Drinking water rules
What an action level is
An action level is a trigger. Crossing it starts required steps. It is not an MCL and not a treatment technique.
Short definition only
The comparison stays on the blog: MCL vs treatment technique vs action level.
The $199 Complete System Report is the cited document. Orevant Pro is $87/month or $870/year.
Orevant is not legal advice and does not report your system to the state.
FAQ
Is an action level a violation by itself?
Not always. It is a trigger. Confirm the duty with your state.
Where do I start?
Check my system with your PWSID.