These notes are for guidance only. They are produced by the Environment Agency in England and Wales, the Scottish
Environment Protection Agency and the Environment and Heritage Service in Northern Ireland, referred to as the
Agency or Agencies. Sites are considered according to the individual circumstances and contact with your local Agency
office is advisable. Contact details will be found at the end of these guidelines.
Note that in these guidelines the term 'oil separator' is used. This has the same meaning as 'oil interceptor'.
1. LEGAL FRAMEWORK
a. The Agencies are responsible for the protection of "controlled waters" from pollution, for the prevention of pollution of the environment and harm to human health by waste management activities and for the regulation of radioactive substances (except in Northern Ireland, where different legislation applies).
"Controlled waters" include all watercourses, canals and water contained in underground
strata (groundwater) and it is an offence to pollute such waters, either deliberately or
accidentally. In addition, the formal consent of the Agency is required for many discharges
to controlled waters, including both direct discharges and discharges to soakaways. Such
consents are granted subject to conditions and are not issued automatically.
b. Discharges to the public foul sewer require authorisation by the sewerage undertaker and
may be subject to the terms and conditions of a trade effluent consent. Where reference is
made to disposal to sewer, this should always be subject to such approval.
c. Any other waste produced on the site will be subject to the Duty of Care (Reference 1) under
the Environmental Protection Act 1990 and may also be subject to control under the Waste
Management Licensing Regulations 1994. In addition, certain hazardous wastes are subject
to the Special Waste Regulations 1996 (Reference 2). Separate legislation applies in Northern
Ireland. Advice is available from the Agencies.
d. The storage, use and disposal of radioactive substances normally needs a licence from the
Most pollution incidents are avoidable. Careful planning of facilities and operational procedures can reduce the risk of spillage and simple precautions can prevent a spillage becoming a pollution incident. Most of the measures needed to prevent pollution cost very little, especially if they are included at the design stage. In contrast, the costs of cleaning up a pollution incident and compensating fisheries owners and other downstream users can be very high. Pollution prevention measures may also offer substantial economic benefits, including saving expensive raw materials and products, minimise the frequency of site accidents, and reduce the risk of prosecution for water pollution offences. Introduction of pollution prevention measures is the first step, but to be effective, employees must understand why they are needed and be trained in their use.
3. SITE DRAINAGE
On most sites there will be two types of drain:
i. Surface water drains should carry only uncontaminated rainwater from roofs and clean yard areas to a watercourse or soakaway. Under some circumstances, treatment may be required
before discharge (see Section 5( a)).
ii. Foul drains should carry contaminated water, trade effluent and domestic sewage to a treatment works.
Wrongly connected effluents can cause severe pollution problems, which are often costly to remedy. Ensure that new or temporary facilities, such as sinks, showers, canteens, laboratories and washdown areas, are properly connected to the foul drain and not just the nearest drain, which might be the surface water system. Internal floor gullies, if provided, are readily contaminated and must be connected to the foul drain.
All drainage systems should be maintained in working order. A programme of regular inspections should be established and gullies and sumps should be cleaned as required by suitably registered contractors.
A frequently occurring factor in pollution incidents is a lack of awareness of the purpose of drains and gullies. Therefore, it is recommended that gullies, grids and manhole covers are colour coded to aid identification, using blue for surface water and red for foul. Use notices where appropriate and keep a set of up-to-date drainage plans on site.
4. SEWAGE AND WASTE WATER DISPOSAL
a. Domestic sewage Care should be taken that all drainage from welfare facilities such as toilets, showers and canteens is connected to the foul drainage system. Such connections may require approval from the sewerage undertaker.
b. Trade effluent In addition to process effluent, trade effluent also includes compressor or boiler blowdown,
steam condensates, cooling water, pressure testing liquids, air conditioning water and vehicle and plant cleaning effluent. Before making a discharge, the alternatives should be
considered carefully, including recycling, minimisation and reuse on site. All such discharges require prior consent either from the local sewerage undertaker for discharges to the foul
sewer, or from the Agency for discharges to watercourse or groundwater. Both of these consents will incur charges and you will be responsible for complying with the terms of the
consent. Failure to do so may result in prosecution. You should ensure that:
i. Responsibility for the discharge is clearly defined.
ii. The effluent discharge point is clearly marked.
iii. The sampling point is safe and accessible at all times.
iv. Regular visual inspections are made, samples taken and tests carried out if appropriate.
5. SURFACE WATER DRAINAGE
Surface water drainage discharges to a watercourse or to groundwater via a soakaway. Surface water must therefore be clean and uncontaminated. A discharge of waste water to the surface water drain will result in pollution.
a. Treatment of surface water drainage Large car parks, access roads and hard surfaced areas can give rise to pollution due to oil drips from vehicles and the accumulation of dust and litter. The run-off from such areas may require treatment before discharge. The Agencies have published guidance on surface water disposal (Reference 3), which describes options for treatment. These range from permeable surfaces and infiltration trenches, offering control at source, to end of pipe systems, such as swales and constructed wetlands. They are collectively known as "Sustainable Urban Drainage Systems".
b. Oil separators Where it is not possible to use sustainable drainage techniques, an oil separator may be
required on the drainage from large parking areas or from the area immediately around above ground oil storage tanks, depending on the risk of contamination or
Guidelines for the selection and installation of oil separators are available (Reference 4). Oil separators need regular inspection and must be emptied when required, by a suitably registered contractor, in order to function effectively.
c. Consent to discharge Should surface water drainage become contaminated, a consent to discharge will generally be required. However, if the guidance in this document is followed, and potential sources of contamination are isolated from the surface water systems, a discharge consent will not usually be required.
d. Cut-off valves A cut-off valve on the drainage system provides improved security if used to isolate designated risk areas, for example during the delivery of hazardous chemicals or for areas regularly cleaned using chemicals. In some cases, these are used with off-line storage tanks.
Their use ensures that a spillage can be retained on site for suitable treatment and disposal. Contaminated 'fire water' could also be contained in the event of a fire.
e. Roof water down pipes Uncontaminated roof water should be discharged directly to the surface water system via
direct drain points or sealed top, side entry gullies. Open gullies or grates should be avoided, as they provide an entry route for contamination. Roof drainage should not normally pass
through any oil separator.
6. DELIVERY AND HANDLING OF MATERIALS
The handling of materials always involves a risk of spillages and accidents. It is therefore important to identify these risks so they can be minimised.
a. Loading and unloading areas should be designated, marked and isolated from the surface water drainage system.
b. The routes used for the movement of materials on site should be identified so that any necessary protection can be incorporated.
c. Yard areas used for storage, handling and manufacturing should be roofed to reduce the volume of contaminated drainage for disposal and drained to the foul sewer.
d. High risk areas, such as refuelling points should be isolated from the surface water system using ramps, roll-over bunds or stepped access.
e. Deliveries of oil and potentially hazardous materials should be supervised. If there is a spill, it should be contained and reported immediately. DO NOT HOSE IT DOWN.
f. Tankers should discharge via a lockable fixed coupling within the bunded area.
g. Automatic cut-off valves should be fitted to delivery pipes to prevent overfilling.
h. Where possible, pipelines should be sited above ground. If a pipeline is to be installed underground, it should be placed in a leak-tight protective sleeve or duct and subject to regular inspection and testing. Pipeline ducts should not be connected to the surface water drainage system.
7. STORAGE FACILITIES
a. Underground storage tanks are susceptible to damage and corrosion, and above ground facilities are preferred. In areas of high groundwater vulnerability (References 5 and 6) the Agency may object to the installation of underground storage tanks. Where underground storage is necessary, protective measures such as double skinned tanks and piping and leak detection may be required. In some circumstances, underground tanks may be fitted within a basement style bund.
b. All above ground storage tanks, drums and containers should be sited on an impermeable base within a bund. The bund should be constructed of a material impermeable to the liquid stored. For guidance on above ground oil storage, see Reference 7. Storage at or above roof level should be avoided.
c. Always use appropriately sized and constructed tanks or containers that will not leak or corrode, ensuring that they are clearly labeled with their contents and volume.
d. Drums and other liquid containers should be provided with drip trays when in use.
8. WASTE MANAGEMENT
Waste management is a complex area of legislation. This section provides a brief outline of the principal issues, but you are advised to contact your local Agency office for site specificguidance and advice.
a. Reduction, re-use and recycling Methods to reduce the amount of wastes, such as re-use and recycling, should be
considered. Significant savings may be made as material and waste disposal costs continue
to rise (Reference 8).
b. Duty of Care and waste legislation Under the Environmental Protection Act 1990, producers of waste have a Duty of Care to
ensure that it is properly managed. Waste must be securely stored on site and the producer
has a duty to ensure that the waste contractor who removes it is registered with the Agency
and is informed of its nature. The burning of waste and on-site disposal are both subject to
the Waste Management Licensing Regulations.
c. Storage If waste cannot be eliminated, it must be stored and disposed of appropriately, which may,
under some circumstances, require a licence from the Agency. Litter is polluting and must
not be allowed to escape. Skips and containers should not be overfilled and should be
covered, or waste storage areas enclosed, to prevent waste being blown out.
d. Swarf skips and compactors Swarf skips and refuse compactors often leak polluting liquids. They should be placed on an
impermeable base and isolated from the surface water drainage system, using a spill tray,
raised kerbs or "roll-over" bunds. It is preferable to cover them, to avoid rainwater
accumulation, and to connect the drainage to the foul sewer. Any leakage should be cleaned
up straight away using sand or
absorbent material. Compactors are exempt from the need
for a waste management licence, but must be registered with the Agency.
e. Packaging regulation If a company handles more than 50 tonnes of packaging per year, and has an annual
turnover in excess of £2 million, it may be required to register with the Agency or a
compliance scheme to ensure that the recovery and recycling obligations of the Producer
Responsibility Obligations (Packaging Waste) Regulations 1997 are met.
f. Liquid wastes Liquid wastes, including solvents and oil, must be securely stored in bunded compounds
prior to collection by a registered waste contractor (see References 9 & 10). Under no
circumstances should any waste liquids be discharged to the surface water system. Some
liquid wastes may be discharged to the foul sewer via a designated facility, if an appropriate
trade effluent consent is in place (see Section 1b).
g. Special wastes Certain hazardous wastes including solvents and oils are defined as being "special wastes"
and a more rigorous consignment note system applies (see Reference 2).
9. ROUTINE INSPECTION AND MAINTENANCE
A routine programme of inspection and maintenance for oil separators, effluent treatment plants, storage tanks (both above and below ground), pipework, drains, bund walls, notices and any pollution prevention equipment should be established. There should be a clear reporting procedure leading to rapid corrective measures where needed. Where possible, give staff personal responsibility for the maintenance programme.
10. CLEANING AND DEGREASING
All cleaning activities, including the cleaning of equipment, yards, floors, containers and vehicles, can produce large volumes of polluted water. All cleaning agents are potentially polluting, even those claimed by manufacturers to be 'biodegradable' or acceptable for discharge to drains. Water containing detergents, disinfectants, degreasers or any other cleaning agent, including effluent arising from pressure or steam cleaners (see Reference 11), must not enter surface water drains or soakaways.
a. All cleaning and washing operations should be carried out in designated areas isolated from
the surface water system and draining to the foul sewer. The area should be clearly marked
and use of a kerb surround or "roll-over" bund is recommended. Consideration should be
given to water recycling.
b. Ensure all staff and contractors working on site are aware of the disposal facilities for wash
waters by using clear signs. Use notices to identify surface water gullies, indicating clearly
that they should not be used for the disposal of waste water.
c. Yard areas draining to the surface water system should not be degreased or steam cleaned
(i) the gullies are sealed off and any liquid soaked up with absorbent material, or
(ii) a valve is fitted at the outlet to the system and closed during the cleaning operation. The accumulated washings should then be removed for disposal by a registered waste carrier.
11. DEMOLITION AND CONSTRUCTION
Construction and demolition activities on your site may generate waste and increase the risk of pollution (Reference 12). Ensure that old tanks and pipework are empty before they are disturbed and that any temporary chemical and oil storage facilities are bunded. Provision should be made for the treatment of silty water and remember that cement and concrete are harmful to watercourses.
12. STAFF TRAINING
Staff should be made aware of the relevant legislation and of their own responsibilities. Include pollution prevention information in on site staff and contractor training. Use newsletters, posters and notices to reinforce the message. Your local Agency office may be able to assist with training materials and speakers. Key staff should be familiar with the drainage systems, and carry out exercises to rehearse actions in the event of a spillage. They should have access to important telephone numbers such as the Emergency Services, the local water company and the Agency. Encourage staff to identify pollution risks and solutions, perhaps by using a staff suggestion scheme.
13. EMERGENCY PLANS
Carry out a complete inspection of the site to identify potential sources of pollution. Where these can be removed by changing practices, materials or other means, draw up an action plan to deal with them. An inventory of chemicals held should be made and kept up to date and available on site. Prepare contingency plans for all eventualities (see Reference 13 for guidance and a plan template) and locate instruction notices, appropriate equipment and materials (such as shovels, sand, absorbent materials and drain bungs) at accessible key locations. Consider the effect of a major fire and plan how to deal with contaminated fire water (Reference 14). Ensure that a named contact is available at all times to deal with emergencies and to liaise with the emergency services and the Agency.
Protect your site from vandalism and theft. Many pollution incidents are the result of poor security. Lock gates, doors and valves and make fences secure. Where possible, store materials under cover.
1. Waste Management -The Duty of Care -A code of practice: ISBN 0-11-753210-X
2. Classification of special waste: Information Sheet 1: Environment Agency
Use of the consignment note: Information Sheet 2: Environment Agency
Obtaining and sending consignment notes: Information Sheet 3: Environment Agency
A Guide to the Special Waste Regulations 1996: SEPA
A Guide to the Special Waste Regulations (Northern Ireland) 1998: Environment and
3. Sustainable Urban Drainage Systems -an introduction: SEPA/ Environment Agency
4. PPG3: The use and design of oil separators in surface water drainage systems
5. Policy and Practice for the Protection of Groundwater: ISBN 0-11-310145-7
6. Groundwater Protection Strategy for Scotland: SEPA
7. PPG2: Above ground oil storage tanks
8. "Money for nothing, waste tips for free" waste minimisation video: Environment Agency:
Telephone 0345 337700 to order a free copy.
9. PPG8: Safe storage and disposal of used oils
10. Solvent pollution and how to avoid it
11. PPG13: High pressure water and steam cleaners
12. PPG6: Working at demolition and construction sites
13. PPG21: Pollution incident response planning
14. PPG18: Pollution prevention measures for the control of spillages and fire fighting run-off
References 1 and 5 are available from the Stationery Office,
Tel: 08706 00 55 22
References 2-4, and 6-14 are available free from the Agencies
E M E R G E N C Y HOT L I N E
0800 80 70 60
The 24-hour emergency hotline number for reporting all environmental incidents relating to air, land and water in
England, Wales, Scotland and Northern Ireland.
ENVIRONMENT & HERITAGE SERVICE SCOTTISH ENVIRONMENT
Peterborough PE2 5ZR
Tel: 01733 371 811
Fax: 01733 231 840
550 Streetsbrook Road
Solihull B91 1QT
Tel: 0121 711 2324
Fax: 0121 711 5824
21 Park Square South
Leeds LS1 2QG
Tel: 0113 244 0191
Fax: 0113 246 1889
Richard Fairclough House
Warrington WA4 1HG
Tel: 01925 653 999
Fax: 01925 415 961
The Castle Business Park
Stirling FK9 4TR
Tel: 01786 457 700
Fax: 01786 446 885
World Wide Web: http: // www. sepa. org. uk
NORTH REGION HQ
Dingwall Business Park
Dingwall IV15 9XB
Tel: 01349 862 021
Fax: 01349 863 987
WEST REGION HQ
5 Redwood Crescent
East Kilbride G74 5PP
Tel: 01355 574 200
Fax: 01355 574 688
EAST REGION HQ
Heriot-Watt Research Park
Edinburgh EH14 4AP
Tel: 0131 449 7296
Fax: 0131 449 7277
23 Castle Place,
Tel: 028 9025 4868
Fax: 028 9025 4777
Rio House, Waterside Drive, , Aztec West
Almondsbury, Bristol BS32 4UD.
Tel: 01454 624 400 Fax: 01454 624 409
World Wide Web: http: // www. environment-agency. gov. uk
West Sussex BN11 1LD
Tel: 01903 832 000
Fax: 01903 821 832
Exeter EX2 7LQ
Tel: 01392 444 000
Fax: 01392 444 238
Kings Meadow House
Kings Meadow Road
Reading RG1 8DQ
Tel: 0118 953 5000
Fax: 0118 950 0388
St Mellons Business Park
Cardiff CF3 0EY
Tel: 029 2077 0088
Fax: 029 2079 8555
All the Agencies' pollution prevention guidance notes are available on the web sites listed below.