Given that the process cannot change, the next questions to ask are:

• Can the process be optimised to minimise waste produced or energy required to operate the process?
  

• Can we twiddle some known factors to improve water efficiency or reduce effluent volume,or improve effluent quality?
  

• Can resource inputs be optimised to reduce wastage?

• Can we make wastes more recoverable?
  

• Can we reduce product rejects or optimise raw material usage?
  

• Can we change existing practices or procedures or monitoring to reduce waste or energy use? Does that compressor need to be on all weekend?