Emerging Contaminants Summit

Spring 2020

springerCharles Springer
Senior Geologist
TRC

Mr. Springer is a Project Manager/Geologist with 17 years of consulting experience and has managed and/or assisted with hundreds of projects ranging from transactional due diligence to site characterization, remediation and restoration across Northeast and the Mid-West.  Mr. Springer has completed projects for a broad range of clients including; developers, municipalities, manufacturing/industrial corporations, generation/transmission utilities, Department of Transportation, the Department of Defense, the Department of Homeland Security, and the Environmental Protection Agency.  Mr. Springer holds a Bachelor's of Science degree in Geology from Lafayette College (2000).  Mr. Springer has held a Professional Geologist's license since 2005 and a Certified Hazardous Material Manager license since 2010.

 

POSTER PRESENTATION

Accurate Measurement of Oxidation-Reduction Potential and Dissolved Oxygen Field Indicator Parameters in Groundwater at a Chromium Site using the Westbay Multilevel Well System®

Accurate measurements of groundwater field indicator parameters, particularly oxidation-reduction potential (ORP) and dissolved oxygen (DO), is an important part of site characterization where metals and/or volatile organic compounds are a concern.  Typically, collection of field indicator parameters is completed through a flow cell during the low-flow sampling process which limits the effect of atmospheric oxygen on ORP and DO.  However, when the Westbay Multilevel Well System® is deployed,  the standard sampling equipment used to collect groundwater samples can expose the sample to oxygen in the air rendering measurements of DO and ORP inaccurate.

TRC was presented with a unique challenge at a confidential site of characterizing chromium (hexavalent vs. trivalent) in groundwater in a fractured bedrock aquifer.  The Westbay Multilevel Well System® had been installed as the sampling system of choice due to the cost effective collection of multiple groundwater samples from discrete fracture zones at depths of up to 400 feet at a given well location, in addition to a significant reduction in drilling cost. 

Collecting representative groundwater samples for total chromium was not an issue.  However, understanding the geochemistry which controls the speciation of chromium into its hexavalent and trivalent states in the hydrogeological system was a challenge.   Oxidation Reduction Potential is an important factor in chromium speciation and can be altered significantly when exposed to atmospheric conditions.  As such, accurate field indicator parameters (specifically DO and ORP) were very important to understand the speciation and mobility of chromium is the fractured rock system.

After exhausting available resources (Westbay Instruments Inc., Waterloo, Schlumberger, etc.), TRC developed a new Standard Operating Procedure (SOP) for the collection of representative field indicator parameters through the Westbay Multilevel Well System®.  Our approach utilizes an inert gas (nitrogen) to purge atmospheric air from the sample collection vessel prior to deployment. Following collection, the same inert gas is used to “push” the sample aliquot out of the sample collection bottle and through a flow cell which limits exposure to atmospheric oxygen and provides representative measurements of DO and ORP in groundwater.

This presentation will discuss site conditions, advantages and limitations of the equipment, and TRC’s newly developed SOP for collecting accurate of field indicator parameters from the Westbay Multilevel Well System®.

 

 

 

Program Agenda  Scientific Advisory Board  Keynotes and Session Chairs  Platform Presenters  Poster Presenters