Texas officials charged with protecting the environment and public health have for years made arbitrary subtractions to the measured levels of radiation delivered by water utilities across the state, according to a series of investigative reports out of Houston.

Those subtractions, based on the test results' margin of error, made all the difference for the Texas Commission on Environmental Quality (TCEQ): without the reduction, demonstrated levels of dangerous radiation would have been in excess of federal limits for years.

This was being done in direct contravention of an order by the US Environmental Protection Agency, which told state regulators in 2000 to stop subtracting the margin of error.