Water News — June 2023

In spite of much publicized environmental consequences, bottled water use is growing rapidly in the UK. “Big water brands are expected to grow more than 10% in the next four years – an equivalent of more than 280m extra plastic bottles. ”  Calling plastic bottled water “a scar on our society,” David Hall, the UK managing director of Brita, noted:  “Plastic bottled water takes about five seconds to make, five minutes to use, and a staggering 500 years to break down in landfill. It’s one of the main culprits of the worldwide plastic pollution crisis.”  The Guardian

3M to stop producing PFAS chemicals by 2025

3M started winding down PFAS production in the 2000s under pressure from the EPA. The company recently announced that it will cease production of forever chemicals entirely by 2025. But the hundreds of millions of pounds of the chemicals the company produced for more than half a century still persist, indefinitely, in the environment. They’re also lingering inside of us: in our blood and our excrement, primarily via the foods we eat and the water we drink.  Reference — Grist  —  3M polluted drinking water with PFAS for decades. Will it have to pay for the clean up? | Grist

Texas Nixes Water Breaks for Construction Workers

In spite of record breaking temperatures and the fact that Texas leads the nation in worker deaths because of heat, Texas Governor Greg Abbott just signed a broad new law that will nullify a wide range of local regulations, including mandated water breaks for construction workers.  Dallas and Austin currently require workers to be given at least 10 minutes to cool down and hydrate every four hours.  Yahoo News.

Could Predatory Bacteria Replace Chlorine?

Research from Lund University in Sweden indicates that harmless predatory bacteria can be introduced into water to eat most other bacteria. This could become a replacement for chlorination.   Interesting Engineering.

The Boring Company, a tunnel-building company founded by Elon Musk, plans to dump 142,500 gallons of wastewater per day into the Colorado River in Texas.  Local residents and food producers are alarmed at the plan and have pushed back strongly against the company’s wastewater permit application. The company plans to do the wastewater treatment itself until a new wastewater treament plant is completed at Bastrop, TX. Yahoo News.

A bridge crossing the Yellowstone River in Montana collapsed on June 24, sending a freight train carrying potentially hazardous materials into the swirling waters below. The derailment forced the shutdown of several drinking water intakes downstream and emergency measures at water treatment plants in neighboring Yellowstone County.  New York Daily News.

Chemical manufacturing giant 3M has agreed pay up to $10.3 billion over 13 years to help municipalities test for and clean up toxic PFAS chemicals in public water supplies. The settlement is trivial compared to the company’s profits from the chemicals and the actual cost of cleanup.

Removal of Groundwater Has Changed the Tilt of the Earth

How safe is America’s drinking water?

There are still millions of Americans without access to clean tap water

by Justin Klawans

While it is generally fine to consume tap water in the United States, there are still millions of Americans who suffer from a lack of safe drinking water. The situation in Flint, Michigan, probably comes to mind, but there are many other areas around the country where drinking water can be hazardous.

Is tap water in America safe to drink?

For the most part, yes. The United States has “one of the safest water supplies in the world,” according to the U.S. Centers for Disease Control and Prevention (CDC). More than 90% of Americans get their tap water from public water systems, the CDC reported, all of which are subject to safe water standards. These standards are enforced by both the U.S. Environmental Protection Agency (EPA) and the Safe Drinking Water Act. The latter “requires many actions to protect drinking water and its sources — rivers, lakes, reservoirs, springs, and groundwater wells” and sets “national health-based standards for drinking water to protect against both naturally-occurring and man-made contaminants that may be found in drinking water.” This includes testing for the presence of dangerous contaminants like E. coli, salmonella, and cryptosporidium.

The CDC admits, though, that contamination can still occur. The most common safety violations are “illegal levels of pathogens (bacteria and viruses), nitrates, arsenic, and harmful byproducts from disinfectants like chlorine,” Maura Allaire, a water quality expert at UC Irvine, told National Geographic. Then there is the commonly held fear of lead exposure from old pipes.

Contamination from lead pipes leeching into the water supply is an ongoing risk, and “the U.S. currently holds approximately 9.2 million lead service lines underground,” ABC News reported. They are a “silent and deadly consequence.” Lead is not the only chemical that has people worried about their water supply. There have been renewed concerns over harmful “forever chemicals,” called PFAs, that can make their way into water systems, some of which have been linked to cancers and reproductive diseases in women.

How many Americans don’t have access to clean water?

In a nation of approximately 335 million, “more than two million Americans live without basic access to safe drinking water and sanitation,” according to the U.S. Water Alliance, and at least 1.4 million of these Americans don’t have access to indoor plumbing at all, the Alliance added.

How Often Should Carbon Filter Cartridges Be Changed?

MatriKX Chloraguard Filter Cartridge, 2.5″ X 9.75″ — Standard Drinking Water Size

The simple and probably the best answer for residential applications is that carbon filter cartridges should be changed at least once a year. The more complicated answer is that it all depends on what you expect of the cartridge, how  much you know about your water, and how willing you are to monitor such things as the amount of water used and the flow rate.

Carbon filters are a very versatile tool that can be applied to many different problems. What they do best and easiest is remove chlorine and improve taste and odor. But they are also the most practical treatment for many more difficult problems, like chemicals in general (see how many times carbon appears as the treatment of choice in this contaminant removal chart),  and very hard to treat items like VOCs and PFAS.

Below is the manufacturer’s lifespan recommendation for the high quality coconut shell carbon block filter pictured above.

• Chlorine: 45,000 @ 1 gpm,
• Chloramine: 4,000 @ 0.5 gpm,
• PFAS: 3,500 @ 0.5 gpm,
• VOC: 750 @ 0.5 gpm,

Note that if your requirement is only the removal of chlorine from drinking water the cartridge should last until you die of old age.  However, if your city uses chloramine rather than chlorine as its disinfectant, it will last only about 1/10 as long, and you’ll have to be sure to run the water half as fast. Running the cartridge at “chlorine speed” will greatly reduce its service life as well as its effectiveness when treating chloramine or difficult contaminants like PFAS and VOCs.

In most cases the once-a year-rule works well and assures excellent performance with most contaminants. If more than a couple of people are using the water and VOCs are a known issue, changing the cartridge twice a year is a good idea.

And then, of course, there are variables to be considered like multi-cartridge filters, position of the cartridge within the unit (a reverse osmosis pre-filter treats much more and much dirtier water than a reverse osmosis post filter), water temperature, pH, etc.  But, for simplicity, the once-a-year cartridge change works pretty well.

Proposed Water Regulations May Not Help The People They Are Supposed To

by Ike Brannon

Gazette Introductory Note: Before you read this article, let me explain what it is about.  The EPA has spent several years trying to decide how much of the “forever chemicals” grouped under the name PFAS can be allowed in US drinking water. This is hard to figure out, especially since they have to find a number that can be more or less acceptable to the interested parties: consumer advocates, environmentalists, public health officials, water utilities, the manufacturers of the offending substance and other business interests that profit from its use, plus loud and often obnoxious elected and unelected officials and lobbyists who represent and take donations from all of the above. Although the EPA will try to rely on science in setting its allowable, the number finally chosen will be a negotiated compromise.

The four parts per trillion PFAS allowable recently announced by the EPA is unlikely to be final. Manufacturers and public water suppliers, who will be pressed to pay for cleanup or face litigation, prefer a higher number. The higher the better. The article below is from Forbes magazine and cites evidence from the Wall Street Journal. This may give a hint about the the concern over the EPA’s low allowable figure. It really isn’t your water bill that Forbes is concerned about.  It is the “existential threat to the companies responsible for these chemicals”  and “the enormous impact that the EPA’s actions have on businesses.” Not even mentioned are your daughter’s miscarriage or your aunt’s liver cancer.  Nor do they bring up the billions upon billions of dollars that 3M and other companies have taken in during the seven decades that they sold these products while knowing that they had devastating public health consequences.–Gene Franks.

Late last year the Environmental Protection Agency proposed a new set of rules that would designate perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) – two types of per- and polyfluoroalkyl substances (PFAS) – as hazardous substances, and other regulations that would reduce the allowable level of these substances in the drinking water to just four parts per trillion.

These stringent limits—which go beyond the UN recommendations of twelve parts per trillion as well as those of any other country and approach or exceed what state-of-the-art technology can currently detect—would dramatically increase costs for water treatment facilities, requiring most of them to make new investments in equipment both to detect and remove the substances. The lower threshold would provide a new impetus for future lawsuits.

However, the EPA’s rules could result in unintended consequences and would not necessarily result in a better outcome. For instance, people living in communities both with and without the chemical in their water supply at detectable limits will find themselves paying much higher water bills for the more stringent testing as well as the removal of the chemicals from the water.

While some may argue that we should not let cost deter us from removing potential health costs, it has not yet been established that the EPA threshold is, in fact, the appropriate threshold to establish safe drinking water. If the higher U.N. standard or the even higher standards in place in Europe are sufficiently safe, then the additional costs to get our standard below theirs will have bought us little or no additional protection.

These artificially lower levels will also leave many companies exposed to lawsuits seeking compensation for potential damages from these pollutants. Given that many of these companies have already faced lawsuits that have resulted in them having to pay hundreds of millions of dollars, establishing even lower limits would doubtless subject them to further litigation from community groups, local governments, and class-action lawsuits instigated by tort lawyers seeking a higher payday.

These lawsuits have already begun: The Wall Street Journal reports that over 300 utilities are seeking to recover the cost of filtering the chemicals out of their water, and that the lawsuits seeking damages represent an “existential threat” to the companies responsible for these chemicals, much of which entered the water table via their use in producing a foam used to put out fires.

There are now rumblings of a potential $10 billion settlement between 3M and municipal providers of consumer drinking water. This litigation and potential settlement illustrates the enormous impact that the EPA’s actions have on businesses.

Article Source: Forbes

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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 the U.S. EPA.

Water News for May, 2023

Home of the EPA in Washington, DC

Certainly the biggest water news of the month was the breakthrough agreement of water managers in Arizona, California and Nevada to cut back water use from the Colorado River to keep the river from falling to a level that could endanger the water supply of farms and cities that depend on the river.  The federal government will pay some $1.2 billion dollars to cities, irrigation districts and Native American tribes if they temporarily use less water. National Public Radio.

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 onto 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.  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.

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.

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.

Typical 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.

“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.

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