Thirsty? Your tap water might be coming with some extra chemicals. An environmental group says its analysis of records in 42 states found 141 unregulated chemicals and an additional 119 for which the Environmental Protection Agency has set health-based limits. Most common among the chemicals found are disinfection byproducts, nitrates, chloroform, barium, arsenic and copper. The Environmental Working Group compiled data from nearly 40-thousand water utilities in states that agreed to provide data they collected from 1998 to 2003. An E-P-A spokeswoman says the agency gathers its own water monitoring data, reviews the latest research and looks at treatment methods and technology.