About Us

CHESTER LabNet (CLN) is an ORELAP accredited laboratory that specializes in 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 their nuances.

CLN was originally founded in 1977 as NEA, Inc. In 1991, the laboratory was sold to Chester Environmental and became part of the Chester LabNet laboratory network. CLN was later purchased by private investors and has been independent since 1994. In 2016, the company became 100% employee-owned. As both owners and employees, we are highly committed to great customer service.

Key Personnel

Paul Duda

Paul Duda – President, Laboratory Director, Client Services Technical Director, Lead Project Manager

Email: pduda@chesterlab.net

Hire Date: December 1989

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

Background: Gravimetric lab technician, XRF analyst, project manager, and LIMS administrator; promoted to President in 2001. Currently a member of the Air and Waste Management Association (A&WMA). Received PNWIS-A&WMA Lab Coat Award in 2012


Lisa Ball

Lisa Ball – Project Manager, Sample Custodian

Email: lball@chesterlab.net

Hire Date: October 1997

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

Background: Environmental analyses of air, soil and water samples; project manager and sample custodian.


Mike May

Mike May – QA Officer and Analyst

Email: mmay@chesterlab.net

Hire Date: August 2008 – November 2011, November 2017 – Present

Education: B.S., Biology, Portland State University

Background:  Analysis of environmental and production samples.  Quality Control/Quality Assurance including EPA CLP and NELAP. Currently a member of The NELAC Institute (TNI).


Richard Sarver

Richard Sarver – XRF Technical Director

Email: rsarver@chesterlab.net

Hire Date: November 1986

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

Background: Source Sampling, XRF analyst.


Sheri Heldstab

Sheri Heldstab – Technical Writer

Email: sheldstab@chesterlab.net

Hire Date: July 1992

Education: B.S. Biology, University of Oregon

Background:  Environmental analyses of air, soil and water samples; technical writing; health and safety oversight; Quality Control/Quality Assurance including EPA CLP and NELAP. Currently Chair of the TNI SSAS Expert Committee.  Current member of ASTM subcomittee D22.03 (source and ambient air).

Publications: Cr VI Paper presented at NEMC, PowerPoint for Cr VI presentation


Jennifer Schleis

Jennifer Schleis – Gravimetric Lab Technical Director, XRF Analyst

Email: jschleis@chesterlab.net

Hire Date: February 2007

Education: B.S.E.S. Environmental Economics and Management, University of Georgia

Background: Environmental analyses of air, soil and water samples; Gravimetric Lab technical director.


Julie Delarue

Julie Delarue – Conventional Chemistry Technical Director and Lead Analyst

Email: jdelarue@chesterlab.net

Hire Date: July 2015

Education: B.S., Environmental Sciences, University of Alberta (CAN), 2000; Chemical Technology Certificate, SAIT Polytechnic (CAN), 2009 (equivalent of M.S., Analytical Chemistry)

Background:  Analysis of environmental and petroleum samples.


Photography: Human Nature Art