water test

What’s the Black Gunk on My Fixtures?!


Common Causes and Ways to Remove Black Slime on Your Faucets

Sludge...slime...gunk–whatever you call it, you probably don’t want it near your drinking water. It’s sticky, it often smells, and it can leave you puzzled. On Tips for Taps, we’ve already addressed common causes of white residue on fixtures, but now it’s time to come over to the dark side…welcome to the world of black residue.

Black residue on faucets and fixtures is a very common problem and we’re here to answer:

  1. What causes black slime?

  2. What are the health effects of black residue?

  3. How you can get rid of the black gunk?

What Exactly is the Black Slime on Your Faucet?!

Before we get into the exact cause of the gross gunk, let’s take a step back and look at what flows from the tap. Along with H2O, tap water often contains dissolved minerals. Two of these minerals are iron and manganese.

Iron and manganese are both naturally occurring, non-hazardous elements found throughout the earth’s crust. As water travels through soil and rock, it can dissolve minerals containing these elements and holds them in solution. Most drinking water contains traces of dissolved iron and manganese. While they don’t produce a health risk, elevated iron and manganese concentrations can be a nuisance in water supplies–producing an unpleasant taste and off-putting odor. Iron and manganese in drinking water are not known to have any health impacts. Because they are chemically similar, manganese and iron often create similar aesthetic problems–which includes black film, gunk, or sludge. The sticky, slimy, stinky residue can make itself at home nearly anywhere water flows in your home.

Whether it accumulates in the faucet aerator, around the tub drain, inside the toilet tank, or even inside your tea kettle–black slime is usually due to bacteria that feeds on oxidized iron and manganese in your water supply.

Is Black Slime on Fixtures Dangerous for Your Health?

There are no federal primary drinking water standards set for either manganese or iron because their presence in drinking water is not associated with health effects, however there are regulations regarding secondary standards for both. These standards are set to fight nuisance problems (e.g. black slime) and aesthetic issues (i.e. taste, odor, color).

Manganese and Manganese-related Bacteria:

The U.S. EPA  recommends maintaining a manganese concentration at or below 0.05 parts per million (ppm) in drinking water. Neither manganese nor manganese-related bacteria are considered dangerous at the levels that typically occur in drinking water. Manganese exposure from water and food (our largest source of exposure) are not known to have a negative health effect. In fact, manganese is an essential nutrient and is required by the human body in small amounts. Similarly, manganese bacteria is categorized as non-pathogenic.  Some evidence does suggest that if manganese is inhaled in high concentrations over time, it can lead to neurological issues–but this is rare and not caused by drinking water.

Iron and Iron-related Bacteria:

Like manganese, iron (and related bacteria) are not dangerous to human health. Drinking water standards for iron are set based on potential nuisance and/or aesthetic issues. The EPA recommends a secondary maximum contaminant level (secondary MCL) of iron in tap water at 0.3 ppm.

While iron-related bacteria often produce reddish-brown slime, when they react with naturally occurring tannins (organic matter from vegetation) it frequently forms black, sludgy residue. This is why many people spot black slime inside their tea pots–as tea contains a high concentration of tannins.

How to Get Rid of Black Slime on Your Fixtures

Although black slime may have a few other causes  (i.e. oxidizing pipes or dissolving rubber seals in your water heater), iron- and manganese-related bacteria are the common culprits (especially in homes supplied by a private well). Subsequently, if you want to know how much manganese or iron are in your tap water, you must test.

Once you’ve confidently identified the presence of iron- or manganese-related bacteria, it’s time to solve the problem once and for all. Unfortunately, online research often points you toward temporary treatment measures, rather than lasting fixes. The temporary “fixes,” such as replacing pipes and regularly cleaning the affected area, will cost you time and money–but will not solve the problem. Because the root of the problem stems from the water supply itself, you must focus your attention there (i.e. the cause) rather than the slime (i.e the effect).

If you are on a private or shared well:

Shock chlorination might be the answer. Take a look at our comprehensive, step-by-step guide to shock chlorination here. Just remember: It is nearly impossible to kill all of the iron- and manganese-related bacteria in your well water system. The bacteria will eventually re-grow, so you may want to repeat the treatment from time to time. Feel free to reach out at hello@simplewater.usif you have any questions about the shock chlorination process!

If you are on a municipal water supply:

If the source of your bacterial problem is your city water system, then using at-home chlorination will not have the desired effect. The best treatment method depends on a variety of factors–such as the concentration and form of iron and manganese in the water, whether or not iron- or manganese-related bacteria are present, and how much water you need to treat. Each of these factors will help determine the most efficient/cost effective treatment method for you. Several treatment options include:

  1. Ion exchange water softener

  2. Sequestering

  3. Oxidizing filters

There you have it. The black sludge at the bottom of your drain is no longer a mystery. While certainly alarming to find, it shouldn’t leave you scared. It’s not as spooky as it seems–just a little stinky and slimy.

If you have black slime on your fixtures and want to test your water, send us a message (hello@simplewater.us) and our team of chemists, engineers, and water treatment experts can point you in the right direction! 























Why People Test Their Water?


There are limitless reasons why people test their drinking water. Whether you want to find the cause of an unusual color or smell, to choose an appropriate water treatment system, or are simply curious about what flows from your tap–beginning the process can be daunting. There are a myriad of testing options across a range of price points, which can make you wonder: what’s the right choice?

We, at Tap Score, are here to give you the inside scoop about when DIY kits are the right choice and when laboratory testing is the way to go.

Why You Might Want to Test Your Water

Changes in Water Color

People often start thinking about testing their water when they notice a visible change in water quality. For example, if your water has turned a strange color. When you’re used to seeing crystal clear water flowing from the faucet, yellow or brown water can certainly be alarming. The good news is that most of the time discolored water does not pose a significant health risk. For details about common causes of discolored water, what it could mean for your health, and ways to fix it take a look at the following articles:

  1. Why Is My Water Yellow?

  2. Why is My Water Brown? (or reddish brown)

Once you’ve gathered some handy Tips for Taps, we still recommend that you investigate changes in your water quality.

There are several different options when it comes to finding the source of the problem. There are both DIY kits and laboratory testing options. As you might have guessed, these two options have different capacities. DIY kits do not typically have detection limits as low as laboratory testing; they can usually provide an indicator of presence or absence as opposed to an accurate concentration at low levels.

For yellow or brown water, a good first step is our Iron-oxidizing Bacteria DIY test. However, changes in water color can happen for a variety of other reasons, and laboratory testing may give you a more complete picture. Take a look at our Yellow Tap Water testing package.

Changes in Water Smell  

Whether it smells like rotten eggs or chlorine, odd smelling water is another instance where at-home testing may be a good first step.

A few good options to help identify causes of smelly water include:

For Chlorine or Bleach-Like Smell: Chlorine Strips are a great way to get an idea of how much chlorine is in your water. Because laboratory testing for chlorine has specific preservation requirements due to its volatile nature, it can be quite expensive. Testing directly at the tap is a much more affordable route, that will give you a good sense of how much Total and Free Chlorine are in your water.

For Rotten Egg Smell: Rotten egg smell is most often attributed to sulfur. Tap Score’s Hydrogen Sulfide Bacteria DIY test can help determine if this is the culprit.

However, if you are looking for more thorough answers (as well a treatment recommendations), our our TapScore home water testing packages will help. Our national team of certified laboratory scientists, engineers, and health experts provide each customer with a personalized Tap Score Water Quality Report.

Before Installing A Water Treatment System:

This is an instance of when we strongly recommend laboratory testing. Treatment systems come in a variety of shapes, sizes, and prices–and before you take the plunge, you should ask yourself: what problem needs treating? Because treatment systems can be targeted towards filtering specific contaminants, how do you know the right system to choose if you don’t know what’s actually in your water?

Filtration units can set you back thousands of dollars (depending on the unit), so you want to be sure that you’re not paying for something you don’t need.

Our Tap Score testing packages will give you a great sense of your overall water quality, allowing you to make an informed decision. With every water quality report, we provide a personalized and unbiased list of treatment options certified by NSF and WQA.

Local Water Quality Issues:

From hurricanes to wildfires to floods–natural disasters can disrupt water quality for months. Immediate danger does not subside once fires are extinguished or flood levels recede. Contaminants can find their way into drinking water supplies–leading to a multitude of health and safety risks. Whether it’s mold, bacteria, or any other contaminant–this is a good time forlaboratory testing, as it will help keep you and your family safe.

Concerns About Infrastructure:

It’s no secret that american infrastructure is failing. In fact, the 2017 Infrastructure Report Card by the  American Society of Civil Engineers (ASCE) granted U.S water infrastructure a measly “D” (on an A through F scale).  This comprehensive assessment of the nation’s 16 major infrastructure categories evaluates their current state and indicates that  the U.S. must invest approximately $3.6 trillion in overall infrastructure repairs and improvements by 2020 to reach acceptable standards. Unfortunately, there is no timetable for if this will happen.

Additionally, 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 and even though the concentrations are lower post 1986, the water quality could lead to leaching. We, at Tap Score, recommend our Essential City Water test if you live in an older home or you are served by old infrastructure.

New Baby, New Concerns

Having a baby is an exciting time, but it brings with it a whole new set of safety concerns. Young children are considered the most vulnerable population group. Children typically drink more water per pound of body weight than adults. This leads greater exposure and subsequently, greater risk. Because their bodies are still developing, toxic chemicals cause more harm to growing tissue.

A common concern for parents with a new baby is too much nitrate–leading to methemoglobinemia (also known as blue baby syndrome). If you have young children in your home, laboratory testing a sure-fire way to know if they are at risk. Read more on our post about Taps for Tots.

Perhaps You’re Just Curious

With knowledge comes power–the power to make informed decisions and to help keep you safe. Laboratory testing is a great way to get a sense of your water’s overall chemistry. Many contaminants–such as lead and arsenic–may be lurking in your water that you can’t smell, taste or see. Home DIY kits and home test trips fall short. Our water testing packages can test for hundreds of contaminants that you didn’t even know were putting you at risk!

Beware of the Free Lab Water test!

If you are interested in water testing, we can’t emphasize enough that you should stay away from “free” water tests. Don’t be fooled–”free” water testing is a scam. Remember the adage, “if it seems too good to be true, it probably is.” If someone is offering you a free water test, be very suspicious, as it is highly likely that these are the same people trying to sell expensive (and perhaps unnecessary) water treatment products or bottled water subscription.

A Final Word on Water Testing:

Whether you want to investigate a change in water quality or if you are just curious about what flows from your tap–testing your water is the way to go. While some instance are suitable for testing at home (such as testing for chlorine), most of the time, laboratory testing is the smart choice. For more information about any of our laboratory test packages, send us a message at hello@simplewater.us and our team of chemists, engineers, and treatment experts will be standing by!








Arsenic and Water Treatment


Testing your water and detecting arsenic at any concentration is never good news, but rest assured there are reliable steps you can take to safely protect your health by treating your water.

Arsenic is a well known human carcinogen that occurs naturally in groundwater. Public water systems are regulated by the US EPA to never exceed 10 parts per billion of arsenic concentration, but health research demonstrates that no level of arsenic is safe to drink. In fact, EPA proposed 5 ppb as a standard in 1996. Levels this low have shown statistically significant impacts on IQ among children, but economic requirements for setting maximum contaminant levels have kept the official threshold higher than levels harmful to health.

If you want to remove arsenic from your tap water, there are a few important things you need to know. We’ve broken it down into a simple FAQ sheet.

What is “total arsenic”?

Your total arsenic concentration is generally comprised of two common oxidation states (or forms), arsenic III (aka arsenite) and arsenic V (aka arsenate). In drinking water, we are usually worried about Arsenic V. If you drink water with Arsenic V, however, it is quickly converted to Arsenic III–which is more toxic and bioreactive inside your body.

Does the source of my water make a difference?

The source of your water makes a difference to the amount of arsenic III versus arsenic V in your water. This matters for choosing appropriate treatment options. If your water is coming from a community or public water treatment system and that treatment system uses chlorine for disinfection, then you can generally assume that most arsenic (if found in your water) is in arsenic V form.

If your drinking water comes from a groundwater well and there is no chlorination (or other oxidative step) installed as existing treatment, then you can’t be sure what fraction of your total arsenic is comprised by arsenic III or arsenic V. A type of water quality test called Arsenic Speciation can help determine if your total arsenic is mostly arsenic III or arsenic V.

Does reverse osmosis remove arsenic?

Reverse osmosis water treatment technology can reliably remove arsenic V but does not reliable remove arsenic III. If your water’s arsenic is all or mostly arsenic V then you can reliably use reverse osmosis technology to remove arsenic from your drinking water.

If your water’s arsenic is mostly comprised of arsenic III then you will either need a special treatment technology OR you will need an additional treatment step to oxidize arsenic III to arsenic V before using reverse osmosis for treatment.

Reverse osmosis is not the ONLY method of arsenic removal, companies like AdEdge and others provide other ion exchange and filtration-based treatment options.

Do I need whole home water treatment to remove arsenic?

Whole home water treatment for arsenic removal is NOT necessary unless you regularly drink water from many of the taps in the house. You can safely choose to treat only the water you ingest or use for drinking by installing a Point of Use filter at your main water source in the home or building (like under your kitchen sink). This can save thousands of dollars, because according to public health research, arsenic does not show an appreciable impact on health via showers, tubs, or brushing teeth (unless concentrations are enormous, >1,000 parts per billion).

It is important to note that no treatment technology can ever truly remove a contaminant 100%. Water treatment with reverse osmosis can remove arsenic as much as 98% however. Most professionals and public health research suggests trying to reduce arsenic intake by drinking water to less than 3 parts per billion. 

Get in touch with the Tap Score team here if you have further question about your water quality or about treating arsenic in your water.

Is My Water Radioactive?

No, we’re not asking if your water is turning you into a monster...radioactivity in water is a real threat.


Radioactivity is not scary in the way that movies and popular culture depict. Sadly, it is much stealthier–it can cause irreparable damage to your body that stays hidden for years, or even across generations.

We are exposed to natural radiation in our daily lives (an example being bananas!). Radioactive particles, or radionuclides, are a part of the natural world–they exist in plants and animals usually as potassium-40 or radium-226. However, increased exposures to radiation occurs in our water or air when nuclear power plants, mining operations, or laboratories release radioactive materials into the environment.

Tap Score has written this guide to help you understand what radiation really is, what the associated risks are, and what types of radioactive elements are common in drinking water, and how they should be treated.

Getting the Terms Right: What Are Radioactive Particles?

Radiation refers to any process that emits energy in the form of electromagnetic waves or particles, such as light or sound. When we talk about radioactive particles, we are specifically referring to ionizing radiation. Ionizing radiation is radiation that causes an atom or molecule to lose electrons and become charged–this charged molecule is called an ion.

Radioactivity is “the act of emitting radiation spontaneously”. An atom can be radioactive when it is unstable and wants to dissipate some of its energy to reach a more stable form.

The different “forms” of stable or unstable radioactive elements are called isotopes. We distinguish these radioactive isotopes by their mass, which is attached to the end of the element name, like Uranium-238.

Radioactive Particles in Water are Alpha or Beta

Radioactive particles are present in rocks and soil, which usually serve as the path to enter groundwater. The two types of radioactive particles present in water are alpha and beta particles–which are present in different sizes and element types.

Alpha particles consist of two protons and two neutrons. Common examples in water are radium-226, radon-222, uranium-238, polonium-210, lead-206. While alpha particles cannot penetrate skin from the outside, they are active in the body and can cause damage if consumed.

Beta particles are radioactive particles made up of one electron. Common examples in water are strontium-90, potassium-40. Beta particles can penetrate the top layer of skin and cause burns. Beta particles likely cause more damage inside the body than alpha particles–they have more energy and can therefore travel farther into body tissue than alpha particles can.

Radioactive Particles in Water

We are concerned about naturally occurring radiation and additional radioactive particles that enter water from rock formations near mining sites, nuclear power plants, or laboratories. Radon, in particular, occurs in gaseous form in soils and can dissolve into groundwater or enter homes as a gas through the basement. Exposures to radon in both air and water are seriously concerning–here, we focus on exposure through drinking water.

Prevalence of Radioactive Particles: Private Wells at Higher Risk

The Environmental Protection Agency (EPA) sets standards for radionuclides in city treated drinking water, but if you are a well water user you are at a much higher risk for radioactive contamination. In a study conducted by the United States Geological Survey (USGS) on radioactive particles in well water, the most abundant element above the EPA health threshold was radon, appearing in 65% of wells. Uranium was present in only 4% of the wells– which makes sense because radon is produced as uranium decays.

Signs that You Have Radioactive Particles in Your Water

Unfortunately, there are no obvious signs of radioactive particles. The only way to identify radon and uranium in your water is through testing. As a company that tests water, we’ve made this pretty easy–our essential test and advanced well water tests include uranium testing, we offer a specific test for radon, and we’ve developed a full radiation test that measures Gross Alpha and Gross Beta particles.

How do radioactive elements in water affect my health?

Unfortunately, the effects from radioactive particles in water can cause cancer and even be fatal. While our skin can protect us against alpha particles in the environment, exposure to radiation through water is particularly dangerous because radioactive elements damage tissues and organs.

Radioactive particles cause damage by breaking chemical bonds essential to our body’s functioning. Changing bonds in a molecule drastically alters its ability to function. Radioactive particles can cause cells in our body to die or slow down their reproduction. If a group of cells crucial to bodily function dies, the effects can be fatal.

After the bonds of normal cells in the body are broken, they release electrons. This can create a chain reaction that can eventually impact DNA molecules. Mutations are consequent to DNA damage, which lead to cancer. And, if germ (sex) cells are mutated, the cancer can be transmitted to children long after the initial exposure. The results of a study done in Iowa show that towns with radium-226 present in their water supply had higher rates of lung, bladder, and breast cancer.

How to protect yourself from Radioactive Particles in Water


There are two primary treatment options for radioactive particles in water–carbon filters and ion exchange:

  • Carbon filters are one option for removing radium and strontium from drinking water. However, if radon is also present the filter must be changed very frequently–carbon can adsorb radon and lead to higher radiation exposure if radon is left to build up. As radon particles accumulate, they may fall out of the filter and back into the water stream.
  • Ion exchange can be used to treat uranium. However, ion exchange creates backwash that contains high concentrations of radionuclides, which makes disposal a concern.

Ultimately, the type of treatment you choose depends on what type of radiation problem you have.

Test Before You Treat

Though these health effects may be frightening, they can be prevented or at least mitigated.  Tap Score offers a Full Radiation Water Test to measures alpha and beta particles as well as a specific Radon Test to help you determine if you are at risk. We’ll also help you choose the right treatment options if you discover a problem. Picking the right filter matters to ensure you properly treat your water.

Have more questions? Feel free to email us at hello@simplewater.us! 







Glyphosate: Most Common Herbicide Puts Tap Water at Risk

Read our quick guide on what you need to know about glyphosate (aka Roundup) and tap water.


Have you ever wondered how the food production industry has been able to keep up with feeding our world’s rapidly growing population? Or perhaps, what your food goes through before it lands on the shelf at the grocery store? The answer to both questions, in part, involves Glyphosate. Glyphosate, more commonly known as “Roundup”, is an herbicide created by Monsanto.

The discovery of glyphosate in 1973 transformed Monsanto’s operations and the global food industry. As the first non-selective herbicide invented, glyphosate can kill any weed in its path, unlike previous herbicides that could only kill specific weeds. Put into production and first commercialized in Malaysia and the UK in 1974, Roundup subsequently became the most widely used agricultural chemical in history. A shocking 9.4 million tons of glyphosate have been sprayed onto fields worldwide since 1974.

The use of Roundup has been under extreme scrutiny recently. There are around 2400 lawsuits and counting against Monsanto, claiming that glyphosate causes cancer. The first case is scheduled to start in June.

We, at SimpleWater, have created a quick guide on understanding exposure to glyphosate through drinking water: how can glyphosate end up in your water, and is glyphosate harmful to humans?

How does glyphosate end up in drinking water?

Several studies suggest that glyphosate, despite its affinity for soil, can make its way into aquatic environments and drinking water wells. Once glyphosate enters water, it becomes stable and does not degrade easily. As a result, glyphosate can enter surface and subsurface water through two main pathways:

  • Roundup windblown into bodies of water adjacent to sprayed fields
  • Irrigation runoff from sprayed fields into distant bodies of water

Humans are most likely to be exposed to glyphosate through direct inhalation and skin contact, crops treated with Roundup, or drinking water contaminated with it.

Of the 2400 lawsuits underway, most people had direct contact with Roundup by using it to spray their homes, schools, and farms. However, one drinking water facility in Florida and two in Louisiana reported glyphosate levels (9.00 parts per billion (ppb), 8.35 & 5.05 ppb respectively) above the Environmental Working Group’s health recommendation of 5ppb. 5 ppb is a much more stringent health goal than the Federal EPA’s legally enforced Maximum Contaminant Level (MCL) of 700 ppb (or 0.7mg/L).

The EWG did not flag Florida and Louisiana for water quality violations. Rather, these results were highlighted because their facilities reported concentrations above the World Health Organization and EPA’s definition of “acceptable risk” for carcinogens–a one-in-a-million chance of developing cancer.

These two facilities serve around 8600 people, all of whom could now potentially have a higher risk of developing cancer than the general population.

What does glyphosate mean for your health?

Glyphosate is classified as a Group 2A chemical by the International Agency for Research on Cancer (IARC), meaning that it is “probably carcinogenic to humans”. The IARC came to this conclusion after many studies conducted on rats in combination with human evidence from accidental exposure. The little data that does exist on humans shows an association for non-Hodgkin lymphoma, and there is sufficient evidence of carcinogenicity in animals.

Glyphosate is also associated with endocrine disruption, harm to fetal growth, and damage to kidneys and the gastrointestinal tract.

Despite the evidence from the IARC for the carcinogenicity of glyphosate, Monsanto still claims that Roundup is safe and will not cause cancer. Monsanto’s studies, however, were conducted or commissioned by pesticide companies in support of Monsanto’s goals and are kept hidden from the public.

How can you protect yourself against glyphosate?

Perhaps the lawsuits against Monsanto will be successful and Roundup will eventually come off the market, but in the meantime, SimpleWater recommends that you protect your water to protect yourself.

The best ways to protect your health and water are:

  • Do not use glyphosate-based herbicides (especially if you are on well water)
  • If you do use herbicides of any kind, do not overuse them in order to avoid run-off
  • Try to limit consumption of crops likely sprayed with glyphosate (unfortunately, this means most non-organic foods)

While the risk of glyphosate in your tap water is likely low if your water is treated by a municipality, well water owners near lawns, gardens, and farms that use herbicides may want to test their water for glyphosate. Tap Score offers a glyphosate test to add-on to any of our essential or advanced water testing kits.

For more information about other water quality issues, take a look at our blog, Tips For Taps, or email us at hello@simplewater.us!