Adding a 4th Stage to your 3-Stage Black and White RO Unit

Black and White filters and RO units are designed for easy modification.  If you want to add a fourth stage to your three-stage Black and White RO unit (a calcite post filter to raise pH is the most common addition), we have a kit with everything you need.

The picture shows the finished modification.

To install, just turn off the inlet water, turn off the tank valve,  open the faucet to relieve pressure, then remove the faucet tube from the white housing.  (Quick connect fittings release by pushing in to the collet and simultaneously pulling out the tube. See website for details. )

Install the inline filter on top of the membrane as shown in the picture.  You’ll want to determine which way the water flows through the filter by looking at the directional arrow.

When the inline is mounted on the membrane, use the 1/4″ tube to connect the white vertical housing to the inlet of the inline filter, then attach the faucet tube to the outlet side of the inline filter.

Turn on the water and check for leaks.  The new filter will need to be rinsed for 3 or 4 minutes.

by Matt Weisser

Donald Trump made some big campaign promises about water during his election campaign. Now that he has been elected president, those promises could dramatically shake up how water is managed in the arid West.

In one of his few direct statements about water, Trump has said he wants to invest in treatment systems to prevent problems caused by aging distribution lines, citing as an example the drinking-water contamination in the Michigan city of Flint. To do this, he proposes to triple funding for a federal loan program, called the state revolving fund, from the current $2 billion to $6 billion.

This could be a boon to local water and wastewater utilities struggling to pay for decaying infrastructure.

Paradoxically, Trump has also vowed to slash Clean Water Act regulations. In particular, he is targeting rules adopted by the Obama administration to protect wetlands and marshes, the nation’s natural water filters.

Like Trump’s vow to build a wall on the Mexican border, these proposed changes would encounter a host of inconvenient realities associated with government. Working that out is certain to be disruptive, whatever the outcome.

“Certainly what we’re hearing out of the Trump administration is encouraging to the water utility sector,” said G. Tracy Mehan, executive director of government affairs at the American Water Works Association. “But I don’t know how you triple the state revolving fund. There’s just a lot of unknowns.”

The AWWA, based in Denver, CO, has identified a need to spend $1 trillion rebuilding the nation’s drinking water systems over the next 25 years – just to maintain existing levels of service. The state revolving fund, a federal low-interest loan program overseen by the Environmental Protection Agency, is the backbone of infrastructure funding for water utilities.

But Mehan – who was an assistant administrator for water programs at the EPA during the George W. Bush administration – said adding $4 billion to the loan program would be a tall order; it would require cutting a similar amount from other government programs. Mehan said it’s “really unclear” how that will happen in a Congress that fights to protect every dollar spent on existing programs.

Trump also plans to convince private investors to spend $1 trillion on public infrastructure projects. He claims he can entice them to do this by giving them generous tax credits.

But Mark Lubell, director of the Center for Environmental Policy and Behavior at the University of California, Davis, said tax breaks are not enough to drive that kind of investment because there is no profit being offered.

“They’re not going to invest in a flood management system, for example, where they get no revenue from somebody – even with the tax breaks,” Lubell said. “That’s where we need to convince the Trump officials that a more traditional infrastructure plan is consistent with their strategy.”

The way to do that, he said, is to highlight the economic benefits that come with building environmental infrastructure. Projects like levee construction, floodplain restoration, modern water lines and sewage treatment facilities all support thousands of jobs; they foster domestic manufacturing and protect the nation from disasters and health crises that harm economic productivity.

“If you connect those issues to climate change or endangered species, I don’t think that’s going to fly in a new Trump administration,” Lubell said. “But what would fly is an economic argument.”

Trump, the first property developer to be elected president, has vowed to eliminate the so-called Clean Water Rule (also known as the “waters of the U.S. rule”) adopted by the outgoing Obama administration. This regulation was crafted to clarify decades of uncertainty about which water bodies are subject to development restrictions under the Clean Water Act.

The rule resulted from a lengthy regulatory process triggered by court rulings. Its goal is to protect surface water expanses – marshes, wetlands, floodplains and small streams – that act as natural filters and conduits for drinking-water sources.

Lubell said eliminating the rule would not be simple; it would require a new rulemaking process that would likely take years. Simply suspending it would mean the regulations reverted to their prior state, which were a source of frustration because they were vague.

“He doesn’t realize what it takes to change a regulation or rule,” Lubell said. “You can’t just go and magic-wand everything, which he apparently thinks is possible.”

One water arena where Trump’s team may have a lot of influence is dams. The new water infrastructure bill approved by Congress in December gives certain cabinet secretaries unprecedented powers to enlarge existing dams and build new ones.

The normal path to federal dam building involves a thorough environmental review by a federal agency such as the Bureau of Reclamation. Then the project is vetted by a congressional authorizing committee, such as the House Natural Resources Committee, which determines if the project is a wise investment of public dollars and a worthy environmental risk.

These practices were pushed through a generation ago by then-president Ronald Reagan to rein in pork-barrel spending.

The new legislation, however, allows the interior secretary single-handedly to approve new dams without congressional authorization. The secretary can also rely on environmental reviews done by a third party.

It also grants the army secretary powers to enlarge Army Corps of Engineers dams for water storage in cases where they now mainly provide flood control.

The bill allocates $335 million for new reclamation dam projects. That is not enough to fund even one new dam, but it could jump-start a number of projects with the assumption that more federal money will be allocated later.

Therein lies the problem, says Ronald Stork, a senior policy adviser at Friends of the River. The existing approval process was created to ensure a reservoir proposal is based on reliable cost estimates and avoids unforeseen obstacles that could halt construction – such as insufficient water to fill it.

That is a concern with projects like the proposed Temperance Flat dam on California’s San Joaquin River. The California Water Resources Control Board, which allocates water rights, has already determined the river is “fully appropriated” – meaning it has no water left for new storage projects.

“The rules have been set up to make sure we don’t have circumstances where these half-baked projects get authorization,” said Stork, who has monitored federal water projects for decades. As a result, he said, “the administration is likely to not be a gatekeeper any more.”

Zinke supported a controversial bill by Rep. David Valadao (R-Hanford) that would have amended the Endangered Species Act to free up water supplies in California. It would also have erased a Bureau of Land Management (BLM) finding that the San Joaquin River canyon to be dammed by Temperance Flat is eligible for federal Wild and Scenic River status.

Valadao recently introduced a new version of the bill, no doubt hoping it will face better odds in the new Republican-controlled Congress.

Zinke also sponsored bills in 2015 requiring the Federal Energy Regulatory Commission to extend licenses for hydro-power development at two existing Montana dams. The licenses expired because the projects either had insufficient funding or no power lines existed to serve them. The bills became law when they were tacked on to the Energy Policy Modernization Act, approved by Congress in April.

As interior secretary, Zinke will be in charge of both the Bureau of Reclamation and the BLM, as well as the U.S. Fish and Wildlife Service, the federal agency that protects freshwater and terrestrial endangered species.

In 2015, Zinke received a 3 percent rating from the League of Conservation Voters for his actions on environment-related legislation in the House. He supported bills to weaken the Clean Water Act, eliminate stream buffers at surface mining projects and allow large logging projects on federal land to skip environmental reviews.

Trump’s appointments to a slightly more obscure agency, the Federal Energy Regulatory Commission (FERC), have received little attention but could have lasting impacts. Within months of inauguration, Trump will be able to seat a new majority on the commission, as well as a new chairman.

The FERC issues federal licenses for hydro-power dams, typically with 50-year terms. Many of the licenses for large dams in the West are now coming due for renewal. In California, for instance, there are 22 hydro-power relicensings pending and another 18 expected to come forward in the next four years.

A 1986 law required the FERC to give equal consideration to energy and environmental issues. It also required it to seek recommendations from federal natural resources agencies during dam relicensing.

As a result, in many recent proceedings it compelled dam owners to install fish ladders for the first time and increase water releases for aquatic habitat and recreation.

But Stork said the federal agencies under Trump could stop making those recommendations, and the new FERC commissioners could place less value on them.

“There is a probability that the resources agencies … are going to be essentially asked to stand down on their environmental mission for the duration of this administration,” said Stork. “They don’t have to change the law to do that. They just have to stop enforcing the law or, basically, reinterpret their mission.”

That would be a big setback for river environments affected by dams. But it would save dam owners billions of dollars and lots of red tape.

Some states have their own rigorous environmental laws that may help take the sting out of any changes in federal policy. California, for instance, has its own clean water law, known as the Porter-Cologne Act, and its own Endangered Species Act, both of which are more rigorous than federal law. So it might be able to avoid backsliding on some environmental reforms.

“I don’t think they can drive it in that direction in California, because we’re a blue state with a healthy Democrat-controlled legislature and a governor that holds environmental values pretty strongly,” said Tim Quinn, executive director of the Association of California Water Agencies. “We don’t want to see those regulations go away at all.”

The ACWA represents 430 public agencies – urban and rural – responsible for 90 percent of the water supplied to California’s farms and cities.

Quinn notes that Trump was elected, in part, by exploiting the issues that divide rural and urban voters. One of those, he said, is water, which makes it an issue that California and other Western states can use to connect with the Trump administration.

“In California, the rural-urban split is not entirely about water, but water is a huge factor in that,” said Quinn. “If we offer up ways to heal those wounds around one of the issues that divides us, I choose to believe we can get them interested.”

Adapted from News Deeply.

Pure Water Gazette Fair Use Statement

California Is Sinking

Joseph Poland of the U.S. Geological Survey used a utility pole to document where a farmer would have been standing in 1925, 1955 and where Poland was then standing in 1977 after land in the San Joaquin Valley had sunk nearly 30 feet.

In the 1930s, scientists noticed that the land in the fertile San Joaquin Valley was sinking. The cause was a mystery. No one blamed corporate farmers who in the 1920s had begun massive pumping of groundwater to support the growth of highly profitable but very thirsty crops.

A legendary hydrologist, Joseph Poland, was assigned to solve the puzzle starting in the 1940s. Poland  realized that underneath the sinking land, groundwater was being pumped rapidly to irrigate crops. It created massive sinkholes that stretched for miles in every direction. In the farming community of Mendota, the land sank about 30 feet between 1925 and 1977.

The sinkhole is so vast that it is essentially impossible for residents to see that they are standing in one. Poland used a utility pole to build a temporary monument to show them just how much the land had sunk.

The sinking did not slow until the 1970s, after California had completed its massive canal system—the most expensive public works project in state history. It delivered water from wetter parts of the state to farmers in the Central Valley and elsewhere, relieving their reliance on groundwater. The problem was fixed—at least for a while.

An extensive report completed in 2012 revealed the astonishing truth that land was subsiding along the San Joaquin River at a rate worse than during the 1987-92 drought. It was nearing the historic rates of sinking recorded by Poland in the late 1960s. Currently, subsidence (the polite word for sinking) seems to be progressing at the astonishing rate of one to two feet per year in some areas.

There is little political will to confront the wealthy corporate “farmers” who are causing the problem, and the taxpayers quietly pay for repair and replacement of roads and bridges being destroyed by subsidence.

Last year, the state passed its first law attempting to regulate groundwater, but farmers won’t be required to meet goals until 2040 at the earliest. And the information on who is pumping what will be kept private.

The outlook for the future? A scientist with the U. S. geological survey predicts devastation of a historic proportion for California. He says that even if farmers stopped pumping groundwater immediately, the damage already done to aquifers now drained to record-low levels will trigger sinking that will last for years, even decades.

Bathing in Well Water With Arsenic

by Gene Franks

Is it safe to shower in water that is contaminated with arsenic?

Only a minimal amount of arsenic is absorbed through the skin.–   Virginia Dept. of Health.

Arsenic is not easily absorbed through the skin. — Maryland Dept. of Health.

For most people, the largest source of arsenic is in the food we eat. Most foods, including vegetables, fish, and seafood, contain some arsenic. Arsenic in groundwater can enter the body by drinking the water or by eating food cooked in the water. Arsenic does not evaporate into the air and is not easily absorbed through the skin. — Illinois Dept. of Public Health.

Neither the National Research Council (1999) or the Agency for Toxic Substances and Disease Registry (2000), nor the additional literature searches, identified any controlled studies of inorganic arsenic absorption through human skin. New Jersey Department of Environmental Protection.

Historical studies indicate that skin absorption of arsenic is negligible,  so handwashing and bathing do not appear to pose a known risk to human or animal health.  Greg Reyneke, MWS, Water Conditioning and Purification Magazine, November 2021.

The statements above are typical. Some sources do note, however, that trivalent arsenic (arsenite) can pass through the skin much more easily than pentavalent arsenic (arsenate). A couple of sources say, in fact, by a factor of as much as 60:

Dermal uptake of arsenic has been underestimated up to now based on low permeability of arsenate. A new study finds that uptake of arsenic as arsenite or dimethylarsinic acid is a factor of 29 and 59 higher than that of arsenate. — Evisa. 

Trivalent arsenic is well absorbed through the skin and is 60 times more toxic than pentavalent arsenic, which is well absorbed by the gut.[1] Arsine gas is highly toxic.–  Patient.  (A UK health professionals reference site.)

 

 A brief article on how to remove arsenic from water.

Are US Dams Safe?

Editor’s Note. The piece below is excerpted and adapted from a Circle of Blue article by Brett Walton.

If you live downstream from a dam, you hope that someone is maintaining it and monitoring its safety. This is not always the case. In Alabama, for example, all but 10% of the state’s dams are privately owned and regulatory oversight is minimal.

The universe of American dams is expansive. There are tailings dams that hold back a slurry of mine wastes, stock ponds for irrigation or watering cattle, and artificial lakes for sailing and speedboats. There are dams to detain flood waters and dams to filter debris. Then there are the hydropower behemoths such as Grand Coulee and Hoover, symbols of 20th-century engineering might. Though iconic, these canyon-bridging concrete plugs are the minority. Most dams are small structures less than 25 feet tall made of packed dirt and rock and built more than 50 years ago.

Surprisingly little is known about why individual dams fail. Few states do autopsies to learn precisely what went wrong. That is why a Stanford University professor founded the National Performance of Dams Program in 1994. The program’s goal is to learn from past failures so that managers can identify problems before they become tragedies. The program’s researchers have found that the U.S. dam industry is far behind the nuclear power and oil and gas pipeline industries in the amount of data it collects.

Not every dam failure is judged by the same criteria. The United States has a three-tier rating system that classifies a dam based on the destruction resulting from failure. The rating system is used to set design standards; the greater the risk the stricter the codes. Low-hazard dams are expected to cause minimal property damage. It is considered acceptable if these dams, as long as they are accurately categorized, fail because the risks to life and property are low. Richland County, South Carolina notes that several of its dams will fail in a 50-year flood. Significant-hazard dams are a step up. They might destroy infrastructure or cause severe property damage if breached. The most worrisome category is high-hazard potential. A rupture at one of these dams could kill people.

A new risk on the industry’s radar is climate change but engineers are still trying to figure out how droughts and severe storms will affect dam performance.

“Climate change is not doing dam safety a benefit at all,” one authority said. “We know it will change risk but it has not been quantified yet.”

Eric Halpin, deputy dam safety officer for the U.S. Army Corps of Engineers, said that the key variable is how a dam’s engineering responds to sharp shifts in weather.

“We’re living off the investments of two to three generations ago,” Halpin said. “Those dams have the science and engineering of their times embedded in them. The pace of change today doesn’t get easier. It gets harder in the future: back to back wettest years followed by five years of drought. All this has an impact on dams.”

Pure Water Gazette Fair Use Statement

Hyponatremia, or Water Intoxication

Drinking too much water left a woman with a urinary tract infection seriously ill, and doctors said water intoxication can kill you. The case in point is a 59-year-old London woman who, in an attempt to “flush out her system,” drank water so copiously that she developed hyponatremia, also called water intoxication.

According to the Mayo Clinic:

Hyponatremia is a condition that occurs when the level of sodium in your blood is abnormally low. Sodium is an electrolyte, and it helps regulate the amount of water that’s in and around your cells.

In hyponatremia, one or more factors — ranging from an underlying medical condition to drinking too much water during endurance sports — causes the sodium in your body to become diluted. When this happens, your body’s water levels rise, and your cells begin to swell. This swelling can cause many health problems, from mild to life-threatening.

Hyponatremia is marked by an abnormally low level of sodium in the blood. Sodium helps regulate the quantity of water in and around cells.

There is a death rate of nearly 30 percent for patients whose sodium level drops drastically below normal. The condition can involve vomiting and significant speech difficulties.

The treatment may require medication, but usually it can be corrected simply by restricting water intake. Recovery may take a week or longer.

“The old adage to ‘drink plenty of water’ should be approached with caution if you are not vomiting, or experiencing diarrhea, or excessive sweating,” advised one doctor. “Your thirst is often the best guide to gauge when you think you need to drink more water if you have no history of kidney disease.”

Other signs of water intoxication include headaches, nausea and vomiting, confusion, loss of energy and fatigue. The illness can cause the brain to swell, coma, seizures and death.

People with normal kidney function who sometimes develop water intoxication are endurance athletes who drink more water while exercising than their kidneys can excrete.

Although doctors commonly advise patients with many ailments to “drink plenty of fluids,”  little evidence supports the recommendation. There are definitely both risks and benefits to increased fluid intake.

Reference: Tucson News was the original source, but the article itself is no longer available.

Not Afraid to Look

Since April, 2016 thousands of demonstrators have been camping out at the confluence of the Cannonball and Missouri Rivers on the Standing Rock Sioux reservation in North Dakota. These peaceful water protectors—representing more than 200 Native-American tribes, plus many nonnative allies—are demanding a halt to the construction of the Dakota Access Pipeline, which threatens the water and sacred land of the Standing Rock Sioux. Tensions are escalating—on the night of Nov. 20, North Dakota law enforcement deployed water cannons, tear gas and rubber bullets against the unarmed group in subfreezing temperatures.

On a hill above the Sacred Stone camp, a metal and concrete statue of a seated man surveys it all—the camp, the rivers, the impending construction, the often intense conflict—his expression calm but resolute. Not Afraid to Look, completed in October, is the work of Charles Rencountre, a Lakota artist based in Santa Fe, New Mexico.

Originally from South Dakota, Rencountre got his start as an artist 30 years ago by teaching himself to carve traditional, effigy-style Lakota pipes, as his grandfather did before him. Today Rencountre still focuses on effigies, though on a different scale, transforming the tiny carvings his ancestors made into monumental sculptures.

The statue at Standing Rock is based on one such effigy, a mid-19th-century Lakota pipe titled Not Afraid to Look the Whiteman in the Face. The piece features a bowl shaped like a white man’s head; on the stem, an American Indian man sits looking directly at him. The pipe was made during a time of intense conflict between indigenous tribes and the U.S. government.

“It was a really difficult time for our people. We’d pretty much lost everything we knew,” Rencountre said. “Some man out there in that world, that reality, was carving a pipe—it was a political piece that was saying, ‘We’re not afraid.'”

Adapted from an excellent article by Clara Chaisson.  Read the full original in EcoWatch.

Trump’s Pledge to ‘Open Up the Water’ for Valley Farms: Easier Said Than Done

by Craig Miller

“We’re gonna solve your water problems.” –Donald Trump.

California Drought Expected to End After January Inauguration

President-elect Donald Trump might have trouble living up to one of his more sweeping campaign promises in California.

On the stump in Fresno last May, he made headlines for declaring, “There is no drought” here.

It’s a bit unclear from his remarks whether he was voicing an opinion or simply reporting what some farmers told him at a pre-rally gathering. Either way, he was badly mistaken.

Though conditions have improved over much of the state since then, about 73 percent of California remains in some level drought, according to the U.S. Drought Monitor, and nearly 43 percent is still classified in “extreme” or “exceptional” drought, including much of the San Joaquin Valley.

‘Don’t Even Think About It’

But Trump also made a pledge to the assembled crowd in Fresno.

“We’re gonna solve your water problem,” he told the audience. “We’re gonna get it done and we’re gonna get it done quick. That one’s an easy one. Don’t even think about it.”

It’s unclear how much the candidate had thought about it as his comments displayed a blend of confidence and confusion. He expressed bewilderment at the current water allocation policies, which require that a certain volume of water remain in the rivers to protect the environment.

“You have a water problem that is so insane. And it’s so ridiculous, where they’re taking the water and shoving it out to sea,” he said.

“And I’m asking everybody, why, why, why, and nobody can explain why they do this.”

Actually, a lot of people could’ve explained that. About a thousand of them were gathered in Sacramento this week for the Bay-Delta Science Conference, where scientists and policy makers meet every other year to review the latest research supporting the environmentally fragile Sacramento-San Joaquin Delta.

“This was more sloganeering than fact, in the middle of the drought,” observed Jeff Mount, a senior fellow at the Public Policy Institute of California. He says a certain amount of California’s river water must flow to the sea, to keep salt water from creeping in and contaminating both drinking water and farm land — especially during droughts.

“The share that went to the environment during the worst of the drought—2014 and 2015—was vanishingly small,” he recalls.

Uphill Battle

It’s unclear how high California’s water issues will actually rank on the Trump administration’s agenda, though anxiety rose in conservation circles last week when Trump gave a spot on his transition team to Devin Nunes, a San Joaquin Valley Republican congressman and vocal proponent of pumping more Delta water to farms. (Nunes floated a “Turn on the Pumps” bill in 2009 that failed in congress.)

“It will be uphill for [Trump] to make big changes here,” suggests Jay Lund, who heads the Center for Watershed Sciences at UC Davis. Like Mount, he’s a grizzled veteran of California water debates.

“There’s a lot of state law, state regulations that would have to be overcome,” says Lund. “I think pretty much anything that anyone wants to do is gonna get petty thoroughly vetted.”

Mount says an executive order from the White House to suddenly crank up the pumps would violate both state and federal law, beginning with the federal Endangered Species Act, which relies on formal studies known as “biological opinions” to set protections for sensitive habitat.

“He could write it, but it would be illegal,” wrote Mount in an email to KQED. “It would be inconsistent with the biological opinions, and the President cannot unilaterally alter the BOs. The project operators would run the risk of civil (and in a different world) criminal penalties.”

Mount says such an order would also run afoul of the Clean Water Act and California law, though in times of drought, even more fundamental laws apply to the distribution of water.

Campaign promises are one thing, says Mount, but, “Now they have to govern, and the laws of physics apply to everyone equally.”

Article Source: KQED.

Pure Water Gazette Fair Use Statement

Water Treatments that Work and Those that Don’t

by Gene Franks

The eminent water treatment specialist Peter S. Cartwright, a man of long experience and unchallenged expertise in the field, recently published a two part article in Water Conditioning and Purification magazine (October and November 2016) that concentrates on some of the shady areas of water treatment. Mr. Cartrwright skips the obvious health-related humbugs like “alkalizers” and concentrates on the technical aspects of genuine water treatment issues like scale prevention, TDS reduction, and removal or inactivation of bacteria and cysts.

Mr. Cartwright focuses first and foremost on  devices that “soften” water. For decades now there have been numerous attempts to replace the conventional ion exchange water softener.  Currently in North America some 785,000 residential and 60,000 commercial water softeners are sold annually, so there are strong incentives to tap into that market with alternative products. Conventional ion exchange water softeners, which actually remove scale-forming calcium carbonate (hardness) from water by exchanging it for sodium, work well and their performance can be easily verified by a simple test. However, there are many environmental and aesthetic objections to conventional softeners, so the quest for a workable alternative has been intense.

Mechanical Vortex Style “Softener”

In his discussion, Cartwright does not include alternate technologies like membrane devices (reverse osmosis and nano filtration) and sequestering systems (polyphosphates). He divides alternative scale reducing systems into five groups:

Magnetic devices that use one or more permanent magnets either attached to a pipe or inside the pipe.

Electromagnetic systems, more sophisticated than natural magnets, that also attempt to influence the way that treated scale-forming minerals behave without actually removing the minerals.

Mechanical devices that are designed to alter the pressure and flow pattern of water and somehow alter its chemistry in the process (see picture above).

Electrostatic systems that typically use two electrodes charged with high voltage DC current which alter the calcium carbonate as the water stream passes between them so that surface scaling is reduced.

Catalytic devices. These come in many configurations and sizes but are mainly housings that hold a proprietary medium designed to impart scale-reducing properties to water that passes through it. Unlike conventional softeners, they do not require power, backwashing, or chemicals. The technology is usually referred to as TAC (Template Assisted Crystallization), although one leading manufacturer calls its product NAC (Nucleation Assisted Crystallization).

What all these systems have in common is that they aim (and claim) to convert calcium carbonate into a form that does not stick to surfaces. The explanation involves the two crystalline forms of calcium carbonate, calcite, which forms hard scale, and aragonite, which supposedly does not attach to surfaces to form scale. (Although there are other constituents of hardness scale, like iron, silica, sulfate, and manganese, the main culprit is calcium carbonate in crystalline form, to that’s what most treatment strategies focus on.)

So, do any of these five strategies actually work?

According to Peter S. Cartwright:

With hundreds of manufacturers who have offered thousands of devices to the industry over the years, it is difficult to make all-inclusive statements. At the risk of doing so, my conclusion is that, with the exception of TAC, no [scale preventing] device has actually survived rigorous third-party scientific credible testing to support the reduction claims made for it.

Cartwright describes TAC technology as follows:

This process, which came on the scene in 1998, appears to minimize scaling without requiring regeneration or utilizing ion exchange. TAC utilizes polymer beads, not unlike the ion exchange resin in traditional water softeners. These beads, however, contain microscopic nucleation sites that cause calcium and magnesium crystals to form at the site and ultimately detach from the resin into the water as insoluble particles. These colloidal-sized particles do not attach to surfaces and are carried out with the water. As a result, although TAC does not actually remove hardness, it does minimize scale attachment to surfaces. This process requires no power, chemical addition or backwashing. The life of the resin is typically about three years. It has been thoroughly tested by credible, third-party institutions and has been shown to generally perform as claimed; however, the local water chemistry appears to have an effect on performance. For example, TAC has been shown to be ineffective for silica removal. 

TAC units are simple upflow systems that contain only a few liters of TAC resin. No regeneration is required, but they should be protected from sediment and media life is extended if they are protected from chlorine.

Reference: Water Conditioning and Purification

See also: Template Assisted Crystallization: A Softening Alternative.

The Emergence of “Emerging Contaminants”

The EPA in 2006 made a deal with eight American companies that make or use perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) to stop doing so. These chemicals are parts of a larger class of chemicals  known as perfluorinated chemicals (PFCs), which in turn falls under the larger group heading of “emerging contaminants.” Emerging contaminants are defined as materials having “a perceived, potential, or real threat to human health or the environment.”

The companies say that they have complied, but the EPA has made little progress in setting up any real standards or guidelines about the dangers of lifetime exposure to the chemicals.

There is a need for such determinatation, since these man-made chemicals have been linked to a disturbing array of health effects, including obesity in children, reproductive problems and cancers. Used as a surface-active agent in a slew of products from coating additives – like Teflon – to cleaning products, these compounds don’t break down under typical conditions and are extremely persistent in the environment, says the EPA.

And while PFCs may no longer be in active production, they are still being used. And, as we’re learning, there is no scarcity of them.

Telflon used in cookware coating, that was generally regarded as safe for many years, is no longer considered so. Teflon has been much in news.  Far less publicized, outside the areas where it is being found in water supplies, mostly around military bases, is PFC-containing firefighting foam.

When jet fuel burns, it makes a fire that isn’t easy to put out. Water doesn’t work. So, half a century ago the 3M Corporation, with the encouragement of the US Navy, developed a product known as AFFF (Aqueous Film-Forming Foam) to put out airplane crash fires. AFFF contains PFOS and other compounds that break down to PFOA and other PFCs.

For years AFFF has been used to put out fires and even more widely in training exercises, demonstrations, and testing activities on military bases around the nation. So it is not surprising that communities near military bases are finding PFCs in the soil and in their drinking water. With a lack of concern that has been characteristic of the military in matters of water safety, no effort was made to construct barriers to contain the foam, which sank down through the earth into the water table.

According to a  Provisional Health Advisory issued by the EPA in 2009, the maximum levels that humans should be exposed to through drinking water is 0.2 ppb for PFOS and 0.4 ppb for PFOA. Although the agency has said repeatedly that it will update these numbers, it hasn’t done so since 2009.

According to one researcher, “In some of these places, huge amounts of chemicals from the foam have been found in soil and water. At Tyndall Air Force Base in Florida, for instance, one of the telomers that can decay into a chemical similar to PFOA was found at 14,600 ppb. Near the Naval Air Station in Fallon, Nevada, where fire-training exercises were conducted for more than 30 years, PFOA has been recorded in the groundwater at levels as high as 6,720 ppb. And, at the former Wurtsmith Air Force Base in Michigan, where crash trainings also took place for more than three decades, one plume of groundwater had concentrations of total PFCs between 100,000 and 250,000 ppb.”

While advanced countries like Sweden, the EU, and Canada have banned the use of existing stockpiles of foam containing PFOS, the US has no restrictions on its use. The US military has a stockpile of a million gallons.

Home water treatment for PFCs in drinking water? Studies done by the Minnesota Department of Health find that both carbon filtration and reverse osmosis effectively remove PFCs.

Reference: Treehugger.com.