Understanding Chlorine: How It Works to Disinfect Water

Introductory Note:  The article below is adapted from information from Blue-White Industries.  It provides a good explanation for the frequently misunderstood terms free chlorine, total chlorine and combined chlorine.

For over a century, chlorine has been used to provide clean drinking water to communities in the U.S. and across the world. In the correct doses, chlorine can kill a broad range of pathogens while remaining safe for people and animals to consume. The key is dosage, as too little chlorine will not have the disinfecting power required to eliminate the most critical pathogens. Too much chlorine can cause water to taste and/or smell unappealing, or worse, have long-term negative impact.

Measuring chlorine isn’t a simple matter of saying, “I have X parts per million in my water.” After all, once chlorine enters water, it begins to change, and when it interacts with pathogens and other matter, it changes again.  There are technically three measurements that must be considered: free chlorine, combined chlorine, and total chlorine.

How Chlorine Works

In water, chlorine breaks down into smaller chemicals such as hypochlorite ion and hypochlorous acid. It is these substances that kill bacteria, viruses, and other microorganisms. They do this by either collapsing proteins in bacterial cells or damaging the outer membrane of viruses and similar pathogens. Not every pathogen is equally vulnerable to chlorine, however. Protozoa such as Giardia lamblia and Cryptosporidium are chlorine-resistant. Fortunately such pathogens are large and can be easily removed via filtration.

Free Chlorine

“Free chlorine” is the amount of chlorine that is available to combine or oxidize contaminants in water. The greater the amount of free chlorine, the greater the disinfection potential. In a drinking water system, the amount of free chlorine should generally be kept between 2 ppm and 4 ppm. When free chlorine levels rise above 4 ppm, the water may take on a strong “swimming pool” smell or taste.  However, too little chlorine means there may not be enough chlorine available to disinfect pathogens.

Combined Chlorine

When hypochlorite ions and hypochlorous acid interact with contaminants, they form new compounds. Generally speaking, these new compounds are no longer available for disinfection. The amount of combined chlorine measures how many pathogens or other contaminants have been using chlorine, which helps to understand how dirty the water is (or was).

Of course, not all combined chlorine chemicals are inert. When chlorine combines with nitrogen, it can form chloramines. These compounds do have some disinfection power, but they are not likely present in high enough quantities to be considered in disinfection potential (unless operators deliberately added ammonia to the system with the intent of forming chloramines).

Other types of combined chlorine include disinfection byproducts (DBPs), such as trihalomethane and haloacetic acid. These substances occur when chlorine reacts with natural organic matter in the water. DBPs can be harmful to human health and are regulated by th the U.S. EPA.

Total chlorine

As the name suggests, this measures the total amount of both combined chlorine and free chlorine. Total chlorine is the easiest to measure and can be done with simple test strips. If you want to test your city water for chloramines, you need a test kit that tests “Total Chlorine.”



Reference Source:  Water Online. 

The Truth About NSF/ANSI/CAN 61 And PVC Pipes

By Dave Purkiss

The ‘Perils of PVC Plastic Pipes’ report published by the Environmental Health Sciences, Beyond Plastics, and Plastic Pollution Coalition contains a great deal of misinformation. While those who are familiar with NSF’s credibility and prominence in the public health and safety arena could spot the misleading and false information in the report, people who have not heard of NSF may not understand the report contained a lot of delusive information.

Who Is NSF?

NSF is an independent, not-for-profit organization with a mission of improving global human and planet health. It takes its mission very seriously. NSF provides testing, auditing, and certification services to help assure suppliers, retailers, regulators, and consumers that an independent organization has reviewed a product or system to comply with specific standards for safety, quality, sustainability, or performance.

As a completely separate operation from NSF’s testing and product certification services, NSF is an ISO accredited standards development organization that coordinates committees of stakeholders, including government regulators, product users (such as water utilities), and product manufacturers to develop and maintain standards such as NSF/ANSI/CAN 61: Drinking Water System Components – Health Effects.

NSF laboratories and certification programs are accredited to ISO 17025 and 17065, to which impartiality is a key feature, by the American National Standards Institute (ANSI), the Standards Council of Canada (SCC) and the International Accreditation Service (IAS). This verifies NSF’s integrity and independence. To maintain accreditation, NSF is audited annually by all three accreditation bodies.

Independent testing means that if a product does not meet the rigorous requirements of a standard, it will not pass or receive certification. As an independent, accredited third-party certifier, NSF tests and certifies a variety of pipe materials, including ductile iron, copper, and cement – not just plastics. The safety evaluation procedures are pre-determined, publicly available ANSI consensus standards that cannot be directly influenced by any one product manufacturer. This is an example of NSF’s impartial work and shows there is no incentive to favor one product material over another.

NSF’s Independent Process

NSF receives no government funding for its standards or certification services, which are done via a feefor-service model in place since its founding in 1944 as part of the University of Michigan’s School of Public Health. This fee-for-service model is the standard practice for certification in most industries and is widely accepted by both industry and federal regulators. Payment for testing services has absolutely no bearing on whether a product will achieve NSF certification or not. In fact, many products do not pass product testing and either must be reformulated for retesting to pass with certification or receive no certification. Approximately 17% of all products initially submitted to NSF for testing fail to meet the NSF Confidential requirements, and those products are kept out of the marketplace. This goes for any standard, not just NSF/ANSI/CAN 61.

As a nonprofit organization, the cost of operating NSF’s laboratories, auditors, toxicologists, scientists, and engineers is covered by the fees charged for certification services.

Certified product manufacturers do not have input on the safety assessment of their products. Testing is conducted in NSF laboratories and any chemical migration is evaluated against published criteria established by NSF toxicologists and externally peer reviewed by the Joint Peer-Review Steering Committee and/or the HAB (Health Advisory Board).

Derivation of drinking water criteria is conducted per NSF/ANSI/CAN 600 risk assessment procedures. These procedures are publicly available and have been peer-reviewed by the standard Joint Committees, the NSF HAB, and the Council for Public Health Consultants (CPHC). Toxicologists that develop drinking water criteria according to these procedures do so independent of client interaction. A pass or fail outcome is reported to the manufacturer.

NSF’s Standard Development

NSF’s standards development process is also approved by the ANSI and SCC. NSF leads the development of voluntary standards that promote public health, safety, sustainability assessment, and the environment. Standards are developed through a public process that ensures balanced input from industry representatives, public health and regulatory officials, certification bodies and testing labs, and users. NSF’s standards development and testing services are distinctly separate and do not jointly operate to maintain NSF’s impartiality, the ANSI and SCC accreditation, and to ensure an independent process.

NSF standards are recognized worldwide and have been adopted in many countries. NSF is dedicated to improving drinking water standards and proudly collaborates with the World Health Organization (WHO) Center of Excellence on drinking water. NSF standards are accepted throughout the industry and are even used by its competitors.

NSF is confident the NSF standard and certification process are thorough, robust, and protective of public health. The NSF standards process is open and transparent for anyone to suggest improvements or changes through the Drinking Water Additives Joint Committee. This committee has a balanced representation of regulators, users, and product manufacturers.

Manufacturers are included in this process due to their practical experience and knowledge of how products can realistically be made. Without manufacturers involved in standard development, the process would face challenges remaining grounded in reality of what can feasibly be produced. This is similar in how people who may not have experience in building cars cannot tell car manufacturers how to build them to meet all their wants and needs. An experienced car professional would need to be present to share knowledge of what of those wants and needs can realistically be produced.

In addition, health effects criteria are also balloted by the NSF Council of Public Health Consultants whose membership includes only representatives from government/regulatory, academia, public health, and public service; there is no industry representation.

As for the standard review process, a two-thirds majority rule vote is required to pass the relevant joint committee, and then a 90% majority vote to pass the CPHC (Council of Public Health Consultants). Any negative votes and comments at both voting stages must be addressed and adjudicated. The general public can also comment on ballots during the joint committee voting period. The final CPHC public health ratification step helps us ensure our mission of improving and protecting public health.

NSF’s Testing Process

NSF has certified PVC pipe to NSF/ANSI/CAN 61 since 1989. Currently, NSF has over a thousand products certified from over 70 companies. The certification process requires manufacturers to provide product formulation information including the identity of suppliers and tradenames of formulary ingredients; however, these data are verified through NSF’s independent inspections of production facilities and extensive independent testing at NSF laboratories.

NSF requires formulation disclosure from the manufacturer as would be consistent with any regulator review. Application of the NSF mark is contingent upon use of this authorized registered formula (ARF). Any changes must be reported to maintain certification and may require additional testing. On-site, unannounced audits are in place to ensure that the raw materials used to make the certified product are as specified on the ARF including review of reported supplier and tradename designations. The auditor then reviews the accuracy of purchasing, production, shipping, training, and quality control records, and verifies that production is within the requirement of the product standard and certification policies.

Once NSF-certified, each PVC plastic pipe production facility receives at least two inspections per year. In addition to annual testing, each NSF-certified product family is tested annually for NSF/ANSI/CAN 61 and minimum of twice per year for residual vinyl chloride monomer (RVCM). Testing requirements for plastic pipe in contact with drinking water are outlined in the publicly available NSF/ANSI/CAN 61 drinking water standard. In addition, the level of allowable exposure to any chemical leachate is provided in the publicly available NSF/ANSI/CAN 600 standard.

NSF does not disclose test reports publicly because they contain confidential information about product design and formulation that could be used by a company’s competitors to reverse engineer a similar product. If this information were made public, this would discourage manufacturers from seeking independent testing and could negatively impact end users by having fewer certified products available to choose from. To obtain certification, manufacturers are required to submit detailed information regarding their product formulation and design. For that reason, NSF only releases test results to the organization seeking certification. That organization is then free to release the report if they choose, but only in its entirety. The certification process itself is highly transparent.

Chemicals in Question

Endocrine Disruptors

NSF has recognized endocrine-disrupting chemicals as threats to public health and has conducted risk assessments to evaluate them further.

2,4-Di-tert-butylphenol was evaluated by NSF in 2012 and the risk assessment was peer-reviewed by NSF’s independent Health Advisory Board. All endpoints were considered including endocrine disruption in the derivation of existing criteria. The peer-review process for the derivation of drinking water criteria is that of consensus, requiring a balance of expertise from industry, academia, and regulatory authorities in addition to participation of toxicology experts employed by NSF. Acceptance of drinking water criteria by the Health Advisory Board requires unanimous approval.

Importantly, evaluation of endocrine disruption is an iterative process that requires definitive evidence of endocrine disruption in vivo in Level 4 and preferably Level 5 animal studies according to OECD protocols (see OECD 2019). Evidence for endocrine activity in screening assays does not provide definitive evidence for endocrine disruption but proves the need to conduct further evaluation within higher tier studies.

In 2019, the U.S. EPA (Environmental Protection Agency) and Health Canada critically evaluated the endocrine potential of 2,4-di-tert-butylphenol and found it to be of low risk for endocrine disruption. They stated: “…Expert judgment of the overall data is consistent with the hypothesis that 2,4-di-tertbutylphenol, like other hindered phenols, is expected not to be potentially estrogenic, whereas nonhindered phenols are.” (See Webster et al., 2019). In this assessment, the U.S. EPA and Health Canada conducted the assessment for endocrine activity using new approach methodologies (NAMs) as has similarly been instituted by NSF toxicology. In addition, NSF toxicology and the HAB critically evaluated the available animal data for 2,4-di-tert-butylphenol that are consistent with U.S. EPA and Health Canada’s conclusion.

Although the NSF assessment of 2,4-di-tert-butylphenol is concordant with authoritative body conclusions, it is not publicly available due to inclusion of confidential data. However, NSF strives for transparency and publishes many of its assessments. Recent assessments by NSF that are publicly available and employing these procedures for endocrine evaluation include 4-tert-butylphenol and benzophenone.

NSF acknowledges the need to reassess chemicals periodically to ensure that existing drinking water criteria are based on the latest science. As such, a chemical prioritization and reassessment process was instituted and published in NSF/ANSI/CAN 600 (2021) as Informative Annex 2. These procedures prioritize chemicals with the highest potential health risk based on the chemical hazard (i.e., capacity of a chemical to do harm) and the level of known exposure based on extractive test data. In addition, NSF regularly monitors the published literature for new data that suggests potential for health concern of any chemical with existing criteria per NSF/ANSI/CAN 600.

NSF intends to maintain drinking water criteria to the highest level of scientific rigor to ensure public health protection. Should any party have concerns regarding existing criteria, those comments are welcomed and will be considered within the framework of the chemical prioritization procedures.


It is important to note that not all PVC and CPVC contain phthalate plasticizers. When phthalates or phthalate plasticizers are present in product formulations, those products are tested for phthalate leaching. Phthalates are typically used in flexible PVC tubing to make it pliable. Phthalates are not present in rigid PVC pipe and fittings formulations. The hazards (i.e., the capacity of a chemical to do harm) are indeed of concern for chemical leachates and thus rigorous safety assessments are conducted NSF Confidential for all relevant human health endpoints to identify a level of exposure where the risk that these hazards would occur is negligible or nonexistent. The drinking water criteria established within NSF/ANSI/CAN 600 represent levels of chronic exposure without appreciable risk to human health.

What To Believe?

NSF understands there are a lot of concerns around drinking water systems, and rightfully so. Having safe and clean drinking water is imperative to human health and not something to be taken lightly. Our impartial work to help protect global human health in this sector shows how seriously we take this. That is why it is so important to NSF that when reports that come out that make false and misleading claims that we set the facts straight and give the public the full picture. NSF is dedicated to operating on fact and science and will continue to educate the public on what is really going on in their drinking water systems.

Dave Purkiss is Vice President of the Global Water Division at NSF.

Article Source: Water Online.

Water News for May, 2023

Posted May 8th, 2023

Water News for May, 2023


Home of the EPA in Washingfton, DC

The US Environmental Protection Agency is taking unprecedented enforcement action over PFAS water pollution by ordering the chemical giant Chemours’ Parkersburg, West Virginia, plant to stop discharging extremely high levels of toxic PFAS waste into the Ohio River. The river is a drinking water source for 5 million people, and the EPA’s Clean Water Act violation order cites 71 instances between September 2018 to March 2023 in which Chemours’ Washington Works facility discharged more PFAS waste than its pollution permit allowed.

The agency also noted damaged facilities and equipment that appeared to be leaking PFAS waste on to the ground. The chemicals are ubiquitous and linked at low levels of exposure to cancer, thyroid disease, kidney dysfunction, birth defects, autoimmune disease and other serious health problems, writes Tom Perkins. The step by the EPA drew praise from some environmental groups, but at least one noted the permit still allows high levels of PFAS pollution and may not adequately protect the environment and human health.  The Guardian.

The U.S. Environmental Protection Agency has ordered the Chemours Company to take corrective measures to address pollution from per-and polyfluoroalkyl substances (PFAS) in stormwater and effluent discharges from the Washington Works facility near Parkersburg, W. Va.  This is the first EPA Clean Water Act enforcement action ever taken to hold polluters accountable for discharging PFAS into the environment.

Five leading water associations — the American Water Works Association (AWWA), Association of Metropolitan Water Agencies (AMWA), National Association of Clean Water Agencies (NACWA), National Association of Water Companies (NAWC), and Water Environment Federation (WEF) — have submitted formal policy recommendations to Congress and the White House on establishing a permanent federal low-income household water assistance program (LIHWAP), according to an AMWA press release.

As part of their recommendations, the groups released also released a detailed analysis, “Low-Income Water Customer Assistance Program Assessment Study,” which establishes that water affordability is a significant challenge for 20 million U.S. households and puts the annual need for federal funding to address this challenge as high as $7.9 billion.

The U.S. Environmental Protection Agency (EPA) announced $2,499,579 in research grant funding to Texas Tech University for research on the behavior of perchlorate after fireworks events near water sources.

“Protecting our water resources and ensuring clean drinking water is one of EPA’s top priorities,” said Chris Frey, Assistant Administrator of EPA’s Office of Research and Development. “With this research grant, Texas Tech University will be able to provide states and utilities with further knowledge on how to protect drinking water from perchlorate contamination.”

Perchlorate is a chemical used in rocket propellants, explosives, flares and fireworks. Recent increases in the use of fireworks have caused concern over potential increases of perchlorate in ambient waters that serve as sources of drinking water. Perchlorate in drinking water sources can be a health concern because above certain exposure levels, perchlorate can interfere with the normal functioning of the thyroid gland. Prior research has investigated water contamination from fireworks; however, there are gaps in understanding the magnitude and extent of perchlorate contamination before, during, and after fireworks are discharged around drinking water sources.  (The best way to remove perchlorate from drinking water is reverse osmosis.)

Racial and ethnic divide in concerns about drinking water quality

An ongoing national poll has found that most adults in the country are significantly worried about contaminated drinking water — results that are notably higher for minority consumers.

“Over the past two decades, Gallup has consistently found that Americans worry more about pollution of drinking water than other environmental concerns,” Gallup reported. “In response to Gallup’s annual environmental polls from 2019 to 2023, 56% of Americans overall said they worry ‘a great deal’ about pollution of drinking water. However, that sentiment was expressed by 76% of Black adults and 70% of Hispanic adults, compared with less than half (48%) of White adults.”

Across all adults polled, 56% indicated that they worry about pollution of drinking water “a great deal” and 24% indicated that they worry about it “a fair amount.”

Gallup attributed the racial disparity to the prevalence of major drinking water contamination emergencies in communities of color, like Flint, Michigan and Jackson, Mississippi.

“Racial and ethnic differences in concern about drinking water likely stem from a mixture of direct experience and media coverage of disasters that have disproportionately affected minority communities,” according to Gallup. “Many low-income Black and Hispanic Americans live in areas with aging infrastructure … Black and Hispanic Americans’ greater likelihood to worry about tainted water suggests a lack of faith in regulators to keep the public safe in light of crises like those in Flint and other cities with large communities of color.”

Indeed, communities of color are disproportionately impacted by drinking water contamination issues, giving them good reason to feel concerned about it. Another recent study found they are more likely to consume one of the most high-profile classes of contaminants than others.

“Residents of communities with bigger Black and Hispanic populations are more likely to be exposed to harmful levels of ‘forever chemicals’ in their water supplies, a new study has found,” per The Hill. “This increased risk of exposure is the result of the disproportionate placement of pollution sources near watersheds that serve these communities.”

As these communities face significant drinking water quality issues and their concerns about these issues grow, water system operators and regulators clearly have a long road ahead in establishing more public trust.


Research reported  in The Guardian  indicates that by the end of the century up to 70% of California’s beaches could be gone.

Basic Heavy Duty Whole House Cartridge Filters



Tough, versatile 20-inch “Big Blue” housings can be used alone or in a variety of combinations to meet virtually any “whole house” filtration situation. They are simple, durable, easy to install, and easy to service. They use standard-sized cartridges so replacements are easy to find. Parallel installation, as pictured below, make them suitable for even large homes.  Installing in parallel greatly reduces pressure loss, enhances the effectiveness of the unit,   and extends the life expectancy of the cartridges.

Cartridge filters are much easier to maintain than tank-style filters.  As for installation, they care compact in size and do not require electricity or connection to a drain.  Most require only an annual cartridge change, which can usually be done by the homeowner.


The  chart below shows sizing suggestions for whole house filtration for water that is treated with chlorine or chloramine.




To Determine Pricing

System 1. One 4.5″ X 20″ 5 micron sediment filter plus one 4.5″ X 20″ high performance carbon filter. Homes with 1 to 3 people. Flow rates to 5 gpm. Price is the same as WH103 on this page.
System 2. One 4.5″ X 20″ 5 micron sediment filter plus two 4.5″ X 20″ carbon filters installed in parallel. Homes with up to 5 people. Flow rates to 10 gpm. Price is the same as one WH103 and one WH102 on this page.
System 3. One 4.5″ X 20″ 5 micron sediment filter plus three 4.5″ X 20″ carbon filters installed in parallel. Homes with up to 8 people. Flow rates to 15 gpm. Price is the same as one WH103 and two WH102 on this page.


Basic Housing and Bracket Setup. The Housing is available for 3 pipe sizes–3/4″, 1″, or 1.5″.  This very versatile “Big Blue” housing will accept any standard 4.5″ X 20″ cartridge. It can be used for sediment cartridges, carbon cartridges, or “media” cartridges for special purposes like iron removal or pH increase.




compactwhdoubleTypical Sediment Carbon Arrangement  (System 1 above.)


Sediment filter with parallel carbons  (System 2 above.)


Sediment filter with three carbons  (System 3 above.)


System 1, pretreating for a TAC unit


Sediment, Triple Carbon (System 3) , pre-treating for a TAC unit. 


Upending A Decades-Long Theory Of Reverse Osmosis Water Desalination

The process of reverse osmosis has proven to be the state-of-the-art method for removing salt from seawater and increasing access to clean water. Other applications include wastewater treatment and energy production.

Now a team of researchers reveal in a new study that the standard explanation for how reverse osmosis works — one that has been accepted for more than five decades — is fundamentally wrong. In the process, the researchers offer an alternate theory. Besides correcting the record, these insights could lead to more effective uses of reverse osmosis. The results of the study, led by the lab of Prof. Menachem Elimelech, are published in Science Advances.

Reverse osmosis — a technology first put to use in the 1960s — removes salt and impurities from water by passing the water through a semipermeable membrane, which allows the water to go through while blocking the contaminants. To explain exactly how it works, researchers have used the theory of solution-diffusion. This theory assumes that the water molecules dissolve and diffuse through the membrane by way of their concentration gradient — that is, the molecules move from areas of high concentration to wherever there are fewer molecules. Although this theory has been widely accepted for more than 50 years and is even taught in textbooks, Elimelech said he has long had questions about it. membranediagram02

“Some of the assumptions do not make any sense,” said Elimelech, the Sterling Professor of Chemical and Environmental Engineering. For instance, he said, the theory is based in part on the idea that pressure across the membrane is constant. “Whenever you have water flow through any porous material, there is always a pressure drop.”

To get a better sense of the physics involved, the research team — which included scientists from the University of Wisconsin-Madison and Texas Tech University — did a combination of experiments and computer simulations. Specifically, they used simulations of the molecules’ movements, which revealed that water transport is driven by changes in pressure within the membranes. They further show that water molecules travel as clusters through a network of pores in the membrane. This contrasts with the conventional theory based on the solution-diffusion model, which assumes that the water molecules separate from each other in the membranes. Supplementing the computer simulations, the scientists performed experiments that allowed them to observe water passing through membranes. The results showed that the way that water permeates the membrane depends on the membrane pore size, the size of the water molecules, and viscosity of the water. This was also inconsistent with the solution-diffusion model.

Overall, the simulations and experiments demonstrated that, rather than being driven by the concentration of molecules, reverse osmosis is driven by pressure changes within the membrane.

Because previous measurements related to reverse osmosis were based on a faulty understanding of it on a molecular level, Elimelech said, many attempts to advance the field have met a dead end. Having a more accurate theory to explain reverse osmosis, he said, could open the way toward developing more effective materials and techniques to improve the process.

Other authors of the study include Li Wang, Mohammad Heiranian, Hanqing Fan (all from Yale); Jinlong He and Ying Li from University of Wisconsin-Madison; and Lianfa Song from Texas Tech University.

This work was supported by the National Alliance for Water Innovation (NAWI), funded by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE), Advanced Manufacturing Office, under Funding Opportunity Announcement Number DE-FOA-0001905 through a subcontract to Yale University and University of Wisconsin-Madison.

Source: Yale School of Engineering & Applied Science via Water Online.

Pure Water Gazette Fair Use Statement

University of Rhode Island Researcher Contributes To Study Confirming Link Between PFAS – ‘Forever Chemicals’ — In Drinking Water And Weight Gain

A University of Rhode Island researcher leads a study that confirms a direct link between certain chemicals in drinking water and human obesity – specifically that increased PFAS content in blood promotes weight gain and makes it harder to keep a lower body weight after weight loss. Philippe Grandjean, M.D., PhD., is physician who holds a research professor appointment within the URI College of Pharmacy and serves on STEEP, a special URI-led science effort helping the public grapple with manmade PFAS (per-and polyfluoroalkyl substances) pollution, including its presence in drinking water resources.

“We’ve previously shown that children with increased PFAS concentrations tend to gain weight and develop higher levels of cholesterol in the blood,” said Grandjean, a professor of environmental medicine at the University of Southern Denmark, who has researched the human health impacts of PFAS in multiple countries and populations, including children, for decades. “We now focused on adults who participated in an experimental study of five different diets in regard to weight gain. Our results add to the concern that environmental pollution may be affecting our metabolism, so that we tend to gain weight.”

For the recent study, the researchers, using STEEP-affiliated laboratories, analyzed PFAS chemicals in 381 blood samples that were already part of a randomized European Commission clinical trial in Europe focused on weight loss planning for obese adults. No matter the diet that these participants were assigned to, they gained weight if they had elevated PFAS exposures. One particular chemical, PFOA, which is commonly found in contaminated drinking water, demonstrated, more so than other PFAS pollutants, ties to obesity. Furthermore, those participants in the European study with the most PFOA in their blood were found, after a one-year follow-up, to have gained about 10 pounds more than those with low levels.

“Our study adds new evidence that being overweight isn’t just about a lack of physical activity and unhealthy eating habits – PFAS are increasingly suspected to be a contributing factor,” said Grandjean. “The PFAS exposures in the European participants are quite comparable to levels in America, so my concern is that our exposures to PFAS are making it difficult for us to avoid getting overweight.”

The study results are useful, too, for informing the ongoing work of the URI STEEP – Sources, Transport, Exposure & Effects of PFAS – Superfund Research Center, which employs research, applied science, student education and training, and outreach approaches to build community capacity for responding to PFAS pollution. PFAS, a large and decades-old family of chemicals, infiltrate many human and natural environments – they are colorless, tasteless, and odorless, and often are used to create barriers or stop liquids from seeping. The chemicals coat pizza boxes and microwave popcorn bags, nonstick cookware, and waterproof clothing, and stop stains from sinking into carpet and furniture.

The heavily used “forever chemicals” have also leached into water, from marine habitats to drinking water resources, with STEEP committing significant effort toward ensuring sound science informs public dialogue about enhancing protections for supplies. “The hard science is the main tool the government has upon which to make changes that move us closer to either lessening or removing PFAS from our water, our lives, our environments,” said Rainer Lohmann, a URI chemical oceanographer and STEEP research director. “PFAS presents a long-term challenge, but we are making steady progress.”

And increasingly, said Lohmann and Grandjean, public policy discussions at the federal and state levels are focused on determining regulatory and legislative paths forward to potentially lower PFAS levels in drinking water sources across the country. “The EPA has recently proposed binding guidelines for water contamination,” said Grandjean. “I hope that the new regulation will be successful, and now I have an additional reason to hope.”

The study appears in the current issues of Obesity, the official journal of The Obesity Society. The National Institute of Environmental Health Sciences (NIEHS) funds STEEP through a Multi-project Center Grant awarded by the NIEHS Superfund Research Program (SRP). The SRP funds university-based multidisciplinary research on human health and environmental issues related to hazardous substances. To learn more about the ongoing URI STEEP Project, a partnership of the University of Rhode Island, Harvard University, and the Silent Spring Institute, visit https://web.uri.edu/steep/.

Source: University of Rhode Island via Water Online.



Water News Briefs

Posted April 20th, 2023

Water News Briefs for April 2023

Lead Pipe Replacement Moves at a Snail’s Pace

In 2018, almost 30 cities across New York state received federal money to carry out a specific, urgent task: removing lead service lines that poison drinking water. The city of Troy – which sits across the Hudson River and just north of Albany – was among them, receiving $500,000. But five years later, city leaders have failed to spend a single dollar of that money, and have yet to remove a single lead pipe. The revelation emerged at a city council meeting this winter, raising all sorts of questions. Chief among them is why the city hasn’t spent the money. Troy’s failure illustrates the challenges small cities face when trying to address environmental injustices like lead pipes.  Full article from The Guardian.


World’s Ocean Temperature Hits All-Time High

The temperature of the world’s ocean surface has hit an all-time high since satellite records began, leading to marine heatwaves around the globe, according to US government data. Climate scientists said preliminary data from the National Oceanic and Atmospheric Administration showed the average temperature at the ocean’s surface has been at 21.1C since the start of April – beating the previous high of 21C set in 2016. “The current trajectory looks like it’s headed off the charts, smashing previous records,” said climate scientist Prof Matthew England. Hotter oceans provide more energy for storms, as well as putting ice sheets at risk and pushing up global sea levels, caused by salt water expanding as it warms. Marine heatwaves can also have devastating effects on marine wildlife and cause coral bleaching on tropical reefs. The Guardian.

Railroads Follow Rivers.

Decisions made more than 150 years ago about where to run railroad tracks have significant consequences today when trains derail. That’s because rail lines usually follow rivers. At a time when climate change is altering rainfall and flooding patterns increasing the risk of washouts and mudslides on tracks, it is increasingly risky and irresponsible to run large trainloads of petroleum and hazardous chemicals along the banks of rivers. The Colorado River, for example, furnishes water for 40 million people.  A significant derailment along the Colorado could be devastating. USA Today.

Industry Knew about the Dangers of PFAS Decades Ago, but Kept It Secret

Industry sponsored studies documented PFAS toxicity in 1978 but this information was not shared with the US EPA until 2000. PFAS have been linked to a range of health problems, including testicular and kidney cancers, decreased birth weight, and thyroid disease. While most companies have stopped producing two forms of PFAS— perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)—the chemicals persist in drinking water systems, and new forms of PFAS are raising concerns. This revelation underlines the basic truth that allowing industry to voluntarily regulate itself does not work. Strong governmental oversight is essential.


Ice Sheets Are Shrinking Much Faster Than Predicted

New research shows that the massive ice sheets at the top and bottom of our planet are shrinking much faster than previously thought. The international study compiled satellite measurements over time and depicts what one researcher described as a “devastating trajectory.” PBS News.



Garden Hose Art Like the Decorative  Basket Above  Was Once Featured in National Garden Hose Day Events


National Garden Hose Day Is On the Ropes Because of the Political Climate

National Garden Hose Day,  a lusty national holiday celebrated in June, reached peak popularity as an early summer good time event in the years preceding the pandemic.  Garden Hose Day festivities were curtailed beginning in 2020 due to public health concerns, and, unfortunately, efforts to bring the holiday back have faltered because of the divisive political climate.

Many US cities have already cancelled Garden Hose celebrations this year because of fears of transgender participation in the Garden Hose Tug, a tug of war event that is often the center of Garden Hose festivities. Critics also point out that the garden hose is not mentioned either in the Bible or the US Constitution and that the shape of the garden hose itself has sexual implications and should not be seen by children under 18. In Texas and Mississippi there are now bills before the state legislature to remove books from libraries that have pictures of garden hoses.

(Since fake news has become so common that it’s hard to recognize these days, the Pure Water Gazette wishes to advise that the article above is completely phony. Please do not sue or write abusive letters. While we’re at it we’ll confess to having invented and shamelessly promoted a non-existent holiday for a number of years. To our credit, we did not try to sell you a Monkey Pox tee shirt or a NFT depiction of Garden Hose Superman blasting the enemies of the Second Amendment with a high powered fire hose. Here’s a Garden Hose Day article from 2013, back in the good old days before politics got so nasty that you couldn’t enjoy a good old summer Garden Hose Tug or Hose Blast competition.)


Can Water Cause Weight Gain?

Important research published in the journal Obesity establishes a definite link between weight gain and PFAS in drinking water. “Our study adds new evidence that being overweight isn’t just about a lack of physical activity and unhealthy eating habits – PFAS are increasingly suspected to be a contributing factor.”  The PFAS exposures in the European participants are quite comparable to levels in America, so my concern is that our exposures to PFAS are making it difficult for us to avoid getting overweight.”  Full article in Pure Water Gazette.






Camp Lejeune Toxic Water Case Payout Could Top $21 Billion


by Peter Chawaga



Camp Lejeune served its soldiers and their families highly contaminated water over a period of 24 years


“Hundreds of thousands of veterans and their relatives exposed to cancer-causing drinking water on the North Carolina Marine base are expected to file claims,” Bloomberg Law reported. “The bill lawmakers passed last summer acknowledged the government’s culpability and had an estimated price tag of $6.1 billion. The Congressional Budget Office says that total could balloon in later years by another $15 billion.”

The issues with Camp Lejeune’s water date back decades, with some speculating that chemicals leaking from a dry-cleaning operation nearby were originally to blame. Service members and their families were exposed to the dangerous effluent for more than three decades, and the recent Congressional act gave anyone who spent more than 30 days on the base between 1953 and 1987 the chance to file a civil claim. As a result, law firm advertisements offering to represent victims have proliferated.

Camp Lejeune served its soldiers and their families highly contaminated water over a period of 24 years

“Law firms and legal marketing agencies spent more than $145 million on advertising last year in a bid to recruit them,” according to Bloomberg Law.

But despite the federal clearance and eagerness of legal representatives, victim health claims have been slow to resolve.

“Even though Congress passed a law last August giving Camp Lejeune victims two years to sue for damages in federal court, the process of compensating the thousands of people affected by the contamination is moving at a snail’s pace,” according to Roll Call. “The Navy and Marine Corps, which have denied responsibility for causing health problems at the base since the contamination was first discovered in 1982, have taken no action on about 20,000 damage claims filed with the Navy Judge Advocate General after the legislation was signed into law.”

As the claims pile up and legal firms continue to push toward resolution per the Congressional approval, it’s clear that this decades-long saga over one of the most shocking drinking water contamination issues in American history is far from over.

“Here we are six-plus months since the bill was passed and to my knowledge not one claim has been settled, not one offer has been made,” Mike Partaine, a man who was born at Camp Lejeune and has since been diagnosed with breast cancer, told Roll Call. “Why is it taking so long? That’s what the community has been saying too.”

To read more about how water systems address harmful chemicals, visit Water Online’s Drinking Water Contaminant Removal Solutions Center.

Water Online

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Water News Briefs

Posted March 21st, 2023

Water News Briefs for March 2023

New studies reveal that toilet paper can be a serious contributor to PFAS levels found in wastewater. Phys.org. For information about the origin of PFAS in toilet paper and significance, see the excellent Guardian report.

Lake Mead continues to shrink and is now at the lowest level it has been since it was first filled. “Lake Powell, the nation’s second-largest reservoir and one that provides water and power to millions of people in southern California, has reached its lowest levels since its first filling in the 1960s,” USA Today reported. “If the lake’s level falls much lower, it won’t be possible to get water out of it … If the lake falls another 32 feet — about the amount it fell in the past year — power generation concerns become more urgent.”  Pure Water Gazette. Ironically, as many areas suffer with record drought, recent storms have filled some California lakes to their highest level in years. Newsweek.

Alarmingly high levels of PFAS have been found in lakes in Alaska’s two largest cities,  Fairbanks and Anchorage.  Some lake water has PFAS levels 1000 times what is considered safe for drinking water. “Use of PFAS compounds began in the 1950s, and there are thousands of them. Most famously, they are found in flame-suppressants. Most of the environmental PFAS contamination in Alaska and many other places is believed to have been caused by use of those firefighting foams at airports, where their use is mandated by the Federal Aviation Administration. Military sites are also known for using such foams. But the PFAS compounds are widespread in consumer and industrial products like nonstick cookware, clothing, upholstery and personal-care goods such as shampoos. They are called “forever chemicals” because they do not degrade.”  Alaska Beacon.

An estimated 8,100 gallons of latex finishing material, a water-soluble acrylic polymer solution, was released into Otter Creek in Bristol, Pennsylvania, on March 25. Boil water alerts are expected. Yahoo.

The EPA has determined that US military bases with cancer-linked PFAS-contaminated drinking water have been significantly undercounted. “Data obtained from the Department of Defense (DOD) by the Environmental Working Group (EWG), under the Freedom of Information Act, show that locations with notably high levels of total PFAS include Fort Leavenworth, in Kansas; the Joint Forces Training Base, in California; Belmont Armory, in Michigan; McChord Air Force Base, in Washington; Fort Hunter Liggett, in California; and the Sierra Army Depot, in California.” When water at military bases is contaminated, communities in their vicinity are usually at risk as well.  Water Online.

The EPA has released new draft Maximum Containment Levels (MCL) for PFOA and PFOS (collectively part of the group of chemicals known as PFAS) permissible in drinking water at a national level.  The new allowable levels are 4 ppt for PFOA and 4 ppt for PFOS.  For context, one part per trillion is one drop per 21 million gallons of water.  See the full article below from Environmental Health News for details.

Chinese archaeologists discovered what may be one of the world’s oldest manual flush toilets — dating back 2,200 to 2,400 years, per Live Science.

A massive 5,000-mile seaweed bloom is approaching the Florida coast and threatening water quality. The seaweed, known as sargassum, can tangle up boats and other marine machinery, release dangerous hydrogen sulfide, and inundate beaches. The seeweed is laced with heavy metals like arsenic which make disposal and reuse extremely difficult. Research suggests the causes for this massive bloom are related to climate change and are similar to those that have been driving increases in source water algal bloom, which threatens drinking water quality, across the country.  Water Online.


Are We Slowly Dying of Thirst?

The world is facing an imminent water crisis, with demand expected to outstrip the supply of fresh water by 40% by the end of this decade, experts have said on the eve of a crucial UN water summit. Governments must urgently stop subsidising the extraction and overuse of water through misdirected agricultural subsidies, and industries from mining to manufacturing must be made to overhaul their wasteful practices, according to a landmark report on the economics of water. Nations must start to manage water as a “global commons”, because most countries are highly dependent on their neighbors for water supplies; and overuse, pollution and the climate crisis threaten water supplies globally, the report’s authors say.  — The Guardian.  Lkewise, the U.N. issued a warning that “vampiric overconsumption” is rapidly depleting the world’s water supply. BC Water News.


The world’s oceans are permeated with plastic waste, from surface waters to some of their deepest reaches. And we know from numerous studies that fish, turtles, seabirds and smaller sea creatures are ingesting bits of plastic when they feed. Now, scientists are starting to pin down the effects of a plastic diet.

Marine scientist Matthew Savoca explains findings from a recent study that identified a new illness, which the authors call plasticosis, in seabirds. Scarring in the birds’ digestive tracts resembles effects in humans who are longtime smokers or have been exposed to asbestos. As Savoca sees it, plasticosis “could be a sign that a new age of disease is upon us because of human overuse of plastics and other long-lasting contaminants, and their leakage into the environment.” The Conversation.

Only Fleck 5600  on Our Website Now



By far our most popular backwashing filters over the years have been those built with the reliable and very user friendly Fleck 5600 control. Now only 5600 filters are shown on our website. We made the change to 5600 only for water softeners a couple of years ago and it has worked out well.

The 5600 has size limitations. It works only on filters that need a backwash rate of 7 gallons per minute or less.  If a larger filter than those shown on our site is needed, we can usually supply it, but it can’t be ordered from the shopping cart. We still stock and support the Fleck 2510 models that were recently taken down, but they are available by phone only so that we can assure that they are properly sized. We also sell much larger filters and softeners with Fleck and Nelsen C-Series (Clack) controls that are not shown on the website.

The very popular Fleck 5600 SXT (simple electronics) control, pictured above, is ideal for customer-maintained filters.  No special tools are needed for repairs and parts are easy to find.  We program the control before it is shipped, and changes in programming are easy. We still supply the time-clock version of the 5600 as well for those who prefer it.

Our Fleck 5600 backwashing  filters.