Common Tap Water Contaminants and other Parameters

Is your water safe to drink? What are the most common tap water contaminants and substances? Which ones are potentially bad for your health and which ones are good? What do I really need to filter from tap water?

Our team of chemical engineers and water experts created a list of tap water contaminants and substances to help answer these questions.

Common contaminants and other substances in tap water

What are the most common contaminants in tap water? Which substances should you worry about?

Here’s the list of tap water substances including where they come from, limits and potential risks.

Chlorine (Cl)

TAPP filters remove 95% of chlorine.

Chlorine is added to tap water to kill bacteria and viruses and keep it safe for drinking. The amount of chlorine added depends on the local quality of the water, climate (temperature), maximum distance to the tap and other variables.

A side effect of chlorine is unfortunately that the tap water may taste and smell poorly. To ensure the tap water is safe to drink the recommended free chlorine is 0.5mg/L at each household tap. The maximum allowable chlorine levels (Maximum Allowable Level = MAL) in drinking water is 4 parts per million (4ppm) and pose no known or expected health risk. This includes an adequate margin of safety. However, bi-products from chlorine such as VOCs and THMs may cause health issues long term. TAPP Filters remove 95% of chlorine and close to 100% of chlorine by-products.

Note: Sometimes Chloramine is added instead of Chlorine. TAPP is equally efficient in removing chloramine.

Chloride (Cl-)

Chloride does not need to be filtered.

Chloride is a natural mineral that helps maintain proper blood volume, blood pressure, and pH of body fluids.

However, excessive Chloride in water may cause salty taste. The Maximum Acceptable Level (MAL) is 250 mg/L. Chloride is a natural component of tap water without any negative health aspects. Chloride is part of the chlorification process of drinking water from harmful bacteria and viruses.

Nitrate (NO32-)

TAPP filters reduce 70-90% of Nitrate.

Nitrate is one of the most important compounds for plants. It is a rich source of Nitrogen, which is essential for plant growth.

Nitrate has no known harm effect on the human body unless it’s extremely high amounts. However, excessive Nitrate in water can cause Methemoglobinemia, or \”blue baby\” disease (Lack of oxygen). The Maximum Accepted Level (MAL) is estimated to be 10 mg/L. Nitrate originates primarily from fertilizers, septic systems, and manure storage or spreading operations.

Sulfate (SO42-

Sulfate does not need to be filtered.

Sulfate is the result of the water passage through mineral rocks. Sulfate might help in protein synthesis.

Excessive sulfate may also contribute to scale buildup in water pipes similar to other minerals and may be associated with a bitter taste in water that can have a laxative effect on humans. The MAL is estimated to be 500 mg/L. Sulfates exist naturally in groundwater that is rich in minerals.

Bicarbonate (HCO3-)

Bicarbonate does not need to be filtered.

Bicarbonate is the result of Carbon dioxide (CO2) dissolution in water. Bicarbonate is an acid buffer; it regulates the pH of your body.

However, high concentration of Bicarbonate may pull calcium from water. The Recommended range is 30 to 400 mg/L. Bicarbonate is the principal alkaline constituent in almost all water supplies. Mineral water in particulate often contains high concentration of Bicarbonate.

Phosphate (PO43-)

TAPP filters remove 70-90% of Phosphate.

Phosphate, like nitrate, is essential for plant growth. Phosphate is a strong corrosion inhibitor.

High concentration of Phosphate has not shown any health risks for human. The MAL is estimated to be 6.7 mg/L. Public water systems (PWSs) commonly add phosphates to the drinking water to prevent the leaching of lead and copper from pipes and fixtures.

Calcium (Ca2+) & Magnesium (Mg2+)

These essential minerals should not be filtered.

Calcium and magnesium exist naturally in water. They are essential minerals for all living beings.

Calcium not only helps in bones and teeth strengthening, but also decreases heart conditions. Magnesium on the other hand, is essential for membrane function, protein construction and muscle contraction. No evidence is available to document harm to human health from hard drinking water. Perhaps only, a high magnesium content (hundreds of mg/l) coupled with a high Sulphate content may cause diarrhea. The Recommended Daily Intakes (RDI) for Calcium and Magnesium are 1000 mg and 400 mg.

Sodium (Na+) & Potassium (K+)

These essential minerals should not be filtered.

Potassium and Sodium occur naturally in all water (groundwater, rainwater, etc). They are the main responsible elements for nerve stimulus fluid levels control and blood pressure regulation. They also prevent cardiovascular disease.

Sodium and potassium exist in the earth’s crust and are not considered toxic. They are common elements in the natural environment and are often found in food and drinking water. High level of Sodium may increase blood pressure and salty taste. On the other hand, Potassium intoxication by ingestion is rare, because potassium is rapidly excreted in the absence of pre-existing kidney damage. The Recommended Daily Intakes (RDI) for Sodium and Potassium are 2400 mg and 3500 mg.

Lithium (Li+)

TAPP filters reduce 70-90% of this element.

Lithium occurs naturally in drinking water. Although it exists at very low rate, Lithium is actually an antidepressant component.

Lithium can be found in continental brine water, geothermal waters, and oil-gas field brines. It has shown no harmful effects on human body. The MAL is 0.7 mg/l.

Fluoride (F-)

TAPP filters reduce up to 80% of Fluoride.

Fluoride is the result of water passage through rocks. At its normal rate, Fluoride reduces teeth cavities.

Fluoride comes from fluorine, which is a common, natural, and abundant element. Excessive exposure to fluoride has been linked to a number of health issues such as bone disease and parathyroid gland damage. The MAL is estimated to be 4 mg/L.

Heavy Metals (Lead, Copper, Arsenic, etc)

TAPP 2 filters reduce 90% of Heavy Metals.

Heavy metals such as Lead, Copper and Arsenic exist naturally in nature. The benefits of these metals are not really accentuated.

Most of the point sources of heavy metal pollutants are industrial wastewater from mining, metal processing, tanneries, pharmaceuticals, pesticides, organic chemicals, rubber and plastics, lumber and wood products. Bioaccumulation of these metals can cause serious health problems related to central nervous function, the cardiovascular and gastrointestinal (GI) systems, lungs, kidneys, liver, endocrine glands, and bones. Therefore these are often listed among the most common tap water contaminants even though they are unusual in Europe.

The maximum values of Heavy Metals should be less than a couple of ug/L. TAPP 2 is specifically tested for removal of heavy metals including lead.

Volatile Organic Compounds (VOC)

TAPP filters removes 95% of these compounds.

VOCs such as pesticides and herbicides exist mostly in agricultural water. They are responsible for the smell and/or the color of water.

Once VOCs get into your water supply, they can be ingested if your water is not adequately filtered. Every chemical is going to be different, obviously, but there are many symptoms that can be caused by these hydrocarbons. While some VOCs cause no known health effects, others are known to be highly toxic. Their effects vary and are dependent upon several factors including, most notably, length of time and level of exposure. The VOCs concentration should be less than a couple of ug/L. Common symptoms associated with exposure to VOCs include eye, nose, and throat irritation, nausea/vomiting, allergic skin irritation, dizziness, and visual disorders.


TAPP filters 95% of pharmaceuticals.

The ubiquitous use of pharmaceuticals has resulted in a relatively continuous discharge of pharmaceuticals and their metabolites into wastewater.

Pharmaceuticals may be released into water sources in the effluents from poorly controlled manufacturing or production facilities, primarily those associated with generic medicines. Current observations suggest that it is very unlikely that exposure to very low levels of pharmaceuticals in drinking-water would result in appreciable adverse risks to human health, as concentrations of pharmaceuticals detected in drinking-water are several orders of magnitude lower than the minimum therapeutic dose.


TAPP filters removes 100% of microplastics.

Microplastics are the result of plastic waste in different kind of sources.

When plastic waste enters waterways, it does not degrade as natural materials do. Instead, exposure to the suns rays, reaction to oxygen, and degradation from physical elements such as waves and sand cause plastic debris to break down into tiny pieces. The smallest microplastics identified in public reports is 2.6 micron. The precise effect of microplastics on human health is difficult to determine for a variety of reasons. There are many different types of plastics, as well as different chemical additives that may or may not be present. WHO claims the health risk of microplastics is low but better to be safe than sorry. TAPP 2 removes all microplastics larger than than 2-microns.

Total Suspended Solids (TSS)

TAPP filters removes 100% of TSS.

Total suspended solids (TSS) exist in all water sources. They can include a wide variety of material, such as silt, decaying plant and animal matter, industrial wastes, and sewage.

Total suspended solids (TSS) are particles that are larger than 2 microns found in the water column. They are rarely found in drinking water. However, high concentrations of suspended solids can cause many problems for stream health and aquatic life.

Pesticides & Herbicids

TAPP filters remove 95% or more of common pesticides.

Pesticides are substances that are meant to control pests, including weeds. The most common of these are herbicides which account for approximately 80% of all pesticide use. Most pesticides are intended to serve as plant protection products (also known as crop protection products), which in general, protect plants from weeds, fungi, or insects. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species.

Adsorption process using activated carbon is among the most effective techniques for the removal of pesticides in the treatment of drinking water.

Bacteria & Viruses

TAPP filters reduces Bacteria and Viruses but does not remove all.

Natural water represents an adequate environment for bacteria and viruses to grow.

Bacteria and viruses exist naturally in water. Generally the chlorine in tap water will kill all bacteria and viruses which is why filtering of these substances is not necessary for public water in Europe and North America. Viruses are the smallest form of microorganisms capable of causing disease, particularly those of a fecal origin infectious to humans by waterborne transmission; bacteria are typically single-celled microorganisms that can also cause health problems in humans, animals or plants, despite many form is ability to aid in water pollution control.


TAPP filters are not intended to change the pH although it might make it slightly more alkaline.

The pH of pure water is 7. In general, water with a pH lower than 7 is considered acidic, and with a pH greater than 7 is considered basic or alkaline. The normal range for pH in drinking water should be 6.5 to 8.5.

What water filter should I buy to remove tap water contaminants?

Based on this comparison with other water filters, TAPP 2 is the best alternative for clean, affordable and sustainable tap water.

Read more about reasons to buy a water filter today, what activated carbon filters from tap water and more.

How do I know that TAPP filters really remove these substances as promised?

We are happy you are questioning this. Here’s an overview of the common tap water contaminants that TAPP filters remove and independent lab tests to prove it.

Comments or Questions?

Please contact us on [email protected] if you have questions about any of the common tap water contaminants on the list, other contaminants or how TAPP filters work.