It’s cheap because it’s industrial waste that has significant cleanup and disposal costs. It was sold to municipalities after there was “research” that it helped tooth health, which it can in much higher concentrations than is in any water supply. But the reason it’s added to water is because the companies that otherwise would have to pay for clean up now make money off the waste product and can afford kickback funds.
It’s cheap because it’s industrial waste that has significant cleanup and disposal costs. It was sold to municipalities after there was “research” that it helped tooth health, which it can in much higher concentrations than is in any water supply. But the reason it’s added to water is because the companies that otherwise would have to pay for clean up now make money off the waste product and can afford kickback funds.