Superfund: Estimates of Number of Future Sites Vary
Released: 1995-01-04T00:00:00

Letter

Background

EPA does not actively seek out sites for the Superfund program but relies on states or interested parties to report them. Once reported, sites are added to EPA’s inventory for evaluation. As of March 1994, EPA’s inventory had 36,785 nonfederal sites, of which 1,192 had been placed on the National Priorities List.

Evaluation of potentially hazardous sites occurs in several stages. At the completion of each stage, EPA may determine that no federal action is needed or it may proceed to the next stage. First, EPA requires that a site receive a preliminary assessment within a year of its entry into the inventory. The preliminary assessment involves a review of available documents and possible site reconnaissance. If the preliminary assessment indicates a potential problem, the site moves to the next stage of evaluation—the site inspection—which involves collecting and analyzing soil and water samples as appropriate.

If warranted by the results of the site inspection, sites enter the final decision process. This process involves other evaluations, including an extended site inspection if needed, scoring under EPA’s hazard ranking system; and a judgment by EPA officials on the appropriateness of listing the site on the priorities list. An extended site inspection requires more samples and could involve installing wells to monitor groundwater or other nonroutine data collection activities. The hazard ranking system is a method of quantifying the severity of site contamination to determine if a site should be placed on the list. The system assigns a numerical score based on the likelihood that a site has released or has the potential to release contaminants into the environment, the characteristics of the contaminants, and the people or environments affected by the release. A site must score at least 28.5 on the hazard ranking scale in order to be placed on the list. Sites can be dropped from further consideration following the extended site inspection or the scoring process. Sites also can be dropped from further consideration if, in the judgment of EPA regional officials, the sites do not pose risks great enough to warrant a Superfund cleanup.

In addition to the sites following the process described above, the EPA inventory includes a large group of sites that have already been inspected but are awaiting reevaluation because of a change in the evaluation process. The Superfund Amendments and Reauthorization Act of 1986 required EPA to revise its evaluation system to make it more comprehensive and accurate in its assessment of threats to human health and the environment. According to EPA site assessment officials, the revision will change the mix of sites, but not necessarily the number of sites, that will end up on the priorities list. The revision was effective in March 1991. During the transition to the revised system, sites were evaluated through the site inspection stage using the original evaluation system. However, EPA decided to use the new system to make final decisions about placing these sites on the priorities list. In October 1991, EPA began to reevaluate these 6,467 sites, which it referred to as its evaluation backlog. Reevaluation could include collecting additional site information as well as limited sampling. As of the close of fiscal year 1993, EPA had completed this process for about 1,600 of the 6,467 sites.

Reported Sites Have Declined in Number but Not in Severity of Contamination

Fewer sites are being reported to EPA for evaluation, but site inspection results indicate that new sites reaching the site inspection stage are as likely to have contamination requiring a Superfund cleanup as those inspected in the past.

Fewer Reported Sites

The number of sites reported annually has been declining since fiscal year 1985. (See fig. 1.) In fiscal year 1993, 1,159 sites were added to the inventory—29 percent less than the prior year and 68 percent less than in fiscal year 1985.

EPA attributed the decline since 1985 to the fact that many states now have their own Superfund programs. According to EPA site assessment officials, states are reluctant to report new sites, preferring instead to manage the cleanup themselves. EPA Region I site assessment officials suggested that states generally report sites that present challenging enforcement or cleanup problems.

Percentages of Sites Judged Potentially Hazardous Have Not Been Declining

The percentage of sites that EPA believes warrant further consideration after completing the site inspection has been fairly steady for the last 10 years. (See fig. 2.)

From program inception through fiscal year 1993, 43 percent of the 17,556 sites inspected were considered hazardous enough to need further consideration for the priorities list. In fiscal year 1993, 43 percent of the 725 sites inspected were also considered for further action. (App. II provides statistics on the number and percent of nonfederal sites accepted and rejected for further consideration after site inspection.)

EPA officials do not expect to find in the future very large, heavily contaminated sites equivalent to Love Canal, which entered the Superfund program early in its history. However, the officials believe that contamination at newly discovered sites is generally not less severe than at previously reported sites—just less obvious. Earlier site discoveries more often included sites where the hazards were visible, such as barrels of hazardous waste above ground. Sites that are being discovered and reported now, according to EPA officials, are those with less obvious—but equally serious—problems, such as groundwater or drinking water contamination.

Estimates of Future Superfund Workload Vary Widely

Recent estimates of the future size of the Superfund workload have differed. In congressional testimony in February 1994, EPA forecast the smallest increase—1,700 new sites. In a report dated January 1994, CBO predicted 3,300 new sites through 2027, although it said that a wide range of additions was possible. EPA’s Inspector General in a January 1994 report estimated that 3,000 of the 6,467 sites in the agency’s evaluation backlog could be added to the Superfund.

EPA Estimated the Smallest Increase in Superfund Sites

In February 1994 congressional testimony, EPA’s Administrator testified that the Superfund National Priorities List could grow to about 3,000 federal and nonfederal sites, or roughly 1,700 more sites than are currently on the list. According to EPA officials, this estimate was based on an internal agency analysis prepared by the Office of Emergency and Remedial Response. The Office prepared low, medium, and high estimates, and EPA based its testimony on the medium estimate. (See app. III for a detailed breakdown of EPA’s estimates.)

EPA’s estimates treated current and future inventory sites differently. In EPA’s medium estimate, 6.5 percent of the currently reported sites were estimated to become Superfund sites compared with 3.5 percent of the sites that will be reported in the future. The inventory of reported sites was estimated to grow by 20,500 sites by the year 2020, or 54 percent more than at present. The estimate projected that the number of sites added to the inventory each year would decline from 1,500 sites in fiscal years 1994 through 1999 to 500 sites in fiscal years 2010 through 2019. EPA officials said that they based the decline on less state reporting, not on the existence of fewer sites that could be reported.

CBO Predicted Largest Increase in Sites

CBO’s estimate of potential future Superfund additions was developed in two parts. (See app. V.) First, CBO estimated the number of sites that would be reported to EPA’s inventory of potential hazardous waste sites by developing trend lines based on the number of sites reported from 1981 to 1992. Because of the data’s variability, CBO developed a base case, or most probable scenario, and low- and high-case scenarios. In the base case, CBO estimated that 25,394 sites would be added to the inventory by the year 2027. This estimate was about 5,000 sites higher than EPA’s medium estimate. In the low and high cases, CBO estimated that 15,151 and 50,000 sites, respectively, would be added.

Second, to determine the percentage of reported sites that would ultimately be placed on the priorities list, CBO relied on EPA staff’s opinion since, according to CBO’s report, usable site evaluation data were not available. When asked by CBO, EPA staff estimated that between 5 and 10 percent of all future inventory sites would be placed on the priorities list. CBO chose 8 percent for its base-case estimate and applied this rate to current and future inventory sites. For its own medium forecast, EPA estimated that 6.5 percent of the current inventory and 3.5 percent of the sites added to the inventory in the future will be placed on the priorities list. CBO’s base-case estimate, after adjustment to eliminate federal sites, resulted in adding 3,300 more sites to the priorities list. The range of additional sites for the low- and high-case scenarios was between 1,100 and 6,600 sites.

Inspector General Estimated Many Backlogged Sites Could Move to Priorities List

EPA’s Inspector General estimated that 3,136 sites in the evaluation backlog could move to the priorities list. This estimate was made as part of a study of EPA’s processing of these backlogged sites. At the time of the Inspector General’s review, EPA had evaluated only 942 of the 6,467 sites. To estimate the number of potential sites for the priorities list, the Inspector General determined the proportion of sites evaluated in each region that were found to warrant consideration for the priorities list. The Inspector General then applied these proportions to the total number of backlogged sites in each region and added the regional numbers. The Inspector General reduced the total to account for an estimated proportion of sites that drop out in the final decision process.

More recent data suggest that the Inspector General’s estimate may be somewhat high. According to EPA’s site evaluation staff, the Inspector General’s estimate of 3,136 additional sites is high since it assumed that in the future, 52 percent of the sites in the backlog could move beyond the site inspection stage, the rate prevailing when the Office of Inspector General did its study. However, data for fiscal year 1993, available after the Inspector General completed the study, showed that the percentage of the backlogged sites warranting priorities list consideration had dropped to 28 percent.

Superfund’s Eventual Workload May Be Higher Than EPA’s Estimate

The number of future Superfund sites cannot be predicted with certainty. However, data from an EPA study of potential U.S. hazardous waste sites and our own analysis indicate that, assuming no major restructuring of the program, EPA’s estimate of 1,700 additional future Superfund sites is conservative. The CBO estimate, especially the upper bounds of that estimate, may be a better predictor of potential program growth. Given the limited pace of site cleanup by the Superfund program to date, any of the increases in Superfund’s size discussed in this report may be difficult for the program to manage.

Large Number of Sites Could Be Added to the Inventory

A September 1991 EPA analysis estimated that 58,000 sites could be added to the inventory in the future. When EPA made this estimate, it already had 34,618 sites in its inventory, for a combined total of 92,618 sites. This total is almost 6,000 sites more than CBO’s high-case scenario estimate for the number of sites that would be in the inventory by 2032 and 1-1/2 times as high as the upper-bound estimate by EPA for the size of the inventory by 2020. Both CBO and EPA based their estimates on the number of sites expected to be reported under current EPA and state policies, not on the number that could be reported. The 58,000-site estimate, on the other hand, is for sites that could be reported.

The estimated 58,000 sites consisted of sites that were assessed as having a high or moderate hazard potential. The estimate was developed from estimates for 12 individual industries provided by EPA divisions familiar with them. Each industry estimate was based on an analysis of data and judgment by EPA officials. Most of the sites were in one of the following categories: Resource Conservation and Recovery Act industrial process waste facilities, municipal solid waste landfills, off-site oil and gas waste management facilities, and large-quantity hazardous waste generators.

EPA officials familiar with seven of the major categories, accounting for 93 percent of the 58,000 sites, told us that the results are still valid. The officials said that the study’s figures represent the best estimates of the potential number of sites that could be added to the inventory in the future, although one official believed that the number of treatment, storage, and disposal facilities was overstated by 2,000 sites. The officials said that in no case did an actual inventory of potential sites exist.

A Larger Percentage of Currently Reported Sites Could Be Placed on the Priorities List

Our analysis indicates that between 10 and 11 percent of the currently reported nonfederal sites could become Superfund sites. This percentage is greater than the 6.5 percent indicated in EPA’s medium estimate and is closer to CBO’s 10 percent high-case estimate. As of September 30, 1993, EPA had completed evaluation for 26,026 of the 35,782 nonfederal sites in its inventory. The remaining 9,756 sites were in various stages of evaluation: 930 sites were awaiting final listing decisions, 4,892 backlog sites were awaiting final evaluation, 2,373 sites were awaiting site inspection, and 1,561 sites were awaiting preliminary assessment. If 1993 screening rates for these categories, as described in appendix IV, were to continue into the future, 2,497 to 2,799 of the 9,756 sites could become Superfund sites. Adding this range to the 1,177 sites already on the priorities list would result in a total estimate of 3,674 to 3,976 Superfund sites, or 10 to 11 percent, of the 35,782 inventoried sites. The Acting Deputy Director for EPA’s Hazardous Site Evaluation Division believed that the 1993 evaluation rates were a reasonable basis for forecasting future Superfund additions from the current inventory.

We also recognize, however, that certain factors make estimates of the number of future Superfund sites subject to substantial uncertainties. First, the rate at which sites move through the assessment process onto the priorities list may change in the future, making projections based on past rates inaccurate. Also, proposed legislation to reauthorize Superfund, which has been considered by the Congress, contains provisions to encourage parties responsible for hazardous waste sites to clean them up outside of the regular Superfund program and to authorize states, in cooperation with EPA, to assume certain cleanup responsibilities. These changes could reduce the number of sites that EPA would have to manage in the Superfund program.

Future Superfund Workload May Be Difficult to Manage

Any of the estimates discussed in this report suggest that EPA will be challenged by its future Superfund workload. In the 14-year history of the program through July 1994, Superfund has completed the construction of remedies (such as the installation of groundwater pumps and filters) at 234 of the 1,300 federal and nonfederal Superfund sites. Two years ago, EPA estimated that 650 sites would reach the construction-completed stage by the year 2000. At these completion rates, it could take many decades for Superfund to clean up its current inventory and future additions to the inventory. Although EPA has recently developed new procedures to speed up the cleanup process, it is too early to tell what impact they will have on the overall pace of the program.

Agency Comments

As agreed with your offices, we did not obtain written agency comments on a draft of this report. However, we discussed the contents of this report with program officials from EPA’s Office of Emergency and Remedial Response (Superfund). EPA’s Acting Site Assessment Branch Chief said that the facts presented in this report were balanced, fair, and accurate. He also said that program changes under consideration by the Congress and EPA, such as proposals to increase the states’ cleanup role, could significantly reduce the number of sites to be added to the Superfund program.

Scope and Methodology

We conducted our work at EPA headquarters in Washington, D.C., and at its regional offices in Boston (Region I), Chicago (Region V), and Denver (Region VIII). We selected these regions because they presented a cross-section of Superfund activity and were geographically diverse. We obtained and reviewed recent reports and studies on the future size of the Superfund workload. We obtained and analyzed site inventory statistics on preliminary assessment and site inspection processing since program inception through the first quarter of fiscal year 1994. We interviewed EPA headquarters officials and program management officials in three EPA regional offices, as well as environmental protection officials in two states, about Superfund site discovery and evaluation. We reviewed the relevance and appropriateness of studies conducted by CBO, EPA, and EPA’s Office of Inspector General and interviewed EPA program officials on the status of major site categories that could affect the Superfund site inventory. We performed our work in accordance with generally accepted government auditing standards between August 1993 and July 1994.

As arranged with your offices, unless you publicly announce its contents earlier, we will make no further distribution of this report until 30 days after the date of this letter. At that time, we will send copies of the report to other appropriate congressional committees; the Administrator, EPA; the Director, Office of Management and Budget; and other interested parties. We will also make copies available to others upon request. Should you need further information, please contact me at (202) 512-6112 if you or your staff have any questions. Major contributors to this report are listed in appendix VI.

Nonfederal Sites Accepted and Rejected for Further Consideration After Preliminary Assessment

Nonfederal Sites Accepted and Rejected for Further Consideration After Site Inspection

EPA’s Estimate of Future National Priorities List Size Through 2020

Nonfederal Sites That Could Be Added to the National Priorities List From the Inventory If Fiscal Year 1993 Evaluation Rates Continue

Number of sites in inventory (col A)

Percent of sites that could be listed (col B)

Range of sites that could col B)

Sites evaluated—not placed on priorities list Sites evaluated—placed on priorities list Sites still to be evaluated Sites awaiting final listing decision Backlogged sites awaiting final evaluation Subtotal of sites still to be evaluated Overall percentage of sites that could be placed on the priorities list(Table notes on next page)

CBO’s Estimate of the Future Number of Nonfederal Sites on the National Priorities List

Number of federal and nonfederal inventory sitesPlacement rate (percent)

Estimated priority list size before rounding Estimated priority list size (rounded)

Major Contributors to This Report

Resources, Community, and Economic Development Division, Washington, D.C.

Chicago/Detroit Regional Office

Boston Regional Office

Bruce Skud, Senior Evaluator The first copy of each GAO report and testimony is free. Additional copies are $2 each. Orders should be sent to the following address, accompanied by a check or money order made out to the Superintendent of Documents, when necessary. Orders for 100 or more copies to be mailed to a single address are discounted 25 percent.

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