Groundwater Treatment Method Options

There are many treatment approaches when it comes to treating a range of problems that can occur in groundwater. Many of these methods use a combination of technologies. When considering the appropriate approach, it is important to note that each site should be treated case by case. Since every site offers a different history, background, and unique landscape. REGENESIS, and our team of technical specialists, focus on the specific needs of every site to deliver the best-suited solution. There is a no one-size-fits-all remediation approach. Providing in situ remediation solutions on over 26,000 sites – the REGENESIS team has been involved in a wide variety of sites and is equipped with the technical knowledge and expertise to recommend an efficient and effective remedial design using our technologies at a lower total cost-to-closure.When looking at treatment methods, we can categorize them into biological, chemical, and physical approaches:


Bioaugmentation is an example of a biological treatment method that biodegrades groundwater contaminants like chlorinated VOC’s. Cultured microorganisms are added into the subsurface that expedite the process as opposed to naturally occurring microbial communities. REGENESIS’ BDI Plus® or Bio-Dechlor INOCULUM Plus® is widely used during bioaugmentation and can be applied alongside 3D-Microemulsion® or 3DME® and HRC® products. This bioaugmentation approach generally demonstrates results within one to five years, but has been proven to successfully achieve reduced dechlorination at a notable cost-savings.


In situ chemical oxidation (ISCO) is an example of a versatile chemical treatment method eliminating a broad range of contaminants. During the ISCO process, chemical oxidants are injected or mixed into groundwater to destroy contaminants upon contact. Chemical oxidants include oxygen gas, ozone, and other liquid chemicals. REGENESIS’s PersulfOx® and RegenOx® are powerful technologies that work as catalysts to ensure dependable oxidation.


Pump and treat is an example of a physical treatment where contaminated groundwater is pumped to the surface and then treated using a combination of biological or chemical treatments. This is a more traditional approach used historically to reduce contaminant levels. Since the advent of in situ approaches, more and more environmental professionals are weighing the high cost of pump and treat systems against the more economical approach now offered with biological and chemical methods.

Overall, there are many factors when looking for a groundwater treatment solution. What treatment will prove to be the most effective, whether biological, chemical, or physical, depends on site conditions, contaminant types, and concentrations. In addition, budget, timeframe, and other factors will impact which treatment approaches are selected. At REGENESIS, we understand the complexities involved. Our team will work with you to explore all the possibilities and provide turn-key support to arrive at an effective solution. Please request a design today and thank you for reading!

How is Groundwater Remediated?

REGENESIS is an expert in remediation and this topic will guide you through how groundwater is remediated.

To begin, groundwater remediation is the process that treats polluted groundwater by removing the pollutants and/or converting them into harmless products. Groundwater is essentially water present below the ground surface, often in underground layers of water-bearing permeable rock, rock fractures, or unconsolidated materials known as aquifers. The goal of remediation is to make groundwater safe for humans and minimize the negative impact contaminants have on the environment. Additionally, soil or sediment can also be remediated if it’s contaminated as a result of coming in contact with contaminated groundwater.

How is Groundwater Remediated?

There are two types of groundwater remediation: in situ (in place or on-site) and ex situ (off-site). The in-situ remediation approach involves cleaning the water where it is presently situated, rather than removing and transferring it elsewhere. This is a less expensive alternative to removing and treating it away from the property. Ex-situ remediation involves having the contaminated water excavated and then eliminated off-site. The advantage to this approach is that it’s impossible for any further damage to be done at the current location, but it extends the process and is more expensive. Ex situ remediation is sometimes more beneficial when subsurface contaminant levels exceed those which can be treated via in situ remediation. Overall, both types get the job done and every project should be taken case by case. REGENESIS technologies focuses on in situ solutions and some examples of successful remediation projects are highlighted here in our project profiles.

The actual remediation of a site, or restoring the soil and groundwater to a usable state, can be achieved utilizing many different methods. Techniques include biological, chemical, and physical treatment technologies. The traditional approach is “pump and treat” which is physically pumping out the contaminated groundwater using a vacuum pump and then purifying the groundwater using materials that absorb the contaminants. In 1994, REGENESIS introduced a revolutionary approach to treating groundwater that offered an alternative to pump and treat. Oxygen Release Compound (ORC) was the first of its kind and quickly became the standard for leading environmental consultant firms to treat a number of sites with groundwater contaminants including benzene, DCE, MTBE, and vinyl chloride. With the advent of chemical in situ groundwater technologies and approaches, environmental consulting firms no longer had just one choice.

Today, backed by scientific research and testing, REGENESIS provides a host of technology-based solutions including but not limited to: in situ sorption and biodegradation, in situ chemical oxidation (ISCO), enhanced aerobic or anaerobic biodegradation, bioaugmentation, and more. The type of site, whether it’s an industrial site or a brownfield, will determine which solution will perform best. Our technological solutions at REGENESIS are state-of-the-art incorporating the appropriate combination of expertise, products, and application methods.

Remediation often requires many different tests and phases of cleaning to restore groundwaterentirely. After each phase, the groundwater must be sampled and tested to see if it meets certain criteria determined by the state, federal, and local government. Ideally, if it meets or exceeds the regulatory standards following the monitoring period, the project is considered complete and contaminant levels are said to be at non-detect. If the data comes back above the required standards, more rounds of testing may occur. It’s not uncommon for projects to take years to complete. In some cases, the property owner may introduce a different approach and strategy for treatment of their site. REGENESIS has worked with many consultants who have been engaged to take over long-lasting projects by providing proven effective technologies and services to the affected site with great success where other approaches may have failed.

Overall, groundwater remediation is an important aspect in protecting the environment and we are proud to do our part by providing a variety of treatment approaches addressing contaminated sites. If you’d like a more in-depth and scientific look at the different types of technologies used to treat contaminated groundwater, check out Remediation Solutions on our site.

Groundwater Remediation Services


What is a Brownfield?

The term “brownfield” is defined as a former industrial or commercial site where future use is affected by real or perceived environmental contamination. In our industry, we work with a lot of brownfields since our main goal is to eliminate the presence of dangerous contaminants affecting the environment and human health.brownfield

In 1980, The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was put into effect which made the owner of any property liable for contaminants in the soil. This has made the issue of contaminants an important topic for business owners and greatly opened the need for REGENESIS products and services. Naturally, any business owner would want to avoid any liability and will undergo an Environmental Site Assessment (ESA), or a detailed investigation of the property.

Ever wonder why a deserted, old warehouse is just taking up space and not being used for something else? Well, this property is probably a brownfield and cannot be used for any business purpose until the contaminants are removed and under control. Brownfields tend to be abandoned or closed industrial or manufacturing facilities but they can also be closer to our daily lives than most would assume. For example, dry cleaning properties can be brownfield sites because they operate with harmful contaminants, specifically chlorinated solvents. Additionally, gas stations can be brownfield sites which also include hazardous chemicals in their processes. Further, any site where pollutants are dumped can turn into a brownfield.

According to the United States Environmental Protection Agency (EPA), there are approximately 450,000 brownfields in America; however, this figure just represents the sites that have had a thorough ESA investigation – the true number is much larger than we’d think. So why is this still such a big issue? This is because brownfield projects tend to be a time-consuming and expensive process, thereby hindering the common businessperson who identifies this type of venture as being too much effort and money. For example, say you’re a franchisor and you come across a cheap property you think has the potential for a new chain restaurant in a busy commercial area. You realize the property contains harmful contaminants and is unusable. Luckily, there are remediation solutions available that can transform this negatively perceived barrier into a worthy, beneficial business investment. REGENESIS Remediation Services provides technology-based, cost-efficient, reliable solutions to brownfield projects making them unique challenges with considerable potential. Our sales team loves to tackle new brownfield projects and our company is overall committed to top remediation services to cultivate a cleaner and safer tomorrow.

In conclusion, cleaning up brownfield sites remains a very important issue in society today involving human health, business development, and the protection of the environment. Whether brownfields are in remote or commercial locations, they can provide excellent opportunities for economic growth and development: The cleanup of one brownfield site in a community can result in substantial job growth. If you’re interested in brownfields or know of a project in demand of a contamination cleanup, please take a look at our website and familiarize yourself with the variety of products REGENESIS offers today.

Thanks for reading!

Innovative Solution to Unmanaged Toxicity Issue Impacting Human Health

By Tricia Rodewald, Vice President of Marketing, REGENESIS®

History has shown that accidents and failed experiments often lead to new inventions and discoveries. Many everyday products used all over the world came from what were once seen as mistakes by their inventors. Examples include the implantable pacemaker, the microwave, ink-jet printer, Velcro and even saccharin found in many kitchens across the country. One of those inventions, Teflon, or polytetrafluoroethylene, was the compound its inventor accidentally discovered while trying to create a new refrigerator coolant. Now it’s famously known as the chemical power behind the non-stick, heat-resistant cookware that earned its creator, Dr. Roy J. Plunkett, an induction into the National Inventors Hall of Fame. Scotchgard, was another accidental discovery.  In 1952 an accidental spill of a fluorochemical rubber on an assistant’s tennis shoe was the beginning to the invention of the product. After exhaustive attempts to remove the spill failed, 3M scientist Patsy Sherman changed her approach from removing the spill to using the spill as a protectant from spills. Sales of Scotchgard began in 1956, and in 1973 Sherman and co-inventor Samuel Smith received a patent for the formula.

Reinventing Social Responsibility   

EPA Great Lakes Restoration Initiative
The EPA’s Great Lakes Restoration Initiative has also been integral in creating a less toxic environment.

How times have changed. In 1999, the United States Environmental Protection Agency (EPA) began an investigation into the class of chemicals used in Scotchgard, after receiving information on the global distribution and toxicity of perfluorooctane sulfonate (PFOS), its “key ingredient”. In May of 2000, under US EPA pressure, 3M announced the production phase-out of PFOA, PFOS, and related products.

Today, as a result of the EPA’s pressure and mounting consumer concern, both Teflon and Scotchgard are no longer available due to the key ingredient PFOS. In addition, consumers have become increasingly aware and more educated about the products they use and the chemicals they are exposed to. Consumer organizations and environmental advocates have been diligently working to keep the public informed of the growing list of hazardous materials relating to PFOA and PFOS and the extended class of polyfluorinated substances (PFAS) contaminants to prevent further environmental and human harm.

This growing trend of environmental awareness is well-supported by the recent Madrid Statement created and signed by over 200 scientists from all over the world to equip the general public with information to encourage them to take proactive measures rather than reactively struggle against something most of them know very little about.

The EPA’s Great Lakes Restoration Initiative has also been integral in creating a less toxic environment. In a project largely funded by this initiative, the River Raisin in Monroe, Michigan, will soon be delisted from “The Great Lakes Region’s Most Toxic List,” a notorious position that the River Raisin has held since 1987 due to contaminants being passed into it from a nearby automobile production site. Since 2012 polychlorinated biphenyls have begun to be cleaned out of the river, giving hope to the nearby residents of Monroe as well as surrounding areas.

Innovative Solutions

As more discoveries are made regarding toxic chemicals, more solutions are being developed to combat widespread contamination. One of the more effective tools to analyze and detect contaminants involves the use of liquid chromatography (LC) and mass spectrometry (MS). While these analysis and detection methods are not new, the application of their use for this specific contaminant type is. LC-MS and LC-MS/MS instruments are now used to gather information on PFAS contaminants in the soil and water supplied through the ground and are able to effectively measure to the parts per trillion (ppt) concentrations required.

The March 2016 Emerging Contaminants Summit brought together researchers and scientists to share insights and findings from ongoing research on how to treat the issue of toxic substances. One of the techniques shared was the pump-and-treat technique, which can take anywhere from 10 to 100 years to resolve contaminated groundwater. This has been an effective long-term method, and now thanks to REGENESIS® there is also an immediate solution that can be used to treat on-site risks. In 2014 REGENESIS® launched PlumeStop® Liquid Activated Carbon. This is a form of in situ technology that immediately captures and contains contaminants to pull them out of groundwater supplies. PlumeStop injects an in situ barrier made up of colloidal-activated carbon, and just one application can last for years. It is a cost-effective and timely technique.

PlumeStop was received favorably among leading-edge environmentalists and researchers at the Emerging Contaminants Summit. It is also currently being used by engineering and environmental consulting firms in Europe as well as in the U.S.

As more discoveries are being made about PFOA and PFOS contaminants, more technological advancements from companies like REGENESIS® continue to be developed to bring hope and restoration to the world.

How Innovative Techniques Are Mitigating Toxic Threats Surrounding The Global Community: Solutions to Address the Proliferation of Polyfluoroalkyl Substances (PFOS/PFOA)

By Tricia Rodewald, Vice President of Marketing, REGENESIS®

Reading the news on a daily basis can be a disconcerting effort, particularly when it concerns health-related risks. Take the recent developments in North New Jersey towns, where residents opened their morning North Jersey Record on Valentine’s Day of 2016 to an article that detailed elevated levels of perfluorooctanoic acid (PFOA). According to the piece, PFOA is “linked to kidney and testicular cancer, as well as high cholesterol, ulcerative colitis, thyroid disease, pregnancy-induced hypertension and other illnesses in a still-growing body of research. There are also probable links to low birth weight and decreased immune responses.”

PFOA and its counterpart perfluorooctanesulfonic acid (PFOS) are just two examples of man-made chemicals that are increasingly being identified in public groundwater resources and are impacting lives. Environmental professionals are actively seeking out solutions designed to counteract the ubiquity of these toxins and provide a level of safety protection for individuals, businesses and governments and are turning to innovative solutions to combat the problem. In short, ingenious techniques, products and services are being designed and implemented around the world to counteract the spread of potentially dangerous substances. At REGENESIS® we are creating ground-breaking solutions that effectively mitigate chemical environmental degradation and over the years we have provided solutions for more than 26,000 soil and groundwater sites globally.

Starting Points

In order to effectively build the resolution formulas to handle complex contamination, it is necessary to first understand the nature of the problem and chemicals in question. What then is behind this most recent revelation of PFOA and PFOS? To start, the first line of thought is determining what PFOA is and why it matters. According to the New Jersey paper, PFOA is “a man-made chemical used in the manufacture of stain-resistant carpets, waterproof clothing, non-stick cooking pans and other products that make life less messy, and has spread so far through the environment that it can be found everywhere from the fish in the Delaware River to polar bears in the Arctic.”

Scale and Scope

PFOS PFOA Contamination Map
An Interactive map where PFC contamination has been detected

According to an August 2015 report by David Andrews, a senior scientist with the Environmental Working Group, in the U.S. alone, nationwide testing indicates that 6.5 million Americans in 27 states are drinking water tainted with PFOA and other related and potentially toxic PFAS chemicals. 94 public water systems in the nation contain some level of these dangerous chemicals, which can cause cancer, birth defects and heart disease and weaken the immune system. An interactive map is included in the report to give readers information on places where contamination has been detected.

Dr. Mariann Lloyd-Smith, who is part of the working group that reviews substances for the United Nations’ Stockholm Convention, aimed at controlling some of the world’s most dangerous chemicals, claims PFOS and PFOA are “poisons without passports” for their ability to spread throughout the world. “We already have PFOS contamination throughout the globe now,” she says.

Time for Action

Recently, top researchers and leading scientists from around the U.S. convened at the 2016 Emerging Contaminants Summit in Westminster, Colorado, to address the mitigation of contaminants such as PFOS and PFOA, which are released into the air, soil, ground and surface water via industrial processes, military and firefighting operations and consumer product use.

At the inaugural summit, renowned experts from multiple disciplines shared insights and ongoing research, including information on the use of highly specialized instruments such as LC-MS and LC-MS/MS, which detect and analyze contaminants down to the parts per trillion (ppt) level. Using a combination of liquid chromatography (LC) with mass spectrometry (MS), these tools have the increased sensitivity capabilities needed to gain more structural information on toxins in the soil and groundwater.

Once identified in the environment, the next question is how to remediate these contaminants. PFOA, PFOS and other similar per- and polyfluorinated substances (PFAS), however, are recalcitrant in the environment and require extreme conditions to initiate chemical transformation reactions. In fact, most physical, chemical, biological and thermal in situ remediation techniques are ineffective, particularly in preventing the spread of plumes underground.

Results from sites around the world indicate that the most common possible treatments, namely pump-and-treat and ex situ techniques, which use activated carbon filters on site, may need to be in place for 10, 20 or, in rare instances, up to 100 years to remediate groundwater contaminated with PFAS. In addition, pump-and-treat technologies do not address on-site risks associated with in-surface soils.

Solution Innovation

One in situ technology, however, does offer a new means to address these challenges. Launched in 2014 by REGENESIS®, PlumeStop® Liquid Activated Carbon™ is an environmentally friendly, patented, in situ remediation substrate that quickly and effectively treats contaminated groundwater and prevents the spread of contaminated plumes. Through highly dispersible, fast-acting, sorption-based technology, which captures and concentrates contaminants within its structure, the groundbreaking product lasts for decades, pulling contaminants directly from groundwater. PlumeStop is composed of very fine particles of activated carbon (1-2µm) suspended in water through the use of unique organic polymer dispersion chemistry. Once in the subsurface, the material behaves as a colloidal biomatrix binding to the aquifer matrix, rapidly removing contaminants from groundwater and expediting permanent contaminant biodegradation. The key elements of this technology, particularly for treating groundwater contaminated with PFOA and PFOS, include its cost-effective ability to inject an in situ barrier of colloidal-activated carbon that distributes widely and evenly under low pressures in the permeable channels. Cutting off migrating plumes, PlumeStop rapidly absorbs PFOA and PFOS even at low concentrations and has years of sorption capacity with a single application. Higher doses or reapplications allow for extended longevity. It is also more cost-effective when compared to other techniques and is being applied by engineering and environmental consulting firms across the U.S. and Europe.

Final Reason for Optimism

PFAS have the potential to cause significant damage to global populations and will continue to impact communities because of their widespread use and capacity to infiltrate the worldwide environmental ecosystem. Yet it is most important now and in the years ahead to develop innovative technologies within environmental remediation techniques. A focus on effective solutions to help mitigate the serious dangers associated with PFOA and PFOS as well as other PFAS contaminants is key.

When considering that chemical compounds both synthetic and natural are found in and make up all aspects of life, it is a mistake to succumb to the fear of these substances. The indomitable spirit of humankind has always embraced the rigor of finding solutions to make life safer and more secure. The importance of discovery and advancement in scientific and technological endeavors will ultimately address the problems associated with PFAS and, throughout the future, the new challenges facing the global community.

5 Helpful Tips for Making Brownfield Sites a Successful Investment

getting-sites-to-closureThroughout Canada, real estate developers and property owners are looking for ways to develop a significant number of brownfield sites as part of their long-term real estate strategy in residential, retail, and commercial property. While the redevelopment of these large parcels may seem to represent attractive investment opportunities, at the same time they also pose a very real challenge due to their contaminated past and the complex and time consuming remediation needed to meet regulatory compliance standards. Because the leftover environmental issues at brownfield sites vary from location to location, and state and provincial agencies and regulators can be involved in the cleanup and redevelopment process, new layers of complication mean success often hinges on covering each and every aspect of a brownfield site’s cleanup.

Fortunately, with today’s turn-key solutions in environmental remediation, there are a variety of steps property owners and developers can take to ensure they avoid a myriad of possible monetary and litigious pitfalls. As a global leader in science-based environmental remediation products and solutions, REGENESIS provides a comprehensive range of turn-key solutions that effectively mitigate the evolving issues and risks associated with these sites. Experts in the field of successful remediation of brownfields, REGENESIS offers the following suggestions to ensure your brownfield redevelopment efforts meet or exceed expectations:

1.) Be Aware of the Exact Type of Contamination and Required Remediation

Since conditions vary, every brownfield site will require careful scrutiny regarding contamination and the acceptable remediation methods. It is wise to begin with a comprehensive evaluation of the contamination and how well it has been documented in the past, both in order to prepare for the cost of mitigating it and to protect the new developer from possible future litigation. This thorough evaluation will help to determine if additional measures in site cleanup will be necessary, such as transporting contaminated soil to a remote location, treating or diverting groundwater, installing vapor mitigation systems, or capping certain types of contamination. Also, be aware that costs can be much higher with a brownfield than with other types of construction projects, due to cleanup and management of contaminated soil and groundwater and design and development tweaks that may need to be made in order to mitigate future issues.

2.) Look for Tax Breaks and other Incentives

Numerous successful brownfield revitalizations across Canada have been completed with the help of grants and other incentives from federal, provincial, and local organizations interested in seeing environmental contamination cleaned up, and forgotten parcels of land used to create jobs and other community benefits. Although it takes time to uncover these sources of potential funding, you may be surprised by the positive results of your efforts. As an example, incentives may be available for projects in disadvantaged communities, and many provinces and municipalities have grant and low-interest loan programs designed to speed the redevelopment process along.

In Ontario, there are a number of programs and tools that may be used to help encourage brownfield redevelopment. Many Ontario municipalities use special financial programs to offer incentives to encourage brownfield redevelopment in their communities. One such program offered is the Brownfields Financial Tax Incentive Program (BFTIP), an initiative of the government of Ontario to encourage the cleanup and redevelopment of brownfield properties. It allows municipalities to provide property tax assistance to property owners in connection with environmental rehabilitation of brownfields properties within an approved community improvement project area.

3.) Secure Protection from Litigation

In addition to letters confirming that no further action or remediation needs to be taken at a brownfield site, other agreements such as covenants not to sue can protect developers from potential exposure to lawsuits resulting from third-party liability issues if contamination spreads to abutting lands or new contamination is discovered. Keep in mind however, that some of these protections can vary by site and should be studied closely, as they may not take effect until after the site has been cleaned up, so during the interim period there can be potential exposure.

That exposure can be addressed in a number of ways, including crafting respective purchaser agreements in which the seller — if a solvent seller is involved — can retain some of the risk. In this situation, the developer often agrees to facilitate remediation of the site and the parties agree not to litigate over the cleanup of contaminants caused by the seller.

In many cases with brownfields, developers also take on environmental insurance, which often takes the form of coverage after a certain cap has been exceeded in connection with cleanup. Once many of the legal and financing issues have been addressed, a developer can secure approval for a project more easily by incorporating any necessary mitigation into the construction plan.

4.) Be Creative with the Development Plan

Almost every brownfield redevelopment project involves some form of remediation, whether it’s digging up contaminated soil, covering up a landfill, or having groundwater tested and treated for pollutants. One way to mitigate the costs of doing this work is to make it part of the overall development plan.

The strategy here is to incorporate the remediation of the site into the overall development plan, so that you’re minimizing the cost of the cleanup as much as possible by having it become part of the construction cost.

One simple but common example is complying with soil removal requirements in connection with digging out space for a subsurface parking lot. The cost of hauling the contaminated soil away may increase the price of excavating the land, but if it can be used to house cars, that cost is offset.
And if developers are willing to adjust their plans slightly, a site on which it previously seemed impossible to build anything but another factory can turn out to be a prime location for a mixed-use or shopping center development.

An example of being flexible and exploring various options is when a team advised a developer to flip his construction plan, moving a parking lot to cover a capped contamination site so the accompanying retail building wouldn’t be negatively affected, saving millions of dollars.

5.) Consider a Proven Remediation Solution through REGENESIS

REGENESIS simplifies the environmental remediation process by providing industry-leading solutions including remediation products, technical support, and the option for expert, in-field application services. As a result, our environmental consulting firm customers benefit from a streamlined process which uniquely brings both product and technology application together with a high-degree of certainty. Since no one knows a product better than the manufacturer, this unique arrangement saves time, energy and money for all parties involved.

Request a Design today. If you don’t need a formal site design but have questions or simply want to explore some ideas Contact Us to get in touch with a local representative.

Remembering C.W. “Bill” Fetter

Contributed by Craig Sandefur, Vice-President of Technical Services, REGENESIS

In my opinion, the recent passing of C.W. “Bill” Fetter marks a significant loss to the Groundwater Remediation industry. Bill Fetter had a long academic career as a staff member at the Department of Geology at the University of Wisconsin – Oshkosh 1971-1996 where he taught hydrogeology. He also practiced contaminant hydrogeology as an environmental consultant for a number of years. It was in his academic role and through two key publications that Fetter influenced a whole generation of groundwater remediation engineers and scientists. In 1980, he authored the classic groundwater textbook “Applied Hydrogeology.” This text remains in publication (in a 4th edition), and recent reviews of this book on indicate that it still serves as both a textbook for students and a resource for many working professionals… including myself. In 1992, Fetter published “Contaminant Hydrogeology,” which was a natural extension of his previous book. Now, some may argue that the classic “Applied Hydrogeology” has too many errors and typo’s or that “Contaminant Hydrogeology” is too stilted and case study driven, for me it is easy to set aside the “errors” and the style issues to see the brilliance of Fetter. I truly appreciate his ability to provide a vast amount of information (some of it fairly complex) in a clear and concise manner. I also think it was his ability to use a “just right” blend of words, figures and equations in a powerful way that readers of all levels found to be useful and appealing. Finding the right balance of math and language is very hard to do but I think Fetter generally got it right. Subsequent to him, many authors have produced some very good work by emulating his style. However, Fetter was the original and his writings will undoubtedly continue to influence a significant number of groundwater remediation professionals for years to come.