Companies
Northwest Environmental Training Center ...
Training
MTCA Spreadsheets Workshop

MTCA Spreadsheets Workshop

FromNorthwest Environmental Training Center (NWETC)

This course is intended for environmental professionals seeking an improved understanding of the 3- and 4-phase partitioning models specified under the Washington State Model Toxics Control Act (MTCA). Both models are prescribed in MTCA as predictive tools for deriving soil cleanup levels that are protective of groundwater. Participants will have their own computer workstation to apply their knowledge to case study data during numerous hands-on exercises. Washington State Department of Ecology recently updated two powerful Excel spreadsheets (MTCATPH11 and MTCASGL11) to assist with the complex model calculations. The instructor will lead participants through a number of hands-on exercises that demonstrate the appropriate use and capabilities of the spreadsheet models. The instructor will also discuss model theory, assumptions, limitations, and alternatives such as empirical demonstrations and leaching tests.

Course Topics

Review of MTCA Soil Cleanup Levels (Methods A, B, and C)
Overview of the Three
and Four-Phase Partitioning Equations
Introduction to the MTCA Spreadsheet Models (MTCATPH11 and MTCASGL11)
Structure and purpose of MTCATPH11 and MTCASGL11 spreadsheets (learning how to navigate them)
Evaluating Data for Input to Spreadsheets (e.g., what data do you need?, avoiding double counting of individual components, handling nondetects, obtaining site-specific soil characteristics)
Running Test Cases for Several Petroleum Mixtures and Nonpetroleum Chemicals (results from saturated vs. unsaturated zone, excluding vs. including the dermal exposure pathway, and cases for using different groundwater CULs)
Results of a Sensitivity Analysis for the Influence of Soil Properties on the Leaching Models (foc, volumetric water content, bulk density, total porosity)
Calculating a Site-Specific Dilution Factor
Limitations and Assumptions of the Leaching Models
Obtaining the Appropriate Input Data
Alternatives to Using the Leaching Models