Pure Water Occasional, November 19, 2019 |
The rupture of a 36" water main in Arlington, VA washed out a bridge and backed up traffic for miles. A boil water advisory was issued for Arlington and a swath of Northwest Washington, D.C.
A comprehensive study conducted by the American Water Works Association concluded that a treatment system for small municipal suppliers featuring ultraviolet (UV) light via non-mercury light-emitting diodes (LEDs) "demonstrated viral and bacterial disinfection efficiency and resilience equivalent to chlorination systems." Full article.
Two boys, 9 and 10, have been arrested for vandalism resulting in $100,000 damage to the Broken Arrow, OK water treatment plant.
Zebra mussels damaged water treatment equipment leaving Plugerville, TX customers susceptible to a disease-causing organism for nearly a year.
The city of Raleigh, NC has made improvements to its wastewater disposal plant that will allow it to harvest enough natural gas from waste products to power 50 of its city buses.
Baltimore's City Council is adopting a progressive billing system designed to relieve poor residents from rising water costs and provide them more recourse if they receive bills that appear to include mistakes. The city would provide income-based discounts for residents at or below 200% of federal poverty guidelines. The city currently offers $236 annual bill credits to the poorest residents needing assistance, and 43% discounts on water rates.
The U.S. Army is “precipitously close to mission failure” when it comes to hydrating soldiers in the kinds of contested, arid environments they are likely to go in the next few decades, according to an Army War College study published this summer. The military's dependence upon increasing amounts of bottled water is not the only issue. The main concern is that warming climate increases need for water and at the same time makes water less available. What is worse, climate change is rapidly driving people from their homes, creating migration problems that lead to wars. Full article in Army Times.
The $68,000 Fish
According to Harper's, "Four out of five salmon in the Pacific Northwest are now born in hatcheries, and the vast majority will die. This has led the Northwest Power and Conservation Council, an organization that advises the region’s governments on environmental and energy matters, to estimate that for fish spawned in the lower river hatcheries, where success is relatively easy, it costs $66 to produce a harvested fish that navigates the trip home. In the middle regions of the watershed, where fewer fish survive the journey, it can cost up to $9,000 to bring a fish back. And the program to breed Chinook in the high mountains of Washington has been even less successful. The Council estimates that the true cost of bringing a single spawner back to that uppermost region is as much as $68,031."
Researchers found microplastics in almost all rivers in Montana. Details.
Blue Ridge Brawlers Win Operations Challenge
The Blue Ridge Brawlers of the Virginia Water Environment Association pulled off a dramatic win at the 29th annual Operations Challenge competition at WEFTEC 2016—the Water Environment Federation’s 89th annual technical exhibition and conference—in New Orleans. As one of the most engaging events on the exhibition floor, Operations Challenge is a unique and fast-paced test of the essential skills needed to operate and maintain wastewater treatment facilities, their collection systems, and laboratories—all vital to the protection of public health and the environment. Over the course of nearly three decades, Operations Challenge has steadily grown from the original 22-team event to this year’s 42-team, two-division format. Teams are judged on the best combination of precision, speed, and safety. The winners are determined by a weighted point system for five events including collection systems, laboratory, maintenance, safety, and process control, which was enhanced this year by new modeling software. [The Occasional's home town favorites, the TRA (Trinity River Authority) Waste Warriors of Dallas, finished 3rd in the second division.] More details about the competition.
The head of EPA's water division this month called waste water treatment workers "America's unsung heroes" and warned that one of our significant problems is the diminishing supply of experienced wastewater treatment professionals.
More than two dozen communities in Long Island have joined together in a lawsuit targeting the companies responsible for producing 1,4-dioxane. Full article.
In a poll of its members, the Water Quality Association found that over 60% said that referrals from other customers is their top source of new customers and that referrals frequently come via email or social media accounts.
We really appreciate all the business our customers have sent us.
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Just Get Yourself a Reverse Osmosis Unit and Stop Worrying
by Gene Franks
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I spend a good part of most days talking on the phone about water treatment and listening to people's concerns about water quality issues. Many calls focus on the perennial items--contaminants that are in the news for awhile, then fade away, then come back strong when a new article or study makes the newscasts. These old stand-bys include lead, chloramines, chlorine, fluoride, arsenic, chromium, MTBE (this one is dying), nitrates, perchlorate, pesticides, VOCs, and "pharmaceuticals." Although I don't often say it in so many words, the sum of my advice in regard to drinking water is usually just "put a good reverse osmosis unit under your kitchen sink and stop worrying about the particulars." Instead of trying to determine if perchorate is in your water and if so is it at a level you can safely consume or fretting about whether you can trust the EPA's suggested allowable for lead or arsenic or speculating about if the nitrate level in your tap water is going to continue going up, install an undersink RO unit. Instead of worrying about all these individual concerns and all the emerging contaminants like the leavings of the teflon industry (a current hot item) and the contaminants that are yet to be discovered and others that may never be discovered, simply install a relatively inexpensive drinking water treatment that is the best known solution for almost all water treatment problems. That is the message of the article that follows: Don't expect the water provider to solve all the problems. Point of use treatment--what water treatment professionals often call "final barrier" treatment--is the sensible answer for drinking water. RO works.
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According to the Environmental Working Group, water supplies for more than 7 million Americans in 27 states are contaminated with an industrial chemical at levels higher than what is generally considered safe. The chemical, known as 1,4-dioxane (often called simply dioxane), is especially troubling in certain areas of high concentration, most notably Long Island, NY, the Cape Fear River area of North Carolina, and Los Angeles county in California.
Although the EPA has set no formal standard for 1,4-dioxane (and don’t expect it soon), the current safe limit being used by most agencies is 0.35 ppb. That’s the level expected to cause no more than one case of cancer for every million people who drink the water daily for a lifetime.
Contaminant levels much higher are being found in the areas mentioned and in other parts of the country. The EPA has classified 1,4-dioxane as “likely to be carcinogenic to humans.” Dioxane is also listed in California’s official registry of chemicals known to cause cancer.
Dioxane is a man-made chemical mainly used (90%) as a stabilizer for another man-made water contaminant, the solvent TCE. The main source of 1,4-dioxane in drinking water is from leaking underground storage tanks at hazardous waste sites and from discharges from manufacturing plants. Other significant sources of exposure to the chemical include personal care products like shampoos, deodorants and lotions as well as laundry products and household cleaning products. 1,4-dioxane is in these products not as an intended ingredient but as a contaminant from the manufacturing process.
As with many contaminants, most of the research done on 1,4-dioxane treatment is focused on large applications like wastewater treatment plants and municipal water suppliers. Often, methods that prove effective for large operations are impossible to apply to residential treatment. In the case of dioxane, advanced oxidation processes involving hydrogen peroxide with ultraviolet (UV) light or ozone and anion exchange with specialty resins are used with some success to treat 1,4-dioxane. These large-scale methods are not practical for residential users.
Information about 1,4-dioxane as a residential contaminant and how to treat it is scarce and inconsistent. For residential treatment the old standby products carbon filtration and reverse osmosis seem to be the best things available, although very little actual testing seems to have been done to establish their effectiveness.
One North Carolina State University researcher says, “Most in-home water filters, including activated carbon filters, don’t remove 1,4-dioxane effectively. Reverse osmosis filters are better, removing a significant portion of the chemical from tap water, but still fall short.” Not exactly helpful if you’re designing a home treatment strategy, but typical of the information available. One leading internet vendor recommends whole house reverse osmosis at $10,000. Between the lines reading of the not-very-helpful advice on residential treatment indicates that filter carbon works, but not as well as one would hope, that it works best if there is long contact time (large filters and reduced flow rates), and that nutshell carbon seems to work better than coal-based. As for reverse osmosis, everyone agrees that it is effective but no one has established any hard information about rejection percentages.
To plan residential treatment for any contaminant, one needs to consider first how the contaminant is taken in by humans. In this area, too, there is a disturbing lack of information and a lot of contradictory information about dioxane. Water contaminants can be ingested by drinking contaminated water, or breathed in as a vapor or taken in through the skin. Showering is a common hazard since the contaminant can be taken in through the skin or breathed in if it vaporizes. Arsenic, to illustrate, does not evaporate into the air and is not easily absorbed through the skin, so there is little need for “whole house” treatment. Chlorine, conversely, vaporizes easily in the shower and also penetrates the skin, so whole house chlorine treatment is important.
Information about dermal and inhalation exposure to dioxane varies so much that it is essentially useless. The consensus is that it evaporates so quickly that dermal uptake is minimal; but this, of course, makes it more likely that it is breathed in during showering. To complicate the issue, because so many bath products are possible sources of the chemical, it is hard to know how much exposure is avoided by treating the water itself. It certainly makes no sense to install an elaborate and expensive system to remove 1, 4-dioxane from the water you shower with and then use a shampoo that contains the contaminant.
Treatment
Our recommendation for residential 1,4-dioxane protection is the same as for contaminants like fluoride, arsenic, and chromium. Install a high quality reverse osmosis unit that has at least two carbon stages for drinking water. An undersink RO unit should be a standard feature in all homes. For the whole house, carbon filtration, either as carbon block cartridge filters or a tank-style backwashing filter, provides broad protection against most contaminants and should reduce exposure to dioxane. We do not believe that installation of over-sized carbon tanks just to treat dioxane is advisable.
Leaking underground storage tanks at hazardous waste sites and discharges from manufacturing plants are important sources of 1,4-dioxane water contamination. Other significant sources of exposure to the chemical include personal care products like shampoos, deodorants and lotions as well as laundry products and household cleaning products.
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The Battleground Beneath Our Feet: The Politics of Water Pipes
by Gene Franks
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A 2017 New York Times article focused on a pressing problem that few Americans are aware of:
America is facing a crisis over its crumbling water infrastructure, and fixing it will be a monumental and expensive task.
Two powerful industries, plastic and iron, are locked in a lobbying war over the estimated $300 billion that local governments will spend on water and sewer pipes over the next decade.
The battleground is beneath our feet. Who wins the plastic vs. iron war will affect the safety and availability of drinking water for generations of Americans.
Some of our water pipes are 150 years old. In just a couple of years the average age of over 1.5 million miles (think of it!) of water and sewer pipes will be 45 years. In hundreds of towns and counties cast iron pipes are more than a century old. There are even said to be a few miles of old wooden pipes that have survived for well over a century. Lead water pipes, once widely used, have been banned for 30 years but more than 10 million old lead pipes are estimated to be still in service. The lead from these pipes, as the Flint experience taught us, can leach into public drinking water supplies at any time if there is a change in water treatment methods or water source.
About two-thirds of our existing water pipes are made from traditional materials like steel or iron. Plastic piping is now growing in popularity as a substitute for existing metal pipes, partially because the plastics industry is taking advantage of fears created by the Flint experience. As much as 80% of new piping is being done with plastics.
The sale of pipe, as is to be expected, is a highly politicized business. Piping standards are often mandated by law, and many laws are outdated but very hard to change, so whether plastic or metal piping is used often depends not so much on economic, health, or safety considerations as on which industry’s trade organization has the deepest pockets.
With $300 billion in pipe sales at stake, politics rules. Corporations that supply pipe pay high dues to trade associations who lobby and initiate legislation on their behalf. Trade associations and large corporations court politicians with campaign donations.
There is much industry-sponsored legislation aimed at modernizing piping standards. Opponents of the industry-backed bills, including many municipal engineers, say they are a thinly veiled effort by the plastics industry to muscle aside traditional pipe suppliers.
At first glance it would seem that plastics are an obvious replacement for the nation’s aging metal pipes. Plastics, after all, have already pushed out copper as the preferred pipe for connecting municipal lines to homes as well as within the homes themselves. Plastic pipe is light, easy to install, corrosion-free, and about 50% less costly than iron pipe.
Not everyone is comfortable with plastic piping, however, and there are rising health concerns.
Although plastic piping has been around for some time, we are just starting to understand the effect of plastic on the quality and safety of drinking water. Concerns have always focused on chemicals that could leach into the water from the pipes themselves. We have not answered completely questions about how water treatment chemicals like chlorine and chloramine react with the plastics in piping. Now there is concern that contaminants can enter plastic piping through surrounding groundwater contamination. It appears that pollutants like benzene and toluene from soil polluted by chemical spills or from groundwater can permeate certain types of plastic pipe and leach into the water. One report identified 150 contaminants that can migrate from plastic pipe into drinking water. The New York Times says, “Scientists are just starting to understand the effect of plastic on the quality and safety of drinking water. . . .”
One thing that should really concern us is there is a total lack of government regulation over the safety of piping used in water supply insfrastructure. There is no federal oversight of the materials or processes used to manufacture plastic water pipes; instead, water pipes are certified and tested by an organization paid for by industry, NSF International.
NSF International is not a government agency, and it has never received regulatory authority from the federal government, yet NSF certification is widely accepted by the public as the ultimate guarantee of product safety and reliability. NSF is paid by the industries it regulates and in the case of pipe it does not disclose test results for the pipes it certifies.
Although NSF International displays a picture of the US Capitol building on its web page, it is not a government agency and does not receive its authority from the government.
There is no doubt that switching to plastic piping exclusively could save water suppliers (and consequently taxpayers) significant amounts of money in the short term, but there are public health concerns that should be addressed. It would be good if these issues could be decided not by politicians but by qualified experts acting in the public interest.
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“Whole House” Reverse Osmosis for Less than $2500
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The usual operating setup for “whole house” reverse osmosis is to allow the RO unit to produce water into an atmospheric (non- pressurized) storage tank and then use a pump to send the water into the home. This arrangement provides a large storage capacity for treated water (300 to 500 gallons is typical for residences). Standard whole house RO units might be capable of producing up to 1000 gallons or more per day to top off the storage tank as water is withdrawn and pumped to the home. Such setups require pretreatment and posttreatment for the RO unit and a shutoff system for the storage tank, plus the re-pressurization pump to deliver water to the point of use.
The system described on this page is a simple RO unit that uses a pressure tank which is a very large version of the storage tanks used on undersink RO units. It is designed for use only in small homes — one or two people with low water use – or in other low use applications like offices, medical offices, or large homes with multiple sinks fed by a single RO unit.
This system features a ready-to-use Axeon 300 gallon-per-day RO unit that includes pre-treatment for sediment and chemicals and has carbon post-filtration built in. It is coupled with a high capacity pressurized RO storage tank. No RO shut-off or re-pressurization pump is needed. The pressurized storage tank sends water to the point of use and the RO unit turns on automatically to refill the tank.
The classy Axeon L1-300 RO unit uses standard-sized housings and membrane for easy replacement. It is a fully automatic unit that shuts off and turns on in response to changes in tank pressure. It is shown here with an optional mounting stand but can also be wall mounted.
Installation consists of connecting the RO unit to the storage tank. We furnish the tee that joins the tank to the RO unit and sends water to the point of use. Tanks come in 40, 60, and 80 gallon sizes.
ROMate 80 gallon pressurized RO storage tank. Large fiberglass reinforced RO tanks function exactly like well tanks. Water goes in and out through the single pipe at the bottom.
Pages with more information:
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EPA Proposes New Regulations For Lead In Drinking Water
by Paolo Zialcita
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This is a National Public Radio news report, issued in late October 2019.
The Environmental Protection Agency (EPA) announced a new proposal that would change how communities test for lead in drinking water. It’s the first major update to the Lead and Copper Rule in nearly 30 years, but it does not go as far as many health advocates had hoped.
The regulations are aimed at stopping people’s water from being contaminated through lead pipes that connect public water supplies to homes.
The EPA’s website points out that ingesting lead “can be harmful to human health even at low exposure levels.”
The proposal that was announced Thursday would require water systems to keep a public inventory of where those lead service lines are and help homeowners replace them if their water is found to be contaminated with lead.
If a water test shows dangerous lead levels, utilities would also have to notify their customers within 24 hours.
“By improving protocols for identifying lead, expanding sampling, and strengthening treatment requirements, our proposal would ensure that more water systems proactively take actions to prevent lead exposure, especially in schools, child care facilities, and the most at-risk communities,” EPA Administrator Andrew Wheeler said.
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Gazette Introductory Note: This article is being reprinted because it presents a concise, easy-to-understand explanation of the ultrafiltration (UF) process. It concerns use of UF for wastewater treatment, but the problems it raises – membrane fouling and scaling, waste stream disposal, etc. – apply as well to residential applications. We (Pure Water Products) do not currently offer residential ultrafiltration units for the whole home partly because the issues detailed in the article should be addressed by professionals rather than home owners, our main customers. –Gene Franks.
One facet of technological advancement is attempting to mitigate the more glaring issues that consistently crop up due to the nature of a system process. Of course, even with decades of improvement nothing is infallible. In this article, we will discuss the common issues that can occur using UF filtration systems.
Ultrafiltration is a pressure driven membrane separation technology that is a compact and refined filtration method utilized in drinking water and tertiary wastewater reuse applications. Its semipermeable membrane can remove solids as small as 0.01 microns, including silt and viruses. However, membrane filtration technologies will have problems without proper care for appropriate pretreatment, operation, and maintenance.
UF filter systems are typically affected by three main issues:
Membrane Fouling
UF filtration, like any other membrane separation technology including reverse osmosis, is susceptible to what is known as membrane fouling. In simple terms, fouling is what happens when particulate matter adheres to the surface of a membrane. The unchecked buildup will eventually cause reduced efficiency, a pressure drop, and increased energy consumption.
There are a few different types of fouling that can occur. Each has its own cause as well as some differences in effects. Of these membrane foulants, some are reversible and others are irreversible.
Solids
Suspended solids and colloidal particles collect on the surface of the ultrafiltration membrane as well as within its pores, preventing the flow of water through the membrane. This fouling occurs more commonly in applications with high turbidity and suspended solids without appropriate pretreatment.
Scaling
Membrane scaling is not unlike what happens in pipes that carry water with high concentrations of hardness materials. When the concentration of these dissolved minerals is high enough to surpass the saturation limit of the solvent solution, they begin to precipitate out of solution onto the surface of the membrane. These minerals can crystalize, which makes them nearly impossible to remove without some sort of chemical cleaning or antiscalant pretreatment. Calcium and magnesium are two primary minerals that can cause scaling to occur on the UF filter system’s membranes.
Microbiological
Biological contaminants like algae and microorganisms are often found in surface water sources. Provided with a warm environment and low flow rates, these contaminants will attach themselves to the surface of a membrane and begin multiplying. Over time, they can form a film that will prevent water from passing through the membrane and cause an increase in the trans membrane pressure differential. This increased pressure differential will put more strain on the pumps and increase the amount of energy they draw.
Waste Stream Disposal
This relates to the UF filter concentrate discharge. The filtration system did what it’s supposed to do and you have clean water that you can safely discharge into an outdoor stream without having to pay any environmental regulation fines. Or maybe you are going to reuse it somehow. Regardless of what is going to happen to it, you have this water resource.
However, what about all the contaminants that were removed? Sadly, this concentrate stream didn’t disappear into thin air, never to be dealt with again. Nope. It’s still there, whether it’s stuck to the membrane or sitting in a concentrate waste tank, and something needs to be done about it.
The problem is, you can’t just toss it out the window and call it a day. This reject wastewater is a concentrated form of whatever was in the feedwater. Therefore, in some cases, it may be safe enough to discharge into the environment; however, in others, the facility would be charged a hefty fine if it contains harmful pollutants.
Increased Permeate Contamination
This point is pretty rare for systems that are well maintained and monitored. To reiterate, permeate refers to the water that has been separated from the contaminating solids. It’s the clean water that you get out of this filtration process. Therefore, it’s definitely an issue when you start noticing that the quality of your permeate water is getting worse. Either there are larger solids or bacteria that should have been retained by the membrane contaminating the water.
This decrease in removal efficiency is usually indicative of a compromised membrane. Polymeric membranes can get worn out over time. High temperature or pH levels can degrade them pretty quickly, and without a decent pretreatment regime, rough particles can damage the inner pores of the membrane. To state the obvious, membranes do not work very well if they are full of additional holes (other than their pores of course). And now the system isn’t meeting it’s designed specifications and you have to replace the membrane and recirculate the contaminated permeate.
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Gazette Editor’s Note: Politics aside, we’re reprinting this article because it presents water issues that should be part of our national political discussion. Private/public ownership of water supplies, regulation of emerging contaminants like PFAS, the Waters of the United States (WOTUS) rule, and development and maintenance of water infrastructure should all be important campaign topics. We should not let political candidates continue to ignore them.
There’s little doubt that the field of candidates vying for U.S. presidential election in 2020 represents a wide array of views on nearly every issue. But two Democratic frontrunners now appear unified on at least one major issue: the privatization of water systems.
Elizabeth Warren, a Democratic presidential nominee who leads her colleague according to some polls, released an environmental plan that emphasized the need for the nation’s water systems to be run publicly, among other things.
“America’s water is a public asset and should be owned by and for the public,” according to Warren’s plan. “A Warren Administration will end decades of disinvestment and privatization of our nation’s water system — our government at every level should invest in safe, affordable drinking water for all of us.”
More specifically, Warren advocates for harsher federal classification of per- and polyfluoroalkyl substances (PFAS), the reinstatement of the Waters of the United States (WOTUS) rule, and investment into public water system infrastructure.
The emphasis on public water system management puts Warren firmly in alliance with Bernie Sanders, who has advocated for the same approach in the WATER Act that he released in February 2019 and in the Green New Deal, an expansive legislative proposal to revamp the country’s approach to environmental issues.
“Sanders introduced the WATER Act, which would help municipalities or state agencies bring treatment works back into public ownership,” per Common Dreams. “Months earlier, in November 2018, Sanders gave a forceful rejection of privately controlled water after voters in Baltimore easily passed Question E, which bans the privatization of the municipal water and sewer systems.”
By discouraging private water systems, both Warren and Sanders are highlighting research that indicates this management structure is less safe for consumers than public utility management.
“The private water industry serves 73 million Americans, according to National Association of Water Companies data,” The Huffington Post reported in a story on Warren’s climate plan. “For-profit water services put public health at risk, a 66-page paper by University of Louisville law professor Craig Anthony Arnold argues, because the profit motive incentivizes companies to provide better services to customers who pay more and to maintain infrastructure with an eye to the length of the firm’s contract.”
While Warren alluded to these inherent flaws with privately-run drinking water systems, her plan did not outline whether or not she’d actively work against their formation as president. But it did make clear that if Warren were to become the next president of the United States, privately-run water systems would become far less common.
“[The] proposal did not make clear whether a Warren White House would take explicit steps to discourage municipalities from switching to private water,” per The Huffington Post. “But the campaign said an influx of federal funding to overhaul water infrastructure should make switching to private water services far less appealing.”
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Places to visit for additional information:
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Thanks for reading and be sure to check out the next Occasional!
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