For you to know that you and your family have good quality water all the time—whether it’s well water or municipal water—it’s necessary to test your water to find out if it contains any contaminants. That’s the only way for you to know if there are toxins that need to be filtered out of your water before your family drinks it. The contaminants in American drinking water range from the harmless to the dangerous. They can be filtered out but first, you have to know what’s there.
Why Water Contaminants Are Measured in PPM
Many contaminants are present in such small quantities that their presence is measured in parts per million or PPM. One part per million is equivalent to one milligram of contaminant in one liter of water. When the Environmental Protection Agency sets purity standards for drinking or industrial water, they set the limits of toxic substances in parts per million, parts per billion (PPB) or even parts per trillion (PPT) for very toxic substances. Despite their very small concentrations, these contaminants can still create health problems.
It may seem incredible, but some substances are so toxic that only four parts per trillion are permitted in drinking water. One group of substances in this category are PFAS (per- and polyfluoroalkyl substances). There are dozens of chemicals in this group, including PFOA, PFOS, and HFPO-DA. These and others have been widely used in industry to manufacture nonstick cookware, water-resistant and stain-resistant fabrics, food packaging, cosmetics and construction materials.
PFAS are just one class of contaminants—there are hundreds of other contaminants that should not be present in your drinking water. A fast and accurate water test from a professional lab is the first step in cleaning up your water so that your family has the purest, healthiest water supply at all times.
Contaminants Measured in PPM That You Don’t Want in Your Water (and Why)
When a household gets a new well or a family moves into a new home supplied by a well, the first thing they should do is get a comprehensive test of the well water by a professional water testing lab. If any of these contaminants exceed the acceptable PPM of drinking water, filtration or water treatment should be implemented to improve the quality of the water. Annual testing should follow to verify that the well has not become contaminated. It is a good idea for households supplied with municipal water to check the quality of their water, as well.
- Lead
The acceptable PPM level of lead in drinking water is zero.
Lead can enter drinking water from natural deposits in rock and soil, industrial contamination and leaching from plumbing fixtures. Older homes may still have lead pipes or solder in their plumbing and lead can leach out into the drinking and cooking water. Exposure to lead, even at low levels, can lead to severe health problems, especially for pregnant women and children. When children drink water contaminated with lead, it can cause lower IQ, behavioral problems, and delayed growth. In adults, lead exposure can lead to cardiovascular issues, kidney damage and reproductive problems. There is no safe level of lead in drinking water.
- Arsenic
The acceptable PPM level of arsenic drinking water is .01 PPM which is equivalent to 10 PPB.
Arsenic is a very well known poison that occurs naturally in rocks and soil. Industrial releases or agricultural use can also release arsenic into the environment so it can then make its way into groundwater and then wells. Long-term exposure to arsenic in drinking water has been linked to several serious health conditions, including lung, skin and bladder cancers, cardiovascular disease, and diabetes.
- Nitrates
The acceptable PPM level of nitrates in drinking water is 10 PPM.
Nitrates occur naturally in the environment but can also enter water supplies due to runoff from fertilizers, leakage from septic systems, and sewage. While undesirable, nitrates are not particularly harmful to most adults but they can be very dangerous for infants. Water can contain enough nitrates to cause methemoglobinemia, or “blue baby syndrome,” where the baby’s blood cannot carry a sufficient quantity of oxygen. If severe, this condition can be life-threatening. If there are agricultural activities or septic systems anywhere near a well, that well water should be tested regularly for nitrates.
- Fluoride
The maximum PPM level of fluoride in drinking water is 4 PPM.
The EPA has also set a non-enforceable recommended level for fluoride of 2 PPM to prevent fluorosis which is a discoloration of the teeth from excessive fluoride consumption. While most fluoride in drinking water is added by community water systems in an effort to make teeth stronger, it can also enter groundwater from natural deposits. In some regions, the level of naturally occurring fluoride in groundwater can be higher than recommended, leading to potential health risks. Some parts of Tennessee, California and Ohio have higher levels of fluoride than are recommended for drinking water.
- Chlorine
The maximum PPM level of chlorine in drinking water is 4 PPM.
Many people know that various chlorine products are used in municipal water systems to disinfect the water supply. Chlorine can also make its way into water from industrial pollution or spills and agricultural activities (from both fertilizers and pesticides). Drinking water with too much chlorine can cause stomach discomfort and irritation of the skin and eyes. There are also four toxic chemicals that can be formed as a byproduct of chlorine disinfection. Three of them contain chlorine atoms. Exposure to these disinfection byproducts is associated with cancer, liver and kidney damage and reproductive problems, among other harmful effects.
- Iron
The maximum PPM level of iron in drinking water is 0.3 PPM.
Iron is a naturally occurring mineral and often finds its way into water sources. While iron is not considered a toxic substance, high levels in drinking water can lead to unpleasant tastes, stained laundry and buildings, and clogged pipes. Iron in well water also promotes the growth of iron bacteria, which doesn’t directly cause health problems other than skin or eye irritation, but can damage plumbing equipment.
- Copper
The maximum PPM level of copper in drinking water is 1 PPM.
Small amounts of copper are important for good health but too much can cause gastrointestinal distress, liver damage and kidney problems. People with Wilson’s disease must restrict the amount of copper they consume so they should be careful to test well water if they rely on a well for drinking water. Copper can leach into water from copper pipes and plumbing fixtures, especially if the water is acidic. To control the amount of copper in drinking water, the PPM for copper should be tested on a regular basis.
- Total Dissolved Solids
The acceptable level of total dissolved solids (TDS) in drinking water is 500 PPM.
TDS refers to the total concentration of dissolved substances in water, including minerals, salts, metals, and organic matter. The level of TDS does not necessarily indicate the presence of harmful contaminants. High TDS levels, however, are associated with poor water taste, odor and appearance. If TDS levels are high, other problems can occur, such as clogged filtration systems and a buildup of scale in plumbing fixtures, resulting in expensive repairs.
- Calcium and Magnesium
There are no limits set by the Environmental Protection Agency on how much calcium or magnesium is in well or municipal water. If the levels are high, however, the water is considered “hard” and this can create problems. Hard water causes scale buildup (mineral deposits) inside pipes and in plumbing fixtures. This buildup can be so heavy that appliances like water heaters, dishwashers and washing machines may need expensive repairs or replacement. Water treatment systems that reduce calcium and magnesium are called water softeners and are readily available. Hardness is measured by how much calcium carbonate is in the water. More than 180 PPM is considered “very hard.” “Soft” or “moderately hard” water is below 120 PPM. Soft water improves the effectiveness of soap and reduces scaling.
- Mercury
The maximum PPM level of mercury in drinking water is 0.002 PPM or 2 PPB.
Mercury is a very toxic heavy metal that can enter water systems from industrial activities, mining operations or natural deposits. Exposure to mercury in drinking water can lead to severe neurological and developmental delays in infants and young children. Long-term exposure for adults can damage the kidneys or nervous system, suppress the immune system or cause reproductive harm including birth defects. Water from new wells should always be tested for mercury and then re-tested at regular intervals if there are any industrial or manufacturing operations or landfills within a few miles.
- Cadmium
The maximum PPM level of cadmium in drinking water is 0.005 PPM or 5 PPB.
Cadmium is another toxic metal that can enter water supplies through industrial activities, mining, or agricultural runoff. Exposure to cadmium can cause kidney damage, bone demineralization, high blood pressure, intestinal distress, reproductive problems including birth defects and an increased risk of cancer. Like mercury, cadmium is dangerous in small amounts, and long-term exposure can lead to serious health problems. If a well is near any industrial or manufacturing activities, the water should be tested at regular intervals.
- PFAS (per- and polyfluoroalkyl substances)
In 2024, the EPA set new enforceable standards for several of the PFAS:
PFOA: Zero.
PFOS: Zero.
PFHxS: 10 PPT (parts per trillion)
PFNA: 10 PPT
The EPA requires public water systems to monitor their water for these and other PFAS and to comply with these levels by 2027. Thousands of household goods were made with PFAS, such as microwave bags for popcorn, fast food wrappers, stain-resistant fabrics, nonstick cookware and raincoats. Due to massive industrial dumping of waste and military uses, these chemicals have entered our environment on a large scale. Exposure to PFAS chemicals is associated with cancer, endocrine disruption, reproductive harm and damage to the immune system. One study estimated that 45% of the nation’s tap water contains one or more PFAS. Water test kits purchased online or in a home improvement store will not detect PFAS. Water testing at a professional lab is needed to find out if well water is contaminated with these dangerous chemicals.
- PCBs (polychlorinated biphenyls)
The maximum PPM level of PCBs in drinking water is 0.0005 PPM or .5 PPB.
While they are now banned, PCBs were used for many years to manufacture electrical equipment, paints, dyes, cable insulation, adhesives, plastics and rubber products. Products that contain PCBs that were made before the ban in 1979 may still be in use. Items that were improperly disposed of and hazardous waste sites that are poorly maintained may still be leaking PCBs into the environment. Once in the environment, PCBs can accumulate in plants and fish. Humans who eat these substances then take the PCBs into their bodies. The health effects of this exposure include cancer, harm to the immune or reproductive systems, damage to the nervous system, endocrine disruption, liver toxicity and high blood pressure.
ETR Laboratories Tests for All These Contaminants and Hundreds More
The list above does not include all the toxic contaminants that could be in your water. This is just a small sample of the thousands of chemicals, metals, bacteria, fungi, parasites or other contaminants that can be found in our environment.
Water tests offered at ETR Laboratories test for as many as 249 different bacteria, metals, radioactive chemicals, industrial and cancer-causing chemicals and herbicides. With the Ultimate Water Test, a well owner or concerned resident supplied by a municipal system can know exactly what is in their drinking water.
With these test results in hand, it is possible to design a filtration or water treatment system that takes out the bad components and leaves pure, healthy water. Don’t rely on an untested water source. Ensuring good quality water starts with a fast, expert and comprehensive analysis. Once you have your test results, ETR Laboratories staff can help you determine the cause of any adverse results and plan your solution. Choose the best water test for your situation now and know exactly what’s in your water in just a few days.