Your article does not go into detail about the costs of remediation. And it does not discuss the different means of remediation available.

I believe that your hunch is based on building the means to remove arsenic from water, which is admittedly expensive.

My hunch is based on the fact that right now, water districts have the means to blend water with non-compliant levels of arsenic, with water that is compliant, with resulting water that is in spec. Right now water districts do this to bring levels of bacteria and pesticides down to legally acceptable levels. We do it all the time, all over the country.

I like my hunch better than yours.