The most widespread water quality problem in the US isn't caused by large commercial operations, but rather from residential yards. Here's one simple solution to the issue.
It's relatively easy to lay the blame for water and air pollution at the foot of large companies and their operations, and while those companies are at least partly responsible for the issue, it doesn't take into account the fact that every year, about 80 million pounds of pesticides are applied to some 30 million acres of lawns in the US. This residential "non-point source pollution" is one of the main culprits in contaminating both surface and groundwater, but it turns out that there's a simple and low-cost solution to it, and it starts at home.
Because most lawn and garden chemicals are essentially invisible to the naked eye after applying them, they often fall under the category of "out of sight, out of mind," but these pesticides and herbicides can often end up in our drinking water supply, either by being absorbed into the groundwater or being washed into surface water by rainfall. A study by the USGS in 2013 found that at least one pesticide (and in most of the samples there were two or more pesticides) could be found in just about every stream, river, and lake in the country, and about half of the wells, so these chemicals don't just "go away" or get filtered out in water treatment plants.
In addition to pesticides and herbicides such as glyphosate, carbaryl, malathion, and 2,4-D, home application of fertilizers can also lead to water contamination, as does the disposal of pharmaceuticals through flushing them down the toilet or drain, all of which can have long term effects not only on our water supply, but also on the wildlife that inhabit and use surface waters.
The known effects of these chemicals include the development of cancer (due todamaged DNA), and hormone disruption (which leads to a host of other related health issues, including autism, ADHD, and diabetes), and these health impacts could be just the tip of the iceberg, as many of the current studies don't account for the cumulative action on the body of more than one chemical, or the effects of the products resulting from the breakdown of the chemicals, or other health effects that aren't currently tested for.