Thursday, June 23, 2011

CBC stats students shed light on new soil sampling method

By Erika Holmes, Community Outreach & Environmental Education Specialist, Nuclear Waste Program

Early in 2011, I emailed just about every college instructor in the Tri-Cities area who taught a class that might be remotely related to Hanford. One of the replies came from Linda Rogers, a statistics teacher at Columbia Basin College in Pasco. She had two statistics classes in the spring and very much wanted to work with us. The feeling was mutual.

The preparation

Having focused on visual art and English in college, I needed help designing a Hanford-related statistics project. Ecology chemist Jerry Yokel answered my call. He had stacks and stacks of soil sample data fresh from a professional laboratory. The data needed to be compiled into a spreadsheet and analyzed.

Linda and her daughter Kelly Rogers, a student at CBC and an aspiring cryptographer (cracking codes using math) or professional statistician, spent hours entering all the data into spreadsheets and then compared their numbers to ensure accuracy.

The project

The data reflected soil contamination levels in a dried waste discharge pond in the 200 Area at Hanford. Those levels guide cleanup decisions, and the contaminated soil was removed in August 2010.

However, this soil sampling process also tested something else: a new method of sample collection. Ecology currently uses a systematic sampling process, in which the goal is to collect and analyze approximately 40 soil samples throughout a contaminated area. This process is time consuming and costly.

To improve efficiency, we are trying a new multi-incremental sampling (MIS) process. MIS involves taking 100 evenly spaced scoops of soil in a given area. These scoops are then combined, and a single sample is taken from this mixture to represent the entire area. The composite sample is then extracted and analyzed for contaminant levels. This scooping, combining and analyzing process is repeated five times. If it can be proved that MIS produces results comparable to systematic sampling, the MIS process could improve state standards for soil sample collection and analysis.

CBC students, along with Linda and Kelly, compared the results of both sampling processes and created graphic displays of their findings. The class focused on the project all quarter, so instead of cranking out book assignments, the students addressed the course learning goals by applying them to the data we provided. This process gave them real-world experience using statistics while also practicing teamwork and project management. And because each student wrote a 30- to 40-page report worth 40% of their grade, they also practiced technical writing by explaining and analyzing the graphs and charts they produced.

The “personal” results (technical findings coming soon)

Yesterday, I met with Linda, Kelly and Jerry. Linda gave us the top five student reports, and we’d all like to recognize the excellent work done by Sarah Pedersen, Lorena Perkins, Angela Shaw, Eileen Sheppard, and Kristen Smith (click the author’s name to see her report).

About the project, Angela said, “I am so proud of the completed project and it feels fantastic to have all of my hard work noticed. … I really appreciate the opportunity you gave me and I feel honored to be a part of this project!”

During Jerry’s and my last visit to the class, Kristen described the synergistic effect of being in a history class at the same time. “In that class, we covered the wars and such, but we also took a field trip to the CREHST Museum in Richland. … Working with the data you provided our stats class, I was able to understand most of what was being said during that tour. … I was impressed that, even though this class was very time consuming and I may have had to put more effort in this term, I was able to relate two of the three classes I took this quarter, which made things a lot easier and gave me motivation to keep going.”

Though Linda had to choose the top five reports, the effort that many of the other students put in is no small feat. The project was challenging, but many found the experience rewarding and useful for their future. Two of the students used their reports as part of their nursing program entrance portfolio; others have included the reports in writing portfolios to apply for admission to four-year universities like Washington State and Eastern Washington.

In an email to Linda, who was formerly a professional statistician with the U.S. Department of Defense, student Martin Lop├ęz said, “Thanks for everything you have done for me and the class. … It was a great journey with a great reward. I never felt so accomplished about anything like this before, it is a great feeling, but it was not possible without your critique for improvement. Thank you so much for a great class!”

Stay tuned...

I’ll be reporting on the results soon. Meanwhile, visit our Hanford Education & Outreach Facebook page to see pictures from the project and CBC’s news release. If you have questions or feedback about the project, please comment below.


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