Water departments to change lead-testing methods after investigation

Instructions provided varied greatly, ranging from those that contained protocols the EPA advised against a decade ago to those that were periodically updated

• At least 33 US cities used water testing 'cheats' over lead concerns

Water departments that use controversial lead-testing practices have told the Guardian they will change their methods after an investigation revealed they were not following environmental guidelines.

Most of the water departments involved said they used the testing methods because state governments told them to, federal guidance was not clear, or they had not received any word that practices may underestimate lead content.