When you turn the tap - you expect clean, safe drinking water to come out of the faucet.

And that's the promise given by Houston city officials.

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But an ABC13 Investigation uncovered allegations that some of the tests weren't true and that an official in the water department told city water testers to report chlorine results in certain parts that weren't accurate.

Chlorine is added to the water to kill bacteria in pipes and water lines. Without it, that bacteria could make you sick.

The state requires the city to check water safety levels from all over Houston to ensure it's safe to drink.

But a former city employee alleges he and his colleagues were told to falsify samples to make it look like water was safe when it was testing below state standards for chlorine.

This story was originally produced in Jan. 2019.