Measuring flow at basin inlet—what solutions are available?
I think you should consult your local water authority to determine first whether any derogations or allowances in the regulation are permissible, given the high cost of any modification and second, what solutions might be possible.
Not sure how a derogation would apply in terms of being objective or applying equally to all facilities. As for the criteria regarding cost, would that item be addressed in the regulations?
My question about the load received by the plant is crucial to understanding how it works—premiums for wastewater treatment, etc.