ABC Engineering

1.WASTE MINIMISATION

Introduction

Waste minimisation is the process of systematically reducing waste production. The process covers raw materials consumption, product loss, energy and water consumption, packaging, effluent production, wasted effort, and all other solid, liquid and gaseous wastes.

Companies that reduce the amount of waste produced not only reduce waste management costs, but also save in raw materials costs through reduced resource wastage. Minimising waste can also help reduce environmental liability and insurance costs, and yield income from the sale of reusable waste.

Waste Survey

A waste survey of ABC Engineering was undertaken on the 15^th November 1999. The survey was carried out as an initial review using data collected on site and involved:

• Identifying wastes. A site tour, detailed discussions with site personnel, and observations were used to identify wastes generated by each process/area.
  
  
• Gathering basic quantity and cost data. Historical waste and purchase record data was collated to determine raw materials consumption, waste quantities and disposal costs. Although information gathered from historical data did not cover all wastes (i.e. product loss, handling costs, etc.), it was sufficient to identify opportunities for reducing waste. The majority of waste routes need to be better defined.
  
  
• Identifying opportunities for reducing waste. Using the available data and our experience of energy and waste management, areas of the business where there are opportunities to reduce waste were identified.
  
  
• Identifying legal obligations. All companies have a duty of care to ensure that wasted materials are managed correctly. An assessment of compliance with relevant legislation was also made.

Recommendations

Firstly, it is not possible to quantify amounts of wastes generated on site as utilities, purchasing and production figures were not made available during the audit. The report therefore gives general recommendations resulting from observations, talking to personnel on site and based upon best practice guidelines for waste reduction.

Processes/Energy/Materials

Rework

• Rework costs at each stage of processing should be determined through consideration of:
  • The cost of additional materials required (for example paints and thinners for coating)
  • The costs of cleaning the job for rework
  • Labour costs required for rework
  • Energy costs required for rework

Painting

• Ancillary materials such as paint in metal fabrication are often poorly managed and wastes could be significant and expensive. Without access to purchase records, it is not possible to quantify losses.
  
  
• ABC need to estimate the amount of paint and solvent used and purchased each year and compare these figures with accurate waste disposal figures. This may not only enable the company to identify areas of significant wastage, but also highlight as to whether ABC are legally required to have an LAPC process authorisation. (Refer to the Environmental Review under Emissions to Air for details). When investigating this, the company should compile and maintain a solvent inventory, through:
  • Obtaining details from solvent supplier(s) concerning solvent purchases and advice on how to work out solvent losses.
  • Obtaining details of paint purchases, including the solvent content of paints from paint suppliers. (Appendix.1 gives the densities of some common industrial solvents).
  • Tracking and recording the amount of waste paint tins / drums generated over a representative period such as 1 month.
  
  
  
• Measure on a weekly basis the amount of energy used and quantity of material (solvent and paint) and compare this to work undertaken such as:
  • Components coated.
  • Area for painting.
  • Amount of spray guns cleaned.
  
  
  
• Improved housekeeping of paints and associated chemicals used in the coating processes undertaken on site will also reduce consumption. Such measures include:
  • Replacing lids and caps on drums and tins.
  • Good storage to avoid spillages.
  • Ensuring that tins / drums are completely empty prior to putting them into the waste skip. (Should they contain in excess of 0.1% liquid residues, then they will be classed as Special waste- this is costly to dispose of).
  • Ensuring that stock is rotated.
  • Measuring out and mixing only the amount of paint for the job.
  • Fixing any leaks in the paint distribution pipework, and setting up a regular preventative maintenance programme.
  • Ensure all relevant personnel are aware of the above.
  • Ensure that the paint plant itself is clean- a dirty plant could contaminate components and thus lead to rework.
  
  
  
• The handling of work pieces also has implications for paint consumption. Consumption can be reduced through:
  • Using hooks to hang pieces during spraying or a wheeled A-frame for larger pieces - this enables the work piece to be sprayed from all sides with ease, and for other pieces to be loaded as those already sprayed are drying.
  
  
  
• Scheduling paint jobs efficiently through coating large batches of components requiring the same finish, for example, will reduce set up times and cleaning.

Processing of Metal / Machining

• Machining is very wasteful of the raw material (steel, stainless steel, brass, bronze and nylon bar). Where possible, the company should substitute this with other processes such as forming.
  
  
• Where machining cannot be avoided, the minimum stock blank size should be used - this also has the potential to reduce tool wear and breakdowns, coupled with metal waste.
  
  
• Components should be nested in blocks or sheets of metal in order to reduce cut off waste.
  
  
• Lengths of metal should also be optimised where a variety of sizes are to be cut.
  
  
• Swarf should always be recovered, segregated by type and put into the scrap metal skip.
  
  
• The company should look into the feasibility of undertaking processes that are currently sub-contracted, such as flame cutting in house.
  
  

Energy / Fuel

• Heating of the site needs to be controlled. The buildings should be heated to a maximum temperature of 19°C for each 1°C overheating, it is widely accepted that costs will rise by around 8%. A general rule is that offices should be heated to around 19°C, Workshops to 16°C and Stores etc to 10°C - 12°C.
  
  
• Air heaters should be serviced at least annually as reduced performance is caused by wear on controls and linkages and deposit build up resulting from combustion.
  
  
• The company should aim to fill up oil tanks during the summer months to take advantage of reduced prices.
  
  
• A feasibility study into the conversion of the heating system from gas oil to natural gas fired should be undertaken. Natural gas is nearly 100% methane. The combustion of methane is much cleaner than that of gas oil, and indirect emissions of greenhouse gases of carbon dioxide considerably reduced.
  
  
• The compressor on site is new and has an oil/water separator- the water can be sent to foul sewer and the oil drained into a suitable drum and disposed of as Special waste around 1-2 times per year. Currently, the mineral oil and water is left to drain into small tubs on the floor of the factory via and open valve, and is not disposed of. This is not only wasting expensive air, (the company should consider fitting an automatic drain valve), but is also contravening environmental regulation concerning hazardous waste and discharges of environmentally polluting substances covered both by the Water Resources Act 1991 and the Special Waste Regulations 1996. Disposal of this waste is covered in greater detail under the recommendations given in the later section on waste management.
  
  
• A compressed air survey should be undertaken to:
  • Ensure that all pipework is correctly sized to reduce pressure and distribution losses.
  • Implement an appropriate maintenance schedule of the system
  • Blank off redundant areas / isolate areas of low use / different operating pressures.
  • Identify areas where compressed air tools could be substituted for electrically operated equipment.
  • Identify all leakages through no load testing and electrical metering.
  • Identify the times when compressors can be switched off as up to 70% of on load power can be consumed when compressed air is not in use.
  • Look into the feasibility of drawing air from outside the building which would increase operation and cut costs by up to 3%.
  • Ensure that the correct air receiver capacity is being used.
  • Look into the feasibility of heat recovery (over 90% of the energy used by a compressor is converted into heat), for space heating.
  
  
  
• The shop floor lighting system in the can be made more energy efficient through the use of high pressure discharge lighting- the current tungsten halogen lights are very expensive to run. Furthermore, raising staff awareness to switch off lights when not in use will also cut electricity costs. There are many means by which the lighting systems on site can be maximised, and the company should look into these further.
  
  
• The feasibility of nightshift work should be investigated to take advantage of the reduced electricity cost.
  
  
• Details of motors on site were not available during the audit. Motors can consume a significant amount of electricity which can be reduced through consideration of the following:
  • Reduction of the speed-through the installation of variable speed drives or rewiring can reduce the speed of the motor.
  • The motor may not be sized correctly - average and peak motor loads should be checked
  • High efficiency motors can be installed - these are around 1-4% more efficient.
  • Replacing old motors - the efficiency of motors declines each time they are re-wound
  
  
  
• A transport improvement strategy should be implemented to:
  • Ensure that all vehicles are regularly maintained and serviced (with emissions testing)
  • Look into all possibilities of alternative vehicles and fuel over the next year
  • Assess vehicle use and route planning methodologies every 6 months
  • Improve the fuel efficiency of the entire fleet (including company cars) by 5% over the next two years
  • Encourage at least 50% of all employees to use car pooling systems, public transport, cycling and walking where possible over the next year.
  
  
  
• Storage space needs to be improved on site:
  • Currently, all steel off-cuts are disposed of as scrap due to lack of storage- this is both an extremely wasteful and costly exercise. Where machining and processing practices mentioned earlier cannot be adopted to minimise off cut waste, an area should be designated to store the steel off-cuts (for future reuse). It is estimated in a typical week that the company can generate in excess of one 8 cubic yard skip of this waste.
  • Work pieces should not be stored in the compound opposite the building - it is not secure and open to vandalism and theft- resulting in waste and thus incurring additional costs.
  
  
  

• All loading and unloading areas of oil and chemicals need to be designated, marked out and isolated from the surface water drainage system.
  
  
• The scrap metal skip should to be lidded to prevent the escape of wind blown litter, and bunded to prevent the escape of oil.
  
  
• Many pollution incidents are a direct result of poor security. The company should therefore ensure that all gates, doors and valves are locked in both the factory area and external storage facilities. All fenced areas should be made secure and materials should all be stored undercover.
  
  
• Oil and chemical storage areas must be bunded. The bund must be impermeable and be able to hold at least 110% of its contents. Detailed guidance on above ground oil storage: PPG2: Above ground Oil Storage Tanks should be obtained from the Environment Agency.
  
  
• The appropriate spill kits should be stored next to all oil and chemical storage areas, and relevant personnel trained in their use.
  
  
• The oil pipe lines running along the internal walls of the factory should be encased in protective sleeves or ducting.
  
  
• All deliveries of oil need to be strictly supervised by a trained member of personnel, and any spillages isolated immediately with the appropriate material. Tankers should discharge oil via a lockable fixed coupling within the bunded area. Personnel should ensure that automatic cut off valves should be fitted to delivery pipes to prevent overflowing.
  
  
• A chemicals inventory should be devised and kept up to date.
  
  
• The company needs to give consideration to fires and how to deal with contaminated fire water. A first step is through obtaining PPG20: Pollution Prevention Measures for the Control of Spillages and Fire Fighting Run-off from the Environment Agency.
  
  
• Compressor condensate should be disposed of as Special Waste using the consignment note system under the Special Waste Regulations 1996.
  
  
• There is no record of a waste licence on site for the waste contractor - SITA - for the general waste skip and East Co. for the scrap metals skip. It is therefore unknown as to whether the companies are licensed to remove and store the waste prior to sending it to landfill / recycling. ABC Engineering do not have copies of waste carrier's certificates which detail a waste carrier's registration - these are important requirements of the Duty of Care provisions under the waste section of the Environmental Protection Act 1990. (refer to the table of legislation at the end of the report). Under this legislation, ABC Engineering are also required to keep waste transfer notes on file for at least two years - these were not on site during the audit.
  
  
• The general waste skip must be used only for solid industrial wastes for food, drinks, office wastes, packaging etc. and not metals or paint tins containing residues. The scrap metal skip should be used for this purpose only. Recycling opportunities for all wastes that cannot be reused / reclaimed on site should be explored, for example plastic cups.
  
  
• Undisposed waste on site should be disposed of as soon as possible, for example - the asbestos waste observed in the external yard should be double bagged, tagged and disposed of as Special Waste by a suitable contractor.
  
  
• Appendix 2 tabulates the responsibilities of each waste holder in relation to the Duty of Care requirements.
  
  
• Training of personnel is required in order to reduce waste. Detailed waste management training is necessary to key employees upon improvements being made.
  
  
• A waste costing exercise will enable the company to understand the true costs of its waste. This involves comparing the cost of the raw material in the waste added to the cost of disposal. This is reliant upon more accurate figures than were made available during the audit and is something that the company should consider undertaking in the near future.
  
  

2. Compliance with waste management legislation

Controlled Waste

Part 2 of the Environmental Protection Act 1990 (EPA) defines any waste that comes from industrial, commercial or domestic sources as being controlled waste. The EPA established a duty of care on anyone (except householders) who has control of, or responsibility for, controlled waste at any stage from its production to its disposal.

Special Waste

Certain controlled wastes are considered to be potentially hazardous and require special handling and treatment. The handling of these wastes is controlled by the Special Waste Regulations 1996 (SWR) as amended, which defines a more stringent system of control.

Appendix 1. Solvent Volumes

The local council will require information concerning the weight in kilograms of solvent consumed and disposed of. To convert solvent volumes to weights their density must be calculated. The table below gives densities of common solvents. The equation below calculates the weight of solvent from its density and Volume:

Appendix 2: Responsibilities of Each Waste Holder