Comment by codyogden

My parent worked at a water treatment plant in a small town. They could have easily screwed around with the chemical compositions without anyone knowing. Nearly anyone could have brute forced the control room: a single key/lock would need to be bypassed. There was no access control or logging to the room itself, and everyone who worked there had a master key to all buildings and facilities. Lab tests were done on site and were recorded manually, so they could easily just lie about the results.