Five criteria and associated weighting factors are used to classify threats that contaminants may pose. These include risks to human population exposed, contaminant stability, contaminant characteristics, threat to a significant environment, and program management considerations.
Each criteria is ranked on a scale of one to five. The highest score for any criteria is five, representing a current risk-current exposure scenario posing risk to human health and the environment. The lowest score for a factor is one, representing a future risk-future exposure scenario.
|A. Risks to human population exposed: Population size, proximity to contaminants, likelihood of exposure.||5|
|B. Stability: Mobility of contaminant, site structure, and effectiveness of any institutional or physical controls.||5|
|C. Contaminant characteristics: Concentration, toxicity and volume.||3|
|D. Threat to a significant environment: Endangered species or their critical habitats, sensitive environmental areas.||3|
|E. Program measurement consideration: Innovative technologies, cost delays, high profile projects, environmental justice, state involvement, Brownfields/economic redevelopment.||4|
The raw score for each factor is multiplied as follows to obtain the maximum score:
|Raw Score Range||x||Weight Factor||= Maximum Total Score|
|A. Population exposed||1 - 5||x||5||25|
|B. Stability||1 - 5||x||5||25|
|C. Contaminant characteristics||1 - 5||x||3||15|
|D. Threat to significant environment||1 - 5||x||3||15|
|E. Program management considerations||1 - 5||x||4||20|
|Maximum total project score||100|