310 CMR, § 40.0995

Current through Register 1536, December 6, 2024

Section 40.0995 - Method 3 Environmental Risk Characterization

The characterization of risk of harm to the environment shall be conducted for all current and reasonably foreseeable Site Activities and Uses identified in 310 CMR 40.0923. Characterization of the risk of harm to the environment shall include an assessment of chemical data, potential contaminant migration pathways, and an evaluation of biota and habitats at and in the vicinity of the disposal site, as described in 310 CMR 40.0995(2), as well as through the application of Method 3 Ceiling Limits, as described in 310 CMR 40.0995(5) and the assessment of the presence of visible coal tar waste deposits as described in 310 CMR 40.0997.

(1) A Method 3 characterization of the risk of harm to the environment shall be based on the site, receptor and exposure information identified in 310 CMR 40.0901 through 310 CMR 40.0920, as well as any relevant data collected during the response action being performed.

(2) The risk of harm to the site biota and habitats shall be characterized by evaluating ecological parameters using a two-stage approach. In Stage I, the objective is to identify and document conditions which do not warrant a Stage II Risk Characterization, either because of the absence of a potentially significant exposure pathway or because environmental harm is readily apparent and therefore additional assessment would be redundant. If a potentially significant exposure pathway is indicated by the available information per 310 CMR 40.0995(3)(a) and (c), then a Stage II Environmental Risk Characterization is required to characterize the risks posed by those exposures.

(a) A Stage I Environmental Screening shall be performed as described in 310 CMR 40.0995(3) for all disposal sites evaluated using Risk Characterization Method 3, and for those disposal sites evaluated using a Method 3 Environmental Risk Characterization in combination with Method 1 or Method 2 as described in 310 CMR 40.0942.

(b) Following a Stage I Environmental Screening and based upon the criteria described in 310 CMR 40.0995(3), it may be concluded that:

1. A Stage II Environmental Risk Characterization is not required because there are no complete exposure pathways that could result in potentially significant exposures, and a condition of no significant risk of harm to site biota and habitats clearly exists; or

2. A Stage II Environmental Risk Characterization is not required because, for each contaminated medium, harm is readily apparent; therefore a condition of no significant risk of harm to the site biota and habitats clearly Does Not Exist, and a Stage II Environmental Risk Characterization would be redundant, or

3. A Stage II Environmental Risk Characterization is required because, for one or more contaminated media, there is not enough information to determine whether or not a condition of no significant risk of harm exists, and therefore those media are considered to present "potentially significant exposures".

(c) The scope and nature of the Stage II Environmental Risk Characterization shall depend on the nature of the disposal site, the Environmental Receptors affected or potentially affected, and the Stage I Environmental Screening criteria which indicated the need for the Stage II Environmental Risk Characterization.

(3)Stage I Environmental Screening. Exposures of site biota and habitats shall be characterized by the Stage I Environmental Screening as follows:

(a) Available evidence shall be evaluated to determine whether there is current or potential future exposure of Environmental Receptors to contamination at or from the disposal site. Sources of such evidence shall include historical records, site data, field observations, statements by present and past residents or employees, and any other relevant source.

1. Evidence of current or potential exposure shall include, but is not limited to:

a. Current or past visible physical evidence that oil and/or hazardous material at or from the disposal site have come to be located in surface soil, surface water, sediment or wetlands. Examples of such evidence include, without limitation, the presence of sheens from oil and/or hazardous material, NAPL, oil, tar or other solid or semisolid hazardous material in surface soil, surface water, sediment or wetlands;

b. Records or other evidence of current or past impacts of oil and/or hazardous material from the disposal site on wildlife, fish, shellfish or other aquatic biota. Examples of such impacts include, without limitation, fish kills and abiotic conditions;

c. Analytical data indicating the presence of oil and/or hazardous material attributable to the site in question in surface water or sediment (including wetlands);

d. The potential for the transport of oil and/or hazardous material in the groundwater or surface runoff to such receptors as surface water or sediments (including wetlands) identified as Environmental Receptors; or

e. The presence of oil and/or hazardous material at the disposal site within two feet of the ground surface and the potential for such contamination to result in exposure to wildlife

2. If no current or potential future exposure is identified, then a condition of "no significant risk of harm" to the site biota and habitats exists or has been achieved, and a Stage II Environmental Risk Characterization is not required.

(b) If any current or potential future exposure is identified, then for each such exposure, site conditions shall be evaluated to determine whether significant environmental harm is "readily apparent."

1. The following conditions shall represent "readily apparent harm:"

a. Visual evidence of stressed biota attributable to the release at the disposal site including, without limitation, fish kills or abiotic conditions;

b. The existence of oil and/or hazardous material attributable to the disposal site in concentrations which exceed Massachusetts Surface Water Quality Standards promulgated in 314 CMR 4.00: Massachusetts Surface Water Quality Standards, which include USEPA Ambient Water Quality Criteria applied pursuant to 314 CMR 4.05(5)(e).

c. Visible presence of oil, tar, or other non-aqueous phase hazardous material in soil within three feet of the ground surface over an area equal to or greater than two acres, or over an area equal to or greater than 1,000 square feet in sediment within one foot of the sediment surface.

2. If a condition of readily apparent harm exists in any environmental medium, then a condition of "no significant risk of harm" does not exist, and a Stage II Environmental Risk Characterization is not required to make that determination for that medium.

(c) Each current and potential future Exposure Pathway identified in 310 CMR 40.0995(3)(a) must be evaluated to determine whether it could result in potentially significant exposure.

1. Any potential exposure identified in 40.0995(3)(a) must be considered a "potentially significant exposure", unless it can be ruled out as such using:

a. USEPA Ambient Water Quality Criteria and Massachusetts Surface Water Quality Standards promulgated in 314 CMR 4.00: Massachusetts Surface Water Quality Standards;

b. environmental concentrations specifically adopted by the Department as screening criteria; or

c. site size, location, and/or landscape characteristics specifically adopted by the Department as screening criteria.

2. If, through the application of the screening criteria identified in 310 CMR 40.0995(3)(c)1., an environmental medium (such as soil, sediment or surface water) can be screened out as a source of "potentially significant exposures", then a Stage II Environmental Risk Characterization is not required for any exposure pathway for which that medium is the contaminant source.

3. If current or potential future exposures to contaminants in any media are not ruled out in Stage I Screening, those exposures are considered to be "potentially significant exposures" and a Stage II Environmental Risk Characterization is required to determine whether a condition of "no significant risk of harm" exists.

(4)Stage II Environmental Risk Characterization: A Stage II Environmental Risk Characterization shall be used to determine whether there is significant risk of environmental harm or evidence of environmental harm.

(a) The Stage II Environmental Risk Characterization shall be conducted under the supervision of an individual trained and knowledgeable in ecological studies.

(b) The Stage II Environmental Risk Characterization shall identify environmental resources associated with the disposal site, such as wetlands, aquatic and terrestrial habitat, fisheries, or rare and endangered species, and shall evaluate whether the release of oil and/or hazardous material has adversely impacted, or may adversely impact the ecological functions which support those resources

1. The evaluation shall focus on ecological functions at the spatial scale of the disposal site.

2. The relevance of potential impacts shall be judged at the spatial scale of the disposal site (e.g., effects on subpopulations that use the site as habitat) rather than the proportional significance of the site to regional environmental resources.

(c) The Stage II Risk Characterization shall include, but is not limited to, the following steps:

1.Problem Formulation. The first phase of the assessment shall establish the goals, scope and focus of the Stage II Environmental Risk Characterization. A baseline site survey to identify biota and exposures of potential concern shall be conducted. Available scientific literature shall be used to identify potential adverse effects of concern.

a. Assessment endpoints shall be identified. The combination of assessment endpoints selected for a site must represent the ecological entities, characteristics and functions most likely to be adversely affected by the oil and/or hazardous material in each contaminated medium at the site. The assertion that the selected assessment endpoints are representative of the exposed biota on the basis of their susceptibility to harm by the contamination of concern must be justified and documented, either on a case-by-case basis or by citing DEP guidance. Assessment endpoints shall be defined in terms of ecological entities and their characteristics and functions, as follows:

i. An ecological entity refers to an organism, a species, a functional group of species, a community, an ecosystem, or a habitat.

ii. Valued characteristics include, but are not limited to, growth, reproduction, survival, nutrient cycling, and habitat functions, health of local populations or subpopulations and community diversity.

b. Measures of exposure shall consider the spatial and temporal distribution of oil and hazardous material, and shall represent the co-occurrence of contamination with the assessment endpoint organisms.

c. Measures of effects shall be selected for each assessment endpoint, such that the results of the measures will enable the detection of adverse effects of oil and hazardous material on the assessment endpoint. The relevance and validity of the proposed measures of effects shall be documented. Measures of effects may include, but are not limited to:

i. Comparison of environmental concentrations to ecologically based benchmarks published in the scientific literature, technical literature or government documents;

ii. toxicity data reported in scientific literature;

iii. site-specific toxicity tests to evaluate the effects of contaminated media on survival, growth, and/or reproduction of the target organisms;

iv. quantitative or semi-quantitative field surveys to evaluate adverse impacts on receptor subpopulations or communities exposed to oil or hazardous materials at or from the site; and v. field experiments.

2.Analysis. The second phase of the risk assessment shall characterize any actual and potential environmental exposures and associated ecological effects.

3.Risk Characterization. In the final phase of the risk assessment, the results of the environmental exposure and effects analysis shall be used to evaluate the likelihood of adverse ecological effects. The documentation of the Risk Characterization shall include a summary of assumptions, scientific uncertainties, strengths and weaknesses of the analyses, and justification of conclusions reached concerning the ecological significance of the risks.

(d) The Stage II Environmental Risk Characterization may also include the development of an environmental risk-based guideline for oil and/or hazardous material for which no environmental standards exists, and to the extent sufficient information concerning the environmental risks posed by the oil and/or hazardous material is available. Such guidelines shall be developed in a manner consistent with scientifically acceptable practices, taking into account guidance published by the Department or the U.S. Environmental Protection Agency, and information from the scientific literature, laboratory studies or field studies.

(e)Conclusions. A level of no significant risk of harm to the environment exists, or has been achieved, if:

1. there is no physical evidence of a continuing release of oil and/or hazardous material at or from the disposal site to surface waters and wetlands which significantly affects Environmental Receptors;

2. there is no evidence of biologically significant harm (at the subpopulation, community, or system-wide level) known or believed to be associated with current or foreseeable future exposure of wildlife, fish, shellfish or other aquatic biota to oil and/or hazardous material at or from the disposal site;

3. concentrations of oil and/or hazardous material at or from the disposal site do not and are not likely to exceed any applicable or suitably analogous environmental standards which have been formally promulgated, including Massachusetts Surface Water Quality Standards promulgated at 314 CMR 4.00: Massachusetts Surface Water Quality Standards at current and reasonably foreseeable Exposure Points; and

4. there is no indication of the potential for biologically significant harm (at the subpopulation, community, or system-wide level), either currently or for any foreseeable period of time, to Environmental Receptors considering their potential exposures to oil and/or hazardous material and the toxicity of the OHM.

(5) The risk of harm to the environment shall also be characterized by comparing the concentration of each oil or hazardous material to the Method 3 Ceiling Limits in Soil and Groundwater as described in 310 CMR 40.0996.

(6) The documentation of the Method 3 environmental Risk Characterization shall clearly state whether or not a condition of no significant risk of harm to environmental resources, biota and habitats exists or has been achieved at the disposal site.