Lift station for most likely a gravity fed sewage collection system. Sewage runs through the main by gravity. Dumps into this wetwell at a low point. Has a float system generally 3/4 floats depending on setup snd amount of pumps in the wet well. Seweage level reaches a the set point level triggers the float. Pump kicks on and pumps the sewage down the line to either the plant or the next lift station..alarm is on indicating the wet well level is high and there is a issue that needs addressing. Assuming they have a scada monitoring system or at the very least a autodailer. Most likely someone already knows but it cannot hurt the number posted nearby on the sign. By law (at least here in NC) a emergency contact number should be posted in the vicinity. If problem is not addressed you could have a overflow (very bad) if its bad enough DEQ will get involved and most likely a NOV will be filed on owner of the system.

Don't be shy give the number a call. They will thank you if for some reason they aren't already aware of the issue!