How Do Reverse Osmosis Units Know That the Storage Tank is Full?

Modern undersink reverse osmosis units use a simple but effective shutoff device to turn off water production when the unit’s storage tank is full. The shutoff system monitors the pressure in the storage tank and shuts off water coming into the RO membrane when tank pressure reaches approximately 2/3 of the pressure of the incoming tap water.  Thus, a “full” tank in a standard RO unit is defined by the pressure of the water entering the RO unit.  If incoming pressure is 60 psi, a full tank holds about 40 psi; if incoming pressure is 50, a “full” tank holds about 30 psi. Shutoff is done at around 2/3 of incoming pressure because as the tank fills increasing back pressure makes production less efficient. It isn’t practical to fill the tank past 2/3 full.

The Payne brand shutoff pictured above is installed as follows:

1. After water leaves the RO unit’s prefilter, it enters the “In” port of the shutoff valve, lower right in the picture. It then makes a horseshoe turn and exits the “Out” port, lower left in the picture, through which it flows to the inlet side of the RO membrane.

2. When the “permeate” water (the product water of the RO unit) leaves the other end of the membrane housing, it flows to one of the “tank” ports on the other side of the shutoff valve. It doesn’t matter which port it enters, since the “tank” ports are interchangeable and water flows either way on the permeate side of the valve. Water then makes a horseshoe turn inside the top side of the valve and leaves through the other tank port. From there it flows to the storage tank.

3. The two halves of the valve are separated by a piston, which keeps the permeate water on one side and the incoming tap water on the other. As long as the pressure on the tank side is less than 2/3 the pressure on the tap water side, the piston remains open and the unit continues to produce water. As the RO produces water and slowly fills the storage tank, however, pressure on the tank side of the piston eventually becomes strong enough to force the piston toward the tap water side and shut off the incoming tap water, stopping production. The RO unit stays off until enough water is removed from the storage tank to drop the pressure on the tank side of the piston, allowing tap water pressure to push the piston toward the tank side and start RO production again.

The Flowmatic shutoff valve above works exactly like the Payne valve, although the flow pattern is straight through rather than horseshoe style. In other words. water enters lower right and flows straight ahead through the valve and out the other side.

It is important to know that in order for the shutoff system to work, a check valve (one-way valve) must me installed in the permeate tube between the membrane and the shutoff valve. Without the check valve to hold the back pressure from the tank, the shutoff valve cannot function.

The Payne shutoff valve is clipped to the membrane housing of the unit above. The tubes on the right side carry tap water to the membrane. On the left, or “tank” side, permeate water leaves the membrane, passes through the cigar-shaped check valve, and enters one of the shutoff valve’s “tank” ports. It leaves via the other tank port and flows to the tee, which sends it to the storage tank.

Note that the inline check valve will not be found on most RO units, since RO manufacturers usually prefer a tiny, inexpensive check valve that”s contained in the elbow fitting where the permeate water leaves the membrane housing.

Troubleshooting your shutoff system

If you hear water running to drain more than you think it should or have some other reason to suspect that your RO unit isn’t shutting off properly, here’s an easy test you can do to check its performance.

Run a few glassfuls of water from the RO unit to start the unit producing water, then turn off the RO faucet and remove the drain line from the drain saddle connected to the undersink drain pipe.  Drop the end of the drain line into a bottle or pan  so that the drain water trickles into the container. Next, turn off the valve at the top of the RO storage tank. Water should stop flowing from the drain line within a couple of minutes. When it stops, leave the valve off, empty the container, put the tube back into the container, and come back in 10 minutes.  If there is no water in the container, the shutoff system is working perfectly.  The unit is shutting off and holding its shutoff.

If the drain fails to shut off, you need to find the reason.  The main suspects are the shutoff valve or the check valve, not necessarily in that order.

If the drain shuts off initially, but comes back on during the 10 minutes, continue to watch it.  If it comes on, runs briefly, then shuts off,  and repeats this pattern over and over, you need a new check valve.

More about reverse osmosis shutoff valves and other reverse osmosis part

Stepping Out of the Bubble

by Elizabeth Cutright, Editor, Water Efficiency.

It can be hard sometimes, when you spend your days focused on one particular topic or issue, to realize that not everyone in the world shares your insights or perspectives. In fact, we often become so entrenched in our own little bubbles that we forget that not everyone is privy to the same facts and figures, the same experiences, or the same common sense.

While I know better, it’s hard sometimes to avoid glancing at the comments that usually appear at the end of a blog post of news story. I’m well aware of the fact that most of the time, Internet commentators are operating from the lowest common denominator and that the “trolls” are there to do nothing more than stir up controversy. And yet … despite my complete understanding of the inevitable, more often than not I find myself scrolling through responses and unregulated opinions that often follow a piece of online content.

I share all of this because today, I was truly surprised to learn that there is perhaps a small, but nevertheless vocal, online contingent that does not believe in water conservation. These folks believe that water scarcity is all “hype”, that it is all part of a “liberal agenda” aimed at curbing economic expansion and turning the US into a fascist, socialist utopia.

Here’s a sampling of the responses to a story aimed at “debunking the myth of peak water.”

* “The only way to truly wastewater would be to launch it out of the atmosphere. Otherwise, all other uses of water puts it back into the system sooner or later.”
* “Just another example of the eco-lemmings having to have something to worry about. I have no doubt that ‘the science is settled’.”
* “These graft-seeking scaremongers would find my generous aquifer quite inconvenient.”
* “The nutty left, God bless them, have picked something that is 100% recyclable, is 100% recycled, and easily made potable (safe to consume).”
* “I don’t see how electrical generation consumes ANY water. Running it through the hydropower turbines does nothing harmful to it. Downstream it goes where it can be drawn by the downriver users.”
* “Baah! If vast amounts of irrigation water (and crops and jobs) can be sacrificed to save the Delta Smelt, it’s not even remotely possible that this is anything resembling an actual ‘issue’. Lots of vilification for urbanization (are liberals so stupid they do not to realize where their ‘base’ is located?) yet nary a snear (sic) for the Smelt! Baah!”

It’s frustrating to see the facts muddled with myth to produce an obstinate view of reality. While all of us could pick apart each of the above statements (as well as the article itself), the truth is we shouldn’t have to. If the public is really questioning water conservation efforts, then those of us working in water resource management have failed.

Water scarcity shouldn’t be up for debate. Water conservation shouldn’t be politicized. Water efficiency shouldn’t be downplayed or mocked.

The truth is, there is no need to label our current water resource situation with cute catchphrases like “peak water” (a term that because of its unsuitable application loses all meaning). Reality speaks for itself.  In the end, it’s not about political affiliation or ideological perspectives; it’s about responsible resource consumption and an awareness that we cannot operate as if we live in a self contained bubble.

As these commentators were so quick to point out the water cycle is all-inclusive—water goes out and water goes in, in equal measure. We may not “lose” what we have, but if we’re not careful, we will lose the ability to use what we have left.

Source: Water Efficiency.

 New York in 200 Years?

adapted from Rising Seas by Tim Folger.

 Why the Seas Rise

Unless we change course dramatically in the coming years, our carbon emissions will create a world utterly different in its very geography from the one in which our species evolved. “With business as usual, the concentration of carbon dioxide in the atmosphere will reach around a thousand parts per million by the end of the century,” says Gavin Foster, a geochemist at the University of Southampton in England. Such concentrations, he says, haven’t been seen on Earth since the early Eocene epoch, 50 million years ago, when the planet was completely ice free. According to the U.S. Geological Survey, sea level on an iceless Earth would be as much as 216 feet higher than it is today. It might take thousands of years and more than a thousand parts per million to create such a world—but if we burn all the fossil fuels, we will get there.

No matter how much we reduce our greenhouse gas emissions, Foster says, we’re already locked in to at least several feet of sea-level rise, and perhaps several dozens of feet, as the planet slowly adjusts to the amount of carbon that’s in the atmosphere already. A recent Dutch study predicted that the Netherlands could engineer solutions at a manageable cost to a rise of as much as five meters, or 16 feet. Poorer countries will struggle to adapt to much less. At different times in different places, engineering solutions will no longer suffice. Then the retreat from the coast will begin. In some places there will be no higher ground to retreat to.

By the next century, if not sooner, large numbers of people will have to abandon coastal areas in Florida and other parts of the world. Some researchers fear a flood tide of climate-change refugees. “From the Bahamas to Bangladesh and a major amount of Florida, we’ll all have to move, and we may have to move at the same time,” says Wanless. “We’re going to see civil unrest, war. You just wonder how—or if—civilization will function. How thin are the threads that hold it all together? We can’t comprehend this. We think Miami has always been here and will always be here. How do you get people to realize that Miami—or London—will not always be there?”

What will New York look like in 200 years? Klaus Jacob, the Columbia geophysicist, sees downtown Manhattan as a kind of Venice, subject to periodic flooding, perhaps with canals and yellow water cabs. Much of the city’s population, he says, will gather on high ground in the other boroughs. “High ground will become expensive, waterfront will become cheap,” he says. But among New Yorkers, as among the rest of us, the idea that the sea is going to rise—a lot—hasn’t really sunk in yet. Of the thousands of people in New York State whose homes were badly damaged or destroyed by Sandy’s surge, only 10 to 15 percent are expected to accept the state’s offer to buy them out at their homes’ pre-storm value. The rest plan to rebuild.

This isn’t an artist’s vision of what New York will look like in 2210.  It is a photo of present-day Manila where the rising sea keeps nibbling away at the waterfront homes of the poor.

Source:  National Geographic.

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Brackish Water: A Slippery Subject 

An exact definition  of what is commonly called “brackish” water is hard to pin down.  Brackish water falls between seawater and fresh water. Brackish water is similar to seawater except the salt content is less, as are the TDS (total dissolved solids).  In another way of classifying, you start with fresh water, then go to brackish water, then to saline water, then to brine.  The specifics of these classifications are often blurred.

Brackish Water Pond

One authority states that brackish water begins at about 1000 ppm TDS and runs upward to around 10,000 or 12,000 ppm TDS.

The basic process of treating brackish water in desalination applications is to pass pressurized water through a membrane. As fresh water passes through the membrane, brine or wastewater is rejected.

Seawater treatment applications differ from brackish mainly in the level of osmotic pressure required to achieve fresh water.

Typically, the pressure needed ranges in brackish water treatment from 5 psi to 75 psi, although the majority of brackish applications fall in the 145 psi to 290 psi range.

Brackish water is generally a surface-type water and as such can be influenced by such environmental factors as rainfall and humidity.

Ion levels and bacteria could be higher in the summer months compared to winter months, and salinity, nitrates, iron, silica and bacteria are a few examples of what is common in untreated brackish water.

Viewed another way, brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root “brak,” meaning “salten” or “salty”.

Certain human activities can produce brackish water, in particular certain civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment.

Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (ppt or ‰). Thus, brackish covers a range of salinity regimes and is not considered a precisely defined condition. It is characteristic of many brackish surface waters that their salinity can vary considerably over space and/or time.

Here is a chart from the Wikipedia:

In summary, brackish water lies in definition somewhere between fresh water and sea water and is defined mainly by its salt content.

Treatment is almost exclusively by membrane technology (reverse osmosis) or by distillation.

References:  Water Technology “Technical Feature” (March 2010) by Rich DiPaolo,  Wikipedia, The Pure Water Occasional.

Pure Water Gazette Fair Use Statement

The Basics of Compression and Pipe Threads Used in Water Filters

Like most professions, the water treatment industry runs on initials. Here are a few more.

There is often confusion about the threads on the fittings and connectors used in water treatment in particular and small-pipe plumbing in general. Things used to be more complicated when undersink plumbing had such exotic creatures as flare, fine flare, and Texas fine flare fittings to contend with.  Now almost everything is done with compression fittings, pipe fittings, or the super convenient plastic push-in fittings.

The push-ins are easy. With threaded fittings,  what confuses people usually is the distinction between a pipe fitting and a compression fitting. The picture below has both threads. It’s hard to see the difference, but there is a difference.

The taper of the threads is what actually distinguishes pipe from compression fittings. On bottom of the fitting in the picture is a male pipe thread; on top is a male compression thread with nut. Pipe threads connect the fitting to another solid component, like a filter housing or a rigid metal pipe. The compression fitting with cap connects a tube to the fitting. The pipe fitting is taped with teflon tape to insure a seal. The compression fitting is not taped.

The real confusion with pipe fittings comes from the fact that they have so many different descriptive names.

MIP stands for Male Iron Pipe, or some would say Male International Pipe. The same pipe size can also be called MPT, for Male Pipe Thread.

FIP means Female Iron (or International) Pipe and can also be called FPT for Female Pipe Thread.

To add confusion, there is NPT, which stands for National Pipe Thread.  The Wikipedia makes this  as confusing as possible:

Sometimes NPT threads are referred to as MPT (‘Male Pipe Thread’), MNPT, or NPT(M) for male (external) threads; and FPT (‘Female Pipe Thread’), FNPT, or NPT(F) for female (internal) threads. An equivalent designation is MIP (Male iron pipe) and FIP (Female iron pipe). Also the terms NPS and NPSM are sometimes used to designate a straight, not tapered, thread. (This should not be confused with NPS meaning Nominal Pipe Size.)

Got it?

I won’t bore you with the actual taper of pipe thread patterns. The main thing you need to know when dealing with water treatment equipment is that compression caps won’t work on pipe threads and you can’t screw male compression thread into a female fitting (like a filter housing port) that’s made for pipe.

See also Pure Water Annie’s Glossary of Water Treatment Terms on the Pure Water Occasional’s website.

China and India ‘water grab’ dams put ecology of Himalayas in danger

More than 400 hydroelectric schemes are planned in the mountain region, which could be a disaster for the environment

by John Vidal 

Gazette Editorial Note: It is ironic that while governments are looking frantically for resources to remove ageing dams, new dams are being built at an alarming rate.  Another of the 10,000 easy to find examples that humans are very bad at learning from our mistakes.–Hardly Waite.

The future of the world’s most famous mountain range could be endangered by a vast dam-building project, as a risky regional race for water resources takes place in Asia.

New academic research shows that India, Nepal, Bhutan and Pakistan are now engaged in a huge “water grab” in the Himalayas, as they seek new sources of electricity to power their economies. Taken together, the countries have plans for more than 400 hydro dams which, if built, could together provide more than 160,000 MW of electricity – three times more than the UK uses.

In addition, China has plans for around 100 dams to generate a similar amount of power from major rivers rising in Tibet. A further 60 or more dams are being planned for the Mekong river which also rises in Tibet and flows south through south-east Asia.

The Ranganadi hydroelectric project in Arunachal Pradesh, India

Most of the Himalayan rivers have been relatively untouched by dams near their sources. Now the two great Asian powers, India and China, are rushing to harness them as they cut through some of the world’s deepest valleys. Many of the proposed dams would be among the tallest in the world, able to generate more than 4,000MW, as much as the Hoover dam on the Colorado river in the US.

The result, over the next 20 years, “could be that the Himalayas become the most dammed region in the world”, said Ed Grumbine, visiting international scientist with the Chinese Academy of Sciences in Kunming. “India aims to construct 292 dams … doubling current hydropower capacity and contributing 6% to projected national energy needs. If all dams are constructed as proposed, in 28 of 32 major river valleys, the Indian Himalayas would have one of the highest average dam densities in the world, with one dam for every 32km of river channel. Every neighbour of India with undeveloped hydropower sites is building or planning to build multiple dams, totalling at minimum 129 projects,” said Grumbine, author of a paper in Science.

China, which is building multiple dams on all the major rivers running off the Tibetan plateau, is likely to emerge as the ultimate controller of water for nearly 40% of the world’s population. “The plateau is the source of the single largest collection of international rivers in the world, including the Mekong, the Brahmaputra, the Yangtse and the Yellow rivers. It is the headwater of rivers on which nearly half the world depends. The net effect of the dam building could be disastrous. We just don’t know the consequences,” said Tashi Tseri, a water resource researcher at the University of British Columbia in Canada.

“China is engaged in the greatest water grab in history. Not only is it damming the rivers on the plateau, it is financing and building mega-dams in Pakistan, Laos, Burma and elsewhere and making agreements to take the power,” said Indian geopolitical analyst Brahma Chellaney.  “China-India disputes have shifted from land to water. Water is the new divide and is going centre stage in politics. Only China has the capacity to build these mega-dams and the power to crush resistance. This is effectively war without a shot being fired.”

According to Chellaney, India is in the weakest position because half its water comes directly from China; however, Bangladesh is fearful of India’s plans for water diversions and hydropower. Bangladeshi government scientists say that even a 10% reduction in the water flow by India could dry out great areas of farmland for much of the year. More than 80% of Bangladesh’s 50 million small farmers depend on water that flows through India.

Engineers and environmentalists say that little work has been done on the human or ecological impact of the dams, which they fear could increase floods and be vulnerable to earthquakes. “We do not have credible environmental and social impact assessments, we have no environmental compliance system, no cumulative impact assessment and no carrying capacity studies. The Indian ministry of environment and forests, developers and consultants are responsible for this mess,” said Himanshu Thakkar, co-ordinator of South Asia Network on Dams, Rivers and People.

China and India have both displaced tens of millions of people with giant dams such as the Narmada and Three Gorges over the last 30 years, but governments have not published estimates of how many people would have to be relocated or how much land would be drowned by the new dams. “This is being totally ignored. No one knows, either, about the impact of climate change on the rivers. The dams are all being built in rivers that are fed by glaciers and snowfields which are melting at a fast rate,” said Tsering.

Climate models suggest that major rivers running off the Himalayas, after increasing flows as glaciers melt, could lose 10-20% of their flow by 2050. This would not only reduce the rivers’ capacity to produce electricity, but would exacerbate regional political tensions.

The dams have already led to protest movements in Uttarakhand, Himachal Pradesh, Sikkim, Assam and other northern states of India and in Tibet. Protests in Uttarakhand, which was devastated by floods last month, were led by Indian professor GD Agarwal, who was taken to hospital after a 50-day fast but who was released this week.

“There is no other way but to continue because the state government is not keen to review the dam policy,” said Mallika Bhanot, a member of Ganga Avahan, a group opposing proposals for a series of dams on the Ganges.

Governments have tried to calm people by saying that many of the dams will not require large reservoirs, but will be “run of the river” constructions which channel water through tunnels to massive turbines. But critics say the damage done can be just as great. “[These] will complete shift the path of the river flow,” said Shripad Dharmadhikary, a leading opponent of the Narmada dams and author of a report into Himalayan dams. “Everyone will be affected because the rivers will dry up between points. The whole hydrology of the rivers will be changed. It is likely to aggravate floods.

“A dam may only need 500 people to move because of submergence, but because the dams stop the river flow it could impact on 20,000 people. They also disrupt the groundwater flows so many people will end up with water running dry. There will be devastation of livelihoods along all the rivers.”

Source: The Guardian.

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The “Sand Trap” — a unique approach to an old problem

The patented “Sand Trap” is a valuable tool for dealing with heavy sand or large sediment in wells. It works by separating out bothersome  sand, shale and oxidized organics found in some water supplies. The Sand Trap system does this not by conventional filtration but by directing the water through an internal swirl chamber then into a diverting plate. The process causes heavier particles to settle to the bottom of the tank for removal via a simple blow down valve.

The Sand Trap can be used independently, if large particles are the only issue, or as a pretreatment for other equipment. It spares treatment devices that follow the heavy burden handling large doses of particulate.  For example, if installed in front of a backwashing sediment filter, it protects the filter from having to deal with more than it can handle and can significantly reduce the frequency of backwash required. When placed in front of a conventional cartridge-style sediment filter, the Sand Trap greatly reduces the bother and expense of frequent cartridge changes.

This “micro” Sand Trap is best at dealing with large sediment flowing at a low flow rate.

The Sand Trap system is virtually maintenance free, with no moving parts and no sophisticated backwash control needed. It does not require electricity and its drain water can be directed anywhere (for lawn irrigation, for example), since no chemicals are added to the water.

Sand trap units come in a variety of sizes,  from a “micro” version that is built from a standard 20-inch “Big Blue” filter housing to a Jumbo model that measures 12″ X 60″. In most cases, with the Sand Trap bigger is better, since larger units allow increased residence time for particles to settle out of water.

10″ X 54″ Sand Trap. This full-sized unit works well at handling heavy sediment for most standard residential situations.

More information about Sand Traps.  

 What’s in Lake Michigan Water?

Many of us like to operate under the assumption that water is water is water.

That is, the water we’re coating ourself in every time we head to a Northern Michigan beach is pure and clean as the driven snow — the driven, non-polluted, bacteria-free snow.

But the truth is we share our water with other mammals and organisms that don’t share our propensity to flush away their waste in a convenient rest room — including other humans who tend to shun toilets or diaper duties.

We also live in a world that has impervious surfaces — concrete parking lots, sidewalks and roads — over which rainwater must run and that rainwater must go somewhere. Often, that’s into other, natural bodies of water such as rivers and lakes.

Luckily, there is enough clean water to wash away and dilute the digested stomach contents of those who walk, crawl or flap the earth. Most of the time.

Still, there’s the natural product of what we might expect from the natural world.

“Anything from cigarette butts to raccoon poop to bird poop,” said Kevin Cronk, monitoring and research coordinator with Tip of the Mitt Watershed Council in Petoskey. “Anything that’s washing off the ground and agricultural fields.”

The Health Department of Northwest Michigan keeps track of the worrisome aspect of fecal material collecting lake water — namely, the E. coli bacteria.

Northern Michigan beaches are closed when E. coli bacteria count exceeds 300 organisms per 100 milliliters, or about a third of a cup, of water, said Scott Kendzierski, director of environmental health services for the health department.

The department tests more than 50 beaches, both inland and Great Lakes, in Antrim, Charlevoix, Emmet and Otsego counties. By the end of the typical 10-week period, the department will have collected about 1,800 samples. At about $18 a pop, testing each of those samples — including a few that come from counties in the Upper Peninsula — could cost the department as much as $28,800.

Dog’s can not only detect excrement, they can distinguish been human excrement and that of other creatures.

“Because we have a lot more beaches than (the 50 monitored), we select the beaches based on risk and risk factor,” said Kendzierski. “A large one is population. If the beach was widely used, we would select that one over a beach perhaps we never saw bathers at.”

In 2011 and 2012, the beach monitoring program — which is funded by the Clean Water Michigan Initiative and the Environmental Protection Agency Great Lakes Beach Act fund — saw an influx of money from the Great Lakes Restoration Initiative.

Funds from the initiative allowed the health department to test more beaches over a longer period of time — 16 weeks — and collect data such as wind direction, wind speed, temperature and rain events. The data told the story of a beach: if a beach was situated north-south, and the wind is predominately from the west, water would constantly be blown against the beach.

By contrast, if a beach is oriented east-west with a westward wind, water would continually be flushed away from that beach. Having that data would allow the department to predict how safe beaches may be under certain conditions and cut down on the amount of costly sampling the health department might have to do.

“That’s the goal,” said Kendzierski. “The problem is that each beach is unique in some way. Some are more vulnerable to storm water, some are more vulnerable to prevailing wind direction and speed. We were starting to finally figure out some of the conditions that are really relevant for a particular beach.”

But this year, because of sequestration cuts, the health department lost the funding allowing them to test extra beaches, though workers still record wind speed, direction and other pieces of data.

Looking for storm water management best practices

Contamination from storm water leads many cities to establish “best management practices” for storm water. What runs off city streets during a rain event can end up in water.

A few storm drains run nearly straight into Little Traverse Bay in Petoskey, including the waterfall at Bayfront Park. The waterfall is a stream that forms out of the Winter Sports Park, but picks up drainage from urban areas before reaching the bay front, said Cronk. He calls it “storm water falls.” Other storm water mains drain into the Bear River out of what Cronk calls “out falls” and then into the bay.

A typical ride for rainwater looks like this: the water drains off streets into storm water drains, then into catchments. There, the water slows and solids, such as those cigarette butts, can settle out. There are some controls in place, said Cronk, for sediment pick-up.

“But beyond that, it flows through the system,” said Cronk. “There isn’t something that will filter out any kind of pollutants.”

That means rain can pick up other material such as oil and gas from cars, heavy metals, pesticides and fertilizers.

“The key thing is, everything goes in it,” said Cronk. “If you spit on the sidewalk, if you dump coffee on pavement, whatever, all the bird poop on the roofs, all the stuff ends up untreated and into the river, then into the bay.”

A simple, dog-sniffing solution

A downstate couple, in 2007, was given the idea to create a much cheaper way to test for E. coli — specifically, E. coli that comes from human sewage.

Scott and Karen Reynolds established Environmental Canine Service in Vermontville in 2009. The two have more than 30 years of combined experience in canine scent training, said Scott Reynolds. His supervisor asked him about using dogs to scent human sewage.

“He asked me if I could train a dog to smell poop,” said Reynolds, laughing.

Dogs have an extraordinarily good sense of smell, but what makes that particularly special is that they can filter out background scents and focus in on one smell. In this case, human sewage, over cow or horse material.

“Humans can’t do that, and that’s what makes dogs so superior,” said Reynolds.

The Reynolds’ dogs — the couple has two in Michigan certified for sniffing human sewage and three more in training, as well as five dogs and four handlers in northern California — sniff out sites such as the outfalls that flow into the Bear River to see if any include human sewage. If the dogs get a positive hit, they sniff other places along the sewer line to see where a line might be broken, or where there are cross-connected pipes that might accidentally be putting human sewage into surface waters.

Reynolds says the dogs don’t replace E. coli testing. Rather, they sniff out these places of contamination, so a city might only test a few spots rather than a few hundred.

“Instead of (the source) being a potential of 200 houses on this street, now we know it’s maybe these four,” said Reynolds.

Cronk wants to bring Reynolds to Petoskey.

“It would help us. Hopefully, we would find nothing. It would all be blank samples,” said Cronk.

Even so, Cronk doesn’t get too ruffled about the water quality around Petoskey.

“On the positive side, the metals, the oils, the grease — those numbers are very low, oftentimes not detectable,” said Cronk.

Cronk isn’t even squeamish about drinking the water.

“We all did it as kids, down at streams. I don’t like to stifle that,” he said. “My daughter did it as a kid. I did it as a kid. … It’s safer in this area, fortunately, than most of the rest of the country and world.”

Source:  Petroskeynews.com

Hotter Isn’t Necessarily Better When It Comes To UV Output

Most ultraviolet systems that are used to disinfect water flowing at less than 40 gallons per minute use what are called “low-pressure” UV lamps.  These lamps contain a small amount of mercury, which vaporizes when current flows through the lamp, producing what is considered the ideal “germicidal” UV wavelength of 254 nanometers.

The ideal dosage of 254 nanometers, however, is dependent on some variables, and not the least of these is temperature.

UV designers speak of the “cold spot” on the lamp.  That is the coolest section on the lamp surface.  The “cold spot” should be at about 108 degrees (42 C.) for the UV unit to operate at the optimal 254 nanometers. As the temperature of the lamp changes, so does the dosage from the lamp.

In standard residential UV units the germicidal lamp is enclosed in a transparent tube called a quartz sleeve.  The sleeve is immersed in water.  It surrounds the lamp and protects it from exposure to water.  Although water does not touch the lamp, the temperature of the water affects the lamp temperature since it cools the air between the sleeve and the lamp.  A change in water temperature, therefore, can have a dramatic effect on the temperature of the lamp itself and consequently on the performance of the UV unit.

How Temperature Affects UV Output

There is an assumption that the higher the temperature within the UV treatment chamber, the greater the effectiveness of the UV unit at disarming pathogens. Not so.  In fact, varying in either direction from the ideal cold spot temperature results in diminished performance.  Cold water can lower the cold-spot temperature so that the UV output will drop as much as 50 percent below its maximum. Hot water around the quartz sleeve will also lower the UV output by as much as 50 percent.  Ideal water temperature for operating a UV unit with the lamp inside a quartz sleeve  is about 22 C (71 F).

One factor that is seldom considered in UV planning is that water standing in the UV treatment chamber can become very hot.  In undersink UV units,  the elevated temperature can send aesthetically unpleasing tepid water out of the spigot, but what is worse,  elevated heat can also  reduce the efficiency of the UV lamp.  This could be a problem if a long period of  inactivity is followed by a period of high flow rate.

Some modern UV manufacturers, like Viqua,  offer an optional solenoid-controlled feature that moves water through the system periodically to prevent heat build-up.

A sewage worker has become an unlikely hero after taking three weeks to defeat a toxic 15-tonne ball of congealed fat the size of a bus that came close to turning parts of the London borough of Kingston upon Thames into a cesspit.

The first sign of trouble came when residents in a block of flats near the royal borough’s main sewer reported difficulty flushing their toilets. Gordon Hailwood and his team found a “fatberg” of solidified grease and oil blocking 95% of the 2.4 metre diameter brick sewer pipe. It took three weeks working in foul conditions to clear with high powered water jets.

“Kingston came very close to being flooded with sewage. We have recorded greater volumes of fat in the past but we don’t believe there’s ever been a single congealed lump of lard matching this one”, said Simon Evans, a Thames Water spokesman.

Not a good likeness. 15 ton blobs of grease are not photogenic.

Fatbergs build up on sewer roofs like mushy stalactites. “I have witnessed one. It’s a heaving, sick-smelling, rotting mass of filth and faeces. It hits the back of your throat, it’s gross,” said Evans.

“It’s steaming and it unleashes an unimaginable stink. Hailwood and his team certainly saved Kingston from a terrible fate.”

Water and sewage companies say fatbergs are becoming more common. London, with the highest concentration of food businesses in the country, produces an estimated 32m-44m litres of used cooking oil every year, much of which is poured down drains.

Also, the use of wet wipes as toilet paper is increasing, with potentially disastrous results below ground.

Thames Water says it has to clear nearly 40,000 blockages a year caused by fat and sanitary wipes being wrongly put down drains by restaurants and households. “We have 59,000 miles of sewer and fat and wet wipes are the main partners in ‘sewer abuse’ crime,” said Evans.

“The wipes break down and collect on joints and then the fat congeals. Then more fat builds up. It’s getting worse. More wet wipes are being used and flushed. It took Hailwood and the guys three weeks to flush this one out with high-powered water jets.

“Given we’ve got the biggest sewers and this is the biggest fatberg we’ve encountered, we reckon it has to be the biggest such berg in British history,” said Hailwood.

“The sewer was almost completely clogged. If we hadn’t discovered it in time, raw sewage could have started spurting out of manholes across the whole of Kingston. It was so big it damaged the sewer and repairs will take up to six weeks.”

However – in what environmental groups call a “win-win” development – waste fat is now being used to generate renewable energy. McDonald’s collects more than 600,000 litres of used cooking oil from its London restaurants each year, converting it to biodiesel to run half its fleet of lorries. London mayor Boris Johnson is pressing for waste fat to be used to run London’s buses.

“By capturing it right here in London and turning it into biodiesel we could provide 20% of the fuel needed to power London’s entire bus fleet while saving thousands of tonnes of CO₂ and creating hundreds of new jobs. There is huge potential to unlock the value in used cooking oil and turn it to our economic advantage,” Johnson said last week.

One consortium plans to generate 130 gigawatt hours (GWh) of renewable electricity each year – enough to run 39,000 average homes – by burning 30 tonnes a day of fat, oil and grease. The oils will be collected from food outlets and manufacturers, and solidified grease will be harvested from “fat traps” installed in restaurant, hospital, stadium and factory kitchens. Thames Water has agreed to buy half the electricity to run London’s largest sewerage works at Beckton.

Keeping drains clear

• Animal fats and vegetable oil, lard, grease, butter and margarine, food scraps and dairy products all contribute to blocked drains, “fatbergs” and sewer blockages. Waste disposal units do not remove fats.

• Wipes, nappies, sanitary towels, rags and condoms do not break down easily and can snag on pipes, drains and the walls of sewers, leading to blockages.

• Pesticides, battery acids, nail polish, motor oil, chlorine-based and other cleaning products, paints and photographic chemicals are all toxic waste and should be disposed of carefully because they do not break down in sewage systems and can pollute rivers and sea water.

• If you have a septic tank, then be extra careful. Don’t flush medicines, coffee grounds, paper towels or egg shells, or anything that breaks down slowly, down the toilet or sink.

Source: The Guardian.