Each written to improve groundwater modeling and its application to professionals, five white papers recently produced by the NGWA Groundwater Modeling Advisory Panel have been approved by the NGWA Board of Directors and are now posted on the Association’s website. The papers are:
The NGWA Groundwater Modeling Advisory Panel was formed in early 2016 with the goal of advancing the state of groundwater modeling through cooperative information exchange and outreach to groundwater professionals.
The nearly 40 prominent groundwater modelers who form the panel identified 33 topics of interest and categorized them into five groups for development. The papers were written as discussion documents and underwent peer review before being finalized and approved by the board.
These papers address questions of:
Modeling groundwater in the subsurface environment provides a view and insight of what cannot be easily seen nor readily observed. The U.S. Geological Survey anticipates future modeling demands will be greater, especially addressing multidisciplinary factors and applied to landscape-level science as scientific questions and resource issues become more complex.
The NGWA Groundwater Modeling Advisory Panel believes sharing their knowledge and experience will assist both long-time practitioners and newly graduated modelers in applying their skills and expertise. Its members also hope modelers will bring questions forward for consideration and development in future groundwater modeling practice discussion papers.
This page was last updated on 11-02-2017
ANN ARBOR, Mich. – Global public health organization NSF International has published a new protocol as part of its commitment to improve building water health – NSF P453: Cooling Towers – Treatment, Operation, and Maintenance to Prevent Legionellosis. This protocol outlines proper maintenance and safety practices associated with evaporative cooling systems. It also addresses health concerns associated with commercial buildings, including health care facilities, whose residents may experience health issues such as Legionellosis from improperly maintained water systems.
“According to the Centers of Disease Control and Prevention (CDC), about 5,000 cases of Legionnaires’ disease are reported each year in the United States, which unfortunately include some deaths,” said Dave Purkiss, General Manager, Water Systems, NSF International. “Legionella bacteria are found naturally in fresh water environments, like lakes and streams, but can quickly become a health concern due to lack of proper treatment, operation and maintenance in building water systems and cooling towers . Rooted in NSF International’s 70-year history of protecting human health, the NSF P453 protocol establishes effective monitoring and cleanliness plans to improve building water health and reduce the number of illnesses and deaths caused by these dangerous bacteria.”
The new protocol uses the water safety plan approach recommended by the World Health Organization (WHO) to assemble a team, identify potential hazards and establish control measures to prevent the growth of Legionella bacteria. The protocol can be used by facilities to establish a management plan for the treatment, operation and maintenance of cooling tower water systems.
NSF P453 allows owners and managers of buildings with cooling tower water systems to create an easy-to-follow, actionable plan with specific means and methods to manage the risk of Legionnaires’ disease. It complies with the New York City and state regulations for cooling towers, which were developed in response to the Legionnaires’ disease outbreak in the summer of 2015. Although cooling towers are not regulated beyond New York state, NSF P453 can be applied across the United States to address the risk of Legionellosis and other diseases associated with cooling tower water systems.
This protocol was developed with input from various industry organizations and benefited from a public review comment period. NSF International has additional services to assist facility operators in establishing and verifying their management plans for cooling tower water systems through education, guidance in developing plans and third-party verification audits.
For more information on NSF International’s building water health related programs, contact Dann Holmes at email@example.com or +1-734-214-6222.
Editor’s Note: Media interested in more information can contact Liz Nowland-Margolis at firstname.lastname@example.org or +1-734-418-6624.
About NSF International: NSF International (nsf.org) is a global independent organization that writes standards, and tests and certifies products for the water, food, health sciences and consumer goods industries to minimize adverse health effects and protect the environment Founded in 1944, NSF is committed to protecting human health and safety worldwide. With clients in more than 170 countries, NSF International is a Pan American Health Organization/World Health Organization (WHO) Collaborating Center on Food Safety, Water Quality and Indoor Environment.
NSF International provides risk assessments, testing, inspection and certification services for the water industry from source to tap. NSF International led the development of the American National Standards for all materials and products that treat or come in contact with drinking water to help protect public health and the environment and minimize adverse health effects. In 1990, the U.S. EPA replaced its own drinking water product advisory program with these NSF International standards.
The human body is one of the most complex and nuanced organisms on the planet. Our entire existence and consciousness depends on a constantly changing interplay between us and our environment. Everything we put into and onto our bodies affects our body; and sometimes even minuscule amounts of a contaminant can have a dramatic effect on our health, longevity, and happiness.
Water comes second only to air on the list of critically important requirements of life. Every drop of water that we ingest is processed through our bodies where it can either help or hurt us. It is crucial to consume water that is as safe and beneficial as possible. In ancient times, humans used their senses to observe the odor, color and cloudiness of water before ever attempting to drink it, knowing that clean, clear water would refresh and hydrate them. Over time, scientific innovation produced testing methods to identify various inorganic and organic contaminants in water. As good as current testing technology is, we are still significantly “behind the curve” when it comes to identifying the true nature of contaminants that can exist in water. We are only now seeing the “tip of the iceberg”.
Emerging contaminants are not new, they have been in our water for a long time, and we only now have the equipment and methods for detecting these low levels of contaminants in water. The United States Geological Survey (USGS) provides a useful definition of Emerging Contaminants as “any synthetic or naturally occurring chemical or any microorganism that is not commonly monitored in the environment but has the potential to enter the environment and cause known or suspected adverse ecological and/or human health effects. In some cases, release of emerging chemical or microbial contaminants to the environment has likely occurred for a long time, but may not have been recognized until new detection methods were developed. In other cases, synthesis of new chemicals or changes in use and disposal of existing chemicals can create new sources of emerging contaminants.”
More than 7 million recognized chemicals are in existence, and approximately 80,000 of them are in common use worldwide; the EPA and FDA have no idea exactly how many specific compounds are used in consumer goods, nor what specific combinations are used in each product. In the 21st century, it is safe to say that all water everywhere is “contaminated” with some kind of man-made chemical at some level.
Evidence that several natural and synthetic compounds can cause endocrine disruption has existed since the early 1930’s. The issue gained significant public awareness in the 1950s and 1960s, with the discovery that DDT, a widely used and declaredly “safe” pesticide, had significant endocrine disrupting properties. Towards the end of the 20th century, evidence began to accumulate that chemicals such as pesticides, surfactants (used in detergents) and synthetic birth control drugs were causing skewed sex ratios, reproductive disorders, and population declines in frogs, alligators and fish. There is little peer-reviewed data to indicate the same relationship in humans. The threat however is real, and endocrine disruption continues to be one of the largest fears related to many emerging contaminants.
Some researchers have suggested that Antibiotics and Antimicrobials can pose a serious threat to human health by enhancing the antibiotic resistance of disease-causing microorganisms due to their (over)use in products such as soaps, mouthwash, toothpaste, and of course the ubiquitous “hand sanitizer”.
Another Category of concern is pathogens. Some of these infectious agents can survive and even thrive after water treatment and can reproduce in downstream piping systems. The most concerning at the moment are Naegleria fowleria (it eats your brain), Legionella pneumophila (It kills you though your lungs), Helicobacter pylori (Stomach cancer and ulcers), and Adenovirus that causes flu-like systems and gastrointestinal distress.
While this might be scary to some, or a simple consequence of “better living through chemistry” to others, we owe it to ourselves to learn more about the types of contaminants that we will see more of in the media and be asked to address by our clients.
|Class of Contaminant||Definition||Example|
Low molecular medications produced by a microorganism that at a low concentration inhibits or kills other microorganisms.
|Penicillin, Carbapenems, Cephalosporins, Tetracyclines|
Chemicals that kill or inhibit the growth of microorganisms such as bacteria, virus, protozoa, and fungi without significantly damaging the host.
Compounds formed from the breakdown of detergents in wastewater treatment processes, or interacting with the environment
Alkylphenol ethoxylates (APEs): Nonylphenol, octylphenol
Chemical agents used on inanimate surfaces to destroy, neutralize, or inhibit the growth of disease-causing microorganisms
|Alcohols, Aldehydes and oxidizing
Compounds formed from the interaction of organic matter in
water with disinfection agents such as chlorine or chloramine
|Estrogenic compounds and Xenoestrogens||
Natural or synthetic chemicals that can elicit an estrogenic response or mimic estrogenic compounds
|Estrone, Estradiol, Nonylphenol,
Materials or coatings that inhibit or resist the start or spread of fire
Polybrominated Diphenyl Ethers
Compounds to impart pleasant odors
Chemicals applied to skin or other surfaces to discourage
insects from touching the surface
|PAHs (poly-aromatic hydrocarbons)||
Chemical compounds found in the environment as a
result of incomplete burning of carbon-containing materials like fossil fuels,
wood, or garbage
Microorganisms that have been discovered recently, identified in a new area or new mode of transmission, and are known to cause serious human disease
|Naegleria fowleri, Legionella pneumophila, H. Pylori, Adenovirus|
|Personal Care Products||
Substances used in a diverse group of personal items including
Toiletries, grooming aids, lotions, moisturizers, and cosmetics.
|Pesticides or Insecticides||
Compounds that kill, incapacitate or otherwise prevent pests from functioning.
Permethrin, Fenitrothion, Bacillus
thuringiensis israelensis (B.t.i.
Medicinal compounds used in the prevention or treatment of disease and/or illness.
Fluoxetine (Prozac), Carbamazepine,
Diphenhydramine, Sildenafil Sulfate
Additive compounds that increase the plasticity or fluidity of a material
|Dioctyl Phthalate (DOP)|
Organic compounds whose purpose is to Stimulate/support certain reproductive functions
Progesterone, Estrone, Estradiol, Testosterone
Chemicals other than water, capable of dissolving other substances.
Fat-soluble organic compounds with a characteristic
molecular structure, which includes many natural and synthetic hormones
Cholesterol, Coprostanol, Estrone,
Compounds that affect the surface tension of a liquid
|Sodium Lauryl Sulfate|
If you consider the list above, you are virtually guaranteed to encounter a contaminant of (emerging) concern at some point, since most are substances that we use every day for all kinds of beneficial purposes, which get flushed, washed, used, or otherwise discarded and end up in water and soil. Some are even parts of the containers, fixtures, piping materials, or even filter housings that we use in bringing cleaner water to our clients.
The true nature of the effects of these contaminants on our health is largely unknown, since some of them are so difficult to test for, and there are many interfering factors. Since multiple, continuous sources of exposure to these contaminants exist in the environment, it will continue to be very difficult to define true causal relationships, so the safest path is to avoid ingestion, especially through drinking water.
Addressing these contaminants is particularly concerning, since testing is time-consuming and expensive, other contaminants can interfere with treatment processes, and these contaminants are quite robust. Currently, Advanced Oxidation processes, Membrane separations, and Activated Carbon Adsorption hold the most promise in cost-effectively addressing these threats.
As technology moves forward our knowledge an understanding will continue to expand. We need to take a cautious, measured approach while keeping the health, safety, and peace of mind of our clients at the forefront of what we do.