Many remain seriously ill even today. There have, of course, been other incidents, including contamination problems that led to boil orders in the Washington, DC area, and parts of New York city. Also, although they have not received the same press attention as the problems in Milwaukee, New York, and Washington, many smaller towns have been affected by contamination incidents afflicting tens of thousands in Texas, Oregon, Missouri, and Georgia. Probably the single most widespread and serious drinking water problem in the United States is not microbial contamination, but contamination from byproducts of the disinfection process, such as chloroform, that can cause cancer. Researchers at the Harvard School of Public Health, the Medical College of Wisconsin, and other institutions have associated these contaminants with more than 10,000 cancer cases each year, including nearly 20 percent of all rectal cancers and 10 percent of all bladder cancers.
Lead contamination is another major problem.
Using industry data, NRDC found that 90 percent of the large public water systems in the United States continue to use technology developed before World War I to clean their water. An additional shortcoming common to most systems is that treatment plants are operated by inadequately trained staffs with minimal oversight. Given these problems, it is perhaps understandable that many cities have problems with even the basic necessity to keep human and animal wastes out of drinking water. As mentioned earlier, the intestinal parasite that contaminated Milwaukee's water is believed to have come from animal or human feces entering Lake Michigan. Even worse, water systems across the country have been coping with a variety of other contamination problems thought to be associated with sewage.