According to the Fluorine Deception, they needed a way to get rid of the effluent so they made it a health product rather than toxic waste. That book however has been dismissed by most supporters of fluoridation as written by a nutbar.
http://www.amazon.com/The-Fluoride-Deception-Christopher-Bry...
"Concerns over fluoridated drinking water have long been derided as the obsession of McCarthyite cranks. But this muckraking j’accuse asserts that fluoride is indeed a dire threat to public health, one foisted upon the nation by a vast conspiracy—not of Communist agents, but of our very own military-industrial complex. Investigative reporter Bryson revisits the decades-long controversy, drawing on mountains of scientific studies, some unearthed from secret archives of government and corporate laboratories, to question the effects of fluoride and the motives of its leading advocates. The efficacy of fluoridated drinking water in preventing tooth decay, he contends, is dubious. Fluoride in its many forms may be one of the most toxic of industrial pollutants, and Bryson cites scientific analyses linking fluoridated drinking water to bone deformities, hyperactivity and a host of other complaints. The post-war campaign to fluoridate drinking water, he claims, was less a public health innovation than a public relations ploy sponsored by industrial users of fluoride—including the government’s nuclear weapons program. Legendary spin doctors like Edward Bernays exploited the tenuous link between dental hygiene and fluoridation to create markets to stimulate fluoride production and to prove the innocuousness of fluoride compounds, thereby heading off lawsuits by factory workers and others poisoned by industrial fluoride pollution. Bryson marshals an impressive amount of research to demonstrate fluoride’s harmfulness, the ties between leading fluoride researchers and the corporations who funded and benefited from their research, and what he says is the duplicity with which fluoridation was sold to the people. The result is a compelling challenge to the reigning dental orthodoxy, which should provoke renewed scientific scrutiny and public debate."
