7 Metals Everyone Should Test For

Why (and When) to Be Concerned about Heavy Metal Contamination in Drinking Water

Metals in Drinking Water_7 Heavy Hitters.png

There's no doubt that you've heard about heavy metals in drinking water. Even if you don’t watch the news or read the paper, you’ve probably heard folks talking about it.

While lead came to the forefront of national consciousness following the onset of the Flint, Michigan drinking water crisis, several other major metals can (and do) find their way into your tap water. Many of these naturally occurring contaminants are insidious threats that cannot be smelled, tasted, or seen. However, they can bioaccumulate–leading to detrimental health impacts, especially for the brain and nervous system.

Even if you are confident that your water is not affected by heavy metal contamination, we have created a short, but crucial list, of the seven heavy metals that should be on your radar.


What is manganese and how does it get into drinking water?

Manganese is a naturally occurring metal used in steel and corrosion-resistant aluminum alloys. It's also an additive in unleaded gasoline, pigment, plumbing materials, battery cells, matches, fireworks, fertilizer, a reagent in organic chemistry, an oxidizing agent, and a component of tobacco smoke.

How much manganese is safe in drinking water?

The U.S. EPA  recommends maintaining a manganese concentration at or below 50 parts per billion (PPB) in drinking water.

Why do we care about manganese in drinking water?

While manganese is an essential nutrient and is required by the human body in small amounts, exposure to high concentrations of manganese over many years has been associated with toxicityto the nervous system.

When to be suspicious?

You may notice a metallic taste, brownish-red color (that can stain clothing or appliances), or black slime if your water contains manganese at concentrations over 50 parts per billion (PPB).


What is lead and how does it get into drinking water?

Lead is a bluish-silver, naturally occurring metal that is fairly soft, highly malleable, and very resistant to corrosion. It is toxic to humans, animals, and most other lifeforms. It can enter your tap water three ways: 1) when household plumbing systems corrode, 2) when natural deposits erode into your water source, and 3) when industrial activity leaks lead into your water source.

How much lead is safe in drinking water?

While the EPA enforces a 15 PPB limit on lead in drinking water, no amount of lead is considered safe according to health research and the maximum contaminant level goal is zero.

Why do we care about lead in drinking water?

Even low levels of lead exposure can be dangerous. It accumulates in your body and has several toxic effects on your brain, liver, kidney, and bones. Children are especially vulnerable to developmental damage from lead poisoning.

When to be suspicious?

You cannot see, taste, or smell lead in your drinking water, but the age of your home can be a clue to your risk level. If you live in a house built prior to 1986, laboratory testing is a wise investment. It is also important to note that lead is legal in many fixtures and pipes. While permitted lead concentrations are lower than they were pre-1986, differences in water quality could lead to leaching.


What is arsenic and how does it get into drinking water?

Arsenic is a common element in the earth's crust and unfortunately, it’s quite toxic to humans.

Natural erosion of arsenic from soil and rocks is the most common pathway for arsenic to get into your tap water. It is also present in agricultural runoff from orchards and waste streams from metals and electronics industry activities.

How much arsenic is safe in drinking water?

The EPA recommends an MCL (Maximum Contaminant Level) for arsenic of no more than 10 PPB. However, the MCL recommendation remains arguably insufficient. A recent study demonstrated that arsenic levels well below the MCL have adverse health impacts–as children drinking well water with levels as low as 5 PPB had significant reductions in IQ and perceptual reasoning relative to children exposed to fewer than 5 PPB of lead.

Why do we care about arsenic in drinking water?

Short term effects of arsenic exposure include skin discoloration, stomach pain, nausea, vomiting and diarrhea. Long term effects include heart, lung, liver, immune, nervous system and reproductive disorders, diabetes and cancer of the bladder, lungs, skin, kidney, liver and prostate.

When to be suspicious?

There are no obvious signs of arsenic contamination. However, a Natural Resources Defense Council (NRDC) study reported that nearly 77 million Americans receive drinking water from systems that violate federal regulations for arsenic (> 10 PPB). They also noted that western states tend to have a higher incidence and elevated average levels of arsenic in their water systems. Additionally, it is estimated that 43 million Americans use private wells as their drinking water source. While community water systems are mandated to test for the toxic metalloid, routine testing for private wells does not usually include assessing arsenic levels.


What is chromium and how does it get into drinking water?

Cast into the spotlight by Erin Brockovich and the largest class action lawsuit to date, chromium occurs in both natural deposits, as well as in manufacturing processes such as electroplating and pigment factories. It can enter groundwater through erosion, mining waste, and industrial waste. The most common forms of chromium that occur in natural waters in the environment are: trivalent chromium (CrIII) and hexavalent chromium (CrVI)–the former of which is an essential nutrient, and that latter is a potent human carcinogen.

How much chromium is safe in drinking water?

While we are most concerned with hexavalent chromium due to its carcinogenic potential, there is no federal or state MCL specific to the hexavalent chromium. In stead, the national drinking water standard is set for “Total Chromium.” Both hexavalent and trivalent chromium are covered under the same drinking water standard because chromium may convert between CrIII and CrVI states in water and the human body depending on the environmental conditions. The EPA currently limits total chromium at 100 PPB.

However, at the time when the Total Chromium Maximum Contaminant Level was established (1991), hexavalent chromium associated with consumption of drinking water was not considered to pose a cancer risk.

2008 study by National Institutes of Health, however has led to new goals and recommendations. While the federal MCL remains at 100 PPB for Total Chromium, scientists at the California Office of Environmental Health Hazard Assessment recommended a public health goal of 0.02 PPB of hexavalent chromium in drinking water.

Why do we care about chromium in drinking water?

While there are many industrial uses for hexavalent chromium, human inhalation or ingestion of the chemical is known to cause cancer. It affects the human liver and kidney and is known to cause circulatory disorders and nerve damage.

When to be suspicious?

Like many metals in drinking water, chromium cannot be seen, tasted or smell–so knowing if it’s in your drinking water is challenging if you haven’t tested it. But if Erin Brockovich is in your local newspaper–it’s definitely time to raise your concern level.

Specifically concerned about testing for hexavalent chromium? Take a look at the Hexavalent Chromium Water Test.


What is copper and how does it get into drinking water?

Copper seldom occurs naturally in the water supply, but is one of the most commonly detected heavy metals in tap water. Corrosion of pipes, faucets and other plumbing fixtures is the most common source of copper in American homes. Changes in water chemistry can dissolve these metals from old pipes and deposit them in your drinking water. Running your water for a minute before drinking can reduce copper buildup at your tap.

How much copper is safe in drinking water?

Small amounts of copper are necessary to our health and the EPA has set a (non-enforceable) health goal of 1.3 PPM.

Why do we care about copper in drinking water?

Copper is an essential element for your health. However, too much of it especially among young children can cause vomiting, diarrhea and stomach cramps. Copper has also been associated with liver and kidney disease.

When to be suspicious?

Above 1 PPM, copper can cause a distasteful, metallic flavor in your water and leave blue-green stains on fixtures.


What is nickel and how does it get into drinking water?

Nickel is a naturally occurring element and is most often exposed to drinking water during mining and smelting activities.

How much nickel is safe in drinking water?

Currently, there are no EPA enforced limits on nickel levels in drinking water. Nickel was regulated from 1992 until 1995 with a level set at 100 PPB. However, the EPA removed the limits when the Nickel Development Institute challenged the methodology used to establish the Maximum Contaminant Level in a petition to the U.S. Court of Appeals.

Why do we care about nickel in drinking water?

Nickel can be a potent human carcinogen at high doses, in lower doses it can lead to decreased lung function and allergic reaction. About 10-20% of the U.S. population is sensitive to nickel.

When to be suspicious?

Nickel is another contaminant that doesn’t make itself easily known. If you think you are suffering from a nickel allergy–the best thing to do is test! Take a look at these Tap Score Packages–all of which include analysis for nickel (and the rest of the metals on this list too!)


What is aluminum and how does it get in drinking water?

Aluminum can come into contact with drinking water sources from natural formations underground or after use, as a water treatment coagulant and additive. It may also be released by metal refineries and mining operations.

How much aluminum is safe in drinking water?

The federal Secondary Maximum Contaminant Level (SMCL) for aluminum is set between 50 to 200 PPB– which means at or above these levels certain aesthetic effects (such coloration of water) can occur.

Why do we care about aluminum in drinking water?

Aluminum is a known nervous system toxicant with possible links to dementia and Alzheimer’s Disease

When to be suspicious?

While elevated levels of aluminum may result in colored water, concentrations of aluminum may be high without present any aesthetic effects.

Time to Test!

Now that you’re up to speed on what metals may be meddling with your water quality, we’ve got some good news for you!

Tap Score offers a water test designed explicitly for testing these (and other) important U.S. water contaminants that pose potential health risks. Learn more here, if you’re interested in investigating your own water.

We recommend that households test their water at least once every 3 to 5 years, especially if you have an old home or an old piping system.

Our team of chemists, water quality experts, and engineers are here to help if you have questions. We’re always standing by–just send us a message at hello@simplewater.us!