WATERVLIET — Township trustees on Monday approved a plan under which the municipality’s mercury-vapor and sodium-vapor streetlights will be replaced with LED fixtures as part of a state-backed plan.

Under Michigan’s lighting-efficiency campaign, the I&M electric utility is to swap out most of the local region’s existing streetlights with LEDs. Towns don’t bear any of the cost, but they can decide to either have all the work done at once, or alternatively to allow the exchange to be made over a long period, with the more-efficient LED’s being put in place when individual lights burn out.