4.1 Purpose—This guide provides a screening risk assessment process for evaluating site use activities at four types of inactive and unregulated solid waste disposal sites and chemically impacted sites. The site use activities include: (1) Active Recreation; and (2) Passive Recreation. Recreation poses potential concerns not only because it can result in ingestion or inhalation of contaminants, but because vulnerable populations may be at greater risk to exposure. More detailed descriptions of these use activities follow.

4.1.1 Active Recreation—Use of an inactive and unregulated solid waste disposal site/chemically impacted site where the likelihood of physical contact with and accidental ingestion and inhalation of surficial soil is high, due to the nature of the sport (for example, football, baseball, rugby, soccer). Note that active sports played on synthetic turf are not active recreational uses in this definition, as the focus is on potential human exposure to chemicals of concern in surficial soil and not on the activity, per se.

4.1.2 Passive Recreation—Use of an inactive and unregulated solid waste disposal site/ chemically impacted site where physical contact with and ingestion of surficial soil is possible but unlikely (for example, biking, walking, bird watching, music or cultural festival).

4.2 Regulatory Context—This guide does not supersede federal, Tribal, State, or local regulations..

4.2.1 The user is responsible for determining the regulatory context and associated constraints and obligations at an inactive and unregulated solid waste disposal site/ chemically impacted site and should comply with all established applicable laws and regulations, including CERCLA, RCRA, TSCA, and other environmental laws, Tribal regulations, and municipal codes in the use of the site for active or passive recreation. The typical inactive and unregulated solid waste disposal site/ chemically impacted site for which this guide is intended to be used are ones that are not currently (and not anticipated to be in the future) within the auspices a regulatory agency program (see 4.3).

4.2.2 The user should comply with health and safety requirements under the applicable federal Occupational Safety and Health Act (OSHA) worker right-to-know laws and parallel requirements of applicable local, State, or tribal (regulatory agency) organizations.

4.2.3 Recognition of Tribal Sovereignty and Tribal Environmental Programs. As discussed in EPA’s Consultation with Indian Tribes (2023) many tribes have environmental programs, game and fish and natural resources programs, brownfields coordinators and Tribal Response Programs that should be consulted for projects impinging on tribal lands (which can include ceded territories, allotments, and other parts of “Indian Country” off reservation). Tribes have various rights with regards to cultural sites off reservation, even in states where they do not currently have reservations.

4.3 Use of Guide—Regulatory agencies may incorporate this guide, in whole or in part, into general guidance documents or site-specific regulatory documents. This guide may also be integrated into complementary standards, guidelines, or contractual agreements, relating to the risk management of inactive and unregulated solid waste disposal sites/ chemically impacted sites.

4.4 Limitations on the use of this Guide: 

4.4.1 This guide entails minimal site characterization. The results of the site screening risk management process shall not be used to support or encourage the use of the site for community gardens or the growth and production of food or crops.

4.4.1.1 When evaluating exposure scenarios, the environmental professional should consider cultural uses of the property that may include ingestion of wetland plants, additional contact and potential inhalation or ingestion of surficial soils due to the nature of active recreation.

4.4.2 Use of this guide is restricted to open land. This guide is not applicable to land with buildings or structures which may be subject to human use or occupation.

4.4.2.1 Indoor air quality assessments and vapor intrusion assessments require sampling and analyses that are beyond the scope of this guide.

4.4.3 This guide is limited to screening risks associated with contact, ingestion, and inhalation of surficial soil. The guide does not address contact or management of leachate, stormwater runoff, or materials below surficial soil.

4.4.3.1 Based upon the records review, the environmental professional may determine that sampling for emissions of landfill gases is required to assess the risks associated with inhalation of landfill gases or migration from the landfill to neighboring areas.

4.4.4 This guide may not be used to characterize (that is, environmentally assess) a site for the purpose of ownership transfer.

Note 1: See EPA’s All Appropriate Inquiries Rule (40 CFR 312) for the minimum requirements of environmental site assessments for transfers of real property.

4.4.5 This guide is not applicable to solid waste disposal sites subject to regulation and permitting under RCRA Subtitle D (40 CFR 239-258), or equivalent state, Tribal, or municipal solid waste management programs.

4.5 Professional Judgment—This guide presumes the active involvement of an Environmental Professional who is knowledgeable in performing a human health risk assessment screening evaluation for specific beneficial uses at an inactive and unregulated solid waste disposal site/ chemically impacted site, including those with community engagement and Environmental Justice concerns. The Environmental Professional must be current (that is, is a qualified professional) in her/his field of expertise, with experience in human exposure assessment.

4.6 Elimination of Uncertainty—Professional judgment, interpretation, and some degree of uncertainty are inherent in the use of the screening processes described herein, even when decisions are based upon objective scientific principles and accepted industry practices. In addition, new methods are continually being developed for this evolving field.

4.6.1 The human health risk screening estimation process described in this guide is not a substitute for rigorous risk assessments that applies to the characterization and redevelopment of sites being remediated under the auspices of federal (CERCLA, RCRA, TSCA), Tribal, or state contaminated site remediation and redevelopment programs.

4.6.2 The completed estimated risk management site evaluation may be revised based upon the use and maintenance of additional engineering controls or institutional controls that prevent or minimize human exposures to chemicals of concern by rendering exposure pathways incomplete.

4.7 Process Entry—This guide may be initiated at any stage or upon discovery of an inactive and unregulated solid wastedisposal sites/ chemically impacted site with unknown environmental impairment conditions.

4.8 Process Reporting and Documentation—The user should decide (in coordination with relevant stakeholders) when site evaluations, reporting, and documentation will occur during Planning and Scoping, Section 5.

4.8.1 The environmental professional is expected to document the exposure assumptions that form the basis for the risk assessment process.

4.9 Process Overview—At initiation, the user should review: Section 3, Terminology; and then proceed to Section 4, Significance and Use; Section 5, Planning and Scoping; Section 6, Background Research and Interviews; Section 7, Site Visit; Section 8, Records Analysis; Section 9, Conceptual Site Model Development; and Section 10, Risk Assessment.

4.9.1 Section 5, Planning and Scoping, describes the Project Team approach (see 3.1.25) for implementing this guide, including but not limited to: (a) selecting the inactive or unregulated waste disposal site / chemically impacted site; (b) selecting a desired site use and making a due diligence assessment of environmental conditions; (c) soliciting concurrence for the Environmental Professional’s proposed approach at a stakeholder and community engagement meeting (see Section 6 of E3356). The Environmental Professional prepares the Project Technical Summary and Risk Assessment Screening Form in Appendix X1.

4.9.2 Section 6, Background Research and Interviews, describes the public records that the project team must gather, assemble and review, as well as interviews to be conducted to determine the past uses of the inactive or unregulated waste disposal site / chemically impacted site.

4.9.3 Section 7, Site Visit, the Environmental Professional may conduct the site visit at the same time he/she is conducting interviews (see Section 6). The purpose of the site visit is to confirm that:

4.9.3.1 Engineering controls, if necessary to render exposure pathways incomplete, are functioning as intended.

4.9.3.2 The planned beneficial use does not represent an unacceptable risk to human health.

4.9.3.3 The current site use and proposed or planned beneficial uses do not represent an imminent threat to human health, public safety, or welfare.

4.9.4 Section 8, Record Analysis is the process by which the environmental professional, based upon his/her review of the records retrieved and assessed in Section 6, and the interviews conducted, determines if and when solid waste disposal activities occurred at the site and the type(s) of solid waste that were disposed of (for example, C&D debris, slag, foundry wastes, coal combustion by-products, storm-related debris, dredge spoils, etc.).

4.9.5 Section 9, Conceptual Site Model, entails the environmental professional’s development of the conceptual site model (CSM). The CSM is an integrated representation of the physical and environmental context, the exposure scenarios, the complete and potentially complete exposure pathways, and the potential fate and transport of chemical(s) of concern at a site. Based upon the CSM, the environmental professional will conclude whether or not complete exposure pathways are present at the site.

4.9.6 Section 10, Screening Risk Assessment, if the CSM confirms the presence of complete exposure pathways, the environmental professional shall prepare a human health screening risk assessment. Using information about the chemicals of concern at the site, presence of complete exposure pathways, and expected exposure durations for employees, vendors, and visitors to the site, the environmental professional determines if the exposure risks are acceptable.

4.9.6.1 The risk assessment is based upon the general population, but should take into account vulnerable populations.

(1) See 10.2.3 for the process to address youth exposures

4.9.6.2 The Environmental Professional, based upon the location of the site, and the regulatory agency having jurisdiction over the site, identifies the applicable restricted use concentration of chemicals of concern in the surficial soil, or Site-Specific Target Levels (SSTLs) must be developed and applied. The rationale for those decisions should be incorporated in to the completed estimated risk management site evaluation. The use of SSTLs may be a technical policy decision.

4.10 The user is responsible for notifying the regulatory agency having jurisdiction of the site in the event that analytical data of samples collected at the site indicate that the concentration of chemicals of concern in surficial soil(s) exceed reporting thresholds.

1.1 This guide provides a site risk management screening framework for the human use of: (1)inactive solid waste disposal sites, unregulated solid waste disposal sites, and sites impacted by chemical releases that are not currently within an environmental regulatory agency cleanup program; (2) sites with anthropogenic background concentrations of chemicals of concern; and (3) sites that have chemical contaminants. These sites may be underutilized or routinely used, for example, pedestrian, recreational, repetitive entertainment, or single event sites.

1.2 This guide provides instruction on evaluating and judging the acceptability of beneficial uses (active and passive recreation) for an inactive or unregulated solid waste disposal site or chemically impacted site.

1.3 This guide may be implemented in conjunction with ASTM's Standard Guide for Stakeholder Engagement on Environmental Risk Management and Climate (E3356) with respect to community engagement activities; see Section 6 of Guide E3356 for more information.

1.4 This guide should not be used as a justification to avoid, minimize, or delay implementation of specific cleanup activities as required by law or regulation.

1.5 This guide may not be used to characterize (that is, environmentally assess) a site for the purpose of ownership transfer.

1.6 Users of this guide make professional judgments that only apply to a particular site, at a particular date and time, and do not warrant safe conditions otherwise. It is possible that a significant environmental exposure condition exists at a site but was missed by the user of this guide or the Environmental Professional who led the risk screening evaluation, or that the condition was introduced subsequent to the evaluation. The risk screening evaluation of a site by an Environmental Professional is not intended to be exhaustive; there may be significant unknown conditions that may not be apparent through reasonable site characterization efforts. Those who use the final reports generated through the use of this guide are cautioned to understand the limits described in the Project Technical Summary and Risk Assessment Screening form in Appendix X1.

1.7 Users of this guide should comply with all applicable federal, Tribal, state, and local statutes and regulations requiring and/or relating to protection of human health. This includes, and is not limited to, laws and regulations relating to health and safety of the people using an inactive or unregulated solid waste disposal site or a chemically impacted site, the surrounding community, and/or public sector and private sector personnel who are involved in the management or oversight of inactive or unregulated solid waste disposal site or chemically impacted sites.

1.8 This guide is composed of the following sections: Referenced Documents; Terminology; Significance and Use; Planning and Scoping; Background Research and Interviews; Site Visit; Records Analysis; Conceptual Site Model; Risk Assessment Screening; and Appendix X1, Example Project Technical Summary and Risk Assessment Screening Form.

1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.