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

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

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

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

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

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

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

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