When approaching any remediation project, the goal is to find the most effective way to bring a site into compliance and protect human and environmental health. While groundwater containment isn’t a method most of us might think of as our method of choice from the perspective of getting the most efficient outcomes, it can be useful as one of the tools used to address site-specific needs.
Groundwater containment can seem somewhat simplistic in comparison to the advanced treatment methods used widely on remediation projects. However, as with all projects of this kind, the many factors that come into play are unique and varied, and what works best at one site might be completely unusable at another. When taking a holistic approach to remediation, as we always aim to do, adjusting course might be necessary at any phase, and in order to be successful, it’s important not to write off measures that might seem less advanced or comprehensive than you might have hoped for in an ideal scenario.
Cases for using groundwater containment
Groundwater remediation technologies have continued to evolve as the needs have, and in many cases it’s feasible to completely remove the contaminant source and restore impacted groundwater to a nearly uncompromised state. However, in many real-world applications of remediation techniques, certain circumstances may make treating affected groundwater especially difficult—for instance, interference with reactivity or biodegradability of a contaminant or hydrogeologic environments such as fractured rock. When these factors make a full source removal or in-situ remediation methods either economically or technologically impractical, groundwater containment can often be the best way to manage a contaminated site. Since containment can often be implemented in a timely manner, it can also be a good way to buy time while continuing to investigate the most complete remedial solution.
Sometimes groundwater containment is a client’s only option, either because regulatory requirements mandate it as a part of the remediation strategy or because of other aforementioned complicating site factors. We’ve had experience with Superfund sites where groundwater containment was either the only option or the best option available to us. At a fractured rock Superfund site in northern New England, we used source-area containment for groundwater that had been impacted during the site’s use as a storage and transfer facility. In the ’90s, more than 800 tons of contaminated soils were excavated and disposed of, but risk assessments conducted a decade later indicated VOCs in groundwater and PCBs in soil exceeded maximum regulated concentrations. Containment ended up being the best option here because of the complex nature of the site and the ability to use containment and institutional controls to limit exposure.
Limiting costs and liability
While there are good technical reasons for every decision made on a remediation project, the reality is that a lot of decisions come down to what makes the most financial sense for the client. In many cases, it makes sense to invest initial capital to save money down the line. However, remediation projects are not always easy to anticipate, and once contamination has been discovered, it’s important to act quickly to avoid negative impacts and additional liability. This can make it difficult to allocate or acquire the necessary funds to invest in a costlier remediation method right away. For those instances, a solution like groundwater containment can work well because it may not require a huge amount of money to implement, and generally, fixed operating costs can be budgeted for in the coming years.
Whether using this approach for technical or economic reasons, groundwater containment can be a reliable, useful tool to have at your disposal. The needs of every site are unique, as are the needs of every client, and this sometimes requires flexibility in our response. In the end, this approach can be effective as part of a remediation strategy, buying a client time while they assess next best steps, providing an affordable immediate option, and demonstrating to regulators you’re serious about protecting human health and the environment.