Water Quality InformationWritten By Actual Experts


Legionnaires' Disease In Flint Tap Water: What You Need To Know

Eric Roy @ Monday, February 5, 2018 at 7:20 pm -0500

Eric Roy, Ph.D. 

A new report was released which confirmed that an outbreak of Legionnaires' disease in Flint, Michigan that killed 12 people and sickened at least 87 during 2014 and 2015 was likely caused by low chlorine levels in the municipal water system. It's another example of Flint's broader water crisis that resulted from widespread incompetence and fraud. We will add to this article as more questions come in.

What Is Legionnaires' Disease?

Legionnaires is a pneumonia, caused the bacterium Legionella pneumophila. Legionella pneumophila grows in water, and can enter the lungs through tiny water droplets. If a person doesn't have a robust immune system, they can become very sick, or even die.

Where Is Legionella Found?

According to Marc Edwards (A professor at Virginia Tech), Legionella is found in about 25 percent of all water samples collected nationally. It's a common bacterium, but it's usually kept under control in municipal water.

How Is Legionella Typically Controlled In Municipal Tap Water

In properly treated municipal water, Legionella is kept under control by chlorine-based disinfectants, so the bacterium cannot reach dangerous levels. In Flint, it appears that not enough chlorine was added to the water to leave enough residual chlorine to keep the bacterium under control, which is what caused the Legionnaires' outbreak in Flint.

Is Flint Still At Risk Of Legionnaires Disease?

According to Edwards, chlorine in Flint's water is now at the correct level, so the likelihood of Legionnaires' disease popping back up is minimal. It is our opinion at Hydroviv that concerned Flint residents should take every piece of advice issued by Dr. Edwards. If he says that there is enough chlorine, there is enough chlorine.

Other Articles We Think You'll Enjoy:
3 Years Of Hell: Reflections of a Flint Water Crisis Victim
Largely Unreported Water Quality Crisis Underway In Flint Michigan
Tap Water Chlorination: What You Need To Know

Absurdity Of The "Raw Water" or "Living Water" Craze

Eric Roy @ Wednesday, January 3, 2018 at 11:41 am -0500

Updated March 9, 2020 to include Vice Article

Eric Roy, Ph.D.

Last week, the New York Times wrote an article about about a new craze called "Raw Water" or "Live Water" where people are buying untreated water that has been collected from a spring, and sold for high prices (often more than $30 per bottle). Normally with this type of rubbish, we take the position of "If people are dumb enough to fall for this... they deserve to lose their money," but this is different because there is a real risk of harm to children and other unwilling participants. We've been getting asked a lot of questions about this article (and others like it), so we'll use this article to answer some of the frequently asked questions. To be clear, the focus of this article is on raw/living water portion of the article, not the company that makes a device that pulls moisture from the atmosphere.

What Are People Referring To When They Talk About Raw Or "Living" Untreated Water?

Simply put, this movement refers to raw water as water collected directly from a spring or other natural source and sold to people without the water being disinfected or otherwise treated. The "living" aspect of it refers to the algae and bacteria that are found in the untreated water. No matter what anyone tells you... water is NOT alive.

What Are Benefits Of Drinking Raw Water?

There are no scientifically documented benefits of drinking raw water. Proponents report "feeling x,y,z," which is another way of saying "placebo effect."

Why Is Drinking Raw Water Such A Terrible Idea?

Raw water can contain bacteria, viruses, parasites, and other things that can make you extremely sick. From mild stomach problems, to Giardia, and even sometimes death, there is no way to control biological contamination in raw water. Even if you have the unfounded belief that spring water is sterile (it's not), contamination can come from the bottler's hands, bottle, or anything that comes in contact with the water or container. Aside from the dangerous health impacts, raw water is extremely expensive. One company out of California charges $16 for a 2.5 gallons container of raw water. 

Why Does Raw Water Turn Green?

In non-disinfected waters... light + nutrients = algae growth. Spring water is often contaminated with nitrates & phosphates from human activities, so when that water is exposed to light, the algae are able to undergo photosynthesis and grow. That's why the water turns green... you're essentially setting up a terrarium in your bottle.

This is bad, because an algae bloom is providing a food source for potentially harmful bacteria to thrive.

Is Raw Water Free Of Chemical Contaminants?

No. Even seemingly pristine springs in remote areas can be contaminated by a variety of chemicals. This is because springs are fed by shallow groundwater, which is very susceptible to contamination from the surrounding areas. There are various websites that highlight areas where individuals have collected water from springs. Some of the springs are near to municipal source water, which knowingly must be treated and tested before being distributed to residents. Some raw water springs are near busy highways where petrochemicals runoff into surrounding groundwater. 

What's Wrong With The New York Times Article On Drinking Raw Water?

The focus of this article (over 90% of the content) was dedicated to the stories of the founders of the companies who stand to profit and supporters of the movement, not scientists or medical experts. The only scientist interviewed was quoted in two short paragraphs near the end of the article. This type of coverage gives the article the feeling of a supportive "puff piece" if you only take a cursory glance at it.

More Questions About Untreated Water?

We'll be updating as questions continue to come in. If you have one, please send it

Chicago's Drinking Water: Problems From Source to Tap

Hydroviv Water Quality Assessments @ Sunday, August 7, 2016 at 9:01 pm -0400

Eric Roy, Ph.D.  |  Scientific Founder

With water quality in the national spotlight, we get a lot of questions about water quality in major US cities. When Hydroviv optimizes a filter for a city's water, we look at a number of factors. This Chicago drinking water quality report gives a quick look at some of the things that went into our assessment, as well as some advice for people who choose not to use a filter in their home. **** We updated this article in March 2017 to add some information about chromium 6***

Chicago’s Water Source: Lake Michigan

Chicago draws its drinking water from Lake Michigan, a body of water that has been historically plagued with problems caused by industrial polluters. According to the most recent available Source Water Assessment prepared by the Illinois EPA, all 63 miles of shoreline were flagged as “Threatened”, because phenols (associated with industrial wastes from coal distillation and chemical manufacturing) were present at concentrations in excess of the allowable limit. Furthermore, a 2016 report prepared by the Illinois EPA categorizes 10 beach segments and several rivers that flow into Lake Michigan as “impaired” (according to Section 303(d) of the Clean Water Act), due to high concentrations of mercury, polychlorinated biphenyls, pesticides, herbicides, and other industrial chemicals like chromium 6. In addition to direct human inputs that impact water quality of Lake Michigan, biomass decomposition in the sediments often generates chemicals that make the water taste and smell bad.

How High Are Chromium 6 Levels In Chicago?

Between 2013-2015, Chicago reported that chromium 6 concentrations were, on average, 190 parts per trillion. Although chromium 6 is not regulated by EPA, the levels reported in Chicago's tap water are roughly 20 times higher than what is considered to be negligible risk.

Does Chicago’s Aging Infrastructure Contaminate Tap Water With Lead?

As most people are now aware, lead can accumulate in tap water that flows through lead-containing pipes, soldered joints, and plumbing fixtures. In Chicago, about 80% of water service lines city-wide are made of lead, so a large portion of the population should consider taking steps to ensure their family's safety.

Several investigative reports by large media outlets have been highly critical of Chicago’s lead testing program. The Chicago Tribune reported that many of the sites selected for lead testing were strategically selected because they are in areas with low risk for lead contamination, often at the homes of current and former water department. The City argued that recruiting water department employees to collect samples would would ensure that samples were properly collected. However, in a different story, published by The Guardian, Chicago city employees were criticized for using sampling “cheats” that make lead concentration seem lower than they really are.

In Chicago, only about 50 samples every 3 years are collected from homes and tested for lead citywide (most recently in 2015). In the 2015 Consumer Confidence Report (CCR) published by the city, 3 out of 50 sampling sites had lead levels that were over the 15 part per billion (ppb) EPA Action Level, and 10 percent of samples had lead concentrations over 9 ppb. While these data indicate that the city as a whole is in compliance with federal regulations, the EPA, CDC, and World Health Organization all agree that there is no such thing as a safe amount of lead exposure for children, so households with children should either get their water tested, or take steps to prevent exposure.

How Chicago Residents Can Minimize Chromium 6 & Lead Exposure 

Chromium 6

Unlike lead, which comes from lead-containing pipes, solder, valves, and fixtures, chromium 6 contamination comes from the water source itself. Therefore the only way to remove it from water is by using a high quality filter.  We are partial to the technology that we use in our system, but reverse osmosis will also work.


The City of Chicago officially recommends that residents take measures to reduce their exposure to lead in water used for drinking, cooking, and preparing infant formula:

  • Allow water to run for at least 5 minutes before using it for drinking or cooking
  • Only operate the faucet at moderate flow when collecting water for drinking, cooking, and preparing infant formula. This practice reduces the likelihood that lead-containing particles are swept into the water as it flows through the pipes.
  • Never use water from the hot water tap for drinking, cooking or preparing infant formula
  • Regularly remove and clean out their faucet aerator, because lead-containing particles can become trapped in the mesh and leach lead into the water as it flow through.

Hydroviv advises Chicago residents who choose not to filter their water for lead to take advantage of the city-sponsored lead testing program, where people can request a free test kit by calling 311.

As always, we encourage everyone to take advantage of Hydroviv's "Help No Matter What" technical support policy, where we answer questions related to Chicago's water pollution, drinking water, and water filtration, even if you have no desire to purchase our products. Drop us a line at support@hydroviv.com

Other Articles We Think You'll Love

5 Most Important Things To Know About Chromium 6 In Drinking Water
How To Filter Chromium 6 From Drinking Water
Summary of Problems With Chicago Tap Water

The Ins And Outs Of Drinking Water Regulation

Analies Dyjak @ Wednesday, August 29, 2018 at 2:06 pm -0400

Analies Dyjak  |  Policy Nerd

As emerging contaminants like GenX, PFOA, and PFOS have been popping up in news headlines all over the country, there has been some confusion as to how these unregulated contaminants are addressed at the federal level. While it may seem like the Unregulated Contaminant Monitoring Rule is in place to protect people from any and all emerging contaminants, it is not a hard and fast rule designed to expedite regulation -- rather, it is a lengthy process that unfortunately has not resulted in many real-world changes. This article discusses aspects of the Unregulated Contaminant Monitoring Rule that may surprise you, and explains how drinking water contaminants become regulated in the United States.

What Is The Unregulated Contaminant Monitoring Rule?

The Unregulated Contaminant Monitoring Rule (UCMR) was created as a part of the 1996 Amendments of the Safe Drinking Water Act (SDWA). SDWA regulates all public drinking water systems throughout the United States. It establishes National Primary Drinking Water Regulations for 90 contaminants, which are known as Maximum Contaminant Levels (MCLs). UCMR is the process that EPA uses to regulate contaminants. However, it has ultimately failed to create meaningful changes in water quality regulation.

How Are Drinking Water Contaminants Regulated In The United States?

Under the Safe Drinking Water Act, EPA typically follows a specific process when determining whether to regulate certain contaminants. Every 5 years, EPA publishes a list of 30 contaminants under the UCMR called the Contaminant Candidate List (CCL). Contaminants on this list are not regulated by National Primary Drinking Water Regulations, but are most likely present in public drinking water systems. These contaminants are placed on the list because they pose the greatest public health risk through ingestion of drinking water. EPA’s job is to whittle down the list of 30 to a handful of priority contaminants. Of that group of priority contaminants, EPA must make a regulatory determination for at least 5. EPA can choose to regulate all, some, or none of these contaminants.

What Is The Criteria For UCMR Regulatory Determination?

  1. EPA must determine that the contaminant does/does not cause adverse health effects in humans.
  2. EPA must determine if the contaminant will be present in public drinking water systems at an unsafe concentration.
  3. EPA Administrator must determine if regulating the contaminant will reduce adverse health effects in humans.

Does A Contaminant Have To Be On The CCL To Become Regulated?

No. EPA is not limited to regulating contaminants that are on the current CCL. EPA can consider other contaminants if they present a serious public health concern in drinking water.

Does the Unregulated Contaminant Monitoring Rule Set Drinking Water Standards?

No. UCMR/CCL contaminants are not subject to regulation. As a part of the UCMR program, EPA establishes Minimum Reporting Levels (MRLs) for each contaminant. National Water Quality Laboratory defines MRLs as ”the smallest measured concentration of a substance that can be reliably measured by using a given analytical method.” MRLs are not to be confused with Maximum Contaminant Levels (MCLs), which are enforceable regulatory thresholds for drinking water contamination.

How Are Contaminants Added To The Contaminant Candidate List?

In order for a contaminant to be considered for the EPA UCMR, it must be registered in the United States and have an analytical reference standard. The National Drinking Water Advisory Council and National Academy of Sciences are instrumental in determining which contaminants should be added to the list. After UCMR 2, EPA allowed for public participation in the CCL decision making process. Additionally, a contaminant can be added to multiple CCLs. For example, Perchlorate was on CCL 1, CCL 2, and CCL 3 before it was regulated.

Common Contaminants Considered Under The Unregulated Contaminant Monitoring Rule

The Third Unregulated Contaminant Monitoring Rule (UCMR 3) was published in May of 2012, and it included two chemicals that you might be familiar with. Perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) were both on Contaminant Candidate List 3. Both of these contaminants fall under a broad category of contaminants called PFAS, which are found in heat resistant and non-stick products such as Scotchguard, Teflon, and fire fighting foam. Unfortunately, neither PFOS or PFOA made it to the Regulatory Determination Assessment Phase, and both were removed from regulatory consideration.

What Is The Contaminant Candidate List?

The Fourth Unregulated Contaminant Monitoring Rule (UCMR 4) is the current batch of contaminants that’s under consideration for a regulatory determination. It was published in December of 2016, and includes nine cyanotoxins, two metals, nine pesticides, three disinfection byproducts, three alcohols, and three semivolatile organic chemicals.

Our Take:

While the 1996 Safe Drinking Water Act Amendments provided regulatory due diligence, they also created an unbearably extensive review process. Industrial manufacturing companies are unrestricted when it comes to developing new products, and chemicals pushed to the market are essentially “safe” until proven otherwise. This sort of regulatory approach comes at a serious cost to human health. Chromium 6 is the best example of the flawed regulatory framework for drinking water. The 2000 blockbuster movie “Erin Brockovich” discussed the dangerous toxicity of Chromium 6 and it still isn’t regulated, nor does it appear on the most recent Contaminant Candidate List (CCL 4). The most important takeaway from the EPA UCMR is that once a new CCL is published, the contaminants on the old list don’t just go away. Millions of Americans are forced to deal with adverse health effects because “scientific uncertainty” didn’t allow for regulation. This regulatory framework can't keep up with the thousands of new contaminants that are currently present in the environment.

Other Articles We Think You Might Enjoy:
Municipal Drinking Water Compliance: What You Need To Know
Why Is The Toxic Substances Control Act Important For Drinking Water?
Key Things To Know About Getting Your Water Tested

What You Need To Know About Groundwater

Analies Dyjak @ Sunday, January 21, 2018 at 11:53 pm -0500

Analies Dyjak  |  Hydroviv Policy Analyst

What Is Groundwater?

Groundwater is submerged water located among soils, cracks and pores, beneath the surface of the earth. Groundwater travels down gradient through geological formations and is stored in aquifers. Aquifers act as holding tanks for readily available drinking water. Rain patterns, hydrology, and ice/snow melt are the primary factors that affect how quickly a groundwater supply is replenished, also known as recharge. The recharge rate is how quickly aquifers are able to replenish the groundwater level after an influx of water.

Why Is Groundwater So Important?

It’s simple: It supplies drinking water to millions of Americans whose municipalities draw from groundwater sources (e.g. NYC, Tucson, Lincoln), as well as the 15% of people living in the U.S that use private wells as their drinking water source. Groundwater is also a major supplier of surface water in oceans, lakes, streams, ponds and wetlands. Crucial habitats and ecosystems are dependent on an influx of healthy groundwater, as well as surface water for public drinking water usage.

How Can Groundwater Become Polluted?

There are really two ways that groundwater can accumulate toxic chemicals:

  1. Natural-occurring chemicals: In some regions of the country, things like arsenic, radium, and uranium are naturally found in the rocks that come in contact with groundwater. 
  2. Man-made Pollution: Groundwater can also become contaminated by human activities including: agriculture, industry, landfills, localized pollution, and anything that involves discharging effluent into a surrounding waterway. Polluted water seeps through soil until it reaches the water table, where it can travel freely depending on the hydrology and permeability of an aquifer. Polluted groundwater then slowly travels through aquifers until reaching nearby surface water or being pumped through a well and consumed as drinking water.

Are There Federal Regulations That Protect Groundwater?

The Ground Water Rule was created in 2006 by the U.S Environmental Protection Agency to improve and inspect drinking water sources that may be potentially polluted by fecal contamination. This rule does not address human-made toxic and carcinogenic groundwater contamination. Additionally, the Ground Water Rule is specific to public water systems and excludes private wells.

The Federal Government does not oversee or have anything to do with regulating private wells. In fact, private wells aren’t even regulated by the Safe Drinking Water Act. This means that it’s at the discretion of the homeowner to determine if their private well water is safe for consumption. Testing private well water is extremely expensive and at times ineffective if the contamination type and concentration is continuously changing. Additionally, The Federal Government doesn’t regulate many of the contaminants in questions today.

How Can I Learn More About My Water?

If you have any questions about groundwater and regional water table information, we encourage you to take advantage of Hydroviv’s “Help No Matter What” approach to technical support, where we will help you, even if you have no desire to purchase one of our water filters. Truth be told, we have access to a much larger pool of water quality data than easily accessible to the general public. You can reach our water nerds by emailing hello@hydroviv.com or opening a Live Chat window in the bottom-left corner of this screen (we don’t use chat bots).

Other Articles We Think You'll Enjoy
Should I Worry About Arsenic Contamination If I Have A Groundwater Source?
What Do I Need To Know About Recent News Reports On Radium?
How Do I Know If My Well Is Contaminated?