WSP USA Tools Raising Standards for Identifying Groundwater Contamination

For more than 100 years, a succession of industrial companies polluted a groundwater aquifer in central Canada so thoroughly that it became toxic to drink. More than 30 years after new water supplies were tapped for residents and remediation began — the groundwater is still contaminated.

That timeline is not unusual. Even with pumping and treating and natural attenuation, contamination can persist for decades in groundwater resources. What is unusual in this case and many others is the fresh and encouraging insights provided to environmental regulators and the community by WSP’s Groundwater Plume Analytics^® tools.

“The project team had been performing data analyses using traditional industry-accepted approaches, including well-by-well analysis and assessing remedial performance by comparing reductions in contaminant plume areal extent,” said Joe Ricker, senior technical principal at WSP USA, who developed one of the foundational tools

Based on the traditional approach, a comparison of plume maps in the annual reports showed that the areal extent of the plume had reduced by about 35 percent over 15 years of pumping and treating, which was not a bad result.

“However, with the application of our tools, we were able to really highlight something much more significant,” Ricker said. “Our analysis showed a similar reduction in areal extent, but we were also able to demonstrate a 98-percent reduction in the plume mass which could not be ascertained by the traditional methods. Emphasizing a 98-percent reduction in contaminant mass instead of a 35 percent reduction in areal extent was a dramatic gamechanger.”

This was such good news for the client that the firm’s managers asked Ricker to present the analysis to a community monitoring group. Thanks to the tool’s presentation capabilities, which translate complex data sets into easily understood graphics, the firm’s presentation was so well received that even the toughest critics in the group were impressed.

“They could see and understand the data in a much more compelling way than usual,” Ricker said.

This kind of “ah-ha!” moment is something that Ricker and his colleagues have seen often from industrial clients with groundwater pollution, from clients themselves, environmental regulators and from public stakeholders.

Contaminated water plumes can spread horizontally and vertically through aquifers, making it hard to determine the source or scope of the contamination, and equally as difficult to manage it.

“One of the biggest challenges we face in the industry is how to convey literally tens of thousands of groundwater sample results consisting of multiple chemicals over periods of months to decades,” said Tim Goist, senior technical principal for WSP. “Our human brain has difficulty sifting through data tables and complicated chemical names and really getting an understanding of what it all means. If we were to just offer the data sets to the public or even many professionals, they would have a very hard time understanding what they mean. Sometimes we get blinded by the science.”

WSP USA’s award-winning Groundwater Plume Analytics^® tool tackles that very challenge and converts all of those numbers, names and tables, making it easier to understand and visualize what is going on with the plume. By taking the complicated and making it easy, seasoned groundwater contamination experts, as well as the general public, can feel better about understanding groundwater contaminant movement.

More than 165 million Americans rely on groundwater for drinking and to irrigate their food, yet according to the U.S. Geological Survey, more than one in five groundwater samples contain contaminants at concentrations concerning for human health.

“This is an urgent issue with an immediate impact on human and environmental health,” Ricker said.

“The Groundwater Plume Analytics^® tool tackles the widespread challenge of polluted groundwater by making it easier to visualize, predict and manage the movement of contaminants,” he added. “It can identify pollution sources and reduce operating costs up to 70 percent vs. traditional water sampling, remediation and management techniques.”

These tools don’t use artificial intelligence or complex computer modeling, but relatively simple techniques based on the use of grid files from commonly used contouring and spreadsheet software. The foundational tool was developed by Ricker more than 20 years ago as he sought methodologies that could use data from multiple monitoring wells to measure plume average concentration and mass, in addition to the more commonly measured areal extent.

The tools are benefitting many of the firm’s clients who are facing similar situations and a need to accelerate change to improve water conditions on their properties. In fact, “Accelerating Change” is the theme of 2023. World Water Day, which is being observed on March 22 with a focus on the need to find solutions to the global water and sanitation crisis.

Groundwater Plume Analytics^® tools are playing a key part in that solution.

After incorporating custom computer coding from David Winchell, WSP senior engineer, Ricker, Goist and Winchell received two additional patents in 2019 for algorithms that Winchell helped develop.

Ricker and Goist, who have worked together as environmental consultants since 2002, had already received a patent for one of the tools in 2016. And since then, the trio have focused on client solutions using the Groundwater Plume Analytics^® tools.

“At WSP, we’re meeting with teams all over the world — Canada, the U.S., Brazil, Australia, several European countries — and they’re bringing it to their clients,” Ricker said.

These tools have been applied to several significant projects throughout the past several years at WSP. A West Coast petroleum company used these Groundwater Plume Analytics^® services as part of the site management strategy for an active bulk fuel terminal in northern California.

The purpose of this project was to demonstrate remedial progress and reduce long-term spending for the site. When the work was concluded in 2020, the overall services were well received by client management, as well as the regulatory agency.

The Ricker Method Plume Stability Analysis that was implemented at the site was used to verify that the cessation of a costly soil vapor extraction and oxygen injection system was effective; the results of which amounted to more than $100,000 in annual savings. Additionally, the Well Sufficiency Analysis™ helped to achieve more than $80,000 savings in monitoring costs.

The tools have been in use for more than a decade with successful results on more than 1,000 groundwater plumes in the U.S. and in more than five international markets.

“One of the gratifying parts of using these tools is helping clients and regulators better allocate money spent on remediation,” Goist said. “We have seen many sites with energy-intensive remedial approaches that, while cleaning groundwater, they are doing it using energy-intensive methods to do so.”

“With our tools, we have found that many of these sites can actually clean up quicker under natural conditions,” Ricker added. “I know that sounds counter-intuitive, but the tools demonstrate that reality. This allows stakeholders to then apply those dollars saved to other sites that are experiencing much more robust problems.”

An exciting development in 2022 was the first application of the tools on groundwater contaminated with per- and polyfluoroalkyl substances (PFAS). PFAS is considered an emerging contaminant and is in the news almost daily.

“We feel this is a groundbreaking moment for us, in particular, and for the industry in general,” Goist said. “There is still a lot of knowledge to be gained in understanding how PFAS behaves in groundwater. The more PFAS data sets we run through our analytics, the more we’re going to learn about PFAS that is currently unknown.”

And while the team is breaking new ground with PFAS, “we are still brainstorming and developing new tools and applications to continue to advance our understanding of groundwater contaminant plume behavior,” said Winchell.  “We are excited about bringing our next ideas to the market.” 

Some of WSP’s Groundwater Plume Analytics^® tools include:

Ricker Method^® Plume Stability Analysis – This is the foundational tool developed by Ricker used to determine whether a dissolved groundwater plume is shrinking, stable or increasing.

Ricker Method^® Spatial-Change Indicator™ (U.S. Pat. No. 10,400,583) – This tool allows the viewer to observe relative changes in a groundwater plume over time. The tool is used to identify areas of potential sourcing, evaluate plume migration, evaluate remedial performance, provide evidence of attenuation and many other powerful interpretations of plume behavior.

Remediation System Benefit Analysis, or RSBA^®(U.S. Pat. No. 9,299,038) – This tool is used to evaluate the relative impact an active groundwater remediation system (such as pump and treat) is having on the stability of a dissolved plume and considers operation and maintenance costs in the context of efficiency and inefficiency. In practice, RSBA^® can demonstrate if the plume is shrinking because of – or despite – the remediation system.

Ricker Method^® Well Sufficiency Analysis™(WSA) (U.S. Pat. No. 10,304,223) – This tool is used to determine the appropriate number of wells needed to monitor plume behavior, with a focus on reducing the monitoring well network and related costs.

Ricker Method^® Transect Analysis – This tool creates a better way to assess mass flux or rate of contaminant flow across an arbitrary boundary. It can be used to answer the question: How much of that contaminant is leaving one site and going to another?