He reported evidence that showed the administration and the engineers who were to be looking out for the best interests of people were aware of another spill in the same area from 1994 on, but they had never released the information to the public and had instead covered it up.
The individual reported evidence showing that the administration and engineers, who were supposed to protect public interests, were aware of a spill in the area since 1994. However, they did not inform the public about this issue; instead, they kept it secret.