How safe is the public tap water?

In January 2014, the worst chemical spill in US history contaminated the Elk River and the drinking water supply in Charleston, West Virginia.  It disrupted water supply for 300,000 residents for an extended period of time.  More importantly, it exposed major gaps in government regulation and monitoring.  It has undermined the public trust.  It also prompted investigations elsewhere and here are some disturbing answers reported by the National Public Radio on March 26, 2014.  Basically, the government regulators could not guarantee that the water was safe to drink nor could they report on the toxicity of the spilled chemical.

Soon after this incident in West Virginia, there were two separate reports of coal ash contamination of rivers in Dan River in Virginia and in Cape Fear River in North Carolina, the latter by illegal discharge of 61 million gallons of toxic sludge by Duke Electric Power.

The US Environmental Protection Agency (U. S. EPA) regulates contaminants in public tap water supplied by Community Water Systems under the Safe Drinking Water Act (SDWA).  These contaminants fall into these broad categories: 

The U. S. EPA regulates the following six types of contaminants shown with their abbreviations:

  1. D - Disinfectant (Chlorine, Chloramine)

  2. IOC - Inorganic Chemical (Lead, Mercury)

  3. OC - Organic Chemical (Pesticides, Herbicides, Solvents)

  4. DBP - Disinfection Byproduct (Bromate, Haloacetic acids)

  5. M - Microorganism (Bacteria such as EColi, Virusus, Protozoa)

  6. R - Radionuclides (Natural & manmade sources of radiation such as Radium 226)

An estimated 285 million Americans depend on public and private water utilities for their drinking water. Your tap-water is legally safe in most areas. But as government regulation sets limits on just 91 contaminants out of hundreds, your legally safe tap-water still may be toxic and unhealthy as shown in this graphic from New York Times.  A recent random sampling of water from utilities by government surprisingly revealed the presence of many cancer causing and endocrine disrupting unregulated toxins in "legally safe" drinking water.


If you live in one of the top 100 U. S. metropolitan area water utility districts, you can read the latest report on the quality of your tap-water here. These annual reports, the best information available today from your water utility, are limited to currently regulated and monitored contaminants by the U. S. Government (EPA). You will not find information on currently known but unmonitored toxic contaminants in tap water in many cities, such as the cancer causing Chromium 6 or the Endocrine Disruptor Perchlorate(More information on Chromium 6 is available here)

You can also find out if your local water utility had reported any violations to the U. S. EPA recently. You can review the record of violations by your local zip code ( or city and state) for recent years here.


Click here to find out about quality of your tap-water (for over 100 major cities in the US)

Posted on January 27, 2014 and filed under Public tap water.