Data Sources was created with the goal of making United States water data as easy to access and understand as possible. We are not the source of any raw water data, we simply collect, sort, filter, manipulate, interpret, and explain data. does not guarantee the accuracy or timeliness of any information on this site. Use this data at your own risk.

Where does’s data come from?

The short answer is that the United States government mandates that vast amounts of water data is made publicly available. downloads that data, warehouses it, and finally makes it available on this website. This is a non-trivial process, once that we are constantly working on improving.

So, where does our data actually come from? The short answer is This is the repository of all US government data that is freely available. Some of the data is retrievable here, other data is listed here, but has to be retrieved from agency that is responsible for it.

Among the data sources we take in, among them federal, state, and local sources, the most important is data from the Safe Drinking Water Information System (SDWIS) Federal Reporting Services. We work with many other tools and datasets as well, such as Lead/Copper data, UCMR, EPA Enforcement and Compliance History, and more.

If you see any data on the site that is wrong or inaccurately presents, please don’t hesitate to email us at: