How Backwashing Filter Controls Work

by Gene Franks

Large tank-style water filters that have the ability to clean and renew their filter media bed are called backwashing filters.  Backwashing is the process by which water is run backward through the filter bed  from bottom to top, lifting and tumbling the media, rinsing away impurities and allowing the bed to resettle without channels created while the filter was in service.  After the backwash operation, the filter is rinsed by running water rapidly downward through the media bed and out the drain,  resettling and packing the bed before it is returned to service.

Although these simple functions of backwash followed by rinse are essentially the same regardless of the control mechanism that performs them, there is a surprising variety of filter control valve styles.  The table below shows the two most basic series of Fleck controls (5600 and 2510). Note that these are filter valves and that similar but different controls are required to run water softeners. Prices are Pure Water Products’ current filter prices and are given for cost comparison.

 

Fleck Filter Control Valve Prices

 

Fleck Control Valve	Current Price	Comments
Fleck 5600 Standard Timer	$223.00	Probably the most popular filter valve in the US.
Fleck 5600 SXT Timer	$268.00
Fleck 5600 Metered SXT (softener and filter)	$337.00
Fleck 5600 AIO Electronic Aerator Control	$385.00
Fleck 2510 Manual Control	$168.00
Fleck 2510 Standard Timer, without Cover	$281.00	Cover: $31
Fleck 2510 SXT Timer, without Cover	$328.00	Cover: $31
Fleck 2510 Metered SXT (softener and filter)	$399.00	Cover: $31
Fleck 2510 AIO Electronic Aerator Control	$449.00	Cover Included.

Function

Here is a concise description of what these controls do, beginning with the most basic.

Fleck’s Simple 2510 Manual Control.  No Electricity Required. It Isn’t Sexy, But It’s Very Functional.

 

Fleck 2510 Manual.  This is the most basic of filter valves, yet in many situations it can be the best.  In spite of the low price, it’s a tough and durable piece of equipment.  The 2510 Manual is a  non-electric control that requires manual backwash and rinse.  It is, therefore, not practical if backwashing needs to be performed daily (as with many iron filters, for example), but for a clean city water application where chlorine removal is the main purpose, a monthly backwash is sufficient and performing it can be a 15-minute task.  The valve operates with a simple selection lever and has only three choices: Service (means the filter is in service, providing water for the home), backwash, and rinse.  Performing the backwash and rinse is like shifting gears in an car: pull the lever to backwash and let it run for five to ten minutes, pull it down to rinse for a couple of minutes, then return it to service.

Fleck 5600 Standard Timer Control.  America’s Most Popular Water Filter Controller

Standard Timer models are available in both 2510 and 5600. The 5600 timer is most most widely used filter control in the United States and is sold under the manufacturer’s name as well as many “private label” brands.  The user needs only select the days the filter will backwash (the most common format has a 12-Day-Clock) and set the time of day. On the 2510 model, the duration of backwash and rinse can also be changed in two-minute increments.  Regeneration times are preset but can be changed by lying to the timer about the time of day.

Fleck 5600 SXT Timer.  

SXT Timer. SXT controls feature a simple electronic face and allow easy programming of the basic functions of the filter. They have the advantage over the standard timer of much greater flexibility in setting up regeneration schedules and length of backwash and rinse. A simple 5600 timer, for example, has a pre-set backwash duration, but with the SXT unit the user can choose and easily change the duration of backwash and rinse or the time that they occur. If the power goes off, the user has only to reset the time of day: the computer remembers the programmed settings.

This control system counts time, not gallons used. The metered system below  keeps count of both time and gallons used.

Fleck 2510 Metered SXT Can Control a Filter or a Water Softener.  Shown without Protective Cover, which is sold separately.

SXT Meter Available in both 2510 and 5600 Formats.  This controller is much more frequently used to control water softeners than filters, but it can be easily adapted for use with a filter by simply shortening or turning off  functions like “brine draw” and “brine refill” that apply only to softeners. The control system offers much more programming variety.  A sediment filter, for example, could be set up to regenerate after every 1000 gallons of service water but to not allow more that 7 days to pass without  regeneration. This system offers more complexity than most filters need, but it works great where precise control of gallon usage is required.

Fleck 2510 AIO Control Valve with Environmental Cover. This is a specialty valve used only on “single tank aeration” filters.

Fleck AIO Electronic Timer Aerator Control.   Available in both 2510 and 5600 Formats.  The AIO is a specialty product designed specifically to control single tank aeration filters for iron and hydrogen sulfide treatment.  It is a very simple electronic timer that keeps time of day and days between regeneration.  Its uniqueness is that it is set up to draw air into the filter for oxidation of iron and hydrogen sulfide during the phase where a softener control would normally bring in water for the making of brine.  This is a very effective product with a limited application.  Programming is simple with only the time of day and the day of regeneration needing attention.

Go here for more information about backwashing filters.

California Drought: Orange County expands ‘toilet to tap’ water recycling

 

by Ed Joyce

 

One way state officials hope to make California better able to withstand the ongoing drought is to stock underground drinking water supplies with recycled wastewater. Water managers across the state could learn a thing from the Orange County Water District: It was an early adopter of recycled water. And now, the district is expanding its use of what some call “toilet to tap.”

But calling it “toilet to tap” isn’t fair. The recycled sewage water makes quite a journey on its path to purification before it comes out of faucets at home. About 2.4 million Orange County residents get their water from a massive underground aquifer, which, since 2008, has been steadily recharged with billions of gallons of purified wastewater.

But, that toilet to tap moniker hangs around. So, we decided to put the Orange County tap water to a blind taste test.

Longtime Orange County resident John Hart sampled one glass filled with Newport Beach tap water and another glass filled with bottled water. He said he couldn’t tell the difference between the tap water and the bottled water.

Hart remembers when the Orange County Water District (OCWD) first proposed taking treated wastewater and turning it into drinking water.

The “yuk factor” associated with the phrase “toilet to tap” had doomed a similar proposal years earlier in San Diego. (The city of San Diego now has a pilot project underway). Orange County Water District officials avoided that fate with a massive public relations campaign that involved more than 2,000 community presentations.

“Most of my neighbors, we talked about it,” said Hart, who lived in Huntington Beach at that time.  “If they [OCWD] could do it and do it right and make sure that it’s proper, then it’s probably a good deal.”

Recycled water’s been such a good deal for Orange County, the water district is spending $140 million to expand its capacity to purify wastewater by 30 percent.

It starts in Fountain Valley where the water district operates a 24-acre facility that takes sewage fom the sanitation plant next door and converts it into millions of gallons a day of pure H2O.

OC Water District President Shawn Dewane said the cost is 30 percent cheaper than imported water.

“So it’s a tremendous savings for our local community to be able to pump from the groundwater basin and about 70 percent of the local demand is supplied from the groundwater,” said Dewane.

Dewane and OCWD Assistant General Manager Michael Wehner showed us around the treatment plant, where shiny stainless steel tubes and tanks fill several large buildings.

Microfiber membranes

First, to filter out bacteria, particles and protozoa, the sewer water is forced by air pressure through a series of microfibers, straw-like plastic membranes, with holes so tiny you can’t see them with the naked eye. The next stop is a pump station.

Wehner said the pump station is “where the water that’s been vacuumed through those hollow fibers is basically accumulated in a tank and transferred over to the reverse osmosis facility.”

Wehner said reverse osmosis or “R-O” is the heart of the largest potable reuse facility in the world. The water is pushed through plastic R-O membranes that remove nearly everything that isn’t H2O. The R-O process removes dissolved chemicals, pharmaceuticals and viruses.

“There is 70 million gallons a day of R-O capacity,” said Wehner, as he pointed to hundreds of tubes. “Each of these units represents five million gallons a day. And you can see all of the units as you look across, you look at endless pressure vessels that hold these spiral wound R-O membranes.”

The last step is to add peroxide (H2O2) to the water before it is sent through pipes where it is exposed to ultraviolet light that “kills anything that’s alive,” Wehner said.  The end result is distilled water.

“It’s actually purer than any other source of water that we have to put into our groundwater basin,” he said.

The water is then shipped northeast through a 14-mile pipe where it feeds a series of recharge basins, which resemble small lakes.

“It percolates through the native soils here at a very high rate up to 14 feet a day,” said Bill Hunt, OCWD executive director of operations, as he showed us where the purified water fills a recharge basin. “We’re putting a lot of water in the ground here. It goes into the ground here in Anaheim, which is sort of the upper end of the (350 square mile) aquifer system. It creates a mound of water underground and it pressurizes the aquifers throughout the county.”

The water is so blue it looks like glacial snowmelt.

“Our Caribbean water,” is what Hunt calls it.

The OC Water District says 1.3 billion gallons of treated wastewater flows through Southern California sewers into the Pacific Ocean every day.  The water district takes some of that water from the Santa Ana river and diverts it to a recharge basin.

While other counties, and even the portion of south Orange County not served by the OCWD, rely heavily on imported water from Northern California and the Colorado River, the district’s Groundwater Replenishment System combined with the aquifer, provide 70 percent of the supply.

So why aren’t more counties moving to ‘tap the toilet?’

The OC Water District’s Wehner says public acceptance and political support are the main obstacles. He also pointed out that there are groundwater resources in Los Angeles County that remain untapped.

“The San Fernando Valley and the San Gabriel Valley have groundwater resources,” said Wehner. “But they face greater challenges in terms of contamination (of that groundwater) over the years. They need to address those issues, but they have groundwater resources they can manage in those areas.”

But California drought cycles and climate change may force more California counties to reclaim their sewage water.

UC Irvine Professor of Earth System Science Jay Famiglietti said reusing wastewater needs to be a greater part of the supply mix going forward.

“Population growth is too great, the traditional sources are being depleted, so there really is no choice,” said Famiglietti. “We need to invest in projects like sewage recycling in a lot more places then we’re currently doing it.”

As for the “yuk factor” of the old toilet to tap objections, Famiglietti has this simple advice: “get over it.”

Meantime, the Orange County Water District has a $142 million expansion project underway at the Fountain Valley reuse facility. By the end of 2015, OCWD officials say the plant will be producing 100 million gallons of potable water a day – at half the cost of imported water.

Source: Southern California Public Radio.

 

Levi Strauss tests 100% recycled water in parts of its jeans production

The jeans manufacturer has developed a new water recycling standard to reduce its impact on the world’s water resources

Editor’s Note:  This article works toward a definition of “100% recycled,” which can mean different things in different contexts and from different sources.  Since in a sense all water is “100% recycled,” none of it being used for the very first time, you could apply the label to any water you use, even if you use it only one time and discharge it.  On the other extreme, 100% recycled water would mean that no new water is introduced into the closed loop of a particular process, with the same water being recirculated for reuse ad infinitum.  As the article below indicates, Levi Strauss’s definition falls somewhere in the middle, and the company is to be applauded for its effort in any event. — Hardly Waite.

Levi Strauss has created a process for using 100% recycled water in parts of its garment production, Michael Kobori, vice president of sustainability at the company, has told the Guardian.

In what the jeans manufacturer claims to be an industry first, the process is the result of a new water recycling standard – verified by third parties – that aims to reduce the impact of garment production on fresh water resources.

The process is being used in one of the brand’s key Chinese factories, which bleaches, dyes and stone washes garments to achieve specific looks or feels.

The factory, located in southern China, worked with Levi Strauss to engineer a system to pipe 100% recycled water into an industrial laundry machine used for finishing one of its jeans lines. Some 100,000 pairs have now been produced with the new technology.

Kobori says the company looked at Environmental Protection Agency (EPA) guidelines on reuse of water, as well as World Health Organization guidelines on managing waste water.

“We then hired engineers from the textile industry to adapt these general guidelines into a set of standards that can be specifically used in our industry,” he says.

The process is still in the testing phases, but the goal is to eventually use 100% recycled water to finish a broader range of Levi Strauss products at factories in other parts of the world, he says.

Different Different Definitions of 100% Recycled

One of the third parties Levi Strauss asked to review the standard was Gilbert O’Neal, president of the Institute of Textile Technology.

O’Neal has worked with some of the largest textile and apparel makers in the world to help them use less water, and discharge less polluted water.

He says it’s not impossible to finish a garment with recycled water, but that the term “100% recycled” can be misleading because saying a garment is made from 100% recycled water is not the same as saying that 100% of the waste water is recycled.

“The garment industry is really good at establishing standards and talking a great game about sustainability,” O’Neal says. “But the challenge is in the implementation.”

For example, there’s no economically feasible way to recycle 100% of laundry machine water in a closed loop system, he says.

“It requires membrane technology that may triple or quadruple the cost of water treatment,” O’Neal says. “That’s a cost that most consumers won’t accept.”

So what does Levi Strauss mean by 100% recycled water? O’Neal says the he has not seen the engineering or other information from the Chinese factory, so he doesn’t know for sure. But he suspects to keep the process economical, they recycle a portion of the waste water that is most easily treated.

O’Neal says Levi Strauss is probably using 100% recycled water, but isn’t achieving “zero liquid discharge” – or zero waste water – the highest standard in industrial water recycling. However, the process likely does reduce the amount of effluent, or waste water, from the factory, he adds.

Levi Strauss, which is expected to announce this news later today, says it hopes the standard will help other apparel brands and retailers increase their use of recycled water and reduce industry effluent.

Article Source– The Guardian.

Pure Water Gazette Fair Use Statement

 

Harvard Research Links Fluoridated Water to ADHD, Mental Disorders

By Ethan A. Huff

A leading cause of ADHD (attention-deficit hyperactivity disorder) and autism in children could be the hidden chemicals lurking in the foods we eat, the water we drink and the products we consume, says a new study recently published in The Lancet. Researchers from the Harvard School of Public Health (HSPH) and the Icahn School of Medicine at Mount Sinai (ISMMS) found that, among other things, the fluoride chemicals added to many public water systems in North America directly contribute to both mental and behavioral disorders in children.

Building upon earlier research published in 2006 that dubbed fluoride as a “developmental neurotoxicant,” the new review included a meta-analysis of 27 additional studies on fluoride, most of which were from China, that linked the chemical to lowered IQ in children. After thorough analysis, it was determined that fluoride obstructs proper brain development and can lead to autism spectrum disorders, dyslexia, ADHD and other health conditions, a “silent epidemic” that many mainstream health authorities continue to ignore.

According to the two main researchers involved in the study, Philippe Grandjean from HSPH and Philip Landrigan from ISMMS, incidences of chemical-related neurodevelopmental disorders have doubled over the past seven years from six to 12. The reason for this is that an increasing number of mostly untested chemicals are being approved for use without the public being told where and in what quantities such chemicals are being used.

“Since 2006, the number of chemicals known to damage the human brain more generally, but that are not regulated to protect children’s health, had increased from 202 to 214,” writes Julia Medew for The Sydney Morning Herald. “The pair said this could be the tip of the iceberg because the vast majority of the more than 80,000 industrial chemicals widely used in the United States have never been tested for their toxic effects on the developing foetus or child.”

Fluoride must be immediately removed from public water supplies for child safety

While pesticides dominated the duo’s list as the most pervasive and damaging chemicals whose presence the public is largely unaware of, fluoride, which is intentionally added to public water supplies as a supposed protectant against tooth decay, is also highly problematic. It is also largely ignored by public health authorities as a possible factor in childhood development problems, even though the science is clear about its dangers.

Like lead, certain industrial solvents and crop chemicals, fluoride is known to accumulate in the human bloodstream, where it eventually deposits into bones and other bodily tissues. In pregnant women, this also includes passing through the bloodstream into the placenta, where it then accumulates in the bones and brain tissue of developing babies. The effects of this are, of course, perpetually damaging, and something that regulatory authorities need to take more seriously.

“The problem is international in scope, and the solution must therefore also be international,” stated Grandjean in a press release, calling for improved regulatory standards for common chemicals. “We have the methods in place to test industrial chemicals for harmful effects on children’s brain development — now is the time to make that testing mandatory.”