Good afternoon, Stuart, and thank you for your inquiry.

Due to the nature of the testing and low quantities of THM's one could expect to find in drinking water, not simple at-home test kit for THM's exists -- that we know of. Testing for THM's takes place in a laboratory environment.

Companies like National Testing Laboratories offer mail-in water testing services that include testing for THM's and other disinfection byproducts. You can find links to various water testing packages from National Testing Laboratories on the following page:

• 'WaterCheck Water' Test Kits by National Testing Laboratories

FYI: As a general rule it takes about 10 business days to get test results back from NTL (National Testing Labs) and the cost of each testing package depends upon the number of different water quality parameters the kit contains.

OK, so where do THM's come from?

Trihalomethanes (THM's) fall into a classification of drinking water contaminants known as disinfection byproducts, or DBP's.  Contaminants of this nature form when disinfectants such as chlorine get added to water that contains organic matter.

As the chlorine 'goes to work' on the organic matter and sets about breaking it down, as part of the chemical interaction between the organic matter and chlorine disinfection byproducts get created.

Scientists and water experts now believe that prolonged exposure to disinfection byproducts possibly increases people's risk of developing various types of cancers.

What removes or reduces levels of THM's in drinking water?

For information on water filtration systems capable of eliminating harmful levels of THM's, we suggest taking a look at water filtration options that contain Granular Activated Carbon (often abbreviated as GAC).  You can find a number of different filter brands and types on the following sites: FilterWater.Com, FiltersFast.Com and Filter-Drinking-Water.Com.

Free (available) chlorine refers to the concentration of chlorine molecules residing a water sample that have not, yet, oxidized contaminants. As a general rule you want to maintain a free chlorine residual in a body of water or water source.

Therefore, if a water sample has a total chlorine residual but no free, available chlorine, then the sample may or may not be ‘safe’. Some public (municipal) drinking water systems use only combined chlorine Why would they do that?

It seems counter-intuitive that a public water systems would choose combined chlorine over free chlorine given free chlorine’s superior disinfecting (oxidizing) properties, but monochloramines do still have oxidizing capabilities and they do not create compounds (disinfection by-products, tri-halomethames, TTHM’s, etc.) that may cause cancer.

So… if you want to know how much free chlorine you have versus how much combined chlorine you have, simply subtract the free chlorine concentration from the total chlorine concentration:

(Total Chlorine) – (Free Chlorine) = Combined Chlorine

For pool water you can use a test strip like the Pool Check 6-Way to determine the free and total chlorine concentrations of a sample.

For drinking water you can use test strips like SenSafe Free Chlorine Water Check to determine the free chlorine concentration of a water sample and SenSafe Total Chlorine Water Check to determine the total chlorine concentration of a water sample.

OR, for an even easier test procedure, you can use the WaterWorks 2 Free & Total Chlorine Test Strip which tests for both free and total chlorine at the same time.

So, without further ado, get ready for a list of chemicals and chemical compounds that call into the VOC category of NSF/ANSI Standard 53:

alachlor	endrin	simazine
atrazine	ethylbenzene	styrene
benzene	ethylene dibromide (EDB)	1,1,2,2-tetrachloroethane
carbofuran	haloacetonitriles	tetrachloroethylene
carbon tetrachloride	bromochloroacetonitrile	toluene
chlorobenzene	dibromoacetonitrile	2,4,5-TP(silvex)
chloropicrin	dichloroacetonitrile	tribromoacetic acid
2,4-D	trichloroacetonitrile	1,2,4-trichlorobenzene
dibromochloropropane (DBCP)	haloketones	1,1,1-trichloroethane
o-dichlorobenzene	1,1-dichloro-2-propanone	1,1,2-trichloroethane
p-dichlorobenzene	1,1,1-trichloro-2-propanone	trichloroethylene
1,2-dichloroethane	heptachlor	trihalomethanes (TTHM)
1,1-dichloroethylene	heptachlor epoxide	(THM) bromodichloromethane
cis-1,2-dichloroethylene	hexachlorobutadiene	bromoform
trans-1,2-dichloroethylene	hexachlorocyclopentadiene	chlorodibromomethane
1,2-dichloropropane	lindane	chloroform
cis-1,3-dichloropropylene	methoxychlor	xylenes
dinoseb	pentachlorophenol

Note: While the NSF/ANSI Standard 53 for VOC Reduction deos specify just 43 compounds, the list above contains extra entries because the Standard considers three ‘families’ of compounds single entries and then goes on to specifically call out the names of individual compounds within those chemical families.

Where do these things called VOC’s come from?

The VOC Fairy brings them while you sleep… but not really. On the NSF Web Site we found the following definition which we think does an excellent job of describing the origin of VOC’s:

“The category of VOC (Volatile Organic Chemical) includes a number of chemicals that are both man-made and naturally occurring. Water from wells and utilities may contain some of these contaminants. Some VOCs are pesticides, herbicides, or insecticides that seep into the ground water after application. Other VOCs enter the water supply through industrial or other waste disposal. This category also includes total trihalomethanes, which are a by-product of chlorination.”

For those who believe VOC’s cannot get into their water supply because you don’t live in close proximity to industrial complexes or agricultural areas, think again. Once these things enter the environment they, like many other categories of drinking water contaminants, could possibly travel many miles before dissipating to a ‘safe’ level.

Thanks for the chemistry lesson, but…

“Why does any of that matter to me?”

In a nutshell, scientists and health officials have agreed that the presence of any of those chemicals in too high a concentration in water poses a potentially serious health risk to people if they consume the water. Devices that have tested and certified to NSF/ANSI Standard 53 for the reduction of VOC’s must satisfactorily reduce levels of all the chemicals on that list to ‘safe’ levels.

Chloramines? What are chloramines? Take a look at this earlier Water Testing Blog entry on Free Chlorine, Combined Chlorine and Total Chlorine and get a quick education on the topic!

Whether created as a byproduct of disinfection via free chlorine or the intended disinfectant in a water system, most people do NOT like the taste and odor of chloramines in their water.

Thankfully Pentek has come out with a product called the Pentek ChlorPlus 10 Chloramine Removal Water Filter Cartridge that fits in standard 10″ (x 2.5″) filter housings used in filter sytems produced by companies such as Pentek (obviously!), US Filter (recently acquired by Pentek!), Cuno, Filterite, Keystone, US Water, Water Resources, Harmsco, and many other popular brands of water filtration systems. If your system uses a standard 10″ x 2.5″ housing, the Pentek ChlorPlus 10 ought to fit just fine!

Having said that last bit, please check the dimensions of your current filter and/or housing before ordering this product!

Looking for a 10″ replacement filter with NSF Certification? The Pentek ChlorPlus 10 uses a component tested certified to NSF Standard 42.

What does the Pentek ChlorPlus 10 remove/reduce? Using 1 micron carbon block technology this product (255416-43) should seriously reduce chloramine concentrations in drinking water and in doing so remove the (offensive) taste and odor associated with chlorine while also helping to pull out unwanted sediment, if present.

One particular disinfection byproduct of, trihalomethanes (often abbreviated as THM’s or TTHM’s), has gained enough notoriety that companies like PUR have started certifying some of their products to NSF/ANSI Standards for the reduction of trihalomethanes in drinking water.

Below you will find a list of several PUR water filtration products that have tested and certified to NSF/ANSI Standard 53 (Drinking Water Treatment Units – Health Effects) for the reduction of TTHM’s and other unwanted drinking water contaminants:

• PUR CR-6000 Filtered Water Pitcher
• PUR CR-6000C Filtered Water Pitcher with LED Light
• PUR Faucet Mount Filter 3-Stage – Flavor Options
• PUR Faucet Mount Filter 3-Stage Horizontal Chrome
• PUR Faucet Mount Filter System 3-Stage Chrome

• PUR Faucet Mount Filter System 2-Stage White

For those unfamiliar with how trihalomethanes get into drinking water, they get created when free chlorine molecules attack, neutralize and become entangled with a biological contaminant. That process chain of events converts free chlorine into combined chlorine and in the process disinfection byproducts get created.

What harm can trihalomethanes in drinking water cause?

Four different trihalomethanes can form as a result of chlorination: Chloroform, Bromodichloromethane, Dibromochloromethane, and Bromoform. The United States Environmental Protection has found that excessive exposure to these compounds has resulted laboratory rats developing cancer.

While many scientists may disagree on the exactly how much exposure to each compound constitutes overexposure, we think it wise to keep tabs on your local water treatment system’s track record of trihalomethane level management (data available in annual reports) and if deemed necessary, install an NSF certified water treatment system capable of reducing trhalomethane levels.

Well we all know how lazy OTHER people… ahem… can be.

Public swimming pools are more dangerous than you might think, a new study suggests. When sweat and urine, among other organics, mix with the disinfectants in pool water, the result can be hazardous to health.

The findings, announced this week, link the application of disinfectants in recreational pools to genetic cell damage that has been shown to be linked with adverse health outcomes such as asthma and bladder cancer.

Pool water represents extreme cases of disinfection that differ from the disinfection of drinking water as pools are continuously exposed to disinfectants. But with so many people cooling off and exercising in pools and water parks (339 million visits across the United States each year), the disinfectants are a must to prevent outbreaks of infectious disease.

Chlorine and Pee Don’t Mix

The problem occurs when the sanitizers mix with organic matter.

“All sources of water possess organic matter that comes from decaying leaves, microbes and other dead life forms,” said study researcher Michael Plewa, University of Illinois professor of genetics. “In addition to organic matter and disinfectants, pool waters contain sweat, hair, skin, urine and consumer products such as cosmetics and sunscreens from swimmers.”

These consumer products are often nitrogen-rich, and when mixed with disinfectants, these products may become chemically modified and converted into more toxic agents.

Long-term exposure to these disinfection byproducts can mutate genes, induce birth defects, accelerate the aging process, cause respiratory ailments, and even induce cancer, according to the researchers. While the new study did not examine actual effects on humans, it suggests such research might be warranted. ( source )

So listen up, all you nasty bastards and batardettes out there who find it too burdensome to cart your fun -in-the-sun frolicking butts to the bathroom: STOP PEEING IN THE POOL!

Oh, and for all of you who think, “It’s my pee, so it won’t hurt me,” all the other pee rule violators think the exact same thing.

Other Articles of Interest

• Swimmers Disobeying ‘Closed’ Signs Run Risk of Serious Illness
• West Nile Virus and Water Quality
• Myth: Chlorine Kills All Bacteria in Water
• Taylor Test Kits for Pools and Spas

We’re building a new house right on the edge of where the local water plant stops delivering water and want to know if we will be better off hooking up to the water line or having well put in. Some people say we’re lucky to have a choice, but really it’s just one more decision we have to make and we already have so many! Can you help? Thanks!

Emma

As Emma implied, sometimes having a choice makes for a lot more work – if you choose to research the options properly.

Hooking up to city water offers the security of knowing that the city has to test its water routinely before distribution and must inform you if it has experienced any ‘incidents’ which may put you in danger. On the flip-side, though, you will receive a bill each month to cover the expense of testing, monitoring, filtering and purifying the water going into your new home.

Investing in a well for your new home will rid you of that pesky water bill each month, but it will also make you 100% responsible for the quality and safety of water it produces once it passes an initial test done by the well drilling company.

We honestly do not have an answer, Emma, because some well water comes up cleaner and more pure than any water company could ever distribute… and other well water comes up nastier than backwoods swamp water and/or containing potentially dangerous chemical compounds whose origin even the best scientists in the World have trouble locating.

Pretty much all city water contains some form of disinfectant which can create unpleasant tastes and odors in drinking water. It can also irritate skin, bleach clothing, etc. and some water systems contain obnoxious (and smelly) levels of chlorine which can make water taste absolutely wretched.

While on the topic of chlorine, the most widely used disinfectant for public water systems, produces trihalomethanes (THM’s), a potentially carcinogenic disinfection byproduct, when chlorine molecules attack organic contaminants in water.

Getting back to the well water, commonly occurring events in the environment can change the quality of well water on a daily basis. Heavy rains, a lack of rain, temperature and even air pressure can radically alter the nature of water pulled from well – and let us not forget about pollution from industry which can seep into the ground 100’s of miles away from a well and still, somehow, make its way into that water that well produces at some point.

So, Emma, in the end, and if you want to make the best possible decision regarding where you will get your drinking water, we suggest you have a sample of water drawn from the aquifer your proposed well will access and have it tested by a certified water testing laboratory such as National Testing Laboratories. Contact the well drilling company you think you may use to drill, if you go that route, and ask them for advice on getting sampling and testing done. Do make sure they submit the sample to a certified water lab, though, and not do the testing themselves!

Then contact the local water company and ask for a copy of their latest water quality report, usually referred to as a Consumer Confidence Report and abbreviated as CCR.

With both reports in hand, weigh the pros and cons of each and remember that no matter which option you choose, you may STILL want to consider having a Whole House Water Filter System installed and/or purchasing point-of-use water filter devices for the shower, faucet and countertop.

“In school we recently learned that chlorine added to drinking water by water treatment facilities reacts with organic contaminants in the water and forms harmful compounds called trihalomethanes. Does the EPA have a guidleine which limits the amount of trihalomethanes are considered safe?” — Trinity in Washington

First of all, we want to clarify something in Trinity’s question: Not all forms of chlorine added by water treatment facilities will cause trihalomethanes to form. Adding ‘free chlorine’ to water containing organinc contaminants will result in the formation of thrihalomethanes while adding ‘combined chlorine’, also referred to as chloramines, to water containing organic contaminants will not.

Unsure of the difference between free chlorine and total chlorine? The following Water Testing Blog postings will help:

• Free Chlorine, Combined Chlorine, Total Chlorine
• Free, Combined and Total Chlorine Re-Visited
• Testing Chlorine Levels — Drinking Water vs. Pool Water

Getting back to Trinity’s question, though, prior to 2004 the EPA set the maximum contaminant level (MCL) for trihalomethanes in drinking water at 100 parts per billion (ppb). In 2004 the EPA lowered the MCl for trihalomethanes in drinking water to 80 ppb. ( source )

“Expectant mothers can expose themselves to the higher risk by drinking the water, swimming in chlorinated water, taking a bath or shower, or even by standing close to a boiling kettle, say researchers.

The finding, based on an analysis of nearly 400,000 infants, is the first that links by-products of water chlorination – chemicals known as trihalomethanes, or THMs – to three specific birth defects.

Exposure to high levels of THMs substantially increased the risk of holes in the heart, cleft palate and anencephalus, which results in the absence of a major portion of the brain, skull, and scalp.” ( source )

Most water systems chlorinate the water they provide in an effort to eliminate parasites and bacteria in drinking water which could lead to waterborne ailments and illnesses.

Not sure if your water contains THMs? Maybe the next few statements will help:

• Public water supplies that use free chlorine as their primary disinfectant (instead of chloramines) may contain THMs. The compounds form when free chlorine molecules lock horns with a biological contaminant during the disinfection process.
• Public water supplies that use chloramines as their primary disinfectant (instead of free chlorine) typically do not contain THMs. However it should be noted that these water systems do periodically ‘burn’ their water lines with free chlorine in an effort to get rid of any biofilm that has formed and THMs do result from those ‘burn’ sessions.

Still unsure as to whether or not your drinking water may contain THMs? You have three options:

1. Call your local water authority and ask them if they use free chlorine as the primary disinfectant or chloramines. If so, then your water most likely contains chloramines.
2. Have your water tested by a certified water testing professional.
3. Use reliable drinking water test kits for both free chlorine AND total chlorine.

“Stop using the TDS (total dissolved solids) meter as the only measurement of water quality. Disinfection Byproducts like Trihalomethanes, Volatile Organic Compounds, METHYL tertiary-butyl ether, chlorine, chloramines, cysts and lead are the primary contaminants to Public Water Systems. They have no impact on the conductivity of the water. Yet these do not register on a TDS meter. And public water systems primarily supply from surface water that tends to have low TDS levels.” ( Water Conditioning & Purification Magazine, March 2009, page 42 )

While TDS does play a large part in the determining whether or not your water will leave deposits on your fixtures, it alone does not indicate the relative safety and purity of your water. As always Water Testing Blog suggests that people get their water tested by Certified Water Analysis Laboratories if they suspect a serious health risk.

For all other water testing needs, simple at home drinking water test kits used in conjunction with TDS meters ought to work just fine. you can find more information about home drinking water test kits on this page. You can also find more information about home drinking water test kits by using the links below:

Arsenic in Water and Soil: Arsenic Quick^TM

Bacteria in Water: Bacteria Check

Chlorine Residual (Free): SenSafe^TM Free Chlorine Water Check

Chlorine Residual (Total): SenSafe^TM Total Chlorine Water Check

Lead in Water: Lead in Water Test Kit

Multi Parameter (6 Parameters): Well Water Check

Multi Parameter (11 Parameters): Well Driller Standard Water Test Kit

Multi Parameter (13 Parameters): COMPLETE Water Test Kit

Multi Parameter (15 Parameters): Water Quality Test Kit