In this early fall Occasional, you'll learn how a California city removes PFAS from its water, how undersink drinking water filters work, how dogs are waging war on clean water. Hear about EOT filters, how river flow can be augmented with waste water, how firefighting foam shut down a Texas city's water system. Read about a leaking highway tunnel in New York, how the EPA is being sued over lax feedlot regulation. Hear about Donald Trump's cure for California's water shortage, how fluoride is
affecting the brain development of children, the demise of the Aral Sea, and, as always, there is much, much more.
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How a California county got PFAS out of its drinking water
Gazette Introductory Note:This NPR report focuses on one of the
treatment options, Ion Exchange, that city water suppliers have for
reducing PFAS levels to meet EPA limits. The other popular treatment
option for cities is activated carbon filtration. For home drinking
water treatment, reverse osmosis and activated carbon are the most
practical solutions; for whole house PFAS reduction, activated carbon is
the best way to go.
Yorba Linda is a small, sunny city southeast of Los Angeles. It’s
perhaps best known for being the birthplace of President Richard Nixon.
But in the past few years, Yorba Linda has picked up another distinction: It’s home to the nation’s largest per- and polyfluoroalkyl (PFAS) water treatment plant of its kind, according to the city.
“This December will be [three] years we’ve been running, and we’re the largest PFAS treatment plant using resin,” says J. Wayne Miller, former board president at the Yorba Linda Water District, for whom the plant is named.
Across the country the Environmental Protection Agency estimates
there are thousands of water systems, serving around 100 million people,
that have harmful levels of PFAS in their drinking water. Under an EPA
rule finalized in April,
affected water districts will have to take action to clean their water
supplies. In Orange County, Calif., the Yorba Linda treatment plant and
others around it provide examples of how it can be done.
In Yorba Linda, all 10 of the district’s groundwater wells exceeded
California’s recommended PFAS levels, which took effect in 2020 – 40
parts per trillion for PFOS and 10 parts per trillion for PFOA, two
common PFAS chemicals. Water providers in the state that exceeded those
limits had to stop using contaminated water or notify the public.
Those state limits, established four years before the EPA set
national limits, put California’s cities ahead of the curve. “I thank my
lucky stars we were on the front end of that,” says Mark Toy, general
manager of the Yorba Linda Water District.
Filtration plants are expensive but cost less than imported water
The next city over is Anaheim, home to Disneyland. A few miles from
Space Mountain, a paved industrial lot houses the second-largest PFAS
water treatment plant of its kind. “This would be a little bit larger
than a basketball court,” says Mike Lyster, spokesman for the city,
estimating the footprint of the 20 filtration tanks at this site.
Lyster says there was a brief time when Anaheim had the largest PFAS
treatment plant. “Kudos to Yorba Linda,” he says, “We’re glad to see
somebody else beat it because that means somebody else is addressing the
issue.”
Anaheim is a larger city, and the public water utility there can
provide water for upwards of 500,000 people a day. Back in 2020, when
California’s PFAS rules came into effect, Anaheim took 14 of its 19
wells offline for excess PFAS.
If high levels of PFAS are found in drinking water, a water provider
can switch to a source without the chemicals in it or filter them out.
At first, both Anaheim and Yorba Linda swapped mostly to water imported from northern California and the Colorado River that met the state
standards. But water from those sources can cost twice as much as local
groundwater. Lyster says Anaheim’s water expenses went up by about $2
million a month. So Anaheim and Yorba Linda fast-tracked construction of those big filtration tanks, to get their wells back in action.
The new EPA PFAS standards are even stricter than California’s: no more than 4 parts per trillion each for PFOA and PFOS, and additional limits for several other PFAS chemicals.
By the EPA’s standards, Anaheim’s remaining wells are now considered
contaminated. Lyster says the city will expand its PFAS treatment
capacity to comply with the federal rule by 2029. All told, building
PFAS filtration for all 19 of Anaheim’s wells is projected to cost $200
million.
Anaheim and Yorba Linda are part of the Orange County Water District — a public agency that manages the region’s groundwater and which helped to design, fund
and build the PFAS filtration plants. Across Orange County, more than 100 wells have exceeded the EPA’s new standards. Fixing the problem in the county
is expected to cost $1.8 billion dollars over 30 years, according to
OCWD.
Pollution from the past is still present
But where is all this PFAS coming from? In Orange County, one of the primary culprits appears to be the Santa Ana River.
Almost a hundred miles long, the Santa Ana River flows through
mountains and canyons, the cities and suburbs of San Bernardino and
Riverside. Along the way, it picks up PFAS. “We find it in some of just
the natural runoff that goes into the river during the winter, during
storms,” says Jason Dadakis,
executive director of water quality and technical resources at the
Orange County Water District.
”We also detect some PFAS coming out of
the sewage treatment plants upstream.” There’s also the legacy of
factories and military bases in the area.
PFAS is found in runoff that makes its way into the Santa Ana River
during the winter, says Jason Dadakis, executive director for water
quality and technical resources for the Orange County Water District.
In Orange County – the Santa Ana River’s last stop before the Pacific
Ocean – some of the river water gets diverted to ponds where it can
seep into the ground and refill the groundwater, which may have
contributed to the contamination, says Dadakis.
And while the PFAS problem in Orange County is currently confined to
the northern and central parts of the groundwater basin, Dadakis says
wells that aren’t contaminated today could be in the future, based on
how water moves underground. “We know that we may have to be prepared to
install additional treatment on those wells as they become impacted,”
he says.
At least Orange County has a head start on solutions. But with the
size of the PFAS problem across the country, its claims on having the
largest PFAS treatment plants of their kind in the nation could soon be
eclipsed.
Undersink Drinking Water Filters Are Getting Better All the Time
An undersink water filter is a treatment device that is inststalled
under the kitchen sink but dispenses its treated water on the sink top.
This is a very practical and efficient arrangement because it leaves the
countertop uncluttered but allows plenty of equipment space for
excellent filtration.
Several improvements in recent years have
made undersink filters extremely effective, practical, and easy to
install and service. These include
The replacement of copper and galvanized undersink piping with flexible connectors.
The
improvement in filter housing and cartridge designs that allows
installation of more compact and easy-to-service filtration units.
The improvement in filtration technology that allows targeted treatment of many more problem contaminants.
The
use of flexible undersink pipes not only makes installation of standard
undersink filters with their own dispensiing faucet much easier and
safer, it also allows very easy installation of “simple” undersink
filters, the type that dispense water through the existing cold water
side of the sink faucet rather than an added ledge faucet. (For the
difference between "simple" and standard undersink filters, see How Undersink Filters Work.)
Modern
filter housings are now available that make cartridge changes as easy
as changing a light bulb. Even traditional housings have been improved
so that the best brands are easy to open and virtually leak-proof.
Carbon
block filters have been steadily improved over the years so that now
extra fine powdered carbon provides much more effective filtration and
greatly increased cartridge life as compared with old granular carbon
filters. In addition, cartridges can now be made to target specific problems like lead, arsenic, fluoride, iron, bacteria, nitrates, low
pH, and cysts.
The use of “media cartridges”
for special purposes is especially effective with multi-filter
undersink units that use two or more canisters with different
cartridges.
The
classy triple undersink filter shown above has exceptional
chlorine/chloramine reduction capacity and can, depending on the
cartridges chosen, remove such contaminants as bacteria, cysts,
nitrates, colors, sediment, odors, lead, iron, arsenic, fluoride, and
more. Go here for a listing of cartridges that will fit this filter.
Pure Water Gazette Numerical Wizard Bee Sharper Reveals that Dogs Are Not Our Best Friends When It Comes to Water
Number of dogs believed to be living in the United States–78,000,000.
Estimated percentage of these dogs that are in the country illegally– 23.9%.
Daily excrement output of these dogs, in tons–30,000.
Yearly excrement output of these dogs, in tons–10,000,000.
Number of 18-wheel tractor trailer trucks that would be required to haul away 10,000,000 tons of dog manure–267,500.
Length in miles of the caravan made by these 267,500 manure wagons if they were lined up bumper to bumper–3,800.
Rank of the roundworm as the most common dog excrement parasite — #1.
Percentage of Americans who tested positive for roundworms in a CDC study – 14%.
Number of canines required to generate enough bacteria in three days to close 20-miles of beach –100.
Approximate percentage of Americans who don’t pick up their dogs’ feces–40%.
Percentage of US households that have at least one dog–60%.
Numerical rank of dog waste among the largest contributors of bacterial pollution in urban watersheds– 3 or 4.
According to a Seattle study, the percentage of watershed pollution that can be attributed to dog wastes–20.
Average daily output in pounds of feces per day per dog–3 to 4.
Pounds of excrement produced by 1000 dogs in a week — 750.
Percentage of the total residential waste stream that was found to be dog waste in a San Francisco study — 4%.
From Pure Water Gazette. This article first appeared in the Gazette in 2012, so the number of dogs and their excrement output are certainly understated.
VOCs For Non-Scientists: Understanding, Detecting, Removing
Note: Below is a straightforward explanation of the highly problematic group of water contaminants known as VOCs. The article is from the Calgon Carbon Corporation, a leading supplier of water treatment media. We’ve edited a bit for clarity.
Volatile organic compounds (VOCs) are a large class of substances that may be found in various water sources. What follows is a straightforward guide to understanding VOCs, specifically, what qualifies a compound as a VOC, how to detect them, and how to treat and remove them from the water system.
As the name implies, a VOC is defined primarily by two things. The first is that the chemical is volatile, which means that it easily changes state from liquid to gas with a relatively small amount of energy. Most VOCs have a comparatively low molecular weight, which is one of the reasons for this volatility. The other key defining factor is that it is organic, meaning the molecule is composed primarily of carbon atoms.
Most VOCs are manmade products, although a few, such as acetone, are also naturally occurring. Nearly all VOCs end up in the water supply via industrial processes, chemical spills, or other human activity. Half come from industrial processes, 45% from motor vehicles, and 5% from consumer solvents.
Federally regulated VOCs are listed under the Safe Drinking Water Act (SDWA). Of course, each individual state may have its own list of regulated VOCs beyond those in the SDWA.
For regulated VOCs, the EPA and state agencies set two levels for each chemical: a maximum contaminant level (MCL) and a maximum contaminant level goal (MCLG). The MCL is the largest permissible concentration of the chemical in water, while the MCLG is the concentration at which there is no known or expected health risk.
VOC Types And Properties
Not all VOCs behave the same. There are three sub-classifications of VOCs based on their boiling points:
VVOCs (very volatile organic compounds). With boiling points of <0°C to 50-100°C, many of these exist solely in a gaseous state. Examples include butane, propane, and trichloromethane.
VOCs (volatile organic compounds). Although the term VOC is often used to describe chemicals from all three subcategories, technically it applies only to those with boiling points in the 50-100°C to 240-260°C range. Some examples are ethanol, acetone, and vinyl chloride.
SVOCs (semi-volatile organic compounds). The least volatile subclass is defined by boiling points from 240-260°C to 380-400°C. Phthalates, many pesticides (including DDT), and nitrobenzene are some such examples.
VOCs can be further categorized as either hydrophobic (repel water) or hydrophilic (attract water). Hydrophobic VOCs (e.g., benzene) usually have smaller molecular weights and do not dissolve easily in water, which makes them relatively easier to move to a gaseous state. By contrast, hydrophilic VOCs (e.g., acetone) tend to have higher molecular weights and are more easily dissolved in water, which makes them relatively harder to move into a gaseous state.
Removing VOCs From Water
There are two primary methods for removing VOCs from source water.
Air Stripping. The process of forcing air through water works well on VOCs with lower boiling points (especially VVOCs) and/or those that are hydrophobic. This includes chemicals such as vinyl chloride, methyl chloride, chlorofluorocarbons, and methane.
Activated Carbon. Higher-molecular-weight VOCs won’t be as responsive to air stripping. For these chemicals, a granular activated carbon (GAC) filter is a more effective solution. The activated carbon can adsorb most VOCs, including those that are more difficult to remove via air stripping. Because VOCs diffuse quickly through the carbon bed, however, it is important to ensure the carbon has a high iodine number. Usually, about 1,000 to 1,100 is ideal to reduce the number of changeouts.
Establishing A Buffer For VOCs
It’s rare for water treatment plants to discover new VOCs in their source water. Most water systems are well established, and the challenge is less about tackling a previously unencountered chemistry but rather struggling to meet established and new MCLs.
That said, chemical spills can happen anywhere. For example, a city that pulls from a riverway with heavy boat traffic is always susceptible to some type of spill, as anything that is on a boat can end up in the water. Even chemical spills on land, such as a tipped gas tanker, can result in VOCs in groundwater. A GAC system that is in place for everyday VOCs will act as a buffer, ready to adsorb new contaminants should they enter the source water.
A much more complete listing of commonly encountered VOCs can be found on the Pure Water Occasional website. Calgon Corporation’s article is intended mainly for water treatment plant operators. Treatment options for residential users do not include air stripping. For residential use, activated carbon is by far the best protection. Coconut shell carbon is generally regarded as the treatment of choice for VOCs and this can be in the form of carbon beds (tank-style whole house filters), cartridge-style whole house or drinking water filters filters, or the carbon filters that are part of undersink reverse osmosis units.
The main thing to know about VOC protection with carbon filters is that VOCs are much more difficult to remove than chlorine. For VOC removal, filters need a slower flow rate to allow more residence time and more frequent replacement. The need for frequent replacement and slower flow rates is evident in the following from the spec sheet of the CTO Plus coconut shell carbon block. Capacity in gallons:
Chlorine: 240,000 @ 7 gpm,
Chloramine: 12,000 @ 3 gpm,
PFAS: 21,000 @ 3 gpm,
VOC: 4,500 @ 2 gpm
Why Don’t Tiny EOT (End of Tap) Filters Work as Well As Standard Filters? Well, Because They Are Tiny
Most of the bad publicity (“filters don’t work”) that resulted from poor performance on tests done on lead filters supplied to homeowners in Flint and Newark during the lead crises in those cities ignored the fact that the filters provided were novelty-sized units meant for off-the-shelf purchase. They could not be expected to “work” as well as serious full-sized filters actually designed for long-term use in homes.
Here is sizing information from the manufacturer of MetSorb®, a heavy metal removal medium that is added to carbon block filters to give them lead-removal capacity.
A nominal 10–inch carbon block, standard for most countertop and undercounter applications, will provide more overall volume and more functional media than the 2 to 2-1/2 inch blocks typically used in end-of-tap (EOT) applications. For example, a nominal 10–inch carbon block can easily perform for 1000 gallons or more of contaminant reduction, while the smaller EOT blocks are rated at several hundred gallons.
The larger block design also gives longer contact times (EBCT or Empty Bed Contact Time) for better contaminant reduction. For example, a nominal 10–inch block will provide an EBCT of 10 - 15 seconds, while a typical 2 1/2 inch EOT block gives only 3 seconds EBCT. Devices designed for slower flow rates, e.g., 0.5 gpm (gallons per minute) versus 1.0 gpm will provide longer contact times and better percentage contaminant reduction.
Water News —September, 2024
Water News for September 2024
Wastewater Restores the Flow of the Santa Cruz River
The Santa Cruz River, which runs through Arizona and New Mexico, was a "dry wash" until University of Arizona scientists began introducing treated wastewater. With the increased water volume, over a two-year period, hundreds of invertebrate species as well as fish, frogs, and turtles have come back.
"I think the biggest surprise in our study was just how quickly species returned to the Santa Cruz River when flow was restored - it was astounding how fast biodiversity could recover when given a chance," the study's co-author Michael Bogan, a professor of aquatic ecology at the University of Arizona, told Salon. MSNBC -- Full story.
Texas City Water Contaminated by Firefighting Agent
Residents of a large portion of Grand Prairie, TX were without water for a couple of days in early September when it was discovered that a foaming agent, which entered the water as a result of firefighting, had contaminated the water supply. Although the chemical was classed as "environmentally friendly" and "non-PFAS," residents were told not to use the water except for flushing until testing proved it safe. Around 60,000 North Texans were affected. City officials were praised for responding quickly, communicating effectively, and providing bottled water free of charge. Texas Commission for Environmental Quality (TCEQ) was faulted for having too few water testing facilities. (Samples had to be flown to test sites in distant parts of the state for testing.)
NY Tunnel Springs a Leak
An underwater tunnel that passes beneath New York City’s East River sprang a leak on Sept. 4 after a city contractor mistakenly drilled a hole through it, sending streams of water into the heavily used tunnel. Officials were left scrambling to plug the opening and block off traffic after the accident. Thousands of drivers who use the busy tunnel were upset.
EPA battles environmentalists in court over regulation of CAFOs and water pollution
A coalition of environmental organizations faced off against the Environmental Protection Agency (EPA) in federal appellate court on September 12 in the latest skirmish in a long-running battle over the agency’s regulatory approach to water contamination connected to industrial agricultural operations.
The groups, led by the nonprofit Food & Water Watch, told a three-judge panel of the 9th US Circuit Court of Appeals that the EPA must strengthen its oversight of what are known as concentrated animal feeding operations (CAFOs).
The agency is unlawfully allowing roughly half of the nation’s more than 20,000 big livestock and poultry feeding facilities around the country to operate without permits required under the 1972 Clean Water Act, the groups argued to the court. And, they said, the agency is violating the law by authorizing CAFOs to store and spread manure so haphazardly that the drinking water for millions of people is at risk as thousands of streams, lakes and other waterways are polluted with harmful bacteria, nitrates, phosphorus and other contaminants.
The agency has “failed” for more than a decade to adequately regulate these operations, Food & Water Watch lawyer Emily Miller told the court. Read the rest of the story in New Lede.
Ingenious Plan to Solve California's Water Shortage by Turning on a Very Large Faucet
Presidential candidate Donald Trump, speaking at a campaign rally in September, said:
"They have, essentially, a very large faucet. And you turn the faucet and it takes one day to turn it, it's massive. It's as big as that wall on that building right there behind you. And you turn that and all of that water goes aimlessly into the Pacific . And if you turned it back all of that water would come right down here and right into Los Angeles." . No one is sure what he was talking about but it has been suggested that he is referring to a scheme he mentioned previously about solving California's water shortage by diverting water from British Columbia.
Trump added that the water from the big faucet could also be “reverted” into the hills of California to prevent wildfires.
“You have all that water that could be used to … what they call water flow — where the land would be damp,” Trump said. “And you’d stop many of these horrible fires that are costing billions and billions of dollars.” Full story.
Fluoride and Neurological Development of Children
Because of the government report acknowledging that high levels of fluoride exposure may harm neurological development and cognitive health in children, there is increased questioning of the wisdom of adding fluoride to public drinking water supplies. See "Is It Time to Rethink Fluoride in Drinking Water?"
Perhaps the most significant water news item of the month was the conclusion of a seven-year court case in which a federal court ruled that the fluoridation of water presents a significant risk to the neurological development of children. See Pure Water Gazette article.
Water Speculators Represent a Major Threat to Sane Water Management
As the West suffers its worst megadrought in 1,200 years, investors have increasingly eyed water as a valuable asset and a resource to be exploited. For years, investment firms have bought up farmland throughout the Southwest, drilling to new depths for their water-hungry crops and causing nearby wells to run dry. Now, new players have entered the scene: “Water management companies” are purchasing up thousands of acres of farmland, with the intention of selling the water rights at a profit to cities and suburbs elsewhere in the state. Some argue that treating water as a commodity can efficiently get it where it is needed most. But others fear that water markets open the door to profiteering and hoarding, leaving poorer communities in the dust. Full article from Truthout.
When Water Turns to Sand: Demise of the Aral Sea.
In Central Asia, the world's youngest desert occupies a basin that once held a vast saline lake. The Aral Sea.
Up until the 1960s, the sea spanned more than 26 thousand square miles across two countries. It supported thriving fishing communities along its shores. But then, in the name of progress and development, much of the river water that fed the sea was diverted for agriculture. Now the Aral Sea has all but disappeared, shrunk to about tenth of its original size. The UN Environment Programme has called the Aral Sea's destruction "one of the most staggering disasters of the 20th century." NPR
