Rule to check multiple items and make sure they have all updated recently before taking action

How can I check multiple items to make sure that none of them are holding stale values before executing a rule? Currently my rule looks like this with some pseudocode explaining what I want it to look like. I want to wrap all of those “if else” statements in one big “if” statement that will check to make sure that the 3 sensor values are not stale before running the inner “if” statement.

rule "sump water level"
when
   Item sumpFloat1 received update or
   Item sumpFloat2 received update or
   Item sumpFloat3 received update
then
	**if(all sensor values are fresh){**
		if(sumpFloat1.state==ON){
			sumpLevel.postUpdate(100)
			sumpTopOffSwitch.postUpdate(OFF)
			Outlet2_1.sendCommand(0)
		}
		else if(sumpFloat2.state==ON){
			sumpLevel.postUpdate(60)
		}
		else if(sumpFloat3.state==ON){
			sumpLevel.postUpdate(10)
			sumpTopOffSwitch.postUpdate(ON)
			Outlet2_1.sendCommand(sumpTopOffTimer.state.toString)
		}
		else{
			sumpLevel.postUpdate(0)
		}
	**}**
	sumpLastUpdate.postUpdate(new DateTimeType)
	
end