Pure Water Occasional, February, 2023
 
Greetings from Pure Water Products, the Pure Water Gazette, and the Pure Water Occasional.
 
 
 
In this almost-Easter Occasional you'll hear about hydrogen sulfide in well water, what it is and how to get rid of it. Read about NSF certification--what it is and is it worth the expense? Where to find  quick reference charts for the treatment of water contaminants and conditions and where to find water treatment products to address them. A concise overview of what water treatment is needed for city and rural water.  And, as always, there is much, much more. 

Thank you for reading, and sincere thanks from Pure Water Products for your continuing support.  
 
Thanks for reading!

Please visit the Pure Water Gazette, where you will find hundreds of articles about water and water treatment, and the Pure Water Products website, where there is much information about water treatment and the products we offer.
 
 

Hydrogen Sulfide

Removing Hydrogen Sulfide from Well Water

The “rotten egg” odor that people complain about in well water can come from many sources, but it is most commonly caused by  “sulfur reducing” bacteria that give off a foul-smelling gas. The bacteria themselves are harmless–they don’t cause disease–but the gas they produce can cause horrible odors and smelly black staining in pipes and appliances.
 
In some parts of the country, most notably Florida, where hydrogen sulfide is common and very severe, the standard treatment is to spray the water into an open air tank, allow the noxious gas to escape into the atmosphere, then use a secondary pump to send the water from the tank into the home. Tanks of this type are expensive, need lots of space, and are subject to freezing in cooler climates. Therefore, another type of treatment known as “precipitation/filtration” is preferred in most areas.
 
With this method, an “oxidizer” causes the trapped hydrogen sulfide gas to “precipitate” to elemental sulfur, then the sulfur is trapped in a filter. It’s a two-step process. The filter is most often carbon.  Filter carbon, especially a specialty carbon called “catalytic carbon,” can perform both steps–precipitation and filtration–but unless the amount of  H2S (hydrogen sulfide) is small, the carbon wears out quickly and has to be replaced. However, when the carbon is helped by a more powerful “oxidizer,” the carbon can last a very long time and the process can be very successful. Many “oxidizers” can cause the precipitation of the gas: air, chlorine, hydrogen peroxide, potassium permanganate, ozone, and more. For residential users, the most practical and the most easily maintained are aeration (air) and chlorination.
 
A full treatment system with chlorine looks like this–
 
1. A dry pellet chlorinator — a device that drops chlorine pellets into the well itself– followed by a carbon filter, or
 
2. A chemical feed pump, installed before the pressure tank, that feeds liquid chlorine (household bleach) into the water line.  After the pressure tank, you must have a retention tank–usually 80 to 120 gallons–to give the chlorine time to work.  After the retention tank, a carbon filter.
 
A full treatment system with aeration looks like this —
 
1. An “Aer-Max” system, which consists of a 10″ X 54″ treatment tank that is fed by a small air compressor.  It is installed after the pressure tank, and it is followed by a carbon filter, or
 
2. A “single tank aerator” installed after the pressure tank. It is a backwashing filter with a special control valve that draws in air to “oxidize” the H2S so that it can be removed by the filter carbon in the bottom 2/3 of the tank.
 
Here are page links that show the various strategies. Many have installation diagrams.
 
 
Chemical Feed Pump and accessories — http://www.purewaterproducts.com/chemical-feed-pumps
 
 
 
The carbon filter used in any of these system (other than the single tank aerator) can be either a “backwashing” tank-style filter or a carbon block filter.  If iron is present in the water, a backwashing filter must be used because a carbon block filter would be clogged quickly with iron.
 
Catalytic carbon is the carbon of choice with hydrogen sulfide, but any good carbon filter will work after proper oxidation.
 
Here are some places on our website to look for carbon filters —
 
 
 
Often the hard part of designing these filters is choosing and sizing the carbon filters.  Do not hesitate to call or email us for help.
 
 

 
 

 
 

ANSI/NSF: What’s it all about?

by Gene Franks

Editor’s Note:  This article first appeared in the Pure Water Occasional for April 2010. The article printed below has been expanded.
 
 
A standard question about water treatment products these days is to ask if they are “NSF certified.” For our products, the answer isn’t simple. Some of them carry full third-party certification obtained by the manufacturer, some have certification on some of their components,  some aren’t certified at all, and some have certification from third parties that have no affiliation with NSF.
 
“Is your product NSF certified?”  implies–and most take it to mean–that there is some federally sponsored (N for national) certifying agency, probably a branch of the EPA, that  “certifies” products the way that USDA puts its stamp on the rump of a dead pig making it an officially edible ham.  That isn’t the way it works at all.
 
First, NSF isn’t a government agency.  NSF used to stand for National Sanitation Foundation, but it is my understanding that the letters don’t “stand for” anything now. The corporate name is simply NSF, a.k.a. NSF International.  NSF started in 1944 when a couple of University of Michigan professors saw a need to set up safety standards for lunch counters and took it upon themselves to start such a service as a university activity.  The agency over the years separated from the university and  grew into a very large and well funded non-profit corporation.
 
So, how did NSF get the right to dictate “standards” for water treatment devices (and a host of other commercial products)?
 
Actually, it didn’t.   ANSI, the American National Standards Institute,  is the official certifying agency in the US.  (Canada has its equivalent in the Standards Council of Canada,  SCC.)   The US EPA, Health Canada, as well as all states of the US and all provinces of Canada rely on ANSI and SCC to determine the standards that are accepted for third party certification of products.
 
So, where does NSF fit in?  NSF plays a double role in the certification process.  First, it “authors” standards, at ANSI’s behest, and it is also one of the many agencies that are licensed to perform the testing that is required in the standards for product certification. ANSI/NSF standards are standards prepared by NSF under the authority and approval of ANSI.
 
NSF is only one of many agencies that are authorized to test products to the standards set by NSF/ANSI.   Others that are equally empowered to perform the rites of certification include the Water Quality Association (WQA), Underwriter Laboratories (UL), the Canadian Standards Association (CSA), Truesdail Laboratories, Mechanical Officials, the International Association of Plumbing, and more.
 
So, when a product is said to be “tested to ANSI/NSF” standards, this means that the product has been tested to standards authored by NSF for ANSI and tested by either NSF or another ANSI-approved testing agency (like the WQA), or even tested by a non-certified third party tester using NSF/ANSI standards. Many manufacturers now do their own testing to the standards set by NSF/ANSI.
 
Something that is often not understood is that if you want to research a product’s certification, you must know the testing agency.  The NSF website lists only products tested by NSF’s testing division.  Products tested to NSF standards by, for example, the International Association of Plumbing, are not listed on NSF’s website. There is no central registrar for all NSF/ANSI tested products.  Each testing agency keeps its own records.  If a product advertiser claims “NSF certification” and you go to NSF’s website for verification and can’t find it, it doesn’t mean that the advertiser is (or isn’t) lying.
 
What All This Means

There is much confusion in the public mind about what “NSF Certification” means.  What it does not necessarily mean is that the certified product is “guaranteed to work,” or that a level of performance is guaranteed.  There are numerous NSF/ANSI standards that apply to water treatment products.  Not all address performance, although advertisers frequently imply that superior performance is guaranteed simply because their product is “NSF certified.” Certainly this misconception is common among consumers.
 
Here are the standards that water treatment devices are most frequently tested and certified under:
 
STANDARD 42: Drinking Water Treatment Devices – Aesthetic Effects
 
STANDARD 44: Cation Exchange Water Softeners
 
STANDARD 53: Drinking Water Treatment Devices – Health Effects
 
STANDARD 55: Ultraviolet Microbiological Water Treatment Systems
 
STANDARD 58: Reverse Osmosis Drinking Water Treatment Systems
 
STANDARD 62: Drinking Water Distillation Systems
 
And the most recent: STANDARD 401: Emerging Contaminants.
 
Most manufacturers of water treatment devices present their certification information in a straightforward manner that really tells you what their certification covers.  As an example, here’s how KX Industries (a.k.a. Filtrex, the nation’s largest maker of extruded carbon block filters) labels one of our favorite products, the MatiriKX PB1 filter cartridge. KX displays this certificate on the product’s fact sheet:
 
The MATRIKX® + Pb1 is Tested and Certified by NSF International under NSF/ANSI Standard 42 for material requirements only.
 
What this says is that NSF International (the testing branch of NSF) has performed the necessary tests to certify the product under the materials requirements only of Standard 42 prepared by NSF for ANSI.  The materials requirement under Standard 42 gives you the assurance that the materials used in the product are safe and non-toxic and that the cartridge isn’t adding anything to the water that will cause harm.   Standard 42 materials certification makes no guarantee of performance.  It does not speak to the product’s ability to remove chlorine, lead, or PFAS. It just tells you that it won’t put lead, arsenic or formaldehyde into the water.
 
Note that this is a “component” certification, not a product performance certification.
 
When looking at water treatment products, some are certified and marked with the word “component” on the product label.  There is a difference between system certification and component certification. A component is an individual piece of a system and requires less rigorous testing for certification. A certified filter cartridge (component) could be put into a reverse osmosis unit (product) with a cheap faucet that leaches lead into the water. The cartridge may be certified, but that does not mean that the entire RO unit is. 
 
The testing a component must undergo to pass requirements for certification include material safety and structural integrity if it is a pressure-bearing component. The material safety test ensures no contaminants are introduced into the the water.The structural integrity test ensures no leaking will occur when exposed to high pressure or repeated fluctuations in pressure.
 
System certification includes the aforementioned testing as well as meeting performance criteria. Performance testing must meet the minimum criteria which includes “testing of minimum and rated service flow rates, testing of pressure drop for larger products, and evaluating product design to ensure replacement components are readily removable, waste connections have an appropriate air gap, and the product does not pose obvious hazards.” Each system may be subject to more rigorous testing requirements as well.
 
Using products that are system or component certified assures the seller and consumer that these water treatment parts will not leak or put contaminants into the water.
 
In addition to this actual certification, the manufacturer’s sheet for the PB1 cartridge informs that lead reduction, chlorine, taste/odor, turbidity and cyst reduction claims are “based on NSF/ANSI Standard 53.” This means that KX didn’t actually submit the cartridge for NSF/ANSI certification under Standard 53 (a health effects performance standard) but that it was tested (by KX or an unspecified third party) and found to perform at the specified levels as determined by NSF/ANSI Standard 53.  (In the case of the PB1, an additional label indicates that the testing to NSF/ANSI standards was done by the Water Quality Association’s testing division.)  [Since this article was written, the PB1 spec sheet has been expanded to include performance data for reduction of PFAS, Chloramine, and VOC as well.]
 
Why  would KX Industries not just have its PB1 cartridge NSF/ANSI certified? Well, cost for one thing, but also because it is a “component” rather than a full product, like an RO unit.  It costs literally tens of thousands of dollars to obtain and maintain NSF/ANSI certification.
 
Many manufacturers use certification as a selling tool.  They spend  large amounts maintaining product certification and they advertise their products accordingly, often with the implication that uncertified products are not to be trusted.  Other manufacturers–KX Industries, for example, as well as many other highly respected manufacturers–rely as much on their own reputation and experience as third-party certification to sell their products.  The lower price they are able to charge because of the the money saved on certification gives an added selling advantage.
 
Certification is important.  It gives the customer confidence that the product meets a certain standard–either in materials it is made from or in its performance.  But if you limit yourself to products that are NSF/ANSI certified you may be depriving yourself of some really superior products as well as spending more than you need to.
 
“Let the buyer beware” is a two-edged sword.  It isn’t good to buy an inferior product, but no one likes the idea of paying an extra $30 for a filter cartridge to support the manufacturer’s advertising campaign.
 

 
 

 
 
Where to Find It
 
Want to know what removes aluminum or chloramines from water? We've put together a complete reference chart of contaminants and conditions arranged alphabetically from Acidic Water to Xylenes.  It isn't designed to be a complete treatment strategy, but it's a good place to start.  It's on the Pure Water Gazette website:
 

Quick Reference Table for Water Contaminant Treatment

Looking for a specific water treatment product or part? See our alphabetical list on the Pure Water Gazette website:
 


 
 
 
 

How Water Is Treated for Use in Homes

If you live in a city  . . .

your water comes to you in pipes from a municipal water supplier who gets water from lakes and rivers and sometimes wells, treats it a bit to make it clear, odor-free, germ-free, non-corrosive, and generally palatable, then pumps it through a maze of pipes to your home.

As part of its treatment, the city water plant adds chlorine or a mixture of chlorine and ammonia called chloramine to the water to kill pathogens. The treatment plant also adds other chemicals to clarify the water and prevent corrosion in pipes.  Some cities also add an industrial waste product called fluoride which is believed to prevent tooth decay.

Between the city water plant and the home lie miles of pipe, some of it very old,  made of a variety of materials and in varying states of repair.  The water is affected a lot by pipe materials and by contaminants that can enter the water if the pipe leaks or is broken. The water that leaves the treatment plant is not the same water that enters the home. A lot of things happen to it along the way.

Most city water plants do a praiseworthy job of taking some pretty dirty raw water from a lake or river, getting the mud and sticks out of it and turning it into water that looks clear, tastes good, and won’t cause a cholera epidemic. They supply water that is of really high quality for hosing down driveways and flushing toilets. People who have watched a plumber cut open a pipe entering their home, however, usually don’t feel good about drinking their tap water anymore, or even bathing in it.

This very decent water delivered by the city can be made excellent in the home, which is, after all, where the fine polishing of water should take place. Home treatment as a final stage in the process makes much more sense than for the city water plant to try to supply top quality drinking water to the home. Only about 1% of the water that leaves the water treatment plant is used for drinking. Most of it is for flushing toilets, watering lawns,  and mopping floors.

Point of entry treatment for city water most often consists of cartridge or tank-style activated carbon filters to remove disinfectants (chlorine or chloramine).  If the water is “hard” (meaning that it has lots of calcium and magnesium in it), it can be treated with a conventional water softener or one of the several newer “salt-free” alternatives. Treatment for hardness is mainly done to protect pipes and fixtures and to make water more aesthetically pleasing.  Adding a point-of-entry ultraviolet (UV) unit to assure bacteria-free, cyst-free water for the whole home is becoming more popular, especially in light of the increasing number of “boil water” alerts.

For point-of-use treatment for the water that you’re going to drink, cook with, or make ice with,  a variety of countertop and under-the-sink systems are available, from simple, very tight carbon filters that improve taste and odor and remove chemicals to the more comprehensive treatment, reverse osmosis. The real king of point of use drinking water systems is reverse osmosis.  A good undersink reverse osmosis unit can provide top quality drinking water for a moderate cost.  RO, as it’s called, removes virtually anything one would want removed from water, including the more difficult contaminants like arsenic, lead, chromium 6, fluoride, chloramines, trihalomethanes, and a wide range of pesticides, herbicides, “pharmaceuticals,” and so-called “emerging contaminants.” Yes, RO removes PFAS as well.

If you live outside the city  . . .

your water usually comes  to you from a well on your own property. A well is essentially a hole in the ground with a pipe through which water in an underground pool is sucked up to the surface. It’s like drinking from a glass with a drinking straw. Also,  many non-city dwellers pull their water through pipes directly from a pond or stream and treat it themselves.

If you have a well or draw water from a lake or river, you are your own water treatment superintendent, so you need to pay attention to what you’re about. The first thing you should do is get a good, comprehensive water test. This will cost you a couple of hundred dollars, but it will pay for itself easily in what you’ll save by not purchasing unnecessary or inappropriate equipment. If the test shows that your water  is perfect, the peace of mind you gain will more than pay for the test.

The reason the well test is needed is that you don’t have the benefit of the testing that’s done for you with city water. If there’s arsenic in the city’s water source, the city is obligated to take care of it and to tell you about it. If there’s arsenic in your well, the only way you’ll know is by having a good test done.

With private water sources there is a much greater chance that extreme treatment will be needed. Here are some of the common issues with well, river and pond water, along with some of the ways they can be corrected.

Bacteria — pathogens like E. coli can be controlled by chlorination or ultraviolet treatment.

Iron and manganese— treated with iron filters that often require pre-treatment with aeration or chlorination. Small amounts of iron and manganese can also be treated with a water softener.

Hydrogen Sulfide (rotten egg odor) — treated by chlorination or aeration followed by filtration.

Arsenic, Chromium — reverse osmosis for drinking water. (Frequently left untreated for point of entry.)

Pesticide, Herbicide, general chemical contamination –Carbon filtration.

Tannins (tea colored water) Ion exchange and carbon filtration.

Hardness--Water Softener.

Sand, Sediment — Backwashing filters or cartridge style sediment filters.



Dissolved Solids (high mineral content) — Reverse osmosis.


Whether your water comes from a city, a lake, or your own well, an undersink reverse osmosis unit is your most complete drinking water option.

 
Undersink Filters
 
 
Double undersink filters are in may ways the best buy in a drinking water filter. 
Doubling up allows you to add specialty items like lead removal, fluoride removal or even bacteria removal without giving up the advantages of a full-sized carbon block filter for chemical removal and taste/odor improvement.
The standard city water filter set-up in our double filters, what you'll get if you don't specify otherwise, is the MatriKX CTO+ (formerly KX-1) and Pb1 cartridges. This combination gives great chemical capacity, superb chlorine reduction, lead reduction, and cyst (giardia/cryptosporidium), PFAS, and VOC removal.
Our Black and White undersink filter series includes single, double, triple and even quadruple filters in either the standard format with its own faucet for filtered water or in the "simple" style which dispenses filtered water through the cold water side of your kitchen faucet. The series uses standard-sized cartridges, so cartridge availability is never a problem. 
 
 
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Places to visit for additional information:

 
 
 
 
 
 
 
Thanks for reading. The next Occasional will be out eventually--when you least expect it.
Pure Water Products, LLC, 523A N. Elm St., Denton, TX, www.purewaterproducts.com. Call us at 888 382 3814.
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