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Why Does EPA Allow “Acceptable Amounts” of Toxic Chemicals In Drinking Water?

Analies Dyjak @ Friday, November 4, 2016 at 10:55 pm -0400

Anya Alvarez |  Contributor   

After a hard-hitting ad campaign ran by one of our competitors, many were surprised to learn that EPA allows “acceptable amounts” of certain toxic chemicals. If you’re like others concerned who don’t want to deal “acceptable levels” of toxicity in water, this article will explain the regulatory definitions and provide tips on how to regulate the water in your home.

Understanding Water Quality Definitions

If something is toxic, you probably don't want it in your water. So why does the government allow small levels of toxic chemicals in our water? Currently the EPA has in place unenforceable water quality goals and enforceable drinking water standards. Below I highlight the difference between the two, why the EPA allows toxic levels, and how to reduce exposure to toxic chemicals in drinking water.

Non-Enforceable Water Quality Goals

Maximum Contaminant Level Goal (MCLG) - The MCLG refers to the concentration of a contaminant that does not pose any health risk to humans. However, one must not forget that MCLGs are unenforceable and therefore have no regulatory limits. For example, the MCLG for Arsenic is 0 parts per billion, but the EPA limit is 10 parts per billion. This is EPA's way of saying "we don't want anyone to drink arsenic, but it would be too expensive to fully remove it."

Enforceable Water Quality Standards/Limits

Maximum Contaminant Level (MCL) - The MCL is the maximum level of a contaminant allowed in water.  Unlike the MCLG, the MCL is an enforceable limit.

Action Level (AL) - For other contaminants like lead, EPA uses a different term (Action Level) for the regulatory water quality standard. Using this definition, a municipality is in violation only if 10% or more of the samples exceed the AL. To put it a bit differently:  up to 10% of the samples can exceed the Action Level, and the water is still in full compliance.

Are Regulatory Water Quality Limits For Contaminants In Line With The No-Risk Goals?

You can still be at risk, even if water quality limits meet the “no-risk goals” of the EPA. The table below shows a few chemicals where allowed concentration is higher than the no-risk goal.  The complete list can be seen here.

 Contaminant

No-Risk Goal

EPA Enforceable Limit

Arsenic

0 ppb 10 ppb
Benzene 0 ppb 5 ppb
Lead 0 ppb 15 ppb
PCBs 0 ppb 0.5 ppb
TCE 0 ppb 5 ppb

Why Does EPA Allow Any Amount Of Toxic Chemicals In Drinking Water?

EPA knows it is not economically feasible for municipalities to yield contaminant free water for large populations, the MCLs are categorized between the health risk involved to the population and the financial cost to remove chemicals such as lead from water.

Lead:

EPA acknowledges that no safe level of lead exists in drinking water (MCLG=0 ppb). However, the EPA acceptable drinking water standards allows 10% of the samples to be over 15 ppb. Homes with plumbing connections and fixtures and cities with a large number of lead-containing water service lines, make it economically unfeasible, politically unacceptable, and extremely difficult to enforce mandates. Doing so would force municipalities to dig up lead pipes and require all citizens to replace their plumbing. To avoid this, the EPA makes publicly available reports, mentioning the involved risks if citizens drink the water, while also entailing steps residents can take to minimize exposure. However, municipalities often try to hide lead levels because they are ultimately reliable. Click here for an example from Newark, New Jersey.

Arsenic:

Arsenic, which occurs naturally in some groundwater sources, does not come from municipal infrastructure or residential plumbing. Because of this, arsenic isn’t economically/politically reasonable to remove it. As a result, municipalities disclose the levels of arsenic in the water report:

"If arsenic is less than the MCL of 10 ppb, your drinking water meets EPA’s standards... EPA’s standard balances the current understanding of arsenic’s possible health effects against the costs of removing arsenic from drinking water." Check out an example of this on page 3 of this Clarkdale, Arizona report. 

How To Further Reduce Exposure To Toxic Chemicals In Drinking Water

Since there are no guarantees that contaminants won’t exceed the enforceable limits, there are steps you can take to protect yourself. This can include installing a quality water filter and remaining up-to-date on water quality reports for your local area. As always, we encourage everyone to take advantage of Hydroviv's "Help No Matter What" technical support policy, where we answer questions related to drinking water and water filtration, even if you have no desire to purchase our products.

Other Articles We Think You Will Enjoy:
5 Things You Need To Know About Chromium 6 In Drinking Water
Why TDS Meters Don't Tell You Anything About Lead Contamination
Does Boiling Or Freezing My Water Purify It?

What’s Causing White Chalky Residue On My Stainless Steel Cookware?

Analies Dyjak @ Thursday, December 1, 2016 at 10:20 pm -0500

Dr. Eric Roy  |  Hydroviv's Founder

We get a lot of questions about the white chalky residue that can sometimes pop up on cookware. While the idea of residues on things used to prepare food in can cause anxiety... they are usually completely harmless! To check out water filters that remove contaminants from drinking water, check out this Duke/NC State study.

What Is The White Chalky Residue On Cookware?

What is hard water? In nearly all cases, the white residue is from calcium and magnesium-containing minerals that are found in tap water. The minerals build up on pans when water boils, evaporates, and leaves them behind. If the mineral deposits have "baked on," a normal dishwasher cycle typically won't be enough to remove them. In fact, if you use a natural dish washing detergent, the residue can actually get worse!

How To Get Rid Of White Residues On Stainless Steel Cookware?

Even though hard water mineral build-ups on cookware are harmless, they are unsightly and some people want them gone. Fortunately, this is very easy to do! Mix up a 3:1 solution of water and vinegar (any kind), put the solution in the affected pot or pan (make sure to completely submerge the mineral deposits), and turn heat it up on the stove. Once the water starts to get near boiling, shut off the burner, and let the hot liquid dissolve the mineral buildup. Sometimes it helps to give the solution a few swirls every once in a while. Once the buildup has dissolved, dump out the vinegar solution, rinse the pot with cool water, and wipe the pot dry. Easy peasy!

Hydroviv's Technical Support Team enjoys answering all kinds of water-related questions, including how to remove hard water stains from pots and pans! Reach out through Live Chat, or by dropping us an email (hello@hydroviv.com).

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How Do I Fix Rotten Egg Smell In Well Water?

Analies Dyjak @ Wednesday, September 7, 2016 at 10:27 pm -0400
If your home draws water from a well, you may have experienced rotten egg smells coming from your water. While not typically harmful, offensive odors are nuisances, and can usually be fixed. In this article, we talk about common causes of tap water odors, how we troubleshoot odor problems, and talk a bit about how the problem can be fixed with a filter.

Tap Water Chlorination: The good, the bad, the unknown

Analies Dyjak @ Monday, July 25, 2016 at 1:36 pm -0400
Eric Roy, Ph.D.  |  Scientific Founder
We get asked about tap water disinfection using a lot. Here's the good, the bad, and what we are still learning about various aspects of chlorine in tap water.

The Good:

Shortly after scientists in the 1800's demonstrated that microorganisms are responsible for many diseases, people began experimenting with ways to disinfect water. Fast forward to 1908, Jersey City began injecting chlorine into the public tap water supply, which marked the beginning of large-scale water disinfection in the United States. Since then, disinfection practices have become commonplace in the developed world,  and the spread of waterborne illness through public water supplies has come to a screeching halt. This is a very good thing.

The Bad:

By design, chlorine-based disinfectants (like bleach) cause damage to living things, otherwise they wouldn’t be effective. Of course, chlorine-based compounds don't kill humans at concentrations found in tap water, but there are known side effects of consuming and showering in chlorinated water, including skin,eye & stomach irritation. While the allowable chlorine levels set by EPA are at a level low enough so they don’t cause adverse effects in the majority of people, some people (myself included) are sensitive to chlorine-based chemicals found at concentrations allowed in tap water.

In addition to these negative “health based” side effects, there are other “nuisances” caused by chlorine in water. For example, anyone who has spent time in a chlorinated pool or hot tub knows that chlorine-based chemicals can cause hair and clothes to fade (picture below), and a quick Google search reveals plenty of reasons for using purified water for things like watering houseplants, watering gardens, and filling fish tanks.
Dedicated hot tub swimsuit. You can clearly see where the waterline is!

It's safe to say that in an ideal world, we wouldn’t need to disinfect our drinking water with chemicals  to make it safe. However, until we find a "magic disinfection wand" that can operate economically on the municipal scale, individual households must use water purification systems if they want to remove chlorine-based chemicals from water used for drinking, bathing, washing food, cooking, watering, etc.  

The Unknown

Here's what we know:
  • We know that untreated water can transmit waterborne diseases (e.g. dysentery, Cholera, E. coli …) 
  • We know that disinfecting water with chlorine-based chemicals greatly minimizes this risk.  
  • We know that the known side effects of chlorine-based disinfectants are minor when compared to the risk of waterborne disease. 

However, as is the case with most things, our understanding of water quality is still progressing. A great deal of research is currently focused on a class of chemicals referred to as "disinfection byproducts." Simply put, disinfection byproducts are the chemicals that form in water when chlorine-based disinfectants react with organic matter. 

Scientists are still studying the chemistry and toxicology of these compounds, but what we do know suggests that these chemicals may not be great for us over the long term. 

Chloramines:

About 25% of municipalities  in the US (including Washington, DC) use chloramines (also known as combined chlorine) as the primary public water supply disinfectant. Chloramines are formed by adding ammonia to chlorinated water. Chloramines (like chlorine) is an effective disinfectant, and it's effect is persistent in the distribution system due to its low volatility. However, this persistence makes it so chloramines do not "go away" if you leave an unsealed container in the fridge overnight, so we have to deal with the associated taste and odor.

Chlorine:  

DC's tap water switches over to a chlorine disinfection cycle for a few weeks each spring. This more aggressive "spring cleaning" kills any microbial buildup that may have occurred throughout the distribution system. During these few weeks, many DC residents may notice a change in their tap water's taste and odor. Fortunately, because chlorine is more volatile than chloramine, the unpleasant taste/odor is minimized if you let a container of water sit out overnight.


Sources:
https://www.britannica.com/science/microbiology
https://www.epa.gov/ccr
https://www.cdc.gov/safewater/chlorination-byproducts.html
http://water.epa.gov/drink/contaminants/basicinformation/disinfectionbyproducts.cfm
https://www.dcwater.com/DrinkingWaterQualityFAQs
https://www.dcwater.com/whats-going-on/news/spring-cleaning-region%C2%92s-drinking-water-system


Other Great Articles From Water Smarts Magazine:
Fluoride in Municipal Tap Water:  What You Need to Know

Lead Contamination in Flint, MI Drinking Water:  Why it Could Happen in Your City?