Course Description

Hands-on Training with the 3- and 4- Phase Partitioning Models
Course ID: 
Policy & Regulations
Continuing Education Units: 

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. 

After completing this class, attendees will be able to:

  • Understand the components, capabilities, and operation of MTCATPH11 and MTCASGL11
  • Select site-specific input parameters for the models
  • Use spreadsheet software to calculate soil cleanup levels that are protective of groundwater
  • Understand the limitations of the models
  • Consider alternative methods to the models for the demonstration of groundwater protection


*Reduced tuition is available for Native American tribes, government employees, nonprofits, students and AFS, NAEP, NEBC, TAEP members.

You may register online or by calling the Northwest Environmental Training Center at (425) 270-3274. Online registration is strongly encouraged.

Please wait to receive a course confirmation email, roughly one month prior to the class, before making any travel arrangements.


Basic working knowledge of MTCA and Microsoft Excel.

Attendees will receive a course manual containing workshop proceedings and reference material.

Once your order has been placed, you are subject to our cancellation policy regardless of the status of your invoice.

  • 31 days prior to training -> 100% refund
  • 30-16 days prior to training -> 50% refund
  • 15 - start of course -> No refund available

Attendee replacement acceptable at anytime.

Course registration fees and cancellation policy are subject to change without notice.

More Information

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

What to Bring

Please bring a pen or pencil, and notepad if you would like to take notes (you may also choose to take notes in your book). Lunch will be on your own, but drinks and snacks will be provided throughout the day.

Billing Information

In order to guarantee a space in a course, the tuition must be paid in full TWO WEEKS before the first day of the course by either check or credit card. State and government agencies paying with a purchase order are allowed payment under the two-week time frame if a copy of the purchase order is received by NWETC.

If You Need to Cancel


  • With 31 or more days notice, we will offer a 100% refund or credit towards a future course. The credit is good for one year and may be applied to any course.
  • With 30-8 days notice, we will offer a course credit towards a future course. The credit is good for one year and may be applied to any course.
  • With fewer than 8 days notice, there is no course credit available

*Please note that attendee replacement is welcome at any time

Disability Accommodations

Disability Accommodations:

No upcoming offerings

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