Flint's contaminated water was among the most expensive in the country

Study of 500 of the nation's largest community water systems found that Flint residents paid $864 a year for water service - roughly double the US average

Despite having to deal with the effects of lead-contaminated water for nearly two years, Flint residents paid the highest water bills in the US, according to a study released Tuesday.

The study, conducted by Washington DC-based public interest group Food & Water Watch, reviewed 500 of the nation's largest community water systems and found Flint residents paid $864 annually for water service - roughly double the US average.