Expert Q&A: John Kastrinos on groundwater fate & transport modeling
John Kastrinos is Lead Hydrogeologist at Haley & Aldrich and has been with the company since 1985. He has worked in regional water resource planning and is also active in strategic consulting for clients seeking cost-effective solutions to environmental liabilities related to historic industrial and manufacturing practices.
What is groundwater fate and transport modeling?
Fate and transport modeling is a means of predicting how groundwater flow patterns will disperse contaminants or carry them in solution. The contaminants may either be present in separate phase (floating on the water table) or, as with contaminants denser than water, near the bottom of an aquifer. More commonly, they are either dissolved in the water or contained in soil and sediment. Modeling is a tool for dealing with the classic groundwater issue, which is protecting water resources and indoor air quality from contaminants.
When might a client need this kind of service?
There are two main scenarios. The first is during the due diligence process before acquiring a property or business. The acquiring company wants to know what type of legacy environmental issues they might be getting themselves into.
The second is forensic examination, generating evidence that will be used to determine liability for environmental damage. We might get a call from either the plaintiff – for example, an insurance company seeking compensation from a responsible party – or from the defendant, who generally wants to limit their exposure as a party responsible for pollution.
What are the main groundwater pollution issues?
One whole category is manufacturing or commercial byproducts, which could be metals like chromium or lead, chlorinated solvents used as cleaning agents by dry cleaners or petroleum distillates like methyl-tert butyl ether (MTBE). People don’t realize is how often naturally occurring conditions can either create environmental problems or be exacerbated through interaction with specific types of groundwater contaminants.
How can naturally occurring conditions be pollution?
Naturally occurring contaminants like arsenic, iron, and manganese can be mobilized by oxygen-depleted conditions that are caused by contaminants such as landfill leachate and petroleum. They’re essentially immobile until the pollutants are introduced, resulting in depleted oxygen conditions due to biological activity that works to degrade the contaminants (i.e, the petroleum or leachate).
Making matters worse, treating one of these problems could trigger another problem. For example, re-oxygenating water can trigger the precipitation of iron (rust), manganese, and other metals in a water supply.
How is Haley & Aldrich unique in this practice area?
We understand the complex, dynamic and interdisciplinary nature of contaminant fate and transport problems and can draw on the expertise of geochemists, biologists, hydrogeologists and modelers to tackle the problem thoughtfully and efficiently.
For more information about Groundwater Fate & Transport Modeling, contact John Kastrinos.