Do KDF Filters Remove Chloramine from Water?

Contrary to popular legends, KDF 55 and KDF 85 do not remove chloramine from water. In filters where KDF is mixed with carbon, there may be some chloramine reduction, but the KDF has nothing to do with it.


 Rainwater Everywhere Contains Unsafe Levels Of PFAS

By Peter Chawaga


Drinking water and wastewater managers throughout the U.S. are keenly aware of just how pervasive per- and polyfluoroalkyl substances (PFAS) can be in the environment. But now, new research has found that all rainwater around the world contains these contaminants to unsafe degrees.

“Atmospheric levels of toxic ‘forever chemicals’ are so high that rainwater everywhere contains amounts that are unsafe for long-term human consumption according to safety guidelines,” Vice reported. “‘Even in these remote and sparsely populated regions, such as Antarctica and the Tibetan plateau, the most stringent PFAS guidelines are exceeded,’ according to a study.”

The rising prevalence of PFAS in drinking water around the country has prompted the U.S. EPA to commit to more stringent regulations around the contaminants, has initiated a “seismic shift” in the legal landscape for industrial polluters, and has prompted existential questions about how drinking water and wastewater operations are supposed to respond.

But this latest study underscored the fact that PFAS are nearly impossible to avoid, no matter what actions water and wastewater systems take.

“This new study, which looks at four specific chemicals in the class, suggests that levels of one PFAS in rainwater around the globe often ‘greatly exceed’ US drinking water advisory levels,” according to the BBC. “The study’s findings lead the authors to conclude that a planetary boundary has been crossed — that there simply is no safe space on Earth to avoid these substances.”

As researchers learn more about PFAS and the potential harm that can come from exposure to them, regulations are becoming stricter. And while the production of products containing PFAS has been largely phased out, these so-called forever chemicals remain in the environment for a notoriously long time.

With the global environment now found to be totally inundated with PFAS, much of the burden for keeping these compounds away from consumers continues to fall on drinking water treatment operations.

“Removing the chemicals in the study from drinking water at treatment plants is possible, if expensive,” per BBC. “But getting below the US advisory levels is extremely challenging, according to the authors.”

Water Online


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Ultrapure Water Is Not For Drinking


While we think that water straight from the RO unit is wonderful, water can indeed by too pure for human consumption.

What is commonly referred to as “ultrapure” water goes beyond what is considered pure drinking water. In fact, it is not considered “fit” for human consumption. It is water so clean that it is used as an industrial solvent for cleaning semiconductors, producing pharmaceutical products, and for cooling in power plants.
Typical production of ultrapure water includes use of microfiltration membranes to remove particles from the water, ion exchange and reverse osmosis (RO) membranes to remove ions, UV light to kill bacteria and degassing membranes to remove dissolved oxygen.
We think of reverse osmosis, which can turn sea water into excellent drinking water, as taking “everything” out of water, but when it comes to water needed for many technical processes RO water isn’t even nearly clean enough. Ultrapure water requires 12 filtration steps beyond RO with the final filter having pores 20 nanometers in width.  (Twenty nanometers is 0.02 microns.)


Posted February 21st, 2024


Scientific developments like  membrane bioreactor technology enable enduring, sustainable development that does not leave permanent scars on the planet.  — Shivali Vora.

Countries all over the world are facing progressively higher levels of water stress — periods when demand exceeds supply. Part of the issue is that demand exists not just for drinking water, but also for water used for agriculture, livestock and electricity generation. From hydropower to nuclear power plants, many forms of energy, renewable and nonrenewable alike, require large volumes of water, as does irrigation for staple crops like sugarcane, wheat and rice, all of which are in high demand as the world population rises relentlessly.

Singapore has one of the highest gross domestic product (GDP) per capita in the world, but it is also one of the most water-stressed nations in the world because of limited land for reservoir construction, few freshwater resources, increasingly common droughts and climbing average temperatures. However, their extensive water reclamation system is alleviating some of the stress and making a heavily limited resource last longer for this island state.

To achieve the goal of water self-sufficiency and independence from foreign imports, Singapore began researching and, in 1998, building a system of 17 reservoirs connected by water reclamation plants — facilities that clean wastewater and in some cases recover the extracted materials for reentry into the ecosystem. Decades of investment into research and development for superior wastewater treatment have resulted in a product called NEWater that is well within World Health Organization (WHO) potability standards. The wastewater first goes through a filter that removes debris and pollutants, followed by passage through a membrane bioreactor, which efficiently combines bioreactors (growing specific biomass that will chemically consume unwanted substances in wastewater) with microfiltration or ultrafiltration. After this, a round of reverse osmosis — the process of using pressure to force water through a semipermeable membrane, thereby separating it from possible contaminants — targets microorganisms, metals, hydrocarbons, pesticides and other impurities. Finally, disinfection with UV light kills any remaining traces.

Most of the end product is used industrially, such as for microchip manufacturing, but small amounts are also added to drinking water reservoirs, especially after periods of evaporation. Singapore now uses NEWater to meet 40% of its water needs, as it is significantly cheaper than desalination. Its success and public acceptance are in large part due to successful collaboration between the scientists who developed it and the community leaders who spread awareness about it. At National Day Parades, for example, bottled NEWater was distributed for people to taste. Engagement and transparency with both the public and partnering sectors like the semiconductor industry — now a significant consumer of NEWater — helped the science make it from the lab to Singapore’s future.

Singapore’s resourcefulness and commitment to water recycling is quite uncommon; 80% of wastewater worldwide flows back into the ecosystem unmanaged. For emerging economies like those in sub-Saharan Africa, where only 30% of people have reliable access to a safe supply of water on tap, adopting Singapore’s innovative technology may help build sustainable water security. Despite the initial burden of financing the design and implementation of a water reclamation system, it will pay off in multitudes.

Ultimately, economic development rests on the shoulders of basic needs like food, water and energy. Pushing toward indiscriminate urbanization and industrialization does no good if long-term sustainability is not adequately considered in parallel, instead of as an afterthought — as evidenced by post-Industrial Revolution development, which left irreversible environmental destruction in its wake. Furthermore, the onus of these efforts falls on wealthier countries, which have the means to finance solutions to this destruction.

Excerpted from “From Field to Future: Wastewater Treatment and the Path to Water Security,” by Shivali Vora.  La Hoya, February 16, 2024.

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Adsorption of Water Contaminants: How Filter Carbon Works

According to the Wikipedia,  “Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. This process differs from absorption, in which a fluid (the absorbate) permeates or is dissolved by a liquid or solid (the absorbent). Note that adsorption is a surface-based process while absorption involves the whole volume of the material.”

Explained more graphically:



This man has adsorbed a pie.



This man is absorbing a pie.

In water treatment, activated carbon is the main adsorbing agent. This is true because filter carbon has an amazing amount of surface area and a strong ability to attract and hold organic chemicals.

Most of the surface area of a particle of carbon is internal.

Enlargement of granular carbon shows countless pores that adsorb contaminants. The surface area of the pores is exceptional. A single pound of activated carbon has more surface area in its pores than 100 football fields.

Carbon’s amazing ability to adsorb organic chemicals varies according to the chemical in question and conditions of the water. In general, chemicals of high molecular weight and low solubility are most easily adsorbed. The lower the concentration of the chemical, the higher the adsorption rate by carbon. Also, the fewer the interfering organic compounds present in the water the better. The pH of the water is also significant, with acidic compounds being most readily adsorbed at low pH. And, as with most other aspects of water filtration, rate of flow of the water being treated is extremely important with carbon adsorption. The more residence time the better.

In regard to specific chemicals, one source lists dozens of common chemicals and ranks them according to the likelihood that they will be removed by carbon adsorption. Here are a few of the more common items from the list:

Very High Probability of Adsorption: Atrazine, Malathion, 1, 3-dichlorobenzene,  DDT, Lindane.

High Probability of Adsorption: Toluene, styrene, benzene, carbon tetrachloride, vinyl acetate,  phenol.

Moderate Probability of Adsorption: Chloroform, vinyl chloride, acetic acid.

Unlikely to be adsorbed by carbon:  Isopropyl alcohol, dimethylformaldehyde, propylene.

It should be remembered that although carbon has great chemical reduction capacity because of its ability to attract and hold chemicals on its surface, it acts in other ways as well. Chlorine, for example, is reduced mainly by catalytic reaction with the carbon, not by the “grab and hold” process of adsorption.

Despite Regulatory Push, U.S. EPA Finds Nutrient Pollution Isn’t Improving

By Peter Chawaga


Despite notable efforts from industrial wastewater operations and treatment utilities alike, the U.S. EPA has seen virtually no progress on one of the country’s most pressing contamination problems.

“The nation’s rivers and streams remain stubbornly polluted with nutrients that contaminate drinking water and fuel a gigantic dead zone for aquatic life in the Gulf of Mexico,” the Associated Press reported. “It’s a problem only expected to get harder to control as climate change produces more intense storms that dump rain on the Midwest and South. Those heavy rains flood farm fields, pick up fertilizers and carry them into nearby rivers.”

The troubling results were uncovered by an EPA assessment of samples collected in 2018 and 2019, comparing river conditions from previous samplings. Phosphorus levels dipped, but nitrogen levels were found to be almost completely unchanged.

As nutrient-driven problems like harmful algal blooms grow worse, regulators are cracking down on sources of nitrogen and phosphorus, like meat processing operations. But as those efforts have yet to make a dent in the problem, calls for additional measures are emerging.

“Anne Schechinger, Midwest director with the Environmental Working Group, said new regulations are needed, not voluntary efforts,” according to the Associated Press. “She said the Biden administration has done a lot to improve drinking water, but not enough to reduce agricultural runoff.”

Stricter regulation alone might not be enough to address the problem. For the Chesapeake Bay, one of the country’s most iconic water bodies as well as one of its most nutrient polluted, significant funding will have to be central to the solution as well.

“In the last decade alone, state and federal agencies have spent more than $2 billion on programs to help farmers in the Chesapeake region install conservation practices,” per Bay Journal. “And spending is dramatically increasing as the 2025 deadline for the Bay’s cleanup goals approaches.”

With nitrogen and phosphorus levels proving to be more stubborn than officials hoped, additional regulation, funding, and technological innovation are likely on the horizon for wastewater treatment operations.


Source: Water Online


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Devastating Drought in Amazon Rainforest

The climate crisis turned the drought that struck the Amazon rainforest in 2023 into a devastating event

 The climate crisis turned the drought that struck the Amazon rainforest in 2023 into a devastating event, a study has found.
The drought was the worst recorded in many places and hit the maximum “exceptional” level on the scientific scale. Without planet-warming emissions from the burning of oil, gas and coal, the drought would have been far less extreme, the analysis found.
It also showed the drought was made 30 times more likely to happen by global heating. The return of the natural El Niño climate phenomenon is associated with drier conditions but played only a small role, the scientists said.
The climate crisis is supercharging extreme weather across the planet, but the extreme Amazon drought is a stark and worrying example because the rainforest is already thought to be close to a tipping point into a drier state. This would result in a mass die-off of trees in the world’s most important store of carbon on land, releasing large amounts of CO2 and driving global temperatures even higher.
Millions of people in the Amazon have been affected by the drought, with some rivers at their lowest levels for more than a century. There have been drinking water shortages, failed crops and power cuts, as hydroelectric plants dried up. The drought also worsened wildfires and high water temperatures were linked to a mass mortality of river life, including the deaths of more than 150 endangered pink river dolphins in a single week.
“The Amazon could make or break our fight against climate change,” said Regina Rodrigues, a professor at the Federal University of Santa Catarina, Brazil, and part of the World Weather Attribution team that did the analysis.

“If we protect the forest, it will continue to act as the world’s largest land-based carbon sink,” she said. “But if we allow human-induced emissions and deforestation to push it through the tipping point, it will release large amounts of CO2. We need to protect the rainforest and move away from fossil fuels as quickly as possible.”



Source: The Guardian  

Reverse Osmosis Shutoff Problems


Here is a typical customer question regarding an undersink reverse osmosis unit that doesn’t seem to be shutting off properly.

In the past week or so we’ve noticed a dramatic uptick — or trickle — of the filter.  That is, we’ve been hearing sometimes for a couple hours at a time, for a week every day, what I’m calling the usual but much less frequent “back flow” into the drain pipe that happens during filtration under normal conditions.  Whereas it used to be heard only once a month — in other words, so infrequently that we almost didn’t notice it.


The “backflow” that the RO owner describes is actually the unit’s normal flow to drain.  Whether you hear it or not, there is always a trickle of water running to the drain while the unit is filling the storage tank.  The drain water’s function is to carry away the impurities that have been rejected by the RO membrane. The trickle to drain happens when the  unit is making water to fill the tank.  When the tank is full, it stops.


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RO Units Don’t Follow Human Logic

There are a number of reasons why you start hearing water run into the drainpipe when you have not heard it before. The most common are a change in water pressure or a change in temperature, causing the water to fall a bit differently into the drain pipe. When drain water slides down the wall of the pipe,  you don’t hear it, but if the pressure is a bit stronger it can fall into a small pool of water that has gathered in the pipe and you’ll hear it fall. (If the drain saddle is installed on a horizonal rather than a vertical pipe, you will hardly ever hear the drain flow.)


If it sometimes takes much longer than  you would expect to fill the tank, that’s usually because the unit’s production was shut off prematurely with the tank only partially full. The next time the unit begins making water, it will take longer than you expect to refill the storage tank.  Here’s a common situation.  The unit is filling the tank when an event like a toilet flush or a shower lowers incoming pressure and the production stops because the shutoff system thinks that the tank is full.  (Yes, I know, RO units don’t think.) The way that the shutoff system determines the amount of water in the tank is by monitoring the pressure inside the tank and comparing it to the pressure of the tap water going into the unit. The unit fills the tank until the pressure in the tank equals about 2/3 of the pressure of the inlet water. If the inlet pressure goes down (as happens when a toilet is flushed), the production of water to fill the tank can be interrupted.  The next time there is a demand for water (e.g., the RO faucet is opened), the pressure in the storage tank goes down, production starts.  In this case it will take a lot longer to top off the tank than you would expect.

To Determine If There Is a Problem

The first thing to do is to determine if the shutoff system is working.

Probably the easiest way to determine if the system is working is before going to bed to run enough water through the unit to start production, then check it the next morning. If it has shut off during the night everything is probably working fine.


A quicker way is to turn off the valve on top of the storage tank (off is with the valve handle at right angles with the tube), then  open the countertop RO faucet. The water should run at a uniform trickle or small stream.  Next, turn off the faucet. Water should stop running to drain within 3 or 4 minutes. If it stops production and keeps it off, the shutoff system is working fine.  Turning off the tank valve simulates a full tank.

If water continues to run with the tank valve closed, the unit needs attention.  The most likely parts that need replacement are the hydraulic shutoff valve (the disc-shaped part mounted on the membrane housing that has 4 tubes) or, less likely, the check valve (one way valve) in the permeate tube.  It is the small cigar-shaped item in the short tube that connects the left end of the membrane housing with the shutoff valve.


Red Flag


If the water you hear in the drain line sounds more like a rushing river than a gentle trickle and it never stops, turn off the inlet water to the unit and leave it off until a repair is made.  The offending part is the flow restrictor. That’s the larger of the two cigar-shaped items in the drain tube.


Does Lead Enter the Body Through the Skin or through Breathing?


Here’s a brief AI answer to the question with excellent reference notes.


According to multiple sources, lead does not enter the body through the skin during bathing or showering, even if the water contains lead1234The US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) agree that human skin does not absorb lead in water2Similarly, Health Canada states that lead will not enter the body through the skin or by breathing in vapors while showering or bathing3The Massachusetts government also confirms that lead is not absorbed through the skin4.

However, it’s important to note that lead can enter the body if it is ingested. For example, you could accidentally swallow lead that is on your hands when you eat, drink, smoke, or apply cosmetics1. Therefore, it’s always a good idea to wash your hands thoroughly after contact with lead-contaminated water.

Water News November 2023

Posted November 30th, 2023

November WATER NEWS  — November 2023

Latest news! Retro Vintage Paper boy shouting with megaphone selling newspaper vendor, Extra! Special edition!


The War Against Lead Pipes

In announcing a significant expansion of the federal government’s efforts under the Bipartisan Infrastructure Law to get “100% of lead pipes out of the nation’s water supply, once and for all,” the EPA estimated that there are still 9.2 million water supply pipes in the nation that contain lead. It noted that most of these pipes serve older homes.




A devastating outbreak of sea lice attacking Icelandic salmon farms has led to the slaughter of countless farmed salmon and has become a major animal rights controversy.  See The Guardian for full details.

The Chemical Industry Has Spent $110 million in Recent Months to Thwart Legislation to Control PFAS 

The US chemical industry likely spent over $110m during the last two election cycles deploying lobbyists to kill dozens of pieces of PFAS legislation and slow administrative regulation around “forever chemicals”, a new analysis of federal lobbying documents has found.

The industry’s onslaught was effective: only eight pieces of legislation that targeted PFAS made it through Congress, the paper prepared by the Food and Water Watch (FWW) nonprofit found.

“There’s an extreme amount of money that’s going into fighting [PFAS legislation],” said Amanda Starbuck, FWW’s research director and the lead author on the report. “It’s hard to win these fights when there’s so much funding being put in from the opposing side.”

PFAS are a class of about 14,000 compounds used to make products resist water, stains and heat. They are known as “forever chemicals” because they do not naturally break down, and they have been linked to cancer, high cholesterol, liver disease, kidney disease, fetal complications and other serious health problems.

As the dangers from PFAS have come into sharper focus over the last decade, lawmakers, the Environmental Protection Agency and other administrative agencies have come under an ever-increasing amount of pressure to rein in the chemicals use and clean up pollution. Chemical manufacturers’ spending has jumped in response, the report noted

“The chemical and associated industries are powerful and have used their army of lobbyists and campaign finance war chests to thwart meaningful action,” the paper states.

Full article from The Guardian.

Measuring PFAS


A major problem in enforcing the EPA’s proposed new 4 parts per trillion limit on the “forever chemicals” is that instrumentation capable of measuring an amount that small is hard to find and very expensive. A practical solution may be to raise the allowable a bit to an amount that city water suppliers can measure. The lesson here is that all EPA allowables are based on science that has been negotiated to meet the realities of the world we live in. 

Nitrates in Wells in Eastern Oregon

High levels of nitrates that are getting worse by the year are making the water impossible to drink in rural areas of Eastern Oregon.”Thousands of Oregonians in Umatilla and north Morrow counties rely on private wells for drinking water, tapping into a massive underground aquifer. But pollution has steadily contaminated that groundwater source in recent decades, turning what was once safe water into a potentially toxic supply.” KGW8 News.

“Toilet-to-Tap.”  Arizona is in the process of making the switch.

It’s often referred to informally as “toilet-to-tap’’ technology. Arizonans eventually will be drinking treated sewage – what the state Department of Environmental Quality and City of Phoenix prefer to call the product of “advanced water purification’’ – for the simple reason that there just isn’t enough water to serve a growing population. Robin Silver, co-founder of the Center for Biological Diversity, said it’s not a question of “if’’ but of “when.’’ The use of reclaimed effluent is inevitable in the arid Southwest, period. That’s not really debatable anymore.’’  Capitol Media Services.

Fraudulent Claims Are Disrupting Camp LeJeune Damage Payouts

According to Bloomberg News, “The government plan to pay billions of dollars to victims of toxic water at Camp Lejeune has unleashed a wave of fraudulent claims that threatens to disrupt or taint what could be one of the largest-ever mass tort cases.  Veterans’ advocates and lawyers also say the fake claims — and the time and effort to identify and weed them out — could dilute the empathy for legitimately ill victims and slow the process of compensating them.”  Water Online.

A Thriving City Is Dying from Lack of Water


The gripping story of a French island city in the Indian Ocean that is literally dying of thirst.  Full story.