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Standards

Drinking Water Standards are divided into two types of standards. Primary Drinking Water Standards are set based on specific health concerns or impacts, whereas, Secondary Drinking Water Standards are based on Aesthetic or Cosmetic issues and concerns or Technical issues related to the use of the water.  For some water quality parameters, there is no formal drinking water standard, so we have put all these parameters under the category No Standards.

For example, water which slightly exceeds the Secondary Drinking Water Standard for Iron would still be safe to drink, but the water might have a metallic taste and/or could leave a reddish-orange stain on plumbing fixtures, laundry, and even glassware.

Primary Drinking Water Standards are also known as Maximum Contaminant Levels (MCLs) and Secondary Drinking Water Standards are known as Secondary Maximum Contaminant Levels (SMCL).

The U.S. EPA and individual states regulate the MCL, and some states regulate the SMCL. The drinking water standards in the states are not all the same and they do not exceed the EPA MCL for a particular contaminant, but in some cases, like Arsenic in New Jersey for example, they may be lower than the EPA MCL.

Primary Drinking Water Standards

In this section we feature a table listing the Primary Standards for Contaminants that the EPA has identified as health concerns and their corresponding Maximum Contaminant Levels (MCLs). Also included in the table are our own KnowYourH2O custom water quality benchmarks to act as quasi standards in order to be able to compare water quality throughout the USA and the World.

Secondary Drinking Water Standards

In this section we show a table listing the Secondary Standards for Contaminants that the EPA has identified as an aesthetic, cosmetic, or technical concern and their corresponding Maximum Contaminant Levels (MCLs). Also included in the table are our own KnowYourH2O custom water quality benchmarks to act as quasi standards in order to be able to compare water quality throughout the USA and the World.

No Standards

A number of water quality parameters have no formal or regulated drinking water limits.  In many cases there are "standards" which are only guidelines or provisional recommendations used until a formal standard can be developed.  

These guidelines are also commonly used by the water industry and water quality professionals to discuss drinking water quality and develop a treatment plan; they may be suggestive of other potential aesthetic or disease-causing problems with the drinking water. This section includes a table featuring these guidelines. 

Also added to the table are our own KnowYourH2O custom water quality benchmarks to act as additional guidelines in order to be able to compare water quality throughout the USA and the World.

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