Arsenic In Drinking Water: Exposure, Toxicity, Removal By Water Filters
We do everything from providing in-depth breakdowns of common contaminants to reports on city tap water quality. We’re keeping it going by writing about another common heavy metal that can contaminate drinking water: Arsenic.
How Are We Exposed To Arsenic?
Humans are exposed to inorganic arsenic mainly through contaminated drinking water. Some water sources in the United States have higher naturally occurring levels of inorganic arsenic than other regions. Levels of inorganic arsenic in soil typically range from 1-40mg/kg and the EPA recommended concentration in water supplies is less than 10µg/L. However, higher levels can occur near natural mineral deposits, mining sites, smelting industries, and regions where pesticides have been applied.
In addition, workers who use arsenic compounds for smelting, pesticide manufacturing and application, and wood preservation are at a higher risk for arsenic poisoning.
Below is a map published by the United States Geological Survey (USGS) which shows the concentration of arsenic in groundwater in the United States. If you live in one of the areas with high arsenic concentration, and get your drinking water from a private well, we highly recommend getting your water tested by a qualified laboratory.
Arsenic is a toxic heavy metal several epidemiological studies have reported a strong association between arsenic exposure, cancer, and systemic diseases. In fact, arsenic exposure affects virtually all organ systems including the cardiovascular, dermatologic, nervous, hepatic, renal, gastrointestinal, and respiratory systems. The severity of the adverse health effects is related to both the chemical form of arsenic and the dosage. Evidence of carcinogenicity due to arsenic exposure is very strong, but the specific mechanism by which it causes cancer is not completely understood.
What Can I Do To Reduce My Exposure To Arsenic?
A growing number of people are realizing that regulatory limits are not always in line with current toxicological studies, and are taking steps to minimize expsoure to heavy metals like arsenic, lead, mercury, and chromium 6 from their drinking water, even if their city is "in compliance" with EPA regulations.
Unlike lead, which leaches into water from pipes, arsenic comes from the source water itself, so flushing pipes or replacing plumbing will not reduce arsenic concentrations. Boiling water also does NOT remove arsenic. Arsenic must be removed using a water filter that is specifically designed to do so.
Whole House Filters
Some whole house filters can be configured to remove arsenic to some degree. We do not typically recommend these systems becasue they are very expensive, and there's no need to filter the water that is used for most household applications (e.g. flush toilet). We strongly believe that point of use water filters are the appropriate tool for the job.
Point Of Use Water Filters For Arsenic
The most cost-effective method of arsenic, chromium 6, and contaminants filtration is through a point of use water filter. When shopping for these systems, we encourage you to make sure that the filter actually filters arsenic (most don't). While we believe that our advanced under sink filters have unique benefits and use filtration media that effectively remove both types of inorganic arsenic, some systems that use reverse osmosis can be a good choice for people who are willing to accept the downsides. No matter what... make sure that your filter removes what you think it does!
As always, feel free to take advantage of our “help no matter what” approach to technical support! While we do make water filters that remove arsenic, our water nerds are happy to answer your questions about the effects of arsenic in water, even if you have no intention of purchasing a Hydroviv Water Filter. Reach out by dropping us an email (email@example.com) or through the live chat on our webpage.
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Rebecca Labranche | Laboratory Director, A&L Laboratory
How Is Drinking Water Regulated?
The Environmental Protection Agency (EPA) sets regulatory limits for over 90 contaminants in water provided by public water systems. The EPA sets these limits in accordance with the Safe Drinking Water Act to protect public health in the communities that are using this water. The EPA limits are divided into two main categories. National Primary Drinking Water Regulations are legally enforceable standards that apply to public water systems. Primary standards protect public health by limiting the levels of contaminants in drinking water that negatively affect human health. National Secondary Drinking Water Regulations are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. In addition to the federal EPA standards, The Safe Drinking Water Act (SDWA) gives individual states the opportunity to establish their own drinking water standards if they are not more lenient than those set by the EPA's national standards.
So how do these federal and state regulations effect private well-owners? These same limits and guidelines used for public water are also adopted by most institutions and lenders for home water testing as a way to determine if the property provides potable, safe water. When a home goes up for sale, if the buyer is financing, they will likely be required to test the water. While lenders may be concerned about a potable water source in order to protect their investment, there are no official rules or regulations for determining potability of private wells. Many states and towns do not even require sampling of private wells after installation. It is the responsibility of the homeowner to maintain their well and water supply.
How Often Should Home Water Testing Be Conducted?
Private well water should be tested a minimum of once per year. Drinking water supplies obtained from shallow dug wells and surface water sources should be tested more frequently as they are more susceptible to contamination. Annual testing of both dug and drilled wells should check for the most common contaminants which are bacteria, nitrates and nitrites. Even if your water has consistently been safe to drink in the past these parameters could change without you knowing and affect the safety of your water. New drilled wells should be tested with a more comprehensive water test which includes bacteria, nitrates, nitrites, metals, minerals and radon. This test identifies many common primary and secondary contaminants typically found in the bedrock surrounding the well. This comprehensive test should be repeated every 3 – 5 years to ensure the well is still providing safe water.
What Are The Most Common Types Of Drinking Water Contaminants?
Drinking water contaminants can be divided into several categories: Inorganic Chemicals, Organic Chemicals, Radionuclides and Microorganisms. Testing for every possible analyte would be prohibitively expensive but we have put together a comprehensive test package which covers common problems found in our area.
Laboratories throughout the United States will offer similar packages based on the geology in their area.
What Is The Process For Analyzing Drinking Water?
The process of analyzing drinking water varies by laboratory and their methods used. However, the basic premise is the same for all of them. The first step is to obtain a water test kit from the certified drinking water laboratory that you intend to use for the analysis. Home water testing kits are specific to each laboratory and their methods so it is important not to use another laboratory’s bottles. These test kits come with all the information that is needed to collect the sample and get it back to the laboratory in the required time frame. The sampling instructions are usually step by step and easy to follow. Once the water is received by the laboratory it will be analyzed for the requested parameters and report will be generated and sent back to the client. The typical turn-a-round time for a comprehensive water test is 2-3 business days.
Using a certified laboratory is very important. They are monitored by their state and undergo periodic inspections to ensure that they are producing the highest quality data. During these inspections their instruments, standard operating procedures, lab technicians, quality control documentation and reporting procedures are reviewed and evaluated. If anything is found to be out of compliance certification for the laboratory can be revoked. In addition to inspections, they also have to complete proficiency tests for each method they conduct to prove that they can perform the method properly and obtain results within the specified limits.
What Are The Risks Associated With Consuming And/Or Using Contaminated Water?
The risks vary greatly depending which contaminants you have in your water. Common health effects include gastrointestinal illness, reproductive problems, neurological disorders and cancer. These health problems pose a greater threat to young children, pregnant women, the elderly, and people with compromised immune systems. The health effects of drinking contaminated water can range from no physical impact to severe illness or even death.
Some of the effects of drinking contaminated water are known almost immediately. Immediate health related issues generally stem from contamination by pathogens such as total coliform and E.coli. Symptoms include gastrointestinal and stomach illnesses such as nausea, vomiting, cramps, and diarrhea.
Other contaminants pose health effects that may not be observed for many years. Some of the most common ones are:
Arsenic in water occurs naturally as well as from industrial activities. Studies have shown that chronic or repeated ingestion of water with arsenic over a person’s lifetime is associated with increased risk of cancer (of the skin, bladder, lung, kidney, nasal passages, liver or prostate) and non-cancerous effects (diabetes, cardiovascular, immunological and neurological disorders).
Uranium is a tasteless, colorless, odorless contaminant. Drinking water with uranium amounts exceeding 30ug/L can lead to increased cancer risk, liver damage, or both.
Copper has both long term and short term effects. Some people with short term exposure, experience gastrointestinal distress, and with long-term exposure may experience liver or kidney damage. It is typically introduced into the water from household plumbing systems.
Fluoride has been shown to reduce tooth decay in children's teeth if they receive an adequate level. The optimal concentration, as recommended by CDC is approximately 1.1 mg/L. In the range of 2.0-4.0 mg/L of fluoride, staining of tooth enamel is possible. Above 4.0 mg/L, studies have shown the possibility of skeletal fluorosis, as well as the staining of teeth.
Radon is the second leading cause of lung cancer. High levels of radon gas occur naturally in Maine soil and water, and can move up into a house from the ground. The house then traps the radon in the air inside. Radon gas can also dissolve into well water, which is then released into the air when you use the water.
What Should I Do If The Laboratory Finds Something In My Water?
If tests on your water indicate problems, the next step is to determine what type of system you need to treat the water. This can be a difficult decision because there is a wide variety of water treatment devices on the market today. Water purifiers range from relatively low-cost, simple filter devices for a kitchen faucet to more expensive, sophisticated systems that treat water from its point of entry into a home. Keep in mind, no one water treatment device can solve every problem.
Rebecca Labranche, the Laboratory Director for A & L Laboratory. A & L Laboratory which specializes in drinking water analysis for both public systems and private wells, throughout the State of Maine.
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5 Things To Know About Arsenic In Drinking Water
Eric Roy, Ph.D. | Scientific Founder
There has been some recent press coverage about arsenic contamination in drinking water. Predictably, our email and support line have been filled with questions on the topic. While we have written other articles in the past about well water in general, the purpose of this article is to specifically answer FAQs about health effects of arsenic in drinking water, and to dispel some myths about arsenic in drinking water.
Why Should I Care About Arsenic In Drinking Water?
Arsenic is a toxic substance that is linked to a long list of health problems in humans. For example, arsenic can cause a number of different cancers (e.g. skin, bladder, lung, liver, prostate), as well as create non-cancerous problems with cardiovascular (heart/blood vessels), pulmonary (lungs), immune, neurological (brain), and endocrine (e.g. diabetes) systems. Simply put, the health effects of arsenic in drinking water are bad news, and you can't see, taste or smell it in water.
What Are The Different Types Of Arsenic Found In Drinking Water?
Nearly all arsenic found in drinking water is inorganic. There are two types of inorganic arsenic, Arsenic(III) and Arsenic(V), and both are toxic. The ratio of the two forms depends on what part of the country you live in, and whether or not your water is chlorinated, becasue chlorine quickly converts Arsenic(III) to Arsenic(V).
How Does Arsenic Contaminate Drinking Water?
While arsenic-containing pesticides can contaminate water, most arsenic contamination comes from the area's natural geology. This means that arsenic can contaminate seemingly pristine water in certain parts of the country, including private wells. The map below is from USGS and shows arsenic groundwater concentrations. In this map, you can see prevalent arsenic hot spots in places like Maine, Wisconsin, Texas, and various areas across the western part of the US.
How Much Arsenic Is Toxic?
EPA acknowldeges that there is no safe level of arsenic for drinking water (MCLG = 0), but has set a regulatory limit of 10 parts per billion (ppb) for arsenic in drinking water. When this level was negotiated, scientists were pushing for a 3 ppb, but ultimately EPA decided that the cost of lowering the allowable level to 3 ppb would "not justify the benefits." We recently wrote a dedicated article on how EPA determines acceptable levels of contaminants in drinking water that you can read if you would like more information on this topic.
It's also worth pointing out that a large number of people in the US draw water from private wells, and that most well water "checks" do NOT test for arsenic. If you live in an area on the map with hot spots, we highly recommend getting arsenic testing done by a qualified water testing lab. Test kits from hardware stores are not accurate, and cheap TDS meters and "water testers" tell you nothing about arsenic.
What Can I Do To Reduce Exposure To Arsenic?
A growing number of people are realizing that regulatory limits are not always in line with current studies, and are choosing to eliminate arsenic, lead, and chromium 6 from their drinking water, even if their city is "in compliance" with EPA regulations.
Unlike lead, which leaches into water from pipes, arsenic comes from the source water itself, so flushing pipes or replacing plumbing will not reduce arsenic concentrations. Boiling water also does NOT remove arsenic. Arsenic must be removed from water using a filter that is specifically designed to do so.
Whole House Filters
Some whole house filters can be configured to remove arsenic. We do not typically recommend these systems becasue they are very expensive, and there's no need to filter the water that is used for most household applications (e.g. flush toilet).
Point Of Use Filters
The most cost-effective way to remove arsenic, chromium 6, and other contaminants is through a point of use filter. When shopping for these systems, we encourage you to make sure that the filter actually filters arsenic (most don't). While we believe that our advanced under sink water filtration systems have unique benefits and use filtration media that effectively remove both Arsenic(III) and Arsenic(V), some systems that use reverse osmosis can be a good choice for people who are willing to accept the downsides. No matter what... make sure that your filter removes what you think it does!
If you have any questions about filtering arsenic from your home's water, we encourage you to take advantage of Hydroviv’s “Help No Matter What” approach to technical support, where we will help you select an effective water filter system, even if it’s not one that we sell. This free service can be reached by emailing firstname.lastname@example.org
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5 Things That Most People Don't Realize About Well Water
Roughly 15 percent of Americans get their tap water from private wells, and this percentage can rise to 40% in rural states like Maine and Vermont. It's no surprise that we receive a lot of questions from people with wells who are are concerned about water quality.
1. Getting A Well “Checked” Is Not The Same As Comprehensive Water Testing
There is a misconception that if someone gets their private well “checked,” it will reveal water quality problems. Unfortunately, that’s not the way it works. A basic water screening has a lot of "blind spots" and gives no information about levels of lead, arsenic, chromium 6, mercury, or VOCs unless you test specifically for those chemicals. Some states have certain testing requirements, but the scope of testing varies from state to state, and most states do not require comprehensive testing Many banks require that certain water tests be conducted before they will issue a mortgage, but the goal of this testing is often to ensure that there are no faulty systems in the home, not to protect the health of the residents.
Bottom line: The well's owner is responsible for having tests run. Don't assume that the tests that were done as part of the home buying process were comprehensive.
2. Well Water Contamination Often Comes From Natural Sources, Not Humans
Some private well owners are surprised to learn that they have contaminated water, because there are no obvious contamination sources nearby. This is because some contaminants (like arsenic) can occur naturally groundwater at unsafe levels.
3. Well Water Is Often Corrosive & Can Leach Lead From Plumbing
The lead crisis in Flint put a spotlight on the fact that corrosive water can leach lead from pipes, soldered joints, and plumbing fixtures. Unfortunately, a lot of well owners don't realize that well water can be inherently corrosive, so if a their plumbing predates 2014 (when lead-free standards were fully adopted for home plumbing components), there is potential for lead to leach into the tap water.
4. Contaminant Concentrations (And Recognized Safe Levels) Change With Time
We cannot emphasize enough that people should get their wells tested on a regular basis, because contaminant concentrations and thresholds for “safe” water both change over time.For example, we commonly hear homeowners in the Northeast and Southwest tell us that they tested their water for arsenic "a few years ago" and everything was fine. They are often surprised to learn that EPA recently lowered the concentration of arsenic that is considered to be “safe." The maximum contaminant level (MCL) used to be 50 parts per billion but was changed to 10 parts per billion a few years ago. This means that many wells with arsenic concentrations that were considered “safe” by EPA a few years ago are now considered unsafe.
5. Private Well Owners Are Responsible For Monitoring Their Water Quality, Not EPA
Private wells are not regulated by EPA or State Regulators, so the owners (or prospective owners) are responsible for all well water quality testing. However, figuring out which tests to do and making sense of the results can be confusing. Some states have guidelines and recommendations, but even these can be confusing and contradictory.
Often times, prospective home owners turn to a real estate agent for advice on water quality testing, but we often hear from people who received terrible advice. Most of the time, the mistakes are honest, but there are times when it looks like the agent was trying to facilitate a quick sale.
Ultimately, ensuring water quality of a private well is the individual responsibility of the well’s owner or prospective owner. In support this responsibility, we encourage people to take advantage our Technical Support Team’s “Help At All Costs” policy, and lean on us to provide guidance on which lab to select in your area, which tests to run, and to help interpret the results. This free (no obligation service) can be reached by emailing us (email@example.com) or by using the live chat function on this page.
We do not have financial agreements or arrangements with water quality test labs, and we do not “over-prescribe” testing.
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How Do I Fix Rotten Egg Smell In Well Water?
Eric Roy, Ph.D. | Scientific Founder
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.
Update: August 8, 2017: After over a year of R&D, we are happy to announce that we have launched a whole house water purifier that is purpose-built to eliminate the rotten egg smell from all of the water that enters your home!
The Likely Culprit: Hydrogen Sulfide!
Rotten egg smells in water are usually caused by volatile sulfur-based chemicals (e.g. hydrogen sulfide), which are produced by naturally-occurring bacteria as part of their metabolism. (For those who just Googled “Hydrogen Sulfide” and saw hazard warnings… keep in mind that while hydrogen sulfide is harmful at very high concentrations… it’s highly unlikely that your water could generate high enough levels in your home to cause health problems). With that said, no one wants their home to smell like rotten eggs, so it’s a problem worth fixing!
Hydroviv’s “Toilet Tank Test” For Rotten Egg Smell
The first thing we do when a customer comes to us with a smelly water problem, is have them take the lid off their toilet’s tank and take a few pictures that can be sent to us (I’m not kidding!). The toilet tank is a great observation point for us because it’s typically the most accessible place in the home where water is constantly resupplied from the source and is rarely cleaned out (though many start cleaning the tank after taking the lid off for the first time).
We examine the pictures to look for clues for what’s going on in the water. For example, if the tank has slimy, rusty deposits, there’s a good chance that the smell is being generated by iron bacteria. If there are brownish/black deposits visible, the water probably has high levels or iron and/or manganese. Based on what’s in the pictures, we can usually custom-blend filtration media to fix the problem!
A family came to us last fall because their water “smelled like farts” and they were sick of replacing inexpensive carbon filters ever week or two. While carbon filtration is a great base technology to use in a wide range of applications, inexpensive cartridges use low quality filtration media with very low capacities for hydrogen sulfide. Unfortunately, (or fortunately… depending on how you look at it), it’s obvious when a filter becomes saturated with hydrogen sulfide… because the rotten egg smell comes back…immediately… in full force.
We ended up formulating a custom water filter for this customer with an extra high capacity for hydrogen sulfide, and the difference was dramatic. Instead of switching out cheap carbon filters every 10-14 days, the customer was able to use the same Hydroviv filter for 6 months, which saved them a great deal of money in replacement filter costs, not to mention the added convenience of not having to change out a filter every 10 days! It was great to get the excited monthly email updates from the user, letting us know that the filters were still going strong! Once they were confident that we could solve their problem, the customer also purchased some shower head water filters to fix rotten egg smells in the bathroom!
Update: August 8, 2017: After over a year of R&D, we are thrilled to announce that we have launched a whole house water filter that is purpose-built to eliminate the rotten egg smell from all of the water that enters your home!
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