New Directions for Improvement of Groundwater Quality

Tuesday, December 4, 2018: 2:30 p.m.
N119/120 (Las Vegas Convention Center)
Bruce Manchon, PG , Janeil Environmental Solutions, Boulder, CO

Well installation and seal construction techniques that are widely accepted may not be working as designed. The importance of isolating the primary producing aquifer cannot be stated strongly enough - an effective seal above and below the aquifer needs to be established. Without a good seal, water quality may be impacted due to changes of the geochemistry of the aquifer from the mixing of waters from different units; the mixing of surface water and groundwater; or, the introduction of oxygen during the cycling of the irrigation season.

For any new well construction or well rehabilitation, the importance of understanding the complete hydrostratigraphy cannot be understated. Additional factors to consider that impact the groundwater quality from poor well construction include: inadequate seals or long screen intervals that cross-connect water bearing units of different water quality; or long screens intervals or breaches in the casing that result in water cascading and oxygenating the water column.

Case studies will be presented showing the long-term increasing trends of metal concentrations in a municipal water supply well due to cross-contamination between aquifers and how to correct those trends.

The well workover technique includes the incorporation of a thorough evaluation of well construction details, borehole geophysical logs, geochemistry of the aquifers penetrated, and historical well data. Key to this technique, is installing a sufficient volume of grout material without destroying the well which provides a competent seal and appropriate groundwater protection.

Even with the new well construction rules in place in Nebraska, Colorado and other states, or more important historical well construction practices (when the rules weren’t in place), our groundwater quality is susceptible to the same risks, today as yesterday. As a consultant or well driller - What Standard of Care do you apply to your practices – what is your environmental liability?

Bruce Manchon, PG, Janeil Environmental Solutions, Boulder, CO
Bruce Manchon is a California, Nebraska and Texas Professional Geologist with over 35 years of professional experience in the environmental and petroleum industries. He received a B.A. in geology from the University of Colorado and is currently a senior hydrogeologist and owner of Janeil Environmental Solutions in Boulder, Colorado. One of Bruce’s previous roles included several years with as a wireline engineer with Schlumberger Offshore Services and later as a petrophysicist. Bruce is responsible for the technical aspects within the project scope relating to geology, hydrogeology, and remediation; and, for ensuring that the technical objectives of the scope of work are met for a variety of commercial clients. He provides the technical direction for the development of Conceptual Site Models, systematic site characterizations, field implementation of direct push technology (DPT) and borehole geophysics, hydrogeology, and in-situ remediation. His scope of experience includes field investigation; legal support; hydrostratigraphic analysis to assess hydrogeologic effects on contaminant fate and transport; geochemistry; and contaminant recovery for vadose and saturated zone remediation programs. Through his various assignments, Bruce has successfully applied either borehole geophysics or DPT for stratigraphic interpretation and correlation, contaminant plume definition, Class I hazardous waste injection well assessment, production well location design and completion; selection of monitor well location and screen placement, and remedial design and application. Bruce has also conducted workshops and presented papers on geophysical log quality control and effective log interpretation for remediation and site investigations since 1988. He has been utilizing DPT since 1987 and has been conducting DPT workshops since 1991. Bruce is part of a team in Nebraska, Groundwater Solutions Group, LLC, that is dedicated to improving groundwater quality in a sustainable and affordable approach.