Risk-Based Corrective Action: Lessons for Brownfields from the Illinois Rulemaking

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1 Risk-Based Corrective Action: Lessons for Brownfields from the Illinois Rulemaking By Raymond T. Reott & E. Lynn Grayson Air & Waste Management Association, Annual Meeting, San Diego, California, June 1998 No. 98-RA98.08 April 30, 1998 Abstract As attention focuses on the redevelopment of brownfield properties, increasing numbers of stakeholders realize that one of the major stumbling blocks to the use of brownfields properties is the uncertainty over future cleanup costs. In Illinois, the Pollution Control Board recently completed a three-year rulemaking which has provided a new, risk-based system for determining corrective action objectives. 35 Ill. Adm. Code 742 (1997). Armed with this system, Illinois property owners and developers may assess potential cleanup exposure with less site investigation than in the past. Because the system may be implemented quickly and predictably, it functions well in a transactional context where speed is critical. This presentation highlights the features of the new Illinois system and identifies potential issues that other states might wish to consider when they evaluate their own programs. Many states are in the process of implementing risk-based corrective action for some or all of their site remediation programs. The lessons learned in Illinois may help these states implement these programs more efficiently and with fewer developmental costs. I. INTRODUCTION In 1997, the Illinois Pollution Control Board changed how Illinois assessed the cleanup of contaminated soil and groundwater. The Tiered Approach to Corrective Action Objectives ("TACO") regulations establish a new system for determining "How Clean is Clean." 35 Ill. Adm. Code 742 (1997). The new system is binding on both the regulators and the regulated community, thereby ending the prior confusion created by ever changing guidance. The new regulations also eliminate uncertainty over how cleanups should be conducted in the future. By taking this step, Illinois has emerged as one of the national leaders in this field. Illinois has adopted a risk-based system for determining cleanup objectives. While virtually every state allows consideration of risk in some fashion as part of the cleanup process, in m ost jurisdictions, the manner by which risk is considered is still evolving. No state has a system of regulations as com prehensive as the new Illinois TACO rules. Accordingly, for those states whose programs are still in development, Illinois provides valuable lessons for how to approach risk-based corrective action. These lessons also provide important guidance about issues related to the redevelopment of brownfield properties. Ultimately, the historic reluctance to invest in brownfield properties can be traced directly to uncertainty over cleanup costs. Illinois is now poised to make real the rhetoric about the redevelopment of brownfield properties that is often repeated by the regulators of many states and communities. In Illinois, unlike virtually every other state in the United States, a party can easily predict the likely cleanup expenditures at a wide range of sites based on the new TACO regulations. Predictability should enable the financial community to assess whether the redevelopment of a particular brownfield site makes sense. W hen coupled with the Illinois Voluntary Cleanup Program, 35 Ill. Adm. Code 740 (1997), a brownfield developer may assess a site and get a release from cleanup liability. In addition, because the Illinois regulations provide for a realistic appraisal of cleanup objectives under a risk-based system, cleanups are conducted to the extent necessary but no further. Thus, potentially marginal brownfields properties can be redeveloped because actual cleanup expenditures should be less under the Illinois system.

2 States which are evaluating their own program s should consider the lessons learned from the Illinois rulemaking. The Illinois Pollution Control Board conducted hearings over a three-year span. Over 100 witnesses testified and presented documentary evidence about how best to incorporate risk-based concepts into the Illinois cleanup system. The Pollution Control Board weighed these various comments and in several respects materially altered the original proposal presented by the Illinois EPA. Other states are in a position to follow this path more efficiently and to focus their attention on certain key issues that were the center of attention in the Illinois rulemaking. To place these issues in context, this paper will first provide an overview of the new Illinois system and then a specific identification of issues that other states may want to consider in light of their own particular environmental policies and objectives. II. Overview of the Illinois System The Illinois TACO regulations are risk-based. That is, they do not presume that any cleanup is necessary even of the most grossly contaminated site unless it can be shown that there is a meaningful risk to human health. In the Matter of Tiered Approach to Corrective Action Objectives, No. R97-12(A) (Ill. Poll. Cntrl. Bd. June 5, 1997) (Opinion at p.3) ("June 1997 Bd. Opinion"). Contaminated soil or groundwater does not pose a risk unless a) there is a source of contamination above levels of concern, b) there is a pathway by which individuals are exposed to that contamination, and c) there is an exposed population which would be affected by the contamination. The Illinois TACO system provides several different options for analyzing any given site so that property owners or developers may weigh these options against the various cost and time components. These options are explored through computer models, generally the American Society for Testing and Materials ("ASTM") RBCA model (ASTM E ) and the United States Environmental Protection Agency's Soil Screening Guidance or SSL Model. These models predict the "safe" level of contamination at the site under various scenarios. The property owner can derive cleanup standards from five potential sources: a Tier 1 generic set of standards applicable to any site, Tier 2 standards that requires more site specific analysis, a Tier 3 standard which is based on a full blown risk assessment, the area background for the contaminant of concern, or, for some contaminants, a state-wide background number. Two of these methodologies, the Tier 1 generic standards or the state-wide background level, can be consulted in lookup table form so that comparison to the standards is immediate. 35 Ill. Adm. Code 742, App. B (Tier 1); 742, App. A, Table G (statewide background for inorganics). As you might expect, the cleanup levels provided by generic lookup tables are conservative. Nonetheless, there is at least certainty as to these conservative standards which enables property owners to assess their options quickly without regulatory involvem ent. For sites where more complex analysis is warranted, the TACO regulations allow you to use a wider range of computer models in Tier 2 and to add site specific geologic data. For the vast majority of sites, the site specific geologic data shows that contaminants are less m obile than predicted by the various default values used for the Tier 1 equations. Thus, by including some minimal geotechnical analysis in your site investigation, you can use TACO Tier 2 analysis to quickly generate alternative cleanup numbers that are much less conservative. Because the models are computer-based, once the data is gathered, the Tier 2 scenarios can be run in a matter of minutes with appropriate software that is commercially available. The site owner also can proceed to a more complete Tier 3 risk analysis. In Tier 3, upon an appropriate showing, Illinois allows you to change the level of acceptable risk from a 1 x 10-6 cancer risk up to a 1 x 10-4 cancer risk. 35 Ill. Adm. Code (i). By itself, this risk change might enable many owners to dem onstrate that cleanup is unnecessary. In addition, the Tier 3 analysis authorizes a more complete consideration of the standard exposure factors in the equations to accommodate actual site usage. As an alternative to evaluating the site through the tiering process, TACO also allows the site owner to expand the analysis of the site by excluding pathways of exposure from consideration. The Illinois regulations focus on exposure through inhalation, ingestion, and the ingestion of groundwater pathways, including the risk of migration from soil to groundwater. 35 Ill. Adm. Code For a given site, however, there may be a means by which the site owner can exclude a pathway from consideration. Depending upon your chemical, excluding the pathway may allow a thousandfold increase in the appropriate cleanup standard. -2-

3 Typical pathway exclusion mechanisms include layers of clean soil above subsurface soil contamination, which may be sufficient to allow the exclusion of either the ingestion or inhalation pathways depending upon the depth of clean soil. See, e.g., 35 Ill. Adm. Code ; In addition, the site owner may be able to exclude the risk of migration to groundwater pathway or groundwater ingestion pathways because the site is located in an urban area which does not use groundwater for drinking water purposes. 35 Ill. Adm. Code (d). Unlike other states, Illinois is committed to a program whereby it will not require the cleanup of groundwater simply to make the groundwater available as a theoretical resource. In urban areas like Chicago, where there is a city ordinance prohibiting the use of groundwater for drinking water purposes, TACO allows owners to ignore the risk to groundwater pathway. For most organic chemicals, the risk to groundwater pathway produces the most stringent cleanup level. Excluding that pathway by itself allows for less stringent cleanup levels. If you exclude a pathway under the Illinois regulations there must be an enforceable mechanism by which the site owner and successor owners can be required to maintain the reason for excluding the pathway. 35 Ill. Adm. Code (a)(6); If the ingestion pathway is excluded, for example, by an engineered barrier such as a parking lot surface, clean soil or structure, than the owner and successor owners must agree to maintain that barrier. 35 Ill. Adm. Code (a)(4). If the pathway is excluded by virtue of an institutional control like the Chicago groundwater ordinance, then that restriction must be enforceable. 35 Ill. Adm. Code Finally, the site owner can approach the problem by changing the exposed population. If the population is different, the formulas allow for the calculation of a different risk to those who are being exposed to the contamination at the site. Principally, this involves the difference between a residential and industrial scenario for the property. Using the industrial scenario allows for much greater ingestion and inhalation cleanup standards because typically the workplace population is not exposed for as long a period of time as the formula assumes is applicable for a residential population. Here again, in order to change the population scenario, the site owner must agree to a deed restriction so that the Illinois EPA can enforce the future industrial use the property. 35 Ill. Adm. Code (a)(1). III. Issues from the Illinois Rulemaking As with any complex process, prom ulgation of the Illinois TACO standards was not free of controversy. Other states that look at the Illinois regulations should focus on the critical issues arising from the Illinois rulemaking so that they can assess whether to modify the process employed by Illinois. Each state has its own public policies that may affect the degree to which it is willing to adopt the Illinois system. A. Tier 1 - Use of USEPA Model The Illinois Tier 1 tables are derived almost entirely by using the formulas set forth in the USEPA's SSL model. June 1997 Bd. Opinion at p. 17. Although Illinois allows use of the RBCA model promulgated by the American Society for Testing and Materials ("ASTM") at Tier 2 and Tier 3, Illinois was unwilling to develop an alternative Tier 1 table based upon the ASTM model. This choice was significant because the ASTM model generally provides for more lenient cleanup standards than you obtain under the SSL m odel. Other than in Tier 1, you m ay use the two models interchangeably for all purposes in Illinois. A state adopting a risk-based program should consider whether to use the USEPA's SSL model, ASTM's RBCA model, or some combination of those or other models for any Tier 1 lookup table. The principal reason favoring the ASTM RBCA model even at Tier 1 is that it is designed specifically for this purpose. In its own guidance related to the SSL model, USEPA advises that it is not designed to set cleanup standards and should not be used for that purpose. See USEPA Soil Screening Guidance: User's Guide (April 1996). Rather, USEPA designed the SSL model as a screening device to assess whether conditions at the site merited further inquiry. Using the SSL model to derive cleanup standards is unduly conservative. B. Adjustment of Risk Criteria for Industrial Properties During the rulemaking, many commentators and even USEPA argued that the Illinois industrial criteria in both Tier 1 and Tier 2 should be based upon a less stringent risk standard. Currently, the SSL equations -3-

4 in Tier 1 and both equations in Tier 2 employ a 1 x 10-6 cancer risk as the allowable maximum target risk. Most states that have considered this issue have set the risk levels for industrial properties at somewhere between 1 x 10-4 to 1 x In Illinois, the Pollution Control Board only allowed shifting the target risk to those levels for industrial or residential properties if the facility undergoes a full risk assessment in Tier Ill. Adm. Code (i). The selection of the appropriate target risk is a pure policy issue. Many states already will have considered this issue as part of rulemakings in other environmental settings. At least in Tier 2, where the appropriate cleanup objectives are being set by reference to site specific data, it would seem appropriate to allow at least industrial facilities to adjust to the more common industrial risk levels, especially if that adjustment would be allowed in Tier 3 in any event upon an appropriate showing. C. Background Levels There are two types of background criteria that a facility can m eet in the Illinois system. First, for certain metals, there are state-wide background standards. 35 Ill. Adm. Code 742, App. A, Table G. If the facility meets the state-wide background numbers, then the level of m etals present in the soil are acceptable even if higher than the Tier 1 numbers. Obviously, each state will have its own geologic history and its own typical background levels. Illinois set those background levels to accommodate the impact of prior human activity, however, by adjusting them (generally upward) in urban areas. Thus, Illinois has a system of background levels where the "background" is higher in urban areas than in the rem ainder of the State. The adjustment is not large but it does sim plify m atters greatly in those areas where, for exam ple, am bient lead levels from autom obile exhaust fumes are sufficient to exceed naturally deposited levels elsewhere in the State. Other states with urban populations m ay wish to do the sam e, particularly if the state is trying to encourage brownfield development, which often occurs in or near urban areas. A system which adjusts the state-wide background for values typically found in urban areas would prom ote brownfield redevelopment. Illinois had data from sampling around the State which it used as a source of the state-wide background numbers. Some commentators argued that Illinois chose a data point that was too low, i.e., given the range of data available to the State, that the State should have chosen something like the 80th percentile value or a sim ilar figure of the range of background values. During the rulemaking, Illinois EPA actually adjusted the background numbers downward from those originally proposed to reach a mid-point in the published range rather than a number that was at the higher end of the range of background values. In any data set, the actual data will spread around some mid-point values with a distribution driven by the nature of the variable. By choosing a mid-point in its background data set, Illinois necessarily put half of the actual background numbers in the State out of compliance. This seems unduly restrictive. While you can argue that you should not accept the highest background anywhere in the jurisdiction as the true background for the entire state, a statistically better approach would allow more sites to qualify for a cleanup based on state-wide background levels than under the current Illinois system. Particularly for arsenic, for example, where the naturally occurring level in most of Illinois exceeds the state-wide background number selected by the Board, many facilities are now negotiating with the Illinois EPA over exceedences that are more imagined than real. The other type of background in the Illinois system is the area background around the site. A facility can demonstrate a compliance with cleanup objectives by meeting the background concentration for the chemical of concern in the area geographically surrounding the site. 35 Ill. Adm. Code (b)(2). The Board adopted a definition, however, which defines area background as the level found outside of the site in question unaffected by activity at the site itself. 35 Ill. Adm. Code Thus, your area background may be significantly affected by human activity as long as that human activity did not occur on the site you are evaluating. This definition of area background leaves room for a significant human contribution to raise ambient background levels and to set cleanup standards higher than perhaps intended. -4-

5 Once again, as a policy matter, other states may wish to reconsider this definition to adopt a definition closer to the more commonly used concepts for background levels. Once the area background level is set by reference to human activity at the adjacent site, you have less assurance that the area background level is fully protective. D. Mixtures of Similar Acting Compounds In December 1997, in a revision to the original TACO rules, the Board modified the rules in a significant way for sites that have m ore than one chemical present in the soil. If you have a site with multiple chemicals, and those chemicals are known to affect the same body organs or systems, the process for setting cleanup standards is far more com plicated. Your ability to use even the generic lookup tables in Tier 1 is reduced. 35 Ill. Adm. Code (b)(3). For non-carcinogens, in all tiers, you may have to consider possible cumulative effects of multiple chemicals on a particular body organ. For carcinogens, that calculation is required for groundwater in Tier 2 and for soil and groundwater in Tier Ill. Adm. Code (c); (h). See also In the Matter of Tiered Approach to Corrective Action Objectives, No (B) (Ill. Pollution Control Bd. Dec. 4, 1997) (Opinion at p. 3) ("Dec Bd. Opinion") The Illinois EPA argued that this adjustment was unnecessary because of the conservatism in the underlying TACO system. Thus, even if you had ten chemicals present at the site at a cancer risk level of 1 x 10-6, their cumulative effects would only reduce the cancer risk level to 1 x Because that number is itself one which is commonly accepted and endorsed by statute in Illinois for non-residential properties, the IEPA was willing to accept the small potential of cumulative effects exceeding the initial risk levels in the tables. The Board rejected the IEPA's position, however, and insisted upon adding this additional level of complexity to protect human health. Dec Bd. Opinion at pp Other states may feel that the conservative exposure assum ptions used by the models make the actual risk level for a site with multiple chemicals still well within the bounds that would be accepted as a policy matter. E. Application of the Residential Criteria to Non-Residential Property The models used in TACO both are based upon certain exposure criteria for both a residential population and then for an industrial/commercial population depending upon the anticipated site usage. If you want to use the industrial criteria for your site, then you must agree to a deed restriction which will enforce the industrial use in the future. Unfortunately, as a result of several different sim ultaneous attem pts to edit the residential definition, Illinois adopted a definition of residential property which includes m any types of property which are not subject to the same typical exposure assumptions. In Illinois, residential property is now defined to include virtually any property where children are exposed to an unpaved ground surface in the course of normal activities. 35 Ill. Adm. Code While at first blush this seems prudent, in actuality it is far more conservative than necessary. In a playground context, for example, the likely exposure of children using the playground, even on a regular basis, is far less than the underlying exposure assumptions used in the residential scenario. If children in that environment are not exposed as significantly as those in the residential environment, then it is not necessary to use the residential criteria for that site. Illinois could have adopted an interim category for mixed use facilities. By adjusting the exposure assumption slightly in the formulas, it would be relatively easy to develop another category for these properties where children are exposed on an intermittent basis. There is no support in the models, however, for applying residential criteria in the expanded setting that Illinois chose to do. Other states may wish to reconsider this choice because it has the effect of bringing many commercial properties and many public open areas into a residential category that may not be appropriate in light of the policy concerns of a particular state. IV. Conclusion Illinois has the most precise and forward-thinking regulations used in any state at this time for cleanup objectives. There are many advantages to the Illinois system to help people develop brownfields projects. In particular, Illinois offers predictable results to enable investors to make sensible investment decisions. The Illinois system is flexible so that there are many different ways to approach a particular problem. The Illinois system also is realistic so that cleanups are undertaken at sites where they are necessary but -5-

6 generally not at other sites. Thus, m oney is not wasted on trying to clean up every site so that it is suitable for every conceivable use. Particularly by using industrial criteria at m any brownfields, the cleanup levels will be adjusted sufficiently to facilitate the redevelopm ent of the facility. Finally, the Illinois system is cost-effective. If you need to move quickly, you have published Tier 1 values that enable you to spend your money on remediation rather than extensive modeling and investigation. If the problem is more significant and you have time, you may choose to spend money on the investigatory or pathway exclusion options to develop a more precise understanding of the risks of the site. Either way, the end result is one that is cost-effective under m ost circumstances. Other states would do well to study the Illinois system and to consult with those who are familiar with its application before adopting their own systems. There are many valuable lessons to be learned from the Illinois experience. Illinois already has identified several issues that other states need to consider in light of their own political, social, and economic policies. -6-