12. Process efficiency
Process efficiency related appropriate measures for biological waste treatment.
The following measures apply to all processes and operations.
1. You must monitor and review how much:
- water, energy and raw materials you use each year
- residue and waste water you generate each year
Residues include the waste and non-waste classified composts and digestate produced.
The following measures apply to all processes and operations at installations only.
1. You must create and implement an energy efficiency plan at your facility in accordance with BAT reference document BAT 23.
2. You must regularly review and update your energy efficiency plan as part of your facility’s management system.
3. You must have operating, maintenance and housekeeping measures in place to make sure you use energy efficiently, for example for:
- air conditioning, process refrigeration and cooling systems (leaks, seals, temperature control, evaporator or condenser maintenance)
- motors and drives
- compressed gas systems (leaks, procedures for use)
- steam distribution systems (leaks, traps, insulation)
- space heating and hot water systems
- lubricating to avoid high friction losses
- boiler operation and maintenance, for example, optimising excess air
- other maintenance relevant to the activities within the facility
4. You must have basic, low cost physical techniques in place to avoid gross energy inefficiencies. These may include for example:
- insulation
- containment methods (such as seals and self closing doors)
- avoiding the unnecessary release of heated water or air (for example, by fitting simple control systems such as timers and sensors)
5. You must regularly review and update your energy balance record as part of your facility’s management system, alongside the energy efficiency plan.
The following measures apply to all processes and operations.
1. You must keep a list of the raw materials you use at your facility and their properties. This includes materials and other substances that could have an environmental impact.
2. You must check if you can use raw materials new to the market that have less environmental impact. This must include, where possible, substituting raw materials with waste.
3. You must justify why you continue to use any substance which has a beneficial alternative.
4. You must have quality assurance procedures in place to control the content of raw materials.
The following measures apply to all processes and operations at installations only.
Whilst this is an IED requirement for installation operations, all operations should consider using potable and clean water efficiently and reducing its use.
1. You must take measures to make sure you optimise water use to:
- reduce the volume of waste water generated
- prevent or, where that is not practicable, reduce emissions to soil and water
2. Measures you must take include:
- implementing a water saving plan (which involves establishing water efficiency objectives, flow diagrams and water mass balances)
- optimising how you use water for washing (for example, dry cleaning instead of hosing down, using trigger control on all washing equipment)
- recirculating and reusing water streams within the plant or facility, if necessary after treatment
- where relevant, reducing water used for vacuum generation (for example, using liquid ring pumps with high boiling point liquids)
3. You must carry out a review of water use (water efficiency audit) at least every 4 years.
4. You must also:
- produce flow diagrams and water mass balances for your activities
- establish water efficiency objectives and identify constraints on reducing water use beyond a certain level (usually this will be site specific)
- have a time-tabled improvement plan for implementing additional water reduction measures
5. To reduce emissions to water, you must apply these general principles in sequence:
- use water efficient techniques at source where possible
- reuse water within the process, by treating it first if necessary – or if not practicable, use it in another part of the process or facility that has a lower water quality requirement
- if you cannot use uncontaminated roof and surface water in the process, you must keep it separate from other discharge streams – at least until after you have treated the contaminated streams in an effluent treatment system and have carried out final monitoring
6. You should establish the water quality requirements for each activity and identify whether you can substitute water from recycled sources and where you can, include it in your improvement plan.
7. Where there is scope for reuse (possibly after some form of treatment) you must keep less contaminated water streams, such as cooling waters, separate from more contaminated streams.
8. You must directly measure fresh water use and record it regularly at every significant usage point – ideally on a daily basis.
The following measures apply to all processes and operations at installations only.
1. You must create and implement a residues management plan that:
- minimises residues generated from treating waste
- optimises the reuse, regeneration, recovery, recycling or energy recovery of residues, including packaging
- makes sure residues are disposed of properly if recovery is technically or economically impractical
2. Where you must dispose of waste, you must carry out a detailed assessment identifying the best environmental options for waste disposal.
3. You must review, on a regular basis, options for recovering and disposing the waste produced at the facility. You must do this as part of your management system. This is to make sure you are still using the best environmental options and promoting the recovery of waste where technically and economically viable.