General:
* Rubbish
* Trash
* Garbage
* Junk
* Refuse
* Scrap
* Debris
Meaningless or unproductive:
* Futile
* Pointless
* Useless
* Ineffective
* Unproductive
Excessive or extravagant:
* Extravagance
* Prodigal
* Profligate
* Squandered
Loss or destruction:
* Spoil
* Ruin
* Degradation
* Deterioration
* Dissipation
Specific to resources:
* Dissipation
* Depletion
* Expenditure
* Consumption
* Overuse
Please provide more context if you need a more specific synonym.