarding public health. In response to this growing concern, the Alliance for Environmental Technology (AET) conducted an analysis of U.S. Environmental Protection Agency (EPA) and state environmental and health authority data for fish consumption advisories. The analysis reveals three important findings regarding fish consumption advisories for dioxin.
Most important is the finding that the number of waterbodies under a dioxin advisory downstream of U.S. bleached chemical pulp mills is a very small and diminishing percentage of the overall total of affected waterbodies in the country.The Report's Findings:
Process changes in pulp manufacture, including the increased use of chlorine dioxide as a bleaching agent, have markedly reduced dioxin discharges and tissue levels in fish living in mill receiving waters. In fact, dioxin levels in mill waste water are now non-measurable at 90 percent of U.S. pulp mills. State officials lift advisories once dioxin fish tissue levels drop and remain below state action levels.
In addition, the number of waterbodies downstream of pulp mills under a dioxin advisory is projected to continue downward. In an EPA study of current dioxin advisories, all such advisories would be lifted following implementation of Agency-proposed measures, which are the same, in this respect, as bleaching with chlorine dioxide.
State environmental and health departments issue fish consumption advisories or bans to protect sport and subsistence anglers, and the general public, from the risk of consuming locally caught, contaminated fish.
Fish consumption advisories are based on the contamination levels of specific target chemicals, which include, among others, mercury, PCBs (polychlorinated biphenyls), and various pesticides. As such, these advisories are one indicator of the environmental status of a particular aquatic eco-system, for example a lake, bay, or river. Removing or partially rescinding a fish consumption advisory or ban generally signals positive change in the aquatic eco-system under study.
Since 1989, when EPA completed the first national survey of state fish/shellfish advisory programs, the number of states reporting advisories has increased, as has the total number of advisories. In 1995, forty-seven states, the District of Columbia, and the Territory of American Somoa, reported a total of 1,740 waterbodies under some type of advisory restricting fish/shellfish consumption, representing more than a 14 percent increase over 1994 data .
The 1995 EPA NLFWCA shows the total number of active advisories on which each target contaminant appears. As shown in Table 1, mercury is listed on 1,308 advisories, PCBs on 438, and all pesticides on 195. b Dioxin appears on 55 advisories.
In 1995, only 18 waterbodies in 13 states have a dioxin advisory downstream of bleached chemical pulp mills. These 18 affected waterbodies represent about one percent of the total 1,740 U.S. waterbodies under some type of an advisory. Figure 2 shows these 13 states and, for each, indicates the number of waterbodies downstream of bleached chemical pulp mills that are under a dioxin advisory.
The EPA National Dioxin Study conducted in the mid-1980s provided one of the first indications that bleached kraft pulp mills were a possible source of dioxin. Following this study, and as a result of other work such as the "104 Mill Study" conducted jointly by EPA and industry in 1988, scientists identified dioxin as an inadvertent by-product of the prevailing pulp bleaching process .
Figure 3 shows the yearly number of waterbodies downstream of pulp mills placed under a dioxin advisory. The single largest yearly increase -- 17 waterbodies in 1990 -- was due to increased federal and state regulatory attention following the results of the national dioxin studies. As a result of process changes at bleached kraft mills, the number of new waterbodies placed under advisory dropped sharply in subsequent years. In fact, no new waterbodies were placed under a dioxin advisory in 1992, 1993, or 1995. These process changes and the resulting dioxin advisory liftings, are discussed in the following sections.
These 18 dioxin advisories downstream of bleached chemical pulp mills are a small and diminishing percentage of the overall total of affected waterbodies in the country. Moreover, it is noteworthy that there are no dioxin advisories on waterbodies downstream of more than 75 percent of U.S. bleached chemical pulp mills, according to EPA's 1995 NLFWCA, and data from state environmental and health authorities.
In response to the discovery of dioxin as an inadvertant by-product of the prevailing bleaching process at kraft mills, the pulp and paper industry introduced a number of technical changes and process modifications. These modifications included, among others, precursor-free defoamers, improved brown stock washing, and low multiple bleaching.
Key to the industry's dioxin reduction strategy has been the increased substitution of chlorine dioxide for chlorine gas as a bleaching agent . As a result of the increased use of chlorine dioxide, and the other technical and process changes adopted by the industry, dioxin discharges have dropped considerably and, in most cases, have been virtually eliminated . More than 90 percent of U.S. mills are at or below a dioxin final effluent concentration of 10 parts per quadrillion, the nominal "minimum level" that can be measured, according to the National Council for Air and Stream Improvement (NCASI) .
Since 1990, states have lifted fish consumption advisories for dioxin, demonstrating that current and declining levels of dioxin in receiving waters downstream of bleached chemical pulp mills are an insignificant risk to the aquatic eco-system. State environmental and health authority data show that since 1990, 13 states have lifted dioxin advisories on 17 waterbodies downstream of pulp mills.
As previously discussed, fish tissue levels of dioxin downstream of bleached chemical pulp mills have dropped significantly following process changes made since dioxin was first linked to pulp bleaching. In general, states lift advisories when the dioxin levels in tissue samples taken from fish species in the waterbodies of concern decline below the state's action level, and remain below this level during subsequent samplings.
Recently, the Maine Department of Environmental Protection issued the 1994 findings of its Dioxin Monitoring Program, which indicate that "concentrations of dioxin in fish tissue have declined in recent years." .
Demonstrating the industry's continued commitment to environmental protection, in April of this year, Maine's seven pulp mills, together with the Governor, announced a mutual plan to eliminate dioxin discharges from mills along the Kennebec, Androscoggin, and Penobscot Rivers within four years .
Furthermore, EPA has stated that process changes to reduce the formation and discharge of dioxin in mill effluent will provide for the potential lifting of fish advisories at sites downstream of pulp mills . In an analysis of the remaining dioxin advisories, using the Dioxin Reassessment Evaluation model approach and the EPA's proposed Best Available Technology (BAT) options, the agency found that all remaining dioxin advisories downstream of pulp mills could be lifted once the proposed guidelines are implemented . Figure 4, shown below, consistent with EPA's projections, shows the declining number of waterbodies under a dioxin advisory.
More recently, on July 15, 1996, EPA published a notice in the Federal Register announcing its preliminary conclusion regarding the technology basis for BAT options as part of its pulp and paper Cluster Rule. The Cluster Rule, once promulgated, will set effluent limitations and pretreatment guidelines for all pulp, paper, and paperboard mills. Both of the options proposed by EPA include the complete (100 percent) substitution of chlorine dioxide for chlorine as the key process technology .
b. Because some fish advisories include more than one contaminant, some waterbodies may appear more than once in the 1995 EPA NLFWCA listings. The 1995 NLFWCA shows the breakdown of these listings by the number of affected waterbodies.