Is it safe to use a pool cover pump on standing water?

Yes, it’s safe, as long as the pump is designed for dirty water and won’t suck the cover itself into the intake. The risk isn’t the water — it’s the pump eating the cover. Set the pump on a flat piece of plastic, scrap of plywood, or an old paver to keep it above the fabric. If your pump has a built-in float switch that turns off automatically, you’re golden; otherwise, unplug it as soon as the water’s below the intake.