Section 40.0955 - Imminent Hazard Risk Characterization and OutcomeRisk Characterizations for Imminent Hazard Evaluations shall be conducted separately for safety, human health, and the environment, depending on the type of condition that triggered the need for the evaluation, in accordance with the following methods:
(1) The characterization of the risk of harm to safety shall be conducted as described in 310 CMR 40.0960. The conditions at the disposal site pose an Imminent Hazard based on safety concerns if a condition of no significant risk to safety has not been achieved at the disposal site under conditions which actually exist or are about to occur.(2) The characterization of the risk of harm to human health shall be conducted using Method 3, as described in 310 CMR 40.0993. (a) The toxicity information used to characterize risk shall be consistent with the type and duration of exposure under evaluation, and shall be clearly identified and documented. Primary consideration shall be given to information developed by the Massachusetts Department of Environmental Protection for the purpose of conducting such risk assessments. Examples of such toxicity information include: 1. Reference Doses and Reference Concentrations; and2. Carcinogenic Slope Factors and Unit Risk values.(b) The conditions at the disposal site pose an Imminent Hazard based upon the potential for carcinogenic health effects if, for the oil and/or hazardous material evaluated and for each receptor, the estimated Excess Lifetime Cancer Risk is equal to or greater than a cancer risk limit which is an Excess Lifetime Cancer Risk equal to one-in-100,000.(c) The conditions at the disposal site pose an Imminent Hazard based upon the potential for non-cancer health effects if, for the oil and/or hazardous material evaluated and for each receptor, the non-cancer risk calculated is equal to or greater than a non-cancer risk limit of: 1. a Hazard Index (or equivalent ratio of exposure) equal to one for oil or hazardous materials that have the potential to cause serious effects (including, but not limited to, lethal, developmental, or neurological effects) following short-term exposures, for example lead or cyanide; and2. a Hazard Index equal to ten for all other oil or hazardous materials.(d) A release to the environment which produces readily apparent effects to human health poses an Imminent Hazard. A quantitative evaluation of such exposures is not required.(e) The mathematical equations used to calculate the risk estimates shall be clearly presented and documented.(3) The risk of harm to the environment shall be characterized based on the data collected pursuant to the response action being performed and the site, receptor and exposure information identified in 310 CMR 40.0995. The following conditions shall constitute an Imminent Hazard to the environment: (a) evidence of stressed biota attributable to the release at the disposal site including, without limitation, fish kills or abiotic conditions; or(b) a release to the environment of oil or hazardous material which produces immediate or acute adverse impacts to freshwater or saltwater fish populations.(4) The documentation of the Imminent Hazard Evaluation shall clearly state whether the conditions at the disposal site pose an Imminent Hazard based upon the criteria described in 310 CMR 40.0955(1) through (3).Amended by Mass Register Issue 1407, eff. 12/27/2019.Amended by Mass Register Issue 1503, eff. 3/1/2024.Amended by Mass Register Issue S1516, eff. 3/1/2024.