Risk Evaluation for Tier 1 and Tier II
Risk Evaluation for Tier 1 and Tier II Tier I Compare maximum contaminant concentrations to DEQ* screening values (sv) for each media in question. If there is no sv for a particular contaminant, contact the applicable DEQ Program for guidance.
NO
Contaminant concentrations exceed sv?
YES
Tier II a. Responsible party calculates risk using the DEQ risk calculator using maximum contaminant concentrations for each media and default values.
NO
Contaminant concentrations exceed target risks?
YES
Clean-up to Tier I sv feasible or desirable?
YES
NO
Clean-up to Tier II target concentrations feasible or desirable?
YES
Tier II b. Collect additional data as needed. Responsible party calculates target concentrations and risk levels using the DEQ risk calculator and an estimation of media averages as appropriate. Some adjustments within the risk calculator are available with documented justification.
NO
Target risks or alternate target concentrations exceeded?
NO
YES
Clean-up Program Identify cost-effective means of achieving clean-up goals.** Implement preferred alternative.
Compliance Monitoring Conduct monitoring program as needed to confirm that clean-up goals are satisfied or that current conditions persist or improve with time.
* DEQ - North Carolina Department of Envionmental Quality ** Will include institutional controls
Site Closure
NO
Contaminant concentrations exceed sv?
YES
Tier II a. Responsible party calculates risk using the DEQ risk calculator using maximum contaminant concentrations for each media and default values.
NO
Contaminant concentrations exceed target risks?
YES
Clean-up to Tier I sv feasible or desirable?
YES
NO
Clean-up to Tier II target concentrations feasible or desirable?
YES
Tier II b. Collect additional data as needed. Responsible party calculates target concentrations and risk levels using the DEQ risk calculator and an estimation of media averages as appropriate. Some adjustments within the risk calculator are available with documented justification.
NO
Target risks or alternate target concentrations exceeded?
NO
YES
Clean-up Program Identify cost-effective means of achieving clean-up goals.** Implement preferred alternative.
Compliance Monitoring Conduct monitoring program as needed to confirm that clean-up goals are satisfied or that current conditions persist or improve with time.
* DEQ - North Carolina Department of Envionmental Quality ** Will include institutional controls
Site Closure
