The MERI Team

Meet the MERI Team


keith olson

Keith Olson – General Manager

Keith has been with MERI since 1996. He was the manager of accounting and operations before taking on the role of General Manager in 2021.  With over 25 years in the medical waste industry, he brings a breadth of knowledge on how to handle, transport and dispose of a wide range of biohazard and hazardous materials.

Keith is married, has three children, and enjoys gardening.

robert rizza

Bob Rizza – Environmental Manager 

A Certified Hazardous Materials Manager (CHMM), Bob’s role as MERI’s Environmental Manager is to help our customers properly manage their hazardous waste. He holds a degree in Biology and Environmental Science from UW-Stevens Point, and is committed to both compliant and sustainable practices. Current on RCRA and DOT hazardous certifications, he works with our drivers to profile, package and economically ship our customer’s hazardous waste. Bob previously worked at Univar as a field technician, and before that, served as a field chemist at Clean Harbors.

Some of Bob’s hobbies include camping, fishing, hunting, snowboarding and mountain biking. He resides in Madison.

Tammy Greiber Employee Photo

Tammy Greiber – Sales Account Manager

Tammy’s goal is to make sure MERI not only provides five-star service, but also finds the most cost-effective solution to your medical waste disposal needs.  She has been in sales for over 25 years and is a graduate of UW Madison. Knowing her customers and providing great service is of utmost importance to her.

In her spare time, she is a personal trainer, fitness instructor, and high school track coach.

Lisa Clark Photo

Lisa H. Clark – Marketing Manager

Lisa enjoys working alongside MERI’s dedicated team. They strive every day to keep MERI’s costs low so that our customers can dedicate their financial resources to patient care. She knows everything about MERI’s sharps disposal mailback program and how it can help small medical waste generators save money. Lisa uses her experience in public relations, content marketing and event planning to stay abreast of the latest medical waste news to share with MERI clients. In addition, she organizes MERI’s hazardous training certification programs.

She holds a journalism degree from Northern Illinois University.

Staci Willems Employee Photo

Staci Willems – Office Manager

Staci brings nearly 30 years of administrative experience. Her varied background of support includes marketing, sales, and high-level executive positions to name a few. She contributes to many different aspects of the business at MERI and thrives on the company culture where everyone on this small but mighty team chips in to provide the best service for our customers.

Outside work, she is an avid reader and stays active by biking, hiking, and kayaking. In addition, she serves as the secretary on the Sun Prairie Public Library Foundation Board.

MERI Drivers, Process Associates, Fulfillment, and Maintenance

Tom Seib Employee Photo
Paul Blaser Employee Photo
Rollie Long Employee Photo
Bill Chadwick Employee Photo
Josh Zacharias Employee Photo
Austin Long Employee Photo
Jeff Halverson Employee Photo
Jim Detter Employee Photo
Juhee Olson Employee Photo