Facts about Legionellosis

Water treatment consultant and author Dr. Joseph Cotruvo recently called Legionaries’ Disease, or Legionellosis, “the most important waterborne disease in the United States.”

According to Dr. Cotruvo, Legionellosis has been a reportable disease only since 2001. The disease is not caused by ingestion of the water, but rather by inhalation of aerosols such as during showering or from inhaling blow down from cooling system heat exchangers, or probably even humidifiers. Those at particular risk are the elderly and especially people with impaired immune systems such as those who are hospitalized and in extended care facilities.  

It is well known that legionella are detectable in a high percentage of plumbing systems, including in homes, hotels and other buildings, and a substantial number of people in the general population are susceptible because of their ages or health or immune status. Several hospital-related outbreaks of legionella-related diseases are reported annually around the world, but undoubtedly most are not identified or attributed to the water system. CDC has estimated that between 8,000 and 18,000 people are hospitalized with Legionnaires’-related disease each year in the U.S. It is not known how many of those are attributable to exposure from the plumbing or cooling systems.

Legionella microorganisms are common environmental and soil bacteria. Water treatment at the central plant is capable of removing them from influent water, but if even a few enter distribution/plumbing systems, through the plant or during main breaks or from being present on pipe interior surfaces at installation, the water distribution environment is conducive to colonization. They can proliferate at temperatures in the range of about 25oC  to 55oC (77oF to 130oF) such as can be found in hot water systems, shower heads and in cold water systems in warm climates, or during warm times of the year. Maintaininghot water temperatures below 120 F for energy efficiency and to reduce water heating costs can actually create an ideal condition for legionella proliferation.

Treatment

Treatment is a real challenge and a cookie cutter approach is not likely to be widely successful. The problem of controlling microorganisms colonizing plumbing and distribution systems is not trivial because many of them are associated with biofilms or protozoa such as amoebas and can be protected by them. Disinfectants that have been employed have had limited success. They include chlorine, chloramine, chlorine dioxide, ozone, UV light, copper/silver ionization and shock thermal and steam treatments. Each of them has its benefits and weaknesses, and often a combination of treatments must be applied on a regular basis supported by monitoring to indicate the conditions of the system and the time to re-treat.

Chlorine is a powerful disinfectant, but even when applied in a temporary hyperchlorination mode (e.g., 50 ppm for several hours) total eradication may not be achieved. Chloramines, which are far less potent than free chlorine, have demonstrated considerable success in reducing legionella counts in some water plumbing systems. This could be due to the lower chemical reactivity of chloramine and greater hydrophobicity that allows greater penetration into biofilms.  Ozone and UV might have some efficacy in recirculating systems, but they will be primarily effective against organisms in the water column. Copper/silver in combination and individually have shown successes when they are properly managed and maintained. Shock thermal treatment for several hours at temperatures above 70oC have shown temporary success, but a complete strategy would require a combination of initial biofilm cleanout with a disinfectant system that will retard regeneration of the biofilm.

The concept of final barrier protection has value in situations where sufficient risk exists. For example, instant hot water delivery systems leave a smaller volume of water to stagnate and provide a growth environment.

Dr. Cotruvo concludes that pathogenic microorganisms such as legionella frequently colonize water plumbing systems, and they now are the most significant public health risk associated with drinking water. Many illnesses and deaths are attributable to that problem and drinking water standards are not designed to deal with them. Indeed, the existing standards may actually result in increased public health risks because they provide a disincentive for health care facilities to take corrective actions. The risk benefit balance is clearly in favor of eliminating the burdens that are imposed upon those facilities, so that they will be more likely to take actions to reduce risks to their patients.

Undersink Water Filters: Better than they used to be.

By Pure Water Annie

Gazette Technical Consultant Pure Water Annie explains how undersink water filters have improved in recent years.

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

1. The replacement of copper and galvanized undersink piping with flexible connectors.
2. The improvement in filter housing and cartridge designs that allows installation of more compact and easy-to-service filtration units.
3. 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 contaminants like lead, arsenic, fluoride, iron, bacteria, nitrates, low pH, and cysts.

This last aspect, 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.

Sludge to Energy: A Dallas Recycling Success Story

The City of Dallas is cleaning waste water, making energy and saving money – all at one plant on the south side of the city.

The Southside Waste Water Treatment Plant receives and cleans about 50 million gallons of dirty water a day. It is water that originates in homes and businesses – down the drains, sinks, toilets and showers – into the sewer system, and piped to the plant.

Through a multi-step process, the water is cleaned – almost to drinking level – then fed back into the Trinity River.
“We try to eliminate as much as possible – the food waste, the grease. It impacts our infrastructure and makes the water itself harder to treat,” said Jesse White, the plant manager at Southside.

White says, the plant also takes on another process: converting sludge – the name for that solid waste – into energy.

The solids are separated out and stabilized. In the process, methane gas is produced as a by-product. At one time the biogas was flared off as a means for disposal.

Around six years ago, the City of Dallas began a co-generation project, allowing that biogas energy to be recaptured and used by the plant for its own power needs.

It reduces dependency on the electricity grid, saving tax payer dollars. Right now the Southside Waste Water Treatment Plant powers about 50-60 percent of its own energy.

“It benefits Dallas citizens because waste water treatment plants are very energy intensive. Waste water plants are probably one of, or the largest consumers of energy throughout the United States,” said White.
The project helps the plant reduce its grid derived electrical needs by 27 million kWh a year.
Along with the solid waste conversion, the plant takes in grease for the same purpose.

The city’s “Cease the Grease” campaign includes more than two dozen cooking oil and grease recycling stations, at grocery stores, college campuses and other locations around the Metroplex.

Right now, the city collects an average of 300 gallons of grease a month, from homeowners who drop off canisters at the stations, and pick up empty bottles to take home to fill again.

“We would like to generate even more. There’s a lot more oil out there in Dallas,” said Helen Dulac, an environmental coordinator for Dallas Water Utilities.

Extra stations are currently available and Dulac says the city is looking for businesses, churches or groups who want to be host sites for collection. The Cease the Grease team will drop off the station and take care of maintenance for free.

It’s also a reminder for water customers to not pour cooking grease or fat down the drain, which can lead to big infrastructure problems.

“Even through bacon grease in the pan might be liquid when you pour it down the drain, it’s going to cool off and turn into a solid. It can clog up your pipes plus our city sewer pipes,” Dulac said.

Excerpted from CBS Local.

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Let free market determine price for water

by John Ford

Gazette’s Introductory Note: This editorial comment by attorney John Ford of Orange County, CA presents ideas that deserve consideration. Although relying strictly on “the free market” to set the price of an essential commodity would certainly create its own set of problems, allowing the real cost of providing water to play a major part in determining of the price we pay would certainly make sense. The Gazette has consistently advocated higher water prices as a means of conservation as well as a necessary part of a well-funded public water system. We forget that we live in a world of subsidized products. Water is not the only commodity for which we pay way less than the real cost. If “the free market” alone determined the price of gasoline, few of us would be driving cars and eating almonds trucked from California. While we certainly need to reform and simplify our antiquated water distribution system and increase the price we pay for water, we believe that water is an essential element that belongs to us all and that allowing “the free market” alone to determine its distribution and availability would result in water being distributed  the same way that money is distributed–with 1% of the population controlling most of it.–Hardly Waite.

As California searches for solutions to our ongoing drought, we would do well to look to how Australia successfully responded to a similarly severe drought nearly 20 years ago. In 1995, Australia found itself in the midst of the most serious drought since European settlement began. Rivers were drying up, and farms were going fallow all over the country. The crisis was so severe that Australia was forced to do something that was considered radical at the time: It adopted a market price for water.

The basic argument for a water market is straightforward. People should pay for the resources they use and they should pay what the resource is actually worth. If people have to pay a market price for water, then they will be encouraged to conserve in the ways that are the most economically efficient. In California, there is no market price for water. Water in this state is artificially cheap – this low price encourages overconsumption that is harmful to both our economy and our environment. A market price for water would solve this problem.

Australia proved the theory behind water markets could work in the real world. Australia is subject to regular (often severe) droughts. The severity of the drought that began in 1995 forced Australia to try a variety of measures to combat water scarcity. It tried everything, from mandated cutbacks to building huge, expensive desalination plants. Nothing worked. Then, in 2007 Australia adopted a national system for trading water rights, building on smaller programs created in a previous drought by some of Australia’s states. In doing so, they created a national market for water.

After water markets were adopted, water consumption in Australia fell by 35 percent. Today, water consumption in Sydney is only about 83 gallons per person per day. Compare this with 193 gallons a day in Irvine, 186 gallons in Anaheim and 219 gallons in Orange. Australia got its citizens to conserve by using prices. Because they have to pay the market price for water, residents of Sydney pay about $6.50 per 1,000 gallons of water. In Irvine, the cost is much less, at only $3.19 per 1,000 gallons. But because people in Sydney use so much less water, the average person there pays only about $196 per year for water, whereas residents of Irvine pay about $228 per year for water.

Put simply, markets worked. A modest price increase resulted in significant conservation with only a modest impact on consumers’ pocket books.

In California, there is no market price for water. Of California’s 58 counties, 22 restrict any trading of water for any reason. Water in California is governed by a convoluted morass of regulations and bureaucracy. The state has 3,000 separate water districts and agencies, many of which exist only to sell water to each other at artificially low prices. Orange County alone has 28 separate water agencies.

This bureaucratic tangle means that instead of adopting a rational system of water trading based on market prices, we have responded to our drought by putting restrictions on when a restaurant can serve a glass of water to its patrons. No serious person believes this sort of rule will have a measurable impact on conservation.

If leaders in Sacramento want to do something that would actually alleviate the drought in a way that would protect both our environment and our economy, they should take inspiration from Australia, do away with pointless red tape and adopt a market price for water.

Source: The Orange County Register.

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Thousands of mines with toxic water lie under the western US

Gazette’s Famous Water Pictures Series

Georg Frideric Handel (left) and King George I on the Thames River, 17 July 1717. Painting by Edouard Hamman (1819–88).

The Water Music is a collection of orchestral movements, often published as three suites, composed by George Frideric Handel. It premiered on 17 July 1717 after King George I had requested a concert on the River Thames.

The usual explanation for the gala on-the-water concert is that the king was feeling heat from an opposing political faction gathering around his son, the Prince of Wales, and he staged a big public event to draw attention away from his son and to himself.

 Akademie für alte Musik Berlin performance.

Full Summer in Texas. Pure Water Products at Denton’s Farmers’ Market.  From left Theresia Munywoki, Kacy Ewing, Katey Shannon, and Kristen Lewis with twins. Visit them at the Denton Farmers’ Market on Saturdays or at our 523 N. Elm location weekdays. Or call 940 382 3814.

Click Picture for Larger View

Bee Sharper Puts the Numbers of Water Treatment into Context

Editor’s Note. Water contaminants like lead and arsenic are measured in parts per billion. To put these tiny amounts into context, here’s a BB Sharper comparison.

Year it was one billion seconds ago: 1959.

Year it was one billion minutes ago: c. AD 110.

Year it was one billion hours ago: BC 110,000.

Year it was one billion days ago: BC 2,640.000.

Parts per million represented by one drop in a bathtub full of water — 2.

Parts per million represented by one second in 12.5 days — 1.

Number of micrograms per litre (μg/L) represented by one part per billion — 1.

Number of micrograms per litre represented by one drop in 250 bathtubs full of water — 1.

Number of parts per billion represented by one second in 32 years — 1.

As Summer Heats Up, Algae in Lakes Cause Concern

As summer temperatures rise, the presence of algae in some surface waters in the US has increased. Not all algae produce toxins that affect public health, but increased growth in recent years of  harmful algal blooms is triggering some concern.  Last August, a major algal bloom in Lake Erie caused the city of Toledo, Ohio, to issue a “do not drink” order for more than 400,000 residents.  The EPA estimated in 2009 that  20 percent of the nation’s lakes are highly impacted by algae, and one-third contains some level of harmful algae.

In response to the rise in harmful algae in lakes, the  EPA determined toxin levels in tap water that are safe for human consumption and offered recommendations for how utilities can monitor and treat drinking water for algal toxins and notify the public if the water exceeds these levels.

Green scum produced by and containing cyanobacteria.

More About Algae

Algae are found naturally in lakes, streams, ponds and other surface waters. When conditions are favorable, they multiply rapidly and cause a “bloom” characterized by a pea-soup green color or blue-green scum. Their nature can be affected by the intensity of sunlight, water temperature, nutrient availability (especially nitrogen and phosphorous), pH, and water movement.

Most algae are not harmful. Last year’s Toledo algae scare was due to fresh water algae known as cyanobacteria, often called blue-green algae.   Cyanobacteria proliferate in stagnant or slow-moving bodies of water with high levels of nutrients — nitrogen and phosphorous — often due to agricultural runoff or wastewater. When the ecosystem becomes unbalanced, non-harmful algae are often replaced by cyanobactria.

These fresh water algae can produce cyanotoxins, one of the more harmful types of algal toxins.

Cyanotoxins can cause health problems primarily affecting the nervous system, liver or skin. If present in recreational water or drinking water at high enough levels, a wide range of symptoms may occur — including fever, headaches, muscle and joint pain, blisters, stomach cramps, diarrhea, vomiting, mouth ulcers and allergic reactions. These symptoms can occur immediately or several days after exposure.

Some of the most common classes of algal toxins are microcystins, anatoxins and cylindrospermopsins. Microcystins have a World Health Organization guideline of 1 mg/l for drinking water,  as do cylindrospermopsins which primarily affect the liver, and anatoxins which affect nerve synapses. However, appropriate standards for these toxins are still in development.

When cyanobacteria are present in a water source, the preferred strategy is to remove them from the water before toxins are released. This can be accomplished through processes such as dissolved air flotation. However, the best approach is to prevent the growth of algae that can produce the toxins through watershed management.

Many solutions are available to treat algal toxins. Disinfectants and oxidants such as chlorine, chloramine, ozone, ultraviolet (UV) and chlorine dioxide are frequently used in standard treatment facilities. Most algal cells can be removed by chlorine disinfection, in addition to coagulation, sedimentation and flocculation. Removal of the toxin is more difficult. Many standard water treatment strategies are used with some success.  These include granular activated carbon (GAC), ozone, advanced oxidation processes, nanofiltration and reverse osmosis (RO). At present there is no single recommended treatment for algal toxins.

Algae in water sources is, of course, of interest mainly as a public water issue. Point of use treatment for residential water has been infrequently considered, but the standard techniques of carbon filtration, chlorination, and reverse osmosis would seem to be the obvious final barrier strategies.

Reference: Water Technology.

Editorial: Water conservation becomes the standard, prudent thing to practice

Gazette Introductory Note: It’s good to be reminded now and again that rules and regulations often make sense. It’s our nature to dislike being “regulated,” but surely no one would honestly deny that the onerous restrictions placed upon Americans by the Clean Air and Clean Water Acts have worked wonders to clean up our environment. The terrible burden of auto emissions standards placed upon the auto industry have performed a miracle in cleaning up our air, and contrary to the predictions of crusty regulation-haters,  requiring catalytic converts has not shut down the auto industry or made cars so expensive that no one can afford them. The following editorial from the Vancouver Sun reminds us that even the government sometimes knows what it’s doing.–Hardly Waite.

Every attempt at broad-brush solutions to problems seems accompanied by its black comedy of peculiarities. For example, bring in watering restrictions to deal with the prolonged dry spell that’s running down Metro Vancouver’s drinking water reservoirs and you generate seemingly wacky contradictions.

If you wash your car in the driveway with a hand-held, spring-loaded shut-off nozzle, that’s an offence but if you take it to a commercial car wash where automated robots do it, that’s fine, and you can do it every day if you are so inclined. You can’t refill your spa tub on the back deck but you can go indoors and use the soaker tub with whirlpool jets as often as you like. You can wash artificial turf but watering the natural lawn is a no-no.

Such oddities are always good for griping about city hall and its endless follies, but that’s all they’re good for. In most cases they are illusions. The robots at that commercial car wash are much more frugal than you. It’s estimated that washing a car by hand uses about from 300-500 litres of water. The car wash robots will use about 170 litres and wax, polish and dispose of the soapy water properly, not down the storm drain. An automatic dishwasher will clean your dinner dishes with one-sixth the water used in hand-washing and, because it’s so efficient with the hot water, will use only about half the energy. That energy is generated by spilling precious water through turbines or by burning fossil fuels, both of which exacerbate the connected problems of water reserves and climate change.

So once we have done with the mandatory Canadian ritual of huffing over apparent contradictions that prove we’re governed by fools, it’s more useful to back the wise philosophy of water frugality as a new norm imposed by climate change. Our rainy winters have encouraged us to think of fresh water as a limitless resource. But as prolonged droughts elsewhere and now in British Columbia and Canada’s western plains indicate, that’s not necessarily so.

If these dry conditions prove to be the new summer normal, prudence suggests we start thinking about water conservation as the standard rather than the exception. We should, even if this drought proves anomalous. On a range of possibilities, one must be that things could prove even more extreme in the future. The time seems ripe for a serious public conversation about what we should be doing to plan for our civic adaptation in the way we live that changing climate seems increasingly likely to impose with increasing severity, frequency and duration.

Source: The Vancouver Sun.

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