1. VLEACH Case Study
Soil Contamination with trichlorethylene (TCE) at the Chase Brass Site - Ohio
1/14/2019

2. Problem
Soil Contamination from previous use of site by BP for brass foundry work
BP sold site to Chase, on the condition it would be remediated by BP under the Ohio Voluntary Action Program
Once remediated, the site would receive a Covenant Not to Sue
1/14/2019

3. Problem (continued)
Contaminants: heavy metals, TCE, others at trace levels
Groundwater not yet impacted
Remedy must insure no groundwater impact (MCL) within a period of 300 years and no contaminant present in NAPL (free phase) form
BP proposed remedy; Chase contested adequacy of such remedy
1/14/2019

4. Objectives of Vadose Zone Modeling
Impact of “No Action” Remedy
Minimum Remedy required to insure no groundwater impact (MCL)
Evaluate Excavation Remedies, as well as Excavation with SVE
1/14/2019

5. Modeling Issues/Concerns
Model Selection
“Zones” for application of Model
Initial Condition of Contaminant Level
BREAK-OUT QUESTION
Soil Non-Homogeneity
Inability to perform calibration simulation – except for “censored data”
1/14/2019

6. Modeling Issues/Concerns
VLEACH doesn’t predict groundwater impact in the form of concentrations!
Don’t know date of release
How to model excavation/SVE with VLEACH?
1/14/2019

7. Ohio VAP Considerations
Generic Clean-up Levels
Csat values
Summer’s Model for estimation of groundwater concentration levels
See Ohio EPA Voluntary Action Program on the web!
1/14/2019

8. TCE Details Solubility: 1100 - 1300 mg/l
Density: more than water 1.46 g/cc
Viscosity: less than water 0.8 cp
USEPA MCL: 5 mg/l (5 ppb)
1/14/2019