How Water Is Recycled in Modern Car Wash Establishments

Editor’s Note:  The piece that follows is adapted from an interview with Thomas Gibney of Verwater Environmental Resource Systems. The Gazette has spoken earlier in favor of using professional carwash facilities rather than relying on fundraising events to keep your car clean or even doing it yourself in your driveway.  The pros not only reuse water, they keep car wash chemicals out of the drainage system.–Hardly Waite.

In years past vehicle washes weren’t too interested in telling the public that they reused the water because the consumers felt they were getting their vehicles washed with dirty water, and they were. In some systems sold yet today the water comes out a brown or grey color because the chemicals haven’t been removed in the treatment process. Today with the advancements in using natural bacteria to consume chemicals from the waste water like sewer treatment plants operate a vehicle wash can feel comfortable in advertising that they are washing the consumers’ vehicles with clean restored water.

With water being the lifeblood of the vehicle wash industry, a waste water treatment system that truly restores the water is a must have

to ensure the wash stays open in drought periods but also to reduce water and sewer bills which add to the profitability of the wash.

Fundraising car wash events may be fun, but they are also an environmental disaster.

Three types of reclaim systems are available today.

1.   The first and oldest type is what I refer as a re-use system. This system relies on settling tanks to settle out the major solids so that the water can be sucked up and re-used on the vehicles. In all cases the water applied to the vehicle has a brown color. In warmer weather this re-used water emits a hydrogen sulphide odor which comes from the anaerobic bacteria growing in the water that is void of oxygen.

2.   The second type is a filtration and ozone system which I refer to as a reclaim system. These systems rely on settling tanks to settle out the heavy solids and they use filtration of various forms to lower the solids down to 10 to 20 micron so as not to void high pressure pump warranties. The last treatment to the water is ozone to oxidize the natural anaerobic bacteria in the waste water so that the water doesn’t contain any odor when re-used. They do little to lower the dissolved chemicals used to wash and wax the vehicles so these remaining chemicals prevent using this reclaim water to mix again with chemicals, which lowers the overall re-use of the waste water.

3.   The last system is a water restoration system. This type of system uses settling tanks to settle out the heavy solids as gravity is free along with hydro cyclones to lower the solid level down to 5 micro. The water is then aerated to switch the anaerobic bacteria to aerobic bacteria since aerobic bacteria are 90 percent more aggressive in consuming waste chemicals in the water. When these natural aerobic bacteria are present they consume the waste chemicals and turn them into CO2 and H2O. CO2 has no odor so these restoration systems never release that sulphur or rotten egg smell when the water is reused. With the chemicals removed by the bacteria this restored water can be re-used throughout the wash to include remixing with chemicals. Only the final rise or spot free rinse is fresh water which means a recovery and reuse rate of 90 to 95 percent can be achieved.

Modern reclamation systems are capable of recycling 100% of all wash water that is captured.

The newer technologies have changed things completely.

 Working with nature rather than fighting nature means the new technology of using natural bacteria to consume the waste chemicals and clean the water means they are easier to maintain, are less costly to keep working and the operators don’t turn them off before the first year of usage. The result is a higher entry cost for the equipment but a lower maintenance cost and a better quality of restored water to use throughout the wash process which means a better return on investment for years to come.

 

Source Reference:  Carwash.com.

The Spin Down (AKA Spin Out) Separator: A Very Useful Tool in Water Treatment

 

The spin down unit above is for 1.5″ pipe. It is only 15 inches long.

The spin down filter is an effective and easy-to-maintain sediment filter. The clear cover allows quick view of collected sediment to know when purging is needed.

It is designed for easy installation on either PVC (glue on) or it can be easily adapted to other pipe style with a glue-in adapter.

The spin down filter uses an easily cleaned and reusable polyester filter screen. The standard model is 100 mesh (152 micron), ideal for medium duty filtration of sand, grit, pipe scale, etc., but both coarser and finer screens are available.

Pipe size of this unit is 1.5″ (can be bushed down for smaller pipe), and it supports flow rates of up to 50 gallons per minute.

A smaller 1″ version supports flow rates to 20 gallons per minute and is, therefore, appropriate for most residential applications.

The flush valve is threaded 1/2″ for easy adaptation to a drain hose. Opening the flush valve quickly purges the filter of collected sediment.

Maximum operating pressure for this unit is 150 psi.

 

The Spin Down filter is renewed by simply opening the ball valve and allowing water pressure to purge the filter.

This “Spin Down” style sediment filter traps large particles and supports a high flow rate. It is manually purged by opening the valve (black handle) which blows out trapped particles and renews the filter. Spin Down filters use replaceable screens ( the core visible through the transparent housing) that are usually measured in mesh sizes rather than microns. With microns, the filter gets tighter as the numbers get smaller. With mesh, the filter gets tighter as the numbers get larger.

This is an extremely versatile water treatment tool.  It is so light that it can be supported by the pipe in which it is installed.  No mounting bracket is needed.

Suggested uses:

Prefilter for “inline” tank style carbon and neutralizing filters to prevent intrusion of large sediment.

Postfilter for “inline” tank style filters to prevent media migration into service lines.

Whole house sediment treatment for large particles like sand and grit.  It also serves as an excellent prefilter for finer sediment  filters to protect them from premature clogging.

An excellent “insurance” filter to protect against sediment intrusion from unexpected breaks in piping even in very clean city or well water.

Reference: Pure Water Products.

Industrial-grade Fluoridation Chemicals

Cost Society $Billions in Arsenic-induced Cancers

Water News in a Nutshell.

 

In a Nutshell: The “fluoride” that’s put in city water supplies, called hydrofluorosilicic acid, or HFSA,  is not the same thing as the pharmaceutical-grade fluoride that is used by dentists.  Among other contaminants in additive-grade fluoride is arsenic.  In fact, ninety percent of the arsenic found in city tap water comes from HFSA.  

Editor’s Note:  The bulk of this article is taken directly from Fluoridealert.org,  but I’ve added a bit from an excellent study of hydrofluorosilicic acid from Waterloowatch.com.  Although the origins of the “fluoride” that is used in municipal water treatment are not secret, the American public is woefully naive on the issue and most people do not realized that the substance they are trusting to to save their children’s teeth is actually a toxic by-product of the fertilizer industry.–Hardly Waite.

Industrial-grade fluoride chemicals added to US public water supplies contain arsenic that the EPA classifies as a human carcinogen. Switching to low-arsenic pharmaceutical-grade fluoride will save society $1 billion to $14 billion annually, according to research published in Environmental Science & Policy, led by former EPA senior scientists who are experts in chemical risk assessment, reports the Fluoride Action Network (FAN).

Almost all hydrofluorosilicic acid used in North America originates in the State of Florida, where phosphate containing rock is strip-mined.  (See picture.)

Hydrofluorosilicic acid is drawn from open air cooling lakes, as is. It is containerized in tankers, and shipped to your municipal drinking water supply. Hydrofluorosilicic acid remains contaminated with trace amounts of lead, arsenic, mercury and radioactive materials. It is delivered unrefined, and in none-pharmaceutical grade, to be used as water fluoridation ‘product’.

Although never studied for safety or efficacy, hydrofluorosilicic acid (HFSA) is added to public water supplies as a purported cavity preventive.  The industry-funded group that regulates water additives, NSF International, allows several toxins in HFSA, including arsenic.

The Safe Drinking Water Act requires EPA to determine the level of certain contaminants in drinking water at which no adverse health effects are likely to occur.  These health goals, based solely on possible health risks and exposure over a lifetime with an adequate margin of safety, are called maximum contaminant level goals (MCLG).  The MCLG for arsenic is zero.  The EPA also sets an enforceable maximum contaminant level (MCL), but concedes this level will not prevent cancers.

Senior researchers, Drs. William Hirzy and Robert Carton , write, “Arsenic levels in this HFSA product vary substantially but are typically about 30-35 mg/kg.”  These levels would qualify it as toxic hazardous waste if not for a legal loophole because it is sold to fluoridate water.  The study found HFSA raised the arsenic level of finished or tap water by anywhere from 0.078 to 0.43 parts per billion (ppb).

Ninety percent of arsenic showing up in tap water comes from fluoridation chemicals, according to a study in the American Water Works Association publication, Opflow, led by Dr. Cheng-nan Weng.

Hirzy and Carton found that industrial-grade HFSA contains from 100 to 500 times more arsenic than pharmaceutical grade sodium fluoride (NaF).

Using EPA’s calculation methods, HFSA would cause from 320 to 1800 arsenic-induced cancers per year.  They calculated these cancers would cost society $1 billion to $6 billion per year.*

The researchers conclude: “Our analysis shows that, if local governments that currently add HFSA to their drinking water wish to continue delivering fluoride to their citizens and at the same time reduce the number of lung and bladder cancers among their citizens, they could do so with a significant net benefit to society by switching to USP NaF [pharmaceutical grade Sodium Fluoride] for fluoridation.”

Reference: Hirzy JW, Carton RJ, Bonanni CD, Montanero CM, Michael F, Nagle MF. 2013. Comparison of hydrofluorosilicic acid and pharmaceutical sodium fluoride as fluoridating agents—A cost–benefit analysis. Environmental Science & Policy 29: 81-86 (May).

Gazette Fair Use Statement

A New Style Water Treatment Called ADMIN Is Being Tested in Waurika, Oklahoma

Editor’s Note:  The town of Waurika, Oklahoma is faced with a dilemma common to many small water suppliers.  The town is being fined for failure to comply with water quality regulations governing disinfection by-products,  but it lacks the money needed to upgrade its water treatment system.  The article below describes a quick fix that Waurika has decided to try.   NSF, incidentally, does not stand for “National Science Foundation.”   The  article is reprinted from the Waurika News-Democrat.  –Hardly Waite.

WAURIKA — When it came his turn to vote, Bill Everett sat staring at the paperwork in front of him. After nearly two minutes of what could be called a “poignant pause,” the Waurika City Commissioner finally spoke.

“I’m having a hard time voting, and I’m not very happy,” Everett said, “but I’ll say ‘yes.’”

Just minutes before, Vice Mayor Carole Eakin had cast the lone “no” vote in taking action on the city signing a contract with Enid-based GPM Environmental Services, which would commit Waurika to testing a water purification product called ADMIN.

The project calls for the city to spend nearly $25,000 to purchase a two-month supply of ADMIN. If the test goes well, the substance will become a permanent part of the water purification process.

Waurika, Oklahoma Courthouse

The 4-1 vote and Everett’s reticence prior to agreeing to the purchase came early in the City Commission and Waurika Public Works Authority regular meetings for May. It followed a 40-minute discussion with GPM representative Johnny Henderson.

He had also addressed the city administrators at their April meeting, presenting ADMIN as a possible solution to Waurika’s long-standing problem with trihalomethanes in its water system.

For years, the city has received almost monthly consent orders from the Department of Environmental because water tests showed TTHM counts that exceed DEQ regulations. The problem eventually drew a negotiated fine of $7,500 from the DEQ, which the city will have paid off at the end of June.

The commissioners and WPWA Trustees have been considering the possibility of investing over $3 million for replacement or massive renovation of the Waurika Water Treatment Facility as a solution to the TTHM situation and other problems associated with the city’s water and sewage system.

City administrators, facing an uncertain economic future, hope a solution — possibly, ADMIN — can put a multi-million dollar program at the water plant on a back burner.

During the discussion, Henderson reiterated that ADMIN would eliminate use of chlorine and chloramine as disinfectants. He provided endorsements from several Oklahoma counties and communities — Nowata, Vinita and Barnsdall among them — that are having success with the product.

Nowata began using ADMIN in November 2012, but a concern for Everett and new Commissioner Jeremie Wilson was “that no plant has used it longer than six months,” Wilson said.

Noting there are still many cast iron water lines in Waurika, Mayor Jim Bernard asked Henderson, “Will (ADMIN) corrode the lines?”

Pointing out ADMIN’s pH count is .2 to .5, “which is very low,” Henderson said, “At 50 parts per million (gallons of water), it won’t chew into any piping system.” He also pointed out the product is certified by the National Science Foundation (NSF).

Henderson said the chemicals in ADMIN “won’t be acidic to the distribution system at all.” Still, injecting a new substance into the water system was a concern for Everett, and Eakin said that was a key reason she voted against the purchase.

When the discussion moved to funding the ADMIN test, Bernard tried to negotiate a month of free use, but Henderson said that wasn’t possible. He did, however, say, “If (ADMIN) doesn’t lower TTHM’s to reasonable levels, you don’t have to pay for the test.”

Ultimately, Commissioner Gayle Johnson made a motion for the city to enter into a two-month test of the product, which also stipulated Henderson must be present when ADMIN is injected into the water system.

“I want verification from you that we’ve set it up right,” she told Henderson, who agreed to be present.

Funding for the two month test will come from the 6 Percent Fund in the General Fund.

City Manager Chuck Brown reminded the commissioners the ADMIN distribution is exclusive and is not part of the city’s other project dealing with repairs at the water plant and the sewage system.

At present, the city is in the process of trying to obtain a Community Development Block Grant of $350,000 to fund repairs at the water plant and sewer lifts. That project is being overseen by engineer David Wyatt.

In March, the city approved a rate hike of $5 per month to water and sewer bills to create a fund for the maintenance project.

 

 Needed: 100 More Colorado Rivers

by Elizabeth Cutright

A  study released by the InterAction Council recommends that the UN Security Council make water scarcity “a top concern.”

“The future political impact of water scarcity may be devastating,” former Canadian Prime Minister Jean Chretien said of the study, which was issued by a consortium of former world leaders, including Nelson Mandela and US President Bill Clinton, and backed by the UN University’s Institute for Water, Environment, and Health (UNWEH) and Canada’s Gordon Foundation.

Pointing to factors as diverse as climate change and geo-political confrontations, the group warned that increasing water scarcity will only exacerbate crises around the globe, including the spread of disease, rising infant mortality rates, and global food production.

“With about 1 billion more mouths to feed worldwide by 2025, global agriculture alone will require another 1,000 cubic km (240 cubic miles) of water per year,” the report states—an increase that is the equivalent of 20 Nile rivers or 100 Colorado Rivers.

Other highlights from the report:

* Currently, 3,800 cubic km (910 cubic miles) of freshwater are extracted from the world’s rivers and streams annually.

* The greatest increase in demand for water will be located in the US, China, and India, in part because of population increases, increased agricultural irrigation, and economic growth.

* By 2030, China’s water needs will exceed its current supplies.

A study shows that by 2025 the world will need the equivalent of 20 more Nile Rivers to feed the increasing population.

* Global warming and GHG emissions are expected to aggravate current climate patterns and impact drought/rainfall totals worldwide, with droughts and floods becoming more common.

* Increasing tensions in the Middle East, particularly between those nations that share the Nile, due to water-related conflicts.

But the report offers solutions as well—solutions familiar to any regular reader of Water Efficiency. Dubbing it the “blue economy,” the report suggests that an emphasis on water conservation could mitigate some of the world’s water scarcity issues. By improving infrastructure—including leak detection and demand reduction—the report estimates that up to 40% of domestic water that is currently wasted could be saved.

But these water efficiency measures won’t come cheap, another familiar challenge for the water purveyor. The UNWEH report calculates infrastructure improvement costs in developing nations to be about $11 billion per year. But that outlay does not come without a payback—for every dollar spent, communities could see an economic return from $3–4 dollars, according to the report.

So what do you think? Can clarion calls like this have any impact on government programs and policies? Is it enough to simply raise awareness of the impending water crisis? And what more can be done to funnel the much-needed funds towards infrastructure rehabilitation and improvement at home and abroad?

Source: Water Efficiency

 

Gazette Fair Use Statement

The Difficulties of Residential Treatment of  Very Fine Particles

Water News in a Nutshell.

 

In a Nutshell:  One of  the most difficult problems in water treatment is how to get rid of  colloidal particles that are too tiny to be caught by anything but the tightest of  filters.  A standard way of doing this–and the method used by most municipal water systems–is to add a chemical to promote coagulation and  flocculation to increase the size and weight of the particle, allowing it to precipitate out of solution or be trapped by a filter.  The process is described in some detail by the WHO document excerpted below. 


 History of Flocculation and Coagulation

Chemical precipitation or coagulation and flocculation with various salts of aluminum (e.g., alum), iron, lime and other inorganic or

Alum

organic chemicals are widely used processes to treat water for the removal of colloidal particles (turbidity) and microbes.

Treatment of water by the addition of chemical coagulants and precipitants has been practiced since ancient times, even though the principles and physico-chemical mechanisms may not have been understood. Sanskrit writings refer to the use of vegetable substances, such as the seed contents of Strychnos potatorum and Moringa oleifera, which are still in use today for household water treatment .

Judeo-Christian, Greek and Roman records document adding “salt”, lime, “aluminous earth”, pulverized barley, polenta as precipitants to purify water. Although alum and iron salts are the most widely used chemical coagulants for community drinking water treatment, other coagulants have been and are being used to coagulate household water at point of use, including alum potash, crushed almonds or beans and the contents of Moringa and Strychnos seeds.  

How the Process Works

Chemical coagulation-flocculation enhances the removal of colloidal particles by destabilizing them, chemically precipitating them and accumulating the precipitated material into larger “floc” particles that can be removed by gravity settling or filtering. Flocculation causes aggregation into even larger floc particles that enhances removal by gravity settling or filtration. Coagulation with aluminum or iron salts results in the formation of insoluble, positively charged aluminum or iron hydroxide (or polymeric aluminum- or iron-hydroxo complexes) that efficiently attracts negatively charged colloidal particles, including microbes. Coagulation-flocculation or precipitation using lime, lime soda ash and caustic soda is used to “soften” water, usually ground water, by removing (precipitating) calcium, magnesium, iron, manganese and other polyvalent, metallic cations that contribute to hardness. However, reductions in microbial contaminants as well as turbidity, and dissolved and colloidal organic matter are also achieved in this process.

Because coagulation-flocculation treatment with alum, iron and other coagulants requires knowledge, skills to optimize treatment conditions, it is generally considered to be beyond the reach of most consumers. Most authorities consider such treatment to be best performed in specialized central facilities by trained personnel. This type of treatment is less likely to be performed reliably at point-of-use for household water treatment. Furthermore, the limited availability and relatively high costs of alum and ferric salts in some places present additional obstacles to widespread implementation of this technology at the household level.

Despite the caveats and limitations, alum coagulation and precipitation to remove turbidity and other visible contaminants from water at the household level has been traditionally practiced for centuries in many parts of the world. When potash alum was evaluated for household water treatment in a suburban community in Myanmar by adding it to water in traditional storage vessels (160L capacity) at 500 mg/L, fecal coliform contamination was reduced by 90-98% and consumer acceptance of the treated water was high. The ability of the intervention to reduce diarrheal disease was not reported. In another study, alum potash was added to household water stored in pitchers of families with an index case of cholera and intervention and control (no alum potash) households were visited to 10 successive days to track cases of enteric illness. Illness among family members was significantly lower (p < 0.05) in intervention households (9.6%) than in control households (17.7%). The authors concluded that household water treatment by adding a pinch of alum potash was effective in reducing cholera transmission during outbreaks and was an appropriate and low cost (1 cent per 20 liters) intervention.

Source Reference:  The World Health Organization.

 

Gazette Fair Use Statement

 

Water on Earth and Moon originated from primitive meteorites

Gazette’s Introductory Note:  Theories (guesses) about the origin of water on the moon are no longer a dime a dozen; they’re more like 4 cents per dozen.  Here is another, this one from The Hindu Business Line.  The Gazette’s theory, by the way, is that the Moon Goddess Diana simply created  Moon water one  Monday afternoon when hunting was out of season because she was bored.--Hardly Waite.

Water on Earth and the Moon may have originated from the same source – primitive meteorites, scientists say.

Researchers used a multi-collector ion micro-probe to study hydrogen-deuterium ratios in lunar rock and on Earth.

Their conclusion: The Moon’s water did not come from comets but was already present on Earth 4.5 billion years ago, when a giant collision sent material from Earth to form the Moon.

Water inside the Moon’s mantle came from primitive meteorites, new research finds, the same source thought to have supplied most of the water on Earth. The findings raise new questions about the process that formed the Moon.

The Moon is thought to have formed from a disc of debris left when a giant object hit Earth 4.5 billion years ago, very early in Earth’s history.

But recently, NASA spacecraft and new research on samples from the Apollo missions have shown that the Moon actually has water, both on its surface and beneath.

By showing that water on the Moon and on Earth came from the same source, this new study offers yet more evidence that the Moon’s water has been there all along. (more…)

How a small “subterranean hydrocarbon seep” put a lot of nasty benzene into hundreds of thousands of gallons of water

Benzene is a highly flammable volatile organic compound used in the manufacture of plastics, rubber, resins, synthetic fabrics, paints and dry cleaning chemicals. It can also be found in car exhaust or cigarette smoke, or it can form naturally, in volcanoes, forest fires and crude oil.

Benzene is added to gasoline to increase octane. Automobile emissions are the main source of benzene in the environment, but it is more likely to arrive in water by way of industrial discharge or landfill leaching.

Health Effects of Benzene

Benzene is toxic in small doses. According to the EPA, acute benzene exposure above the maximum contaminant level (0.005 milligrams per Liter) can cause “temporary nervous system disorders, immune system depression [and] anemia.” It’s also a carcinogen, and can lead to “chromosome aberrations” with long-term exposure.

The above is from Pure Water Products’ Water Treatment Issues.

An event that scarcely made national news, a small leak at a gas processing plant in western Colorado,  put out enough benzene and other nasty chemicals to pollute hundreds of thousands of gallons of groundwater.  The description of the cleanup, which we’ve excerpted below from an AP story by Alexandra Tilsley, gives a step-by-step description of the elaborate process necessary to contain even a small “seep” at a petroleum processing plant.

The obvious questions that arise from such incidents are how effective is the cleanup, that is, how much of the contaminant is actually removed in the process, and how many such seemingly insignificant “seeps” go undetected and therefore never treated.

Tilsley writes: 

DENVER — As vacuum trucks continue to suck up tainted groundwater from the site of a hydrocarbon leak near a stream in western Colorado, those in charge are beginning to think about the next step: what to do with all that dirty water.

About 180,000 gallons of contaminated water have been pumped out of the ground since the subterranean hydrocarbon seep was discovered near the Williams gas company’s Parachute processing plant, which sits close to Parachute Creek.

One of the main contaminants in the groundwater is benzene, according to Mark Salley, a spokesman for the Colorado Department of Public Health and Environment, which is currently overseeing the remediation efforts. Benzene, a known carcinogen, was also found earlier this month in Parachute Creek in concentrations above the state’s health standard, but levels have since dropped and officials insist there is no threat.

To remove the benzene from the creek, Williams injected air into the surface water to strip the hydrocarbons, a process known as air-sparging. The same technique is [used] to remove surface hydrocarbons that are floating on top of the groundwater.

How to handle all the benzene-infected groundwater is the next question. The recovered water is currently being stored in tanks, and Williams said Friday it is planning to install a water treatment system that can separate the benzene from the water.

“They’re working on the plans right now for a water treatment system,” said Tom Droege, a Williams spokesman. “It’s not in place yet, but once it’s up and running, then they’ll begin to treat the groundwater on a regular basis.”

The system will remove the benzene and any other hydrocarbons from the water through a multistep process. Contaminated water will first go through an oil and water separator. Then, it will move through an air stripper, which works like air-sparging. Finally, the water will be moved through activated carbon polishing tanks.

The treated water will then return to a holding tank, where it will be tested to ensure it meets state health department and U.S. Environmental Protection Agency standards. Once officials have confirmed the water is safe, it will be returned to the aquifer.

Any air emissions from the treatment system will be captured and treated according to the procedures approved by the Air Pollution Control Division of the state’s health department, Salley said.

The system is expected to be functional by the end of May.

An effective home water treatment (point of use or point of entry) for benzene is activated carbon.  As with other volatile organics, benzene is best treated with coconut shell carbon because of its very tight pore structure, but any good carbon can be effective.

Source Reference: The Republic (Columbus, Indiana).

Gazette Fair Use Statement

 

Nominal, Absolute, and Beta Ratio.  What They Mean.

Ratings of water filters that screen out particulate are usually stated in micron size. The micron is a standard measure of size that is used by filter makers. The diameter of a human hair is about 90 microns. Sediment filters are used to catch particles 1/300 of that.

Most sediment filters are given ratings by their manufacturers that describe their effectiveness at removing particles down to a specified size. The most common of these are”nominal” and “absolute.”

Nominal, according to the Water Quality Association (WQA), means that the filter will filter out at least 85% of the particles of the size it is rated for. In other words, a filter that is rated as a 1 micron nominal can be expected to pick out 85% of the particles that are 1 micron or larger from the water that passes through it.

Absolute, theoretically, means that the filter will reject virtually all of the particles of the given size. The usual expectation is a 3-log rejection–or 99.9%. Absolute ratings are usually used for the tightest filters and for purposes where efficiency really matters. For example, if a filter maker promises removal of E. coli, more or less 85% efficiency isn’t good enough. If you’re going to trust your life to the filter, you expect an absolute 3-log or 4-log rating at the very least.

The problem with the absolute vs. nominal system is that there is really no universal standard that assures uniformity. Some makers of filters for non-critical applications, for example, might consider 70% rejection suitable for a nominal filter. Definitions vary from one manufacturer to another, and there is really no way for the end user to verify the claim.

Beta Ratio is less frequently used. It establishes a ratio between the particles that are retained and the particles that pass through the filter. The formula is Particles In divided by Particles Out. Thus, the higher the Beta Ratio rating the better. A beta ratio of 1000 would mean that the filter allows only one particle per 1000 to pass through. A beta ratio of 100 means one particle per 100. The 1000-rated unit, therefore, is 10 times as effective. Note, however, that the beta ratio is no guarantee that the filter will perform as well in areas other than what it was tested for. The filter that works best in one application may not be effective in another.

Here are suggested maximum flow rates in gallons-per-minute for the four most common cartridge sizes in the popular Flow Max series of pleated sediment cartridges.

Micron Rating 2.5 X 9.75 2.5 X 20 4.5 X 10 4.5 X 20
1 Absolute 3 6 8 12
0.35 Nominal 4 8 9 13
1 Nominal 4 8 10 15
5 Nominal 7 14 15 25
20 Nominal 8 16 15 25
50 Nominal 10 20 15 25

Reference Source:  The Pure Water Occasional.

How to Get Big Performance Out of Small Water Filters

Frequently the most advantageous way to achieve high flow rates on a small budget is to use two or more small water filters installed in parallel so that only a part of the water is treated by each filter.

For example, removal of chloramines from city water requires considerable “contact time.”  This means that water must flow more slowly through the filter than would be necessary for removing chlorine.  Contact time can be increased by increasing the size of the filter, but it is usually not practical to install massively sized  and very high-priced tank-style filters in residences. A single filter that will treat nine gallons per minute for chloramines is large and costly, but three filters each capable of treating three gallons per minute are much more affordable and much easier to install and maintain.  Multiple small tightly constructed  carbon block filters are also usually a better treatment for hard-to-remove chemicals like chloramines or pharmaceuticals than a large granular carbon unit.

Below are installation pictures featuring such multi-filter installations.

 

 

Above is a double carbon filter installed in a home in Missoula, Montana by Roger’s Plumbing Service. The whole house filter installation splits the flow of water so that each of the carbon block filters handles only half the water at a reduced flow rate.

claytolinwh

This McKinney, Texas installation shows the water flowing from the right through a sediment filter then splitting to pass through two carbon block filters.  A softener, not shown in the picture, is located to the right.

The Three-Filter Manifold was built by Denton, TX plumber Larry Sawyer for a New Jersey car wash. It divides the water stream into thirds to provide sediment filtration for a 60 gallon-per-minute water demand.

Above is a high-flow triple filter setup installed on a large home in Trophy Club, TX.  The water enters from the left and goes through a single sediment filter, then the stream splits to pass through three catalytic carbon block filters for chloramine removal.  The final stage, at right in the picture,  is a Watts ScaleNet TAC anti-scale unit.

Above is a split-stream setup near Valley View, TX installed by Ricky George Plumbing Service of Sanger, TX.  Water enters from the left, goes through a single sediment filter, then splits to go through two carbon block filters.  The final unit, at right, is a Pura Big Boy series ultraviolet system.  The excellent installation features a plumber-built bypass (the three yellow-handled valves at bottom) plus drain taps on the vertical pipes to facilitate cartridge replacement.

Above is an outdoor installation in a California home.  It features easy-to-service Viqua housings which work well without brackets.  Use of stainless flexible connectors allows some “wiggle room” for cartridge replacement.  Flow is from left: sediment filter, two carbon block filters, and a ScaleNet no-salt scale prevention unit.

This is a double carbon filter installation in Denton, TX  by Sawyer Plumbing.  Each filter treats half of the home’s service water flow. The installation features PEX plumbing and a plumber-built bypass. A protective cover will be added to prevent freezing.

 installationkkimesIn this installation in  Brentwood, CA water enters a sediment filter (lowest filter in the picture), then the stream splits to flow through two carbon block filters, then a water softener (white cabinet), and finally through an ultraviolet purifier. Note that the Pura “Big Boy” UV unit is built in the same size housing as the 4.5″ X 20″ cartridge filters.  (Click picture for larger image.)