About Us

CHESTER LabNet (CLN) is a specialty laboratory that focuses on inorganic air quality analysis. Our staff is dedicated to the satisfaction of our clients, and responsive to the unique needs of the air quality industry. CLN has a great depth of knowledge of air quality methods and nuances.

Paul Duda

Paul Duda

President, Laboratory Manager and Lead Project Manager
pduda@chesterlab.net
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Richard Sarver

Richard Sarver

XRF Technical Director
and Analyst rsarver@chesterlab.net
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Lisa Ball

Lisa Ball

Project Manager and Sample Custodian
lball@chesterlab.net
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Sheri Heldstab

Sheri Heldstab

Inorganics Lab Manager and QA/QC coordinator
sheldstab@chesterlab.net
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Jennifer Schleis

Jennifer Schleis

Chemist and Weighroom Technician jschleis@chesterlab.net
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Ryan Johnson

Ryan Johnson

Chemist and Weighroom Technician
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Paul Duda Paul Duda
President, Laboratory Manager and Lead Project Manager

Hire Date: December 1989

Education: B.S. Engineering Management, University of Portland

Duties: Corporate affairs including proposal writing, marketing and sales, program and project management, overall profit/loss for company, all accounting/payroll and purchasing; oversees all procedures, QA/QC, and corrective actions associated with sample receipt, log-in, chain-of-custody, and storage; project management and general report production; client management; oversees operation of laboratory information management system (LIMS), including all software and hardware, general data entry, QA/QC, coordination with other project managers and technical staff, training of new users.

Background: Years of experience weighing air quality filters and analyzing samples by XRF; years of experience as a project manager and LIMS administrator; promoted to President in 2001. Currently a member of the Air and Waste Management Association (AWMA)

Personal Personal: Paul grew up on a dairy farm in Mount Angel, Oregon and now resides in Portland Oregon with his wife and four kids. Paul is a profound source of sports, music and entertainment trivia. He enjoys spending as much time with his family as he can. He mourns the loss of the Portland Beavers, and longs for professional baseball to return to Portland. Paul spends weekends and evenings coaching little league, watching swim lessons, dance lessons and numerous other sports and activities his kids participate in. He also tries to sneak in a little time on his Wii. During the week Paul keeps the rest of CLN running smoothly.

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Lisa Ball Lisa Ball
Project Manager, Sample Custodian

Hire Date: October 1997

Education: B.S. Integrated Science, Portland State University

Duties: Perform sample receipt, log-in, and storage; project management and general report production; client management; general data entry, QA/QC, coordination with other project managers and technical staff.

Background: Years of experience in environmental chemistry, including" gravimetric and chemical analysis of air quality samples; extraction methods for the analysis of organic pollutants; hazardous waste wet chemical methods such as TKN and cyanide; various wet chemical methods for the analysis of anions in wastewater and soil.

PersonalPersonal: Lisa was born in Portland, and has lived in the area her entire life. She and her husband both enjoy watching as well as playing sports. Going to the zoo, trips to the park, and shuttling kids to activities is how she spends most of her free time. Lisa enjoys living in the great Northwest with her husband and two children.

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Richard Sarver Richard Sarver
XRF Scientist

Hire Date: November 1986

Education: A.A.S. Chemical Technology, Chemeketa, Community College

Duties: Coordinate all XRF activities with President, Laboratory Supervisor, sample custodian and project managers as needed; serve as technical resource for analysts and clients with respect to XRF; train XRF technicians and oversee all XRF operations; market XRF capabilities to outside clients; responsible for maintenance and repair of instruments, supervise sample flow, analysis of samples by XRF, data interpretation, QA/QC and report generation from XRF analysis; perform highly specialized sample preparation for non-deposit samples, including size fraction and resuspensions.

Background: Twenty years analytical chemistry experience, including six years experience in biochemical applications and fourteen years experience in environmental air quality analysis, specializing in the analysis of air particulates by x-ray fluorescence. Currently a member of Air and Waste Management Association (AWMA).

PersonalPersonal: Rick, a Portland native, now lives in Beaverton, Oregon with his wife and son. When not staring at a computer monitor at work, he spends much of his time struggling to learn Thai, and enjoys gardening, woodworking, and coaching his son's baseball team.

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Sheri Heldstab Sheri Heldstab
Inorganics Lab Manager and QA/QC coordinator

Hire Date: July 1992

Education: B.S. Biology, University of Oregon

Duties: Oversight of standard operation procedure production, implementation and maintenance; QA/QC review of data; technical guidance on general technical guidance for clients and in-house staff; supervision of technical and support staff; bringing online new instrumentation; provide technical guidance to clients as needed. In addition, she acts as a backup analyst in all areas of the Inorganics Laboratory.

Background: Over 15 years experience in analytical chemistry. Experience with a wide variety of analytical methodologies including EPA methods, EPA SW846 methods, Code of Federal Regulations methods, California Air Resources Board, Standard Methods for the Examination of water and Waste Waters, NIOSH and ASTM; experience in method development of unusual sample matrices; experience in data interpretation and data validation; experience in technical writing of Standard Operating Procedures and other documentation. Currently a member of the American Chemical Society (ACS).

Personal Personal: Born in The Dalles Oregon, during the Vietnam war, Sheri grew up the child of an active duty Army officer, living all over the United States and in Germany. She now lives in Lake Oswego, Oregon with her husband, two dogs and two parrots. When not at work, she enjoys playing piano, reading, writing fiction and tandem biking with her husband.

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Jennifer Schleis Jennifer Schleis
Weighroom Technical Director and Chemist

Hire Date: February 2007

Education: BSES Environmental Economics and Management, University of Georgia

Duties: Sample preparation and digestion; analysis of a variety of samples for ionic and metallic constituents by IC, ICP, GFAA and CVAA; performance of level 1 data review in real time; maintenance and repair of instruments; oversees all operations of the filter gravimetry laboratory, including maintaining filter supplies, acceptance testing of all filter media, gravimetric analyses at milligram and microgram levels following EPA 40 CRF 50 protocols, QA/QC and corrective actions, record keeping and minor maintenance and repairs.

Background: Several years experience in laboratory analyses including: genetic analysis utilizing gel electrophoresis, PCR, sequencing and DNA isolation; extractions; media preparation; wet chemical analyses to include pH, conductivity, TKN, turbidity, and hexavalent chromium; air quality analytical experience.

Personal - Jennifer SchleisPersonal: Jen was born in Nebraska, but grew up in numerous places, including Maine, Georgia, and Washington thanks to the United States Air Force. Jen currently resides in Portland with her husband and son. She enjoys all the northwest has to offer such as camping, live music, long walks on the beach, pina coladas and getting caught in the rain.

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Micahel May Ryan Johnson
Chemist and Weighroom Technician

Hire Date: November, 2011

Education: M.S. Forensic Science, University of New Haven
B.S. Chemistry, George Fox University                                                               

Duties: Sample preparation and digestion; analysis of a variety of samples for ionic and metallic constituents by IC, ICP, GFAA and CVAA; performance of level I data review in real time; maintenance and repair of instruments; gravimetric analysis including maintaining filter supplies, acceptance testing of all filter media, gravimetric analyses at milligram and microgram levels following EPA 40 CRF 50 protocols, QA/QC and corrective actions, and recorded keeping.

Background: Several years experience in environmental chemistry working in various departments including wet chemistry, volatiles and sample control. He has conducted PCB analysis by Gas-Chromatography, Dissolved Gas analysis of headspace-GC, flow injection analysis of cyanides, ammonia and numerous other methods.

PersonalPersonal: Ryan was born in Portland, raised in Vancouver, WA and a true child of the Northwest. He loves books, the outdoors, all living creatures, music, movies, videogames, experiencing everything life has to offer and trying to understand it better each day.

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