EPA Maximum Contaminants List

EPA maximum contaminants list is a recommended maximum for a number of unwanted contaminants in safe drinking water. Having a good grasp on what these numbers mean is very helpful in determining the proper water filtration or treatment system for the home or business. Keep in mind that these numbers are also maximums recommended for public drinking water supplies.

Municipal water supply (City water) companies struggle to comply with these maximums at times so the EPA seems slow to amend them in any way. For example, many states set the maximum sodium level far lower that the EPA maximum of 150. The American Heart Association suggests a lower amount as well. WaterFiltersOfAmerica.com tries to suggest more reasonable maximums in some instances. An example of this is the EPA minimum pH level of 6.5.

pH should be above 7.0 for drinking

We feel that not only is this too low and acidic for good drinking water, it can also be harmful to copper and other metals used for water lines and fixtures in the home. And finally, a pH that low can certainly damage water treatment equipment such as iron filters, water softeners and other filter equipment. Also a pH that low can drop even lower with the use of reverse osmosis drinking water systems. And if you start at a pH of 6.5 and then the pH drops; that could be a serious situation indeed.

Be very wary of people who say that a pH of 7.0 (Neutral pH) is a "Perfect pH" or "Normal". Over the years many people and water treatment providers have mistakenly taken the term "Neutral" to mean normal. Actually, with drinking water and certainly water treatment filtration or devices the best pH is usually a pH ABOVE 7.5.

For example, any good oxidizing iron filter application would require a pH of 7.5 or higher for the oxidizing process to happen properly. At lower pH ranges clear water iron has trouble oxidizing properly to turn it into red water or sediment iron for removal by the mineral bed. The best rule of thumb is to keep these devices at a pH range of 7.5 or higher at all times.

EPA Maximum contaminants list
EPA numbers are often too conservative
While we will never tell you that a number lower than EPA recommendations are harmful, we will tell you if by those numbers we think you should further refine your water for the correct result. Remember that the EPA numbers are simply drinking water recommendations, not water treatment equipment system recommendations.

We think the EPA does a great job with the resources and limitations they endure. Our job is to give you additional information so that you can make a sound and logical decision about your water.


Nitrates in drinking water usually come from human or animal waste, including fertilizer. By human or animal waste we mean human or animal feces. Private wells, especially in rural areas or near horse, cattle, chickens, wildlife, farms and agriculture, as well as municipal water suppliers (City Water) where sewage treatment plants are used and/or cities or towns who get their water from wells are places where nitrates are very commonly present.

The maximum contaminants EPA list for nitrates is 10 PPM before they consider it a health hazard. But there are other things to take into consideration. Infants are far more susceptible to nitrates than adults. We would prefer not to have infants ingest them. Most of us that work here at WFOA™ don't want any nitrates in our water. And nitrates are easy and inexpensive to remove with reverse osmosis drinking water systems ($199). Be sure to tell our techs if you are concerned about nitrates when talking to them about Reverse Osmosis.

If you KNOW you have high nitrate levels in your water we can even add an aggressive nitrate selective filter to that unit at no extra charge. Most municipal water supplies have some amount of nitrates, especially if they recycle sewage for reuse. Reverse Osmosis also removes many other unwanted contaminants and dissolved solids from the water. The mfcl for nitrate is 0.8.


Most people who have water softeners do not realize that they should not drink from them due to high sodium levels that these water softener systems produce. The maximum contaminants EPA list for sodium levels are a great way of proving this point. If you have a water softener in the home and do NOT use reverse osmosis in the kitchen to remove sodium, you should not drink the water.

Drink bottled water instead. Anyone who has a water softener and is actually drinking that water can greatly increase the risk of high blood pressure and heart issues.

If you already have such issues then a water softener producing drinking water can really be a foolish thing to do. PROVE it to yourself by taking a sample to a local lab for sodium testing. If your softener is working properly the sodium levels will be high in most cases.

If you prefer not to have the expense of bottled water and the environmental drawbacks of bottled water, you can correct this sodium issue quite easily and inexpensively by installing reverse osmosis drinking water filtration in your kitchen for all cooking and drinking water. The mcl for sodium is 30. But most lab MCLs are listed at 150 for some reason. We think that is shameful.


Chlorine is used to reduce the risk of infectious disease in drinking water. It is also used to combat microbial contamination, but the problem is that it can react with organic matter in the water and form dangerous, carcinogenic Trihalomethane's or THMs (chlorine by products).

People who regularly drink tap water containing high levels of chlorine by-products have a greater risk of developing bladder and rectal cancers than people who drink unchlorinated water. The drinking of chlorinated water has finally been officially linked to an increase in colon cancer. Greenpeace reports have found chlorine-based compounds to be the most common toxic and persistent pollutants in the Great Lakes.

Another problem directly related to chlorine disinfection are the aesthetic properties formed when chlorine mixes with organic compounds that are natural to open bodies of water (surface water). This creates the "taste and odor" problems. Contaminants can enter our water supplies at many points before actually reaching the tap. The carcinogens in drinking water at the point of use may result from contamination of source waters, from the treatment processes, or enter as the water is transported to the customer.

The best alternative is point of use water treatment systems. Such as whole house water filtration and reverse osmosis. The most practical and efficient method for removing chlorine, chlorine by-products, and taste and odor problems, is to filter it with granular activated carbon (GAC) or other suitable chemical-removing filter media. The mfcl for chlorine is 4.0.


We are Arsenic removal experts. Arsenic can be found in water which has flowed through arsenic-rich rocks. Severe health effects have been observed in people drinking arsenic-rich water over long periods. Drinking-water poses the greatest threat to public health from arsenic. Long-term exposure to arsenic from drinking-water causes cancer of the skin. As well as cancer of  lungs, bladder, and kidney, as well as other skin changes such as thickening and pigmentation changes.

Increased risks of lung and bladder cancer. And of arsenic-associated skin lesions. Have been observed at drinking-water arsenic concentrations of less than 0.05 mg/L. The most important immediate action is prevention of further exposure by providing safe drinking water.

Boiling water will not remove arsenic. And could increase the concentration of arsenic in your water. Chlorine disinfection will also not remove arsenic. The best treatment choices for arsenic removal is an Arsenic Filter. Or a Reverse Osmosis Drinking Water System with and Arsenic selective cartridge added. The maximum contaminant level for arsenic is: 0.010 ppm.

Filtration systems in the home provide the best technology available for treating your drinking water. We offer all types of residential water treatment systems. Find the water treatment products you need at WaterFiltersOfAmerica.com.

EPA Maximum Contaminant List