East Providence residents are notified the city's water system is in violation of drinking water standards. Required testing has found elevated level of DBP, a byproduct of disinfectants.  While long-term use can cause health problems for some people, officials say it's not an emergency and that the use of bottled water isn't necessary.  An aeration system is going to be installed in the city's holding tank, which experts say should resolve the problem by August.