9.2.1. Trends in Toxics Release Inventory (TRI) Data

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As shown in Table 9-1, reported TRI releases have decreased 44.1% since 1988. Decreases have been reported in most industry SIC codes. Because all figures have been rounded to one decimal place, percentage changes may not correspond exactly with release data and total releases might differ slightly from the sums of the columns. Not included in these data are delisted chemicals, chemicals added in 1990, 1991, or 1994, and aluminum oxide, ammonia, ammonium sulfate (solution) and sulfuric acid.

Although the data in Table 9-1 suggest significant reductions in toxic releases, there are several reasons why they may not be equal to actual decreases in releases. EPA points out that TRI increases and decreases can be "real changes" or "paper changes." 1994 Toxics Release Inventory, p. 201. The latter result from errors, changes in facilities' estimation or calculation techniques, changes in reporting guidance and facilities' interpretation of that guidance, and facilities' use of exemptions. Companies generally determine their TRI release amounts through estimation rather than monitoring. EPA guidance has not been issued for all aspects of TRI reporting, and companies can sometimes lower reported releases by using different estimation techniques.

EPA says that estimation errors are more likely for releases such as fugitive air emissions and complex wastewater for which little monitoring data are available. However, EPA audits have found companies' estimation techniques to be reasonably accurate. An audit of 1987 data at selected facilities led to the conclusion that releases had been under-reported by 2%, but a 1988 audit found that companies reported about the same amount as the auditor's own estimate. Ibid, pp. C2-C3.

Another potential problem is that most chemicals have not been subject to TRI requirements. A 1994 GAO study stated that over 70,000 chemicals are used commercially in the United States, of which only 320 had been included in the TRI. "Consequently," the study added, "the companies may maintain or even increase their usage of toxic chemicals while concurrently reducing the chemicals that are reported to EPA." GAO (September 1994), p. 14. The original list focused on the most important toxics, and, as noted above, EPA included another 286 chemicals in TRI requirements effective 1995. However, some highly toxic chemicals have not been included because they are generated in amounts that are too small to meet criteria for inclusion.

In addition, a number of small sources in SIC codes 20-39 and all sources outside that code range are currently excluded from the TRI. It is not known what percentage of releases are currently exempt from reporting. As noted above, however, EPA intends to include other SIC codes in the system.

Releases are not weighted according to toxicity or the dangers posed by various methods of disposing of various types of chemicals and do not indicate exposure or potential effects on human health and the environment. Moreover, the TRI does not include information on the quantity of toxic chemicals in products leaving the facility. Such products themselves can eventually be released into the environment.

Although a reduction in releases is generally desirable, another important question is how the reduction is achieved. Methods include controlled disposal, recycling, conversion to energy, and source reduction. The 1990 Pollution Prevention Act set source reduction as the preferred method of reducing releases, but the transfer data in table 9-2 show no clear trend toward this method. Since recycling and conversion to energy were not reported as transfers until 1991 (as required under the 1990 Pollution Prevention Act), 1988 total transfers are difficult to compare with total transfers in the period 1992-1994. Excluding these two types of transfers, reported transfers have decreased significantly since 1988 but show no clear trend since 1992. Total releases and transfers decreased significantly from 1992 to 1993 but increased slightly from 1993 to 1994. The decrease in releases from 1993 to 1994 coincided with an increase in transfers.

The assessment of source reduction achievements is complicated by the lack of TRI data on quantities of waste decreased by source reduction measures. Only the practices used to reduce waste and not their results are included in the TRI. Changes in waste generation reported in the TRI could be due to factors other than source reduction, including estimation errors or changes in production levels of specific products. Lack of information on source reduction and on chemicals in facilities' products is one of the main issues surrounding the phase III expansion of the TRI noted above.

As discussed in Section 10, the trend of decreases in releases and transfers is more pronounced under the voluntary 33/50 program. Total releases and transfers under this voluntary program have decreased every year from 1988 to 1994, with a total reduction of 51% during that period.

9.2.1. Trends in Toxics Release Inventory (TRI) Data

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