We have a manufacturing process that can generate wastewater.  We would like to capture this wastewater cost at the WO level so our finished good being produced has this included as part of its mfg cost.  The problem is we run custom jobs so each WO would "produce" different quantities of wastewater; which means I need a way to enter the correct quantity after the mfg process is complete .  I can think really of only 2 methods to capture this cost. 1 - create a raw material "waste" and consume it during production tracking.  That is fine except we have to have inventory of wastewater with a value.  That would artificially inflate our inventory valuation.  2- create a work center for waste and track "time" as quantity so the cost rolls up to the finished good.  

I think an overhead is great method for this - I am just not aware of a way to adjust the quantity independently for EACH work order at the time of production tracking.  Thanks!