Common VAP Risk Assessment Issues Certified Professional Annual Training October 2015 Mike Allen

Today Leaching to Unrestricted Potable Use Standards (UPUS) and Multiple Chemical Adjustment (MCA) and the Rules Quick Notes – Identified Area (IA) to Exposure Unit (EU) – Applicable Standards and MCA – Conceptual Site Model (CSM): Literal to Graphic – Complete Exposure Pathway and CSM Catch as Catch Can (CACC)

Leaching to UPUS and MCA Contaminated Soil above Ground Water Meeting Unrestricted Potable Use Standards (UPUS) UPUS as defined in the VAP – Maximum Contaminant Level (MCL) Appendix A, Table VI – Risk Based Standards Appendix A, Table VII Unrestricted Potable Use (UPUS) and the Protection therein.. POGWMUPUS

Leaching to UPUS ~ Determinations and Demonstrations

Leaching to UPUS ~ Demonstrations The NFA must demonstrate that UPUS will be protected, but let’s go back to what UPUS is: UPUS as defined in the VAP – Maximum Contaminant Level (MCL) Appendix A, Table VI – Risk Based Standards Appendix A, Table VII … and be clear that we may need to pay attention to Rule -08 (A)(2)

Generic Numerical Standards ~ Applicability ~ Assumptions ~~ …except for… … Rule -08 (A)(2) (2) Assumptions. The following assumptions apply for all generic numerical standards except for the generic direct contact soil standards for petroleum described in paragraph (B) of this rule, direct contact soil standards for lead as described in paragraph (C)(3)(e) of this rule, the generic unrestricted potable use standards based on maximum contaminant levels or other regulatory established criteria as described in paragraph (E), …

Generic Numerical Standards ~ Applicability ~ Assumptions ~~ …except for… … Rule -08 (A)(2) Meaning that, the Ohio EPA expects the Generic Standards for Potable Use based on MCLs (Table VI) to be met without alteration. Generic Standards for Potable Use that are based on a risk (Table VII) need to be handle as a Generic Standard.

Soil Leaching to Ground Water Applicable Standards UPUSs.. MCL? Or Risk Based? Soil

Soil Leaching to Ground Water Applicable Standards Typically back calculated from the UPUS concentrations to Chemical of Concern (COC) concentrations in soil If the UPUSs are based on MCLs the MCLs are used for each COC If the UPUSs are based on a risk based concentration the risk based concentrations are adjusted to account for other risk based COCs

Quick Notes from Risk Identified Area (IA) to Exposure Unit (EU) Applicable Standards and MCA Complete Exposure Pathway and CSM Conceptual Site Model (CSM): Literal to Graphic

Identified Area (IA) to Exposure Unit (EU) EU concept is controlled in (D)(3)(b) of Rule 09 (D)(3)(b) Exposure assessment – (i) Identification receptor populations – (ii) Evaluation of exposure pathways – (iii) Quantification of chemical-specific intake – (iv) Criteria for use of property-specific data

Identified Area (IA) to Exposure Unit (EU) EU concept is controlled in (D)(3)(b)of Rule 09 (D)(3)(b) Exposure assessment – The exposure assessment must determine the reasonably anticipated magnitude, frequency, duration and routes of exposure Please look into Technical Guidance Compendium (VA ) – Difference Between Identified Areas and Exposure Units in the VAP

Identified Area (IA) to Exposure Unit (EU) More often than not, characterizing one Exposure Unit that contains three Identified Areas with one sample in each IA does not satisfy (D)(3)(b) of Rule 09, that is the determination of magnitude, frequency and duration of the exposure.

Applicable Standards (AS) and MCA

Again, lets assume that the GNSa, b, c and d = 10, 8, 3 and 2, respectively… Remember that the GNS is based on being the only COC. MCSa = 2.5, MCSb = 2, MCSc = 0.75, MCSd = 0.5 What if the respective Soil Concentrations are SCa = 0.25, SCb = 0.2, SCc = 0.05, and SCd = 1.8, We’re still good to go, right? YES.. Good to go.. But why? Applicable Standards (AS) and MCA

In the two examples what were the Applicable Standards used? The single generic standards? The single generic standards divided by four? The site wide risk goal? The soil concentrations for each COC? The soil concentrations divided by the single generic standards? Applicable Standards (AS) and MCA

Rule -07 (I)(3)(b) To verify compliance with applicable standards, the volunteer must compare the concentration of each chemical of concern determined in accordance with paragraph (F)(6) of this rule to the applicable standard identified in paragraph (F)(5) of this rule. Compliance with an applicable standard is verified if the concentration of each chemical of concern does not exceed the applicable standard. Applicable Standards (AS) and MCA

– Conceptual Site Model (CSM): Literal to Graphic – Complete Exposure Pathway and CSM Quick Notes

Questions? Please if you have questions now or particular training on VAP risk issues you’d like to have presented more formally let me know and we can do that for you. Mike Allen