Water Quality Articles | Written By Actual Experts – Hydroviv

Water Quality Information | Written By Actual Experts

Arsenic In Drinking Water: Exposure, Toxicity, Removal By Water Filters

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 in well water

Source: https://water.usgs.gov/nawqa/trace/arsenic/

Arsenic Toxicity

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 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 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, even if you have no intention of purchasing a Hydroviv Water Filter.  Reach out by dropping us an email (hello@hydroviv.com) or through the live chat on our webpage.

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EPA Superfund Sites:  An Overview On Environmental Hazards And Superfund Process

EPA Superfund Sites: An Overview On Environmental Hazards And Superfund Process

Emma Schultz, M.S.  |  Scientific Contributor

Do you know where your nearest Superfund site is? Chances are there is one close by, given that one out of every six Americans lives within three miles of an EPA-designated major hazardous waste site. There are two sites located within four miles of my childhood home, in an idyllic and quiet suburb of St. Paul, Minnesota. I now live within the same distance of five sites -- and I had no clue. 

Superfund Sites - Environmental Hazards

What does it mean to be living so close to so much waste? Common contaminants found at Superfund sites include asbestos, lead, radiation, and dioxins; these all pose significant risks to human and environmental health. In addition, hazardous substances can leach into the soil from ground level or contaminated water, and can then migrate into nearby homes through subsurface intrusion, entering buildings through foundation cracks and sewer lines. This vapor intrusion then poses further risk to nearby residents, inside of their homes where they would otherwise be inclined to feel safe. Obviously, proximity to a Superfund site is critical; four miles' distance poses a decreased health risk as compared to a mere forty feet.

What Is The Superfund Process?

The concept of Superfund sites is widely known and understood, but the intricacies of the program and the approach to hazardous waste mitigation are elaborate and prolonged, as can be expected of any federally-funded long-term project.

In December of 1980, President Jimmy Carter signed into law the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), now known better as Superfund, which authorized the EPA to remediate hazardous waste spills and sites, and obliged those responsible for the waste - the Potential Responsible Party - to either clean it up on their own dollar or offset the cost of EPA-led cleanup efforts. Superfund had abundant funding early in its existence due to taxes levied on chemicals and oil; those taxes, however, lapsed in 1995, and financing now comes from taxpayers.

There are multiple stages in the Superfund process once a site is identified, with the first step being a Preliminary Assessment or Site Inspection. If the site is an emergency such as a chemical spill, Removal Action is taken. Otherwise, Remedial Action is planned for, which often leads to years-long planning, cleanup, and remediation. Community involvement is frequently key during the early stages of Superfund designation, and the Technical Assistance Services for Communities (TASC) program is an outreach effort designed to connect with citizens and businesses for the duration of a Superfund's existence.

After initial study, sites are given a score on the Hazard Ranking System. If a site poses enough of a threat to environmental and human health, the EPA announces its addition to the National Priorities List (NPL), pending public comment and input. NPL sites are eligible for extensive, and often long-term, federal funding through the Superfund program. These NPL-listed sites are now officially Superfund sites.

Following NPL designation, a Remedial Investigation and Feasibility Study is conducted. The Remedial Investigation collects information on-site such as water and soil samples, and the follow-up Feasibility Study analyzes various cleanup methods. The EPA then selects the most suitable cleanup alternative and provides it to the community as a Proposed Plan.

A Record of Decision notes the cleanup alternative chosen for the site. In the Remedial Design phase, the cleanup plans are drawn up, and are finally acted upon in the Remedial Action stage. A goal of Remedial Action is to return sites to productive use as quickly as possible. Whether 'productive' means industrial, housing, commercial, or greenspace depends on conversations and input from the surrounding community.

A review of site cleanup efforts occurs every five years. If cleanup goals have all been met, a portion or whole of a Superfund site may then be listed for removal from the NPL. In theory, meeting all cleanup goals sounds achievable - especially given the lengthy planning and implementation phases - but there are many sites that remain listed decades later, because groundwater and soil are still polluted.

Where Can You Learn More About Superfund Sites?

Finding out if there are Superfund sites near your home is the first step that all concerned citizens should take. There are 10 Regional Superfund Community Involvement Offices around the country that exist to take your questions and concerns regarding existing or potential Superfund sites. 

Resources for homeowners:

Search for NPL Sites Where You Live - lists NPL sites near your zip code of interest
Cleanups in My Community - shows NPL sites and more in map format
To report oil or chemical spills, or other environmental emergencies, call the National Response Center at 1-800-424-8802, or visit this help page to learn more.
Hydroviv makes it our business to help you better understand your water. 
As always, feel free to take advantage of our “help no matter what” approach to technical support!  Our water nerds will work to answer your questions, even if you have no intention of purchasing one of our water filters.  Reach out by dropping us an email (hello@hydroviv.com) or through our live chat. You can also find us on Twitter or Facebook!
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Whole House Water Filters:  Frequently Asked Questions

Whole House Water Filters: Frequently Asked Questions

We get a lot of questions from people about Whole House Filters. Because Hydroviv has a “Help No Matter What” mindset when it comes to technical support, we sometimes find ourselves helping our website's visitors evaluate products that we don’t sell!

Update:  August 8, 2017:  After over a year of R&D, we are thrilled to announce that we have launched a purpose-built whole house water filter to remove rotten egg smell from all of the water that enters your home!

What Is a Whole House Water Filter?

As the name suggests, whole house filters are installed on a home’s main water supply, so they process all water that comes into the house, including water used to flush toilets, do laundry, and water the lawn.

How Much Should I Expect To Pay For A Whole House Water Filter?

Systems marketed as whole house systems can range in price from less than $100 to $10,000.  Because the system is installed on the main water supply line, these systems typically require a licensed plumber for installation, which can add considerably to the overall system cost.  

Replacement cartridges can also be a significant cost for  whole house filter systems.  Because ALL incoming water is filtered by whole house systems, cartridges need to be replaced more frequently than if the same cartridge is used in a point of use application.

How Effective Are Whole House Water Filters?

Chemical Removal 
With whole house filters, you typically get what you pay for.  Most whole house systems are designed to process large volumes of water for water softening and chlorine removal, and are not designed to remove things like chloramine, arsenic, disinfection byproducts, or lead.  If you spend several thousand dollars on a high-end whole house system, pay to have it installed by a plumber, and replace the filtration media as prescribed, the system will probably perform as advertised. Just make sure that the system is designed to filter the chemicals you want removed... we have talked to people that have spent thousands on a whole house filter only to learn after the fact that it does not filter lead!  On the other end of the price spectrum, most of the low cost whole house filters are only good for removing sediment from the water, and don't do a good job removing dissolved chemicals.  The other thing to keep in mind is that if you remove chlorine from your home's water at the point where it enters the home, you introduce the risk of bacteria growing in all pipes downstream of the filter, because the filter removes the disinfectant.

Flow Rate & Impact On Water Pressure
Another performance aspect to consider is the impact on your home's water pressure, because a whole house filter can act as a "choke point" for water delivery.  You don't want to run into a situation where there isn't enough water pressure to take a shower because the dishwasher is running and someone is brushing their teeth.  Be sure to take into account that the cartridges used in single stage whole house filters become clogged over time, and the water pressure can drop dramatically throughout the filter's lifetime.  A good plumber is a very good resource for helping you calculate your home's water demand.  

How Good Are "General Purpose" Whole House Water Filters?

Simply put, it's not possible to build a water filter that "filters everything bad" from your water on a whole house scale.  For that level of filtration, you need to filter at the point of use (e.g. individual faucets- more on this below).  However, there are some applications where whole house filtration makes sense.  For example, we just launched a whole house water filter that is purpose-built to remove sulfur (rotten egg smell) from water.  

Hydroviv’s point of use filtration systems are designed to filter the water in your home used for drinking, washing food, cooking, and showering.  By remaining focused on these applications (and ignoring the water used in toilets & washing machines), we are able offer consumers high-performance water filtration systems that cost less than the competition, and don’t require a plumber to install.  

It's also important to point out that whole house filters and point of use filters serve different purposes, but they can work well together.  If you have a whole house filter that removes sulfur, it will take some pressure off your point of use system and extend its lifetime.   

Where Can You Go For Advice On Whole House Water Filters?

If you’re considering a whole house system, feel free to take advantage of Hydroviv’s “Help No Matter What” mindset to technical support, and we can will do our best to help you find a system that suits your needs.  We're happy to help!

Other Great Articles We Think You'd Enjoy:

How To Filter Chromium 6 From Drinking Water
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Is Lead Lurking In New York City Tap Water?
Polychlorinated Biphenyls (PCBs):  Everything You Need To Know

Polychlorinated Biphenyls (PCBs): Everything You Need To Know

Stephanie Angione, Ph.D.  |  Scientific Contributor   

What Are Polychlorinated Biphenyls (PCBs)? 

Polychlorinated Biphenyls (PCBs) are a class of industrial that were widely manufactured in the US from the 1930s through the 1970s for use in electric equipment such as capacitors and transformers, and also as heat transfer fluids, plasticizers, adhesives, fire retardants, inks, lubricants, cutting oils, pesticide extenders, and in carbonless copy paper.
While PCB production slowed in the 1960s and was banned completely in the US in 1979, they are still found in industrial applications due to their chemical longevity. The US congressional ban was enacted due to the fact that PCBs are persistent organic pollutants, which create long lasting environmental toxicity and cause harmful health effects. Products that contain PCBs include old fluorescent lighting fixtures, PCB capacitors in old electrical appliances (pre-1978) and certain hydraulic fluids.
Nearly 2 million tons of PCBs have been produced since 1929, 10% of which persists in the environment today. Generally, environmental concentrations of PCBs are low, but due to their chemical inertness they are largely resistant to chemical breakdown or thermal destruction, and thus accumulate in the environment. Additionally, PCBs are highly fat soluble, resulting in the build up of PCBs in animal fat, resulting in higher concentrations of PCBs in top food chain consumers (e.g. predatory fish, large mammals, humans).

Where Are PCBs Found In The Environment?

PCBs accumulate primarily in water sources, organic portions of surface soil, and in living organisms.


Surface water that is contaminated with PCB waste generally has high levels of PCBs in sediment, as the PCBs attach to organic matter. PCBs can be slowly released from the sediment into the water and evaporate into the air, especially at higher temperatures.


PCBs have been detected throughout the atmosphere, and can be transported globally through air. Concentrations of PCBs in the air are generally the lowest in rural areas and highest in large cites. Areas that are close to bodies of water that were highly contaminated with PCBs from industrial waste (e.g. Lake Michigan, Hudson River) can have higher air concentrations, due to evaporation of PCBs into the air over time.  

Living Organisms

PCBs accumulate in living organisms via bioaccumulation, or uptake from the environment, as well as biomagnification, from consumption along the food chain. Bioaccumulation is typically highest in aquatic species, with bottom feeding species having the highest levels of PCBs due to accumulation in sediment.  PCBs biomagnify up the food chain, as bottom feeders like shellfish are eaten by other species, and thus the greatest levels are found in large predatory fish. This process can also occur on land, as PCB contamination in soil is transferred up the food chain to insects, birds and mammals. Thus, one of the largest sources of PCB exposure and accumulation in humans is from food, specifically meat and fish.   

How Do PCBs Impact Humans?

While PCBs have been classified as probable human carcinogens, there is no evidence that the low levels of PCBs in the environment cause cancer. Exposure to high levels of PCBs have primarily occurred through workplace exposure in people who work in plants that manufacture the chemicals. Studies of workers exposed to high PCB levels have shown association with certain types of cancer. These high levels of exposure have also been known to cause liver damage, skin lesions called chloracne, and respiratory problems.

Exposure to PCBs during pregnancy can result in developmental and behavioral deficits in newborns. Additionally, there is evidence that reproductive function can be disrupted due to PCB exposure. Women of childbearing age, or those who are pregnant or nursing should be aware of fish and shellfish advisories to limit consumption of PCB contaminated fish.
There are additional studies that suggest PCB exposure can cause thyroid dysfunction, liver dysfunction, as well as adverse cardiovascular, gastrointestinal, immune, musculoskeletal, and neurological effects.

How Are PCBs Regulated & Monitored In The US?

With so many sources of PCB exposure from food and water sources, the US government has guidelines on the amount of allowable environmental PCB contamination for each.  


The FDA enforces a tolerance level in fish of 2 ppm, and overall 0.2 -3.0 ppm for all foods. PCBs in paper food packaging are limited to 10 ppm.
If fishing recreationally and you plan to eat your catch, check if any local fish consumption guidelines exist for your area. The EPA maintains a national database of fish and shellfish advisories issued by each state. These consumption advisories may recommend limiting the amount of a certain fish consumed, or from specific waters or water sources. As of 2011, five areas have advisories for PCBs in freshwater sources (Missouri, Minnesota, Maryland, Indiana, and District of Columbia) and nine states (Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, and Rhode Island) have PCB advisories for coastal waters.

Drinking Water

Under the Clean Water Act, industrial discharge of PCBs is prohibited. The goal is to reach zero contamination in drinking water, but the enforceable maximum level is 0.0005 part per million (ppm).  Additionally, industries are required to report spills or accidental releases to the EPA. 

Routine monitoring of PCB levels in drinking water require the water supplier to maintain the limit enforced by the EPA and must make the data regarding water quality and contaminants public. Every year, the EPA requires water suppliers nationwide to provide a Consumer Confidence Report (CCR), which will include information about water treatment and any known contaminants. These reports are available on the EPA website and should be available on your water company’s website. Additionally, the supplier is required to alert customers of increased levels of PCB contamination as soon as possible.
If you get water from a household well, the local health department should have information about ground water quality and contaminants of concern, but it is often a good idea to have your water tested by a certified laboratory if you are worried about PCB (or other) contaminants. The EPA’s Safe Drinking Water Hotline (800-426-4791) can provide additional resources in your local area.

How Can I Remove PCBs From My Water?

If your water has high levels of PCBs in it,  the water should also not be used to drink, prepare or cook food,  or given to pets for consumption without first treating it.  Fortunately, PCBs are effectively removed from water by filters that use activated carbon as part of their active filtration media blend.
Hydroviv makes it our business to help you better understand your water.  As always, feel free to take advantage of our “help no matter what” approach to technical support!  Our water nerds will work to answer your questions, even if you have no intention of purchasing one of our water filters.  Reach out by dropping us an email (hello@hydroviv.com) or through our live chat. You can also find us on Twitter or Facebook!

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Digging Into The Environmental Working Group Tap Water Database

Digging Into The Environmental Working Group Tap Water Database

Eric Roy, Ph.D.  |  Scientific Founder   

This past week, the Environmental Working Group (EWG) released a website where people punch in their zip code, and view contaminants found in their water.  As a company that uses water quality data to optimize each customer’s water filter, we applaud EWG for putting in the enormous amount of time & effort to build the database so the public can learn about their water.  Unfortunately, we are seeing that these data are being used to generate inflammatory headlines, which can leave consumers confused and unnecessarily panicked.   

We will be updating this blog post as more questions come in.  If you have your own question, please reach out to us (hello@hydroviv.com).  One of our water nerds will do their best to get back to you very quickly, even if it’s outside of our business hours.

Frequently Asked Questions 

Updated July 31, 2017

Are All Potential Contaminants Listed In The EWG Tap Water Database?  

No.  The EWG Tap Water Database pulls data from municipal measurements, but municipalities are only required to test for certain things.  Simply put, you can’t detect what you don’t look for.  One example of this can be seen by punching in Zip Code 28402 (Wilmington, North Carolina) into the EWG Tap Water Database.  GenX, a chemical that has been discharged into the Cape Fear River by Chemours since PFOA since 2010, is not listed, even though it’s been in the center of a huge topic of conversation for the past 2 months in the local media.

Why Is The “Health Guideline” Different Than The “Legal Limit?”

The two different thresholds use different criteria.  For example, the “Health Guideline” cited by EWG for carcinogens is defined by the California Office of Environmental Health Hazard Assessment (OEHHA) as a one-in-a-million lifetime risk of cancer, while the “Legal Limit” refers to the MCL which is the limit that triggers a violation by EPA.  The OEHHA's criteria are established by toxicological techniques, while the EPA limits are negotiated through political channels.  We wrote an article that addresses this topic in much more detail for those who are interested.

Why Am I Just Learning About This Now?

The EPA's Safe Drinking Water Act requires municipalities to make water quality test data public in Consumer Confidence Reports.  These reports are required to talk about the water's source, information about any regulated contaminants found in the water, health effects of any regulated contaminant found above the regulated limit, and a few other things.  As discussed before, the data in the EWG report use different criteria than the EPA, and it's hard for people to make sense of what's what.  

Are The Data Correct If My Water Comes From A Private Well?

No.  The EWG Tap Water Database only has data for municipal tap water.  Private wells are completely unregulated, and there's no requirement to conduct testing.  If you'd like us to dig into our additional water quality databases to help you understand likely contaminants in your private well, we're happy to do so.  We don't offer testing services, but we're happy to help you find an accredited lab in your area, give advice on which tests to run, and help you interpret the results!  We offer this service for free.

What About My City's Water Quality?

Hydroviv makes it our business to help you better understand your water.  As always, feel free to take advantage of our “help no matter what” approach to technical support!  Our water nerds will work to answer your questions, even if you have no intention of purchasing one of our water filters.  Reach out by dropping us an email (hello@hydroviv.com) or through our live chat. You can also find us on Twitter or Facebook!

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How Do I Filter Chromium 6 From Drinking Water?
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Lead:  What You Need To Know About This Toxic Heavy Metal With A Long History

Lead: What You Need To Know About This Toxic Heavy Metal With A Long History

Wendy Spicer, M.S.  |  Scientific Contributor   

Where Do I Find Lead?

Lead is a common ingredient in paints, gasoline, ceramic products, caulking, and pipe solder.  Most commonly, lead is used in the production of lead-acid batteries, ammunition, metal products (solder and pipes), and x-ray shielding. An estimated 1.52 million metric tons of lead were used for various industrial applications in the United States in 2004. The majority of that tonnage (83%) was used for lead-acid battery production.

While useful, lead is highly toxic. Federal, state, and local governments have worked to reduce the use of lead in many products over the past 40 years. Lead screening programs have helped to both prevent and treat exposed individuals.  Despite making great progress to create awareness of the dangers of lead exposure, roughly 25% of households in the United States with children under the age of six contain significant amounts of lead-contaminated paint, dust, or soil.

How Are People Exposed To Lead?

Exposure to lead occurs mainly via inhalation of lead-contaminated dust particles or aerosols and ingestion of lead-contaminated food, water, and paints. Adults absorb 35-50% of lead intake through drinking water and the absorption rate for children is potentially even greater.

Factors like age and physiological status increase the likelihood of absorption. In the human body, the greatest amount of lead is in our bones. Lead is also absorbed by soft tissue organs like the kidneys, liver, heart, and brain. The nervous system is very susceptible to lead poisoning. Prolonged lead exposure can cause headaches, poor attention span, irritability, memory loss, and apathy. Lead exposure is especially harmful to infants, fetuses, and children due to the developing nature of their brains.

What Are Adverse Health Effects Of Lead Poisoning?

Unfortunately, lead poisoning remains a common pediatric health problem in the United States. Pregnant mothers exposed to lead can transfer this heavy metal to their developing fetus.

The effects of lead exposure in children include, but are not limited to:

  • Lower IQ
  • Delayed or impaired neurological development
  • Decreased hearing, speech and language disabilities
  • Poor attention span, learning disabilities, and anti-social behaviors

Adults exposed to lead may experience gastrointestinal diseases and/or damage to the cardiovascular system, reproductive system, brain, kidneys, and liver.

One of the mechanisms by which lead induces toxicity in the body is that it essentially mimics other metals like calcium, leading to interference with many major biochemical processes. This interference can also inhibit enzyme activity, and cause cellular damage. It can often cause problems with bones, replacing calcium. Studies have shown that lead might also induce renal tumors in rodents, and is likely carcinogenic to humans as well.

How Can I Avoid/Minimize Lead Exposure?

From Lead Paint & Contaminated Soil

  • Keep your home well-maintained. If your home has lead-based paint, check regularly for peeling paint and fix problems promptly. Avoiding sanding lead paint, which makes lead airborne. If in doubt, hire a company with experience removing lead-based paints from homes
  • Wash hands and toys which may have come into contact surfaces or soil containing lead
  • Prevent children from playing on bare soil. Provide them with a sandbox that's covered when not in use. Plant grass or cover bare soil with mulch
  • Remove shoes before entering the house. This will help keep lead-based soil outside

From Contaminated Drinking Water

Hydroviv makes it our business to make your water safe. As always, feel free to take advantage of our “help no matter what” approach to technical support!  Our water nerds will work to answer your questions, even if you have no intention of purchasing one of our water filters.  Reach out by dropping us an email (hello@hydroviv.com) or through our live chat. You can also engage with us on Twitter or Facebook!

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How Do I Test My Home's Water For Lead?
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