Columnist: The Hoopton municipal water treatment plant recently discovered a major problem with the adsorptive medium used in its treatment process. This medium helps remove iron and manganese from drinking water, but during the time that this part of the treatment process was not functional, residents suffered no adverse health effects. The insignificant outcome of this supposed disaster suggests that the presence of these minerals in drinking water is not as detrimental as watchdog groups would have us believe.
Which of the following, if true, would most seriously weaken the columnist’s argument?
【选项】
Because the municipal treatment plant is so small, it was exempted from disinfection requirements after meeting certain strict criteria.
选项是否正确？