3 Regulatory Framework
This section presents federal and state regulations and statutes that are applicable during the assessment and cleanup of petroleum releases to the environment. It describes how regulations and statutes have been applied for risk-based closure of petroleum-contaminated sites. It also presents some of the regulatory challenges that both regulators and practitioners face regarding TPH and provides options and guidance to navigate those challenges. Finally, it discusses some of the interesting regulatory tools that one may use or encounter during the cleanup and risk assessment process.
Both federal and state statutes require either the cleanup or the management of petroleum released to the environment. However, the approaches for the remediation and risk management of TPH contamination are not consistent across the United States and may not consistently address both short- and long-term environmental concerns associated with petroleum contaminant mass. Regulatory programs may address TPH in the jurisdiction of hazardous waste programs, nonhazardous waste programs, or specific programs or agencies that regulate the oil and gas industry exclusively. TPH cleanup programs are implemented mainly through threshold concentration metrics, such as screening, cleanup, or target levels (e.g., 100 ppm in soil, 1 ppm in water), or a combination of threshold concentration metrics and risk evaluation.
Well into the 1990s, many states and local regulators required petroleum cleanup to nondetect concentrations, which is often technically and/or economically infeasible. Presently, most states have moved forward with statute, regulation, and/or guidance based on risk (see States Survey). It is commonplace for sites to be managed and closed using risk-based methodologies that leave residual petroleum in soil and groundwater, usually anticipating that natural biodegradation will complete the final remedial steps. Less commonly, sites can be closed with small volumes of source petroleum left in place when it is not practicable to access the source and completely remove or remediate.
In developing this guidance, the ITRC team conducted a survey of all 50 states and territories; the results are provided in States Survey. A variety of risk-based corrective action (RBCA) and state-specific cleanup approaches were reported. We present survey results throughout this portion of the guidance.
3.1 History of TPH Regulation
Both TPH cleanup levels and TPH analytical methods have changed over time from what were generally arbitrarily selected cleanup levels to risk-based cleanup levels. The adoption of various analytical methods by the USEPA and their inclusion in state regulatory approaches for petroleum risk evaluation has been documented over time through surveys of state cleanup standards Tomlinson and Ruby 2016.
The first TPH test methods were gravimetrically based (based on weight, i.e., EPA Method 413) and were used to measure oil and grease concentrations, as this parameter was required early on in federally regulated wastewater treatment monitoring programs. At that time, only a few states used methods analyzing broad TPH ranges such as gasoline range organics (GRO) and diesel range organics (DRO) or evaluated individual chemicals, such as benzene, toluene, ethylbenzene, and xylenes (BTEX).
In the mid-1990s, there was a rise of risk-based evaluation methods for corrective action at petroleum-impacted sites (for example, the release of ASTM E1739 Standard Guide for Risk-Based Corrective Action Applied at Petroleum Release Sites in 1995) . These risk-based evaluations commonly used concentrations of indicator compounds (i.e., BTEX) in addition to TPH. At this time, tests for fractionated ranges of hydrocarbons were also developed to measure specific molecular weight ranges for both aliphatics and aromatics, such as “C6–C12 aromatics” or “C12–C28 aliphatics” with better defined toxicity (see TPH Fundamentals). These methods were first used by the Massachusetts Department of Environmental Protection (DEP) for regulatory purposes in the early 1990s.
Survey data from 2000 indicated that total TPH analysis was widely superseded by fractionated measurements of GRO/DRO/oil range organics (ORO) and that a dozen states had abandoned TPH analysis entirely while only a small number of states adopted further fractionated TPH cleanup standards. In contrast, at that time, measurement of individual chemicals (e.g., BTEX) had become almost universal for regulatory compliance purposes. That general trend has slowly continued with several additional states eliminating TPH standards entirely and a few others adopting fractionated TPH standards by 2012/2014. However, Tomlinson and Ruby 2016 report that TPH cleanup levels, while nominally risk-based, still evidence wide variability.
The current status of the application of fractionated TPH to the regulatory management of petroleum release sites was documented through questions 5 and 11 of the States Survey. When asked about why fractionated hydrocarbons are not used, 30% of respondents indicated they currently use fractionated hydrocarbons in some capacity while a similar fraction feel that total TPH standards are adequate or that indicator compounds are adequate. Only a small number of respondents expressed concern for the cost of fractionated analysis.
3.1.1 Federal TPH Regulations
18.104.22.168 Clean Water Act (CWA)
Typically, the United States invokes sovereign immunity regarding the need to comply with state laws that might be different or more stringent than federal law (Clean Water Act: Sections 313 and 404, subdivision (t)). However, in the case of the federal Clean Water Act, established in 1973, the United States has waived its sovereign immunity with respect to state water pollution laws and is required to comply with state law when it is more stringent than federal law, just like other responsible parties and dischargers. It is important to understand this hierarchy when petroleum cleanup is occurring on federal property.
3.2 What is the Legal Basis for Risk-Based Closure of Petroleum Sites?
3.2.1 What Is a Permit in the TPH Cleanup World?—How Regulatory Permission Is Granted Based on Risk
The word “permit” literally means “permission,” or as it applies to the regulation of TPH cleanup, an authoritative or special certificate of permission. Throughout this section we use the word “permit” to mean formal or informal permission from a regulatory agency.
Both federal and state statutes require permits from regulatory agencies for the discharge of anything to the waters of the state or the United States. This is clear in the wastewater world where sewage treatment plants receive permits from agencies to discharge their effluent to surface waters or the ground. It is clear for construction and industrial sites that are required to have permits to discharge the stormwater that runs across their facility. How does it work in the TPH cleanup world? How does permitting work when a responsible party is doing a TPH cleanup? Although there are not typically “permits,” there are approvals, concurrences, no further action letters, and orders. These regulatory communications constitute the permits in the TPH cleanup world. Once you have “regulation” through the documents referenced previously, you have been granted permission, which in statute is called a “permit.”
One of the most misunderstood concepts is the “low risk closure” concurrence. What is tricky about these closures is that they appear to approve leaving waste (TPH contamination) in place, when in fact they are just approving a long-term cleanup strategy that will lead to restoration of the beneficial uses and/or “acceptable risk” within a longer time frame. Actually leaving waste in place, without a cleanup time frame, requires a different type of permit that in some states is called waste discharge requirements. These are the types of permits granted to municipal and hazardous waste landfills and surface impoundments. See the ITRC report on institutional controls for more information.
3.2.2 No Vested Discharge Right—How to Talk to Your Regulator
The frequency of the likely approval of a TPH risk-based closure has at times led to the false impression that dischargers/responsible parties have the right to leave residual petroleum in place, rather than the goal of restoring the natural resource beneficial uses and corresponding environmental health benefits to the people of the state or United States. This misconception often leads to argumentative and unproductive negotiations regarding appropriate remedial goals. Our hope is that a better understanding of the actual regulatory framework will improve those conversations.
Generally, under both state and federal law, leaving residual petroleum in soil and groundwater based on risk is not a right without appropriate regulatory oversight. The approval to leave residual petroleum in place is usually granted through a state review process that involves the collection and evaluation of data and the determination that managing residual petroleum in place will not pose an unacceptable risk to human health, the environment, or beneficial uses. In some states, regulatory concurrence is granted with the understanding that residual petroleum can remain in soil and groundwater for a limited and reasonable time, with the expectation that biodegradation will restore the water resource to beneficial uses. The federal CWA reinforces the notion that there is no vested right in causing contamination by stating that except as in compliance with a permit, the discharge of any pollutant by any person shall be unlawful and that the permit can be terminated or modified for cause (33 U.S.C 1311(a), 33 U.S.C. 1342 (b)(1)(c)).
Question 8 of our States Survey polled 48 states to assess whether there are exceptions to the need for regulatory concurrence for risk-based closures. Most states indicated that regulatory review was required prior to leaving low risk TPH behind. Those that indicated yes, dischargers/responsible parties have the right to leave low risk petroleum in place, largely indicated as a comment that some regulatory approval was still required.
3.2.3 Enforcement Discretion—Allowing Time to Clean Up
The phrase “enforcement discretion” refers to the discretion that regulatory agencies can employ with regards to enforcing the “letter of the law.” The discretion allows the agency to ensure that overall, their regulatory enforcement provides the most benefit to the people of the state or United States. One example would be the determination that a spill volume is “de minimis,” which means that the spill is too trivial or minor to merit consideration. Such discretionary determinations allow regulatory agencies to focus on spills that really matter and require regulatory intervention and oversight.
The volume and magnitude of TPH release sites across the country, along with the significant resources that are required to enforce the many associated laws and regulations, and the relatively low risk associated with many TPH cases, all combine to make practical enforcement approaches necessary, which makes discretionary enforcement significant for TPH sites. It allows flexibility for regulators to recognize the good-faith efforts of responsible parties to return to full regulatory compliance and allows work to move forward, which clearly benefits water quality.
State and federal regulators grant cleanup permits using regulatory vehicles, such as a reviewed work plan or closure request. However, they can also use enforcement discretion to allow cleanup activities to move forward without a formal permit (e.g., voluntary cleanups). Discretionary measures may include: (1) choosing not to complete formal enforcement, such as a cleanup and abatement order, at their discretion, which gives the discharger time to abate the petroleum; or (2) approval of a plan to allow petroleum to remain in place for a specific amount of time with specific requirements, also at regulators’ discretion. These regulatory actions are completed in place of requiring immediate abatement and may be rescinded should human health, safety, or environmental health be threatened. In states with low-threat closure policies, the enforcement discretion regulatory tool is formalized in policy and would not typically be considered discretionary.
Enforcement discretion is often used to allow work to move forward without a permit when there are clear benefits to the environment, such as improved water quality. Such measures may include the injection of chemicals to enhance TPH biodegradation or the test of a remediation system that requires the discharge of its effluent to surface water for a short period of time. Usually the letter of the law would require a formal permitting process for these activities, but many regulatory agencies will use their enforcement discretion and allow the activities to move forward without a formal permit.
3.3 TPH-Specific Regulatory Challenges
A brief discussion of some TPH-specific technical issues is included here because there can be significant misunderstandings at the regulatory level regarding how these issues can affect regulatory decision making.
3.3.1 Screening Levels vs. Cleanup Goals
It is important to not confuse screening levels with site-specific cleanup goals. Most state regulatory programs have screening levels for TPH (see States Survey). They may be called screening levels, Tier 1 risk-based screening levels, initial screening criteria, or similar. They are often developed for various media and even for various exposure scenarios and/or exposure pathways (see Conceptual Site Models). Screening levels applied as cleanup goals or final remediation target levels can result in overly conservative cleanups. Actual cleanup goals are typically site-specific and tailored to the site’s unique characteristics, complete exposure pathways, and projected future land use. This refinement process is often called a Tier 2 or Tier 3 risk assessment.
Regulatory review and concurrence for the site conceptual model should be established before calculating site-specific cleanup goals (see Risk Calculators), especially if the regulatory agency’s goal is to restore or protect the resource from health risk or water resource concerns. Risk calculators allow for the adjustment of hydrogeologic, exposure, and toxicologic parameters and may lead to site-specific cleanup goals that are higher than Tier 1 screening levels.
3.4 TPH-Specific Regulatory Tools
3.4.1 Long-Term Stewardship
Due to the chemical characteristics of TPH, its relatively low solubility and mobility, and the high likelihood of significant natural biodegradation in most geologic settings over time (meaning it generally gets safer with time), it lends itself to regulatory risk-based closures, which are ubiquitous throughout the country, and may require long-term stewardship (see also Special Considerations).
3.4.2 Natural Resource Damage/Injury Assessment
The cleanup of petroleum-impacted soil and groundwater usually takes a significant amount of time. In fact, the beneficial use of the groundwater resource is often not restored for decades, with the final remedy consisting of monitored natural bioattenuation. The administrative assessment of fines for the initial illicit discharge (spill) of petroleum to surface and groundwater is commonplace and is usually based on the volume of the spill and/or the number of days of discharge. It is less common for a fine to be assessed for the temporal loss of the groundwater resource during the remediation process. At this time there are about 22 states (see States Survey) that assess a fee/fine for the temporal loss during remediation, with four states considering implementing a similar program. The State of New Jersey has a standardized and well-presented Natural Resource Injury Assessment process, including a calculator, for the temporal loss of the groundwater resource during remediation NJDEP 2017b. These programs incentivize the discharger to restore groundwater beneficial uses quickly, thereby avoiding a larger fine.
 33 U.S.C. § 1251 et seq.