Fluoride result is over half of the MAC(1.5), does sampling increase too every 3 months until results reduce to < half?
I looked into your question and here is the response provided by the OWWA's Small Systems Committee:
For Fluoride, even if you exceed half the MAC there is no requirement to test every 3 months. But the Health Unit will likely step in and may provide some direction in case you exceed more than MAC. The same thing applies to Nitrate, Nitrite, sodium and THM.
Hope this helps.