Hrm.

My big issue I'm going to take with this is "individuals can always install a filter or consume bottled water."

1. No, individuals cannot always do these things. Filters cost money. Bottled water costs money. I have to use filters myself, and I don't know what I would do if I ended up poor.

2. We should not be encouraging the consumption of bottled water because of the ridiculous amount of plastic used and because companies are not always careful where they extract this water, aggravating drought conditions.

Putting a "brain altering substance" in the water might seem like a good idea, but it would result in many, many issues. It would increase the consumption of bottled water dramatically, especially amongst the more conservative population (How dare you put that in the water?) and the Black population, who already have very good reasons not to trust tap water.

So, my answer to your question is no. Public health groups should not do this because despite the benefits, it would cause a lot of fear and problems for a different vulnerable population.