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Pollution Prevention Guidelines

Refuelling Facilities: PPG7


These guidelines are intended to help you reduce the risk of pollution occurring from your site by giving guidance about the design, construction, modification, management and operation of liquid fuel refuelling facilities of all sizes inretail and non-retail locations. The guidelines provide the background information needed to help you protect the environment through correct delivery, storage and dispensing of fuels. They highlight relevant current legislation and recommended good practice, and refer to other more detailed documents where appropriate. These guidelines are not intended for IPC and PPC processes regulated by the Agencies where Best Available Techniques (BAT) would apply.

These notes have been produced by the Environment Agency for England and Wales, the Scottish Environment Protection Agency and the Environment and Heritage Service in Northern Ireland, which are referred to here as the Agency or Agencies.

1. Introduction

Oil is the most common water pollutant, with the potential to harm watercourses and groundwaters. In addition, certain fuels, such as petrol, are highly flammable and are tightly regulated for safety reasons. The guidance in this document is applicable to all refuelling facilities and should be consulted regardless of the type of facility. Additional legislation, levels of good practice and guidance may apply, depending on the:
• type of fuel stored
• quantity of fuel stored
• type of facility used
• intended use of the fuel
• environmental sensitivity of the location.

The flowchart shown in Figure 1 highlights other guidance that may apply to your refuelling facility. These should be read in addition to this document.

Figure 1
Other guidance on preventing pollution from refuelling facilities

Additionally, Guidance for the design, construction, modification and maintenance of petrol filling stations (Reference 1) – known as the ‘Blue Book’ – covers many aspects of design and construction. Although this guidance refers primarily to retail facilities, it is often applicable to delivery, storage and dispensing from non-retail facilities and should be consulted for more detailed technical guidance.

The Health and Safety Executive’s Local Authorities Enforcement Liaison Committee (HELA) issues circulars in order to achieve consistent standards in health and safety enforcement between local authorities. HELA’s petroleum enforcement liaison circulars (PETELs) provide local authorities with advice and guidance on enforcement and technical matters. The guidance in these circulars covers many aspects of a refuelling facility and may be applicable to nonretail facilities which dispense fuels other than petrol. Further guidance on other specific aspects of pollution prevention that may be applicable to your site is available from the Agencies (see the contact details at the end of this guidance).

2. Legal Framework
(a) Pollution control
The Agencies are responsible for protecting controlled waters from pollution and for preventing pollution of the environment, harm to human health and detriment to local amenities. Controlled waters include all watercourses, lakes, lochs, coastal waters and water contained in underground strata (groundwater). It is an offence to pollute such waters, either deliberately or accidentally.

In addition, regulations introduced in 1998 to protect groundwater specify that certain groups of substances, including most liquid fuels, should not be allowed to enter groundwater. Groundwater Protection Codes for the use of underground storage tanks have been developed (Reference 2) under these regulations.

If an activity such as the delivery, storage and dispensing of fuels presents an unacceptably high risk of causing pollution, the Agencies may serve a notice before pollution has occurred, which prohibits the activity altogether or requires compliance with specific conditions. The conditions of a notice can relate to any aspect of your site that may increase the risk of pollution and may apply controls over and above precautions identified in any relevant codes of practice or Groundwater Protection Codes (Reference 2). Failure to comply with the conditions of a notice is a criminal offence.

(b) Drainage from the site
The formal consent of the Agencies is required before any discharge of potentially contaminated drainage to controlled waters. This applies to all direct discharges into surface waters or groundwaters, and to discharges into groundwater via soakaways. Such consents are granted subject to conditions and are not issued automatically.

All discharges to the public foul sewers (foul or surface water) require prior authorisation from your local sewer provider and may be subject to the terms and conditions of a trade effluent consent or trade effluent agreement.

(c) Storage of petrol
The keeping of petrol is regulated under the Petroleum (Consolidation) Act 1928 and the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR). Operators dispensing petrol must liase with the local Petroleum Licensing Authority (PLA), which will provide further advice.

(d) Planning permission
Approval from your local planning authority is likely to be required for new or modified refuelling facilities.

(e) Storage of all fuels above or below ground
Although it may not be a legal requirement, the Agencies recommend that fuel tanks and pipework are installed above ground wherever possible. This can make it easier to carry out regular maintenance checks and to identify leaks earlier.

The Agencies have published specific guidance relating to above ground oil storage (see Reference 3). In England, above ground fuel storage may have to comply with specific legislation, the Control of Pollution (Oil Storage) (England) Regulations 2001, a key requirement of which is the provision of secondary containment such as a bund or a drip tray.

Any above ground facilities not covered by specific regulations should be designed, operated and maintained in accordance with PPG2 (Reference 3) in order to prevent pollution.

Note: Similar regulations are expected to be introduced in Scotland during 2005 and may follow in Northern Ireland and Wales. Check with the relevant Agency for up to date information.

The storage and handling of fuels in drums and intermediate bulk containers are covered in separate Agency guidance (see Reference 4).

Activities that pose a threat to groundwaters, including the storage of fuels in underground storage tanks, are primarily covered by the Groundwater Regulations 1998 and accompanying Groundwater Protection Codes. The relevant Groundwater Protection Codes (Reference 2) should be consulted wherever an underground facility is present or planned.

Note: The Agencies do not endorse or approve any particular oil storage products and express no preference for the materials used.
 

3. Assessing environmental risk
An Environmental risk assessment should be undertaken for every facility regardless of size. Risk assessment is a technique by which the ‘dangers’ or hazards present in any situation are evaluated to determine whether they are acceptable or whether action is required to reduce them to an acceptable level. Environmental risk assessment and the management of risk are the bases for preventing pollution of the environment. When designing new facilities, however, emphasis should be placed on hazard prevention rather than risk management, i.e. avoiding the problems in the first place rather than attempting to control them through engineering and operational solutions.

Environmental risk assessments should be based on the source–pathway–receptor model, which works on the theory that, if there is no linkage or the linkage between one or more of these components is broken, then there is no unacceptable risk. For a refuelling facility, one source or hazard would be the fuel stored, while one receptor might be an adjacent river and one pathway could be the site drainage system. An example of risk management that breaks this particular source–pathway–receptor linkage is the use of compliant fuel storage and drainage systems.

In any risk assessment, all the possible source–pathway–receptor linkages need to be considered as there are likely to be several. For example, you may also need to consider the risk to the groundwater under the site and the subsequent impact on local abstractors, or the movement of contaminants via groundwater to the river.

Groundwater can be both the target receptor itself and/or the pathway to other receptors.

Any site environmental risk assessment should take account of the following:
Hazard identification. Identify polluting materials such as fuels, detergents, lubricants, solvents and all wastes or processes that may give rise to pollution such as fuel delivery, dispensing and storage.
Possible scenarios. Consider what could go wrong, e.g. spillages, leaks, fire, vandalism, flood and any other accidents, incidents and emergencies.
The impact of possible scenarios. Consider the potential scale of the incident and the environmental sensitivity of your site. Will controlled waters be affected? Could there be an impact on-site and off-site, near or far, short or long-lived, permanent, immediate or delayed or potential impact on human health and safety?
Likelihood of scenario occurring. Consider how likely an incident is to happen. This can be done by making a simple judgement of high, medium or low probability, or by using relevant data (where available) in a more in-depth analysis.

The next step is to consider whether or not the risks are unacceptable, and what options are available to reduce these risks. Risk reduction can be achieved by:
• complying with relevant regulations and good practice guidance
• putting good operational, management and emergency procedures in place (see Section 5).

In addition, the costs, benefits and social considerations should be considered as outlined in more detail in Guidelines for Environmental Risk Assessment and Management (Reference 5).

The extent to which each of the above factors needs to be considered will depend on the circumstances and the magnitude of the hazard.

Information about local environmental sensitivities can be obtained by contacting your local Agency office or, in England and Wales, by following the links to the ‘What’s in your backyard’ section of the Environment Agency’s website (www.environment-agency.gov.uk).

When determining the environmental sensitivity of your location, the following should be considered:
• proximity to surface waters such as springs, ditches, lakes, streams and rivers;
• groundwater vulnerability and proximity to abstraction sources (e.g. wells and boreholes);
• proximity to sensitive ecological systems such as Sites of Special Scientific Interest (SSSIs)

Simple guidance on how to carry out a risk assessment for underground storage tanks is available in the Groundwater Protection Codes (Reference 2).

4. Site drainage
(a)
Types of drainage system
There are two types of drainage system.

In a separate system, foul sewers carry contaminated water (sewage and/or trade effluent) to a sewage treatment works, which may either be owned privately or by the local sewage treatment provider. The separate network of surface or clean water drains should only carry uncontaminated rainwater because it leads directly to ditches, streams, rivers or soakaways.

A combined system has one drain, which carries both foul and surface water to a sewage treatment works. A combined system may overflow directly into a watercourse during periods of high rainfall.

Where public foul sewers are unavailable, additional guidance is available (see Reference 6).

Incorrect or poorly maintained site drainage systems are a common pathway for both small spillages and major leaks of fuels to enter the wider environment and cause pollution. To help prevent this:
• Produce a comprehensive and up-to-date drainage plan of the site, which identifies accurately the destination of all drains and shows them as foul, surface or combined. If this cannot be done in-house, employ a reputable drainage company.
• Identify drains and gullies clearly in the plan and on the ground. The standard colour coding is blue for surface water, red for foul sewer and a red ‘C’ for combined systems.
• Maintain the system regularly.
• Make plans of the drainage system readily available on site.
• If there are any changes on site, check the drainage plan to ensure new connections are made to the right drains. Update the plan when the work has been finished.
• If there are any changes on site, check the drainage plan to ensure new connections are made to the
right drains. Update the plan when the work has been finished.

For guidance on producing drainage plans see Reference 7.

(b) Clean water
All clean, uncontaminated rainwater should be channelled to:
• a surface water drainage system
• a combined drainage system downstream of the oil separator
• directly to a local watercourse or soakaway.

This includes roof water and uncontaminated drainage from those areas of the site where vehicles are not stored, repaired, refuelled or washed. Such discharges may require prior permission from the Agencies or the local sewer provider.

(c) Contaminated water
The entire area where fuel is delivered, stored and dispensed should be isolated from the surface water drainage system, open ground or other porous surfaces. This can be achieved using drainage grids, gullies or kerbs in conjunction with surfaces impermeable to the products used. Potentially contaminated water and spills should be directed through an oil separator (see Reference 8) and prevented from seeping into the soil and groundwater below the site. The separator should be of an adequate size to serve the surface area catchment of the site.

Note: the term ‘separator’ is used here instead of ‘interceptor’. These terms have the same meaning.

(d) Sustainable drainage systems (SUDS)
The use of sustainable drainage systems (SUDS) should be considered. SUDS such as constructed wetlands or reed beds may offer an environmentally friendly alternative to traditional methods of treating drainage effluent. Wetland or equivalent technology can be used for a variety of wastewater treatment purposes at refuelling facilities. It may also be suitable as a replacement for on-site separators for oily water run-off, provided the system is compatible with local groundwater conditions.

Wetlands systems can offer an acceptable level of environmental protection provided they are properly designed, installed and maintained. In some situations, they may provide better environmental protection than conventional drainage systems. Further information is given in PETEL 65/45 (Reference 9).

Note: The Agencies should be contacted during the early design stages of a wetland system to ensure that they provide an adequate level of treatment and to ascertain the requirements for the permitting of any discharges.

(e) Washing activities
All washing and cleaning operations, including the washing of all vehicles or plant, should be carried out in a designated area clearly marked on the ground and in any plans. The cleaning area should be isolated from both the surface water drainage system and unmade ground or porous surfaces (e.g. using drainage grids, gullies or kerbs).

Wash water should be recirculated whenever possible. Otherwise it should drain to, or be disposed of, via the foul sewer (where available); check with your local sewer provider before making a disposal to the foul sewer.

Cleaning agents such as detergents (including biodegradable ones) should never be allowed to enter the surface water system or to soak into groundwater unless specifically permitted after appropriate treatment.

They should not enter oil separators because they reduce their effectiveness (the oil will be dispersed and washed through).

(f) Further information
More detailed information on site drainage is given in Pollution Prevention Pays (Reference 10) and Reference 11. Additional information is also available about managing firewater and major spillages in Reference 12.

5. Operation, management and maintenance of the refuelling facility
The implementation of a site specific environmental management system (EMS) which details the correct operational control procedures for the site will greatly reduce the risk of a pollution incident occurring. As a minimum, the EMS produced for your site should include:
• operational control procedures
• training provision and records
• maintenance regimes and records
• leak detection and environmental monitoring
• appropriate emergency plans.

Activities that may need specific operational control procedures include:
• delivery
• dispensing
• maintenance
• training
• product volume monitoring
• response to major and minor spillages
• leak detection and notification.

(a) Maintenance
Even a small fuel leak can result in significant pollution. It is essential that all equipment on site, both above and below ground, is inspected frequently and maintained effectively to reduce the risk of leaks. A written record of such activities should be kept on-site and made available for inspection.

As a minimum, the maintenance programme should cover:
• checking the tanks
• pipework
• monitoring equipment
• dispensers
• separators
• manhole chambers
• drainage channels
• any other associated equipment or areas.

Where problems are identified, these should be recorded and corrected as soon as possible. Maintenance should be carried out in accordance with the manufacturer’s instructions (where available) or as necessary to prevention pollution of the environment.

(b) Training in dealing with emergencies
Staff should be trained to deal with an environmental incident. This may be a legal requirement. Set up a system of written training records and make these available for inspection. Training should include a background to environmental sensitivities around the site and a formal emergency procedure that details actions to be taken in the event of:
• a spillage
• a fire
• a collision with equipment
• odours being detected off-site
• a suspected leak being identified.

Make this procedure available on-site in case an emergency arises. It can take the form of a Pollution Incident Response Plan (PIRP). Guidance on the preparation of a PIRP is given in Reference 7 and more general guidance on spillage control methods is contained in Reference 13

6. Fuel storage and leak detection
The details in this section refer mainly to the underground storage of fuels. For further information about above ground tanks, refer to Reference 3. The Groundwater Protection Codes (Reference 2) should be consulted whenever an underground facility is present or planned.

A major leak involving the loss of large volumes of product in a short time period should be easy to detect. Smaller leaks from storage tanks and pipework are more common and may be difficult to detect, as they can be masked by normal variances in fuel throughput volume. Over a long period, this can result in the loss of a large volume of fuel. Leak detection equipment and techniques are available as new installations or as modifications on existing equipment.

Different leak detection equipment, techniques and systems can identify leaks at varying minimum detectable volumes. The most appropriate for use at a particular site may depend on the environmental sensitivity of the site and the outcome of an environmental risk assessment (see Section 3).

References 1 and 14 provide detailed guidance on storage tanks and leak detection systems. The Agencies recommend that the chosen leak detection system should comply with the BS EN 13160 series (Reference 15) or be of a similar acceptable level of standard.

Summarised information about different leak detection systems is given below. The preferred hierarchy for detecting the loss of product is:
• automatic leak detection system
• wetstock monitoring
• environmental monitoring
• integrity testing.

7. Waste management
A waste minimisation review may help you save money on raw materials and waste disposal costs. Further advice on waste minimisation and initiatives in your area can be obtained from your local Agency office. Free independent information and advice on waste minimisation is available from Envirowise (call the Environment and Energy Helpline on 0800 585794 or visit www.envirowise.gov.uk).

To avoid pollution, all waste (including separator waste and oil spill adsorbent materials) must be handled, stored and disposed of correctly. Waste producers and holders must ensure that waste:
• does not escape from their control
• is passed only to a registered waste carrier for recycling or disposal at a suitably licensed facility
• is accompanied by a transfer note with a full written description of the waste.

Guidance on how to comply with these Regulations is given in Reference 18.

Wastes generated from refuelling facilities are often classified as hazardous and may also be designated as ‘special wastes’. Consequently, they will be subject to additional controls on their storage, movement and disposal. Care should be taken to identify those wastes which are hazardous or special, to understand the requirements and to ensure compliance with legislation. The NetRegs website (www.netregs.co.uk) provides full details of waste legislation and how to comply. Alternatively, contact your local Agency office for advice or visit the waste areas of the Agencies’ websites.

8. Fuel delivery, dispensing and pipework
Many environmental incidents are caused during deliveries or dispensing, and by pipework failures especially underground pipework.

Refer to the Blue Book (Reference 1) for full technical guidance about deliveries and the requirements of dispensing systems and pipework. Additional guidance on deliveries, dispensing and pipework from above ground fuel stores is given in Reference 3. Also refer to this document if you have underground pipework from an above ground facility.

(a) Delivery
Staff trained in the delivery and emergency procedures should supervise all deliveries. This helps to avoid spillages, prevent damage to the environment and saves valuable fuel oils. A detailed discussion with your fuel delivery company covering the environmental risk assessment practices is advised to agree safe delivery and emergency procedures.

• Display a notice giving details of safe delivery procedures and what to do in an emergency at the delivery point (your Pollution Incident Response Plan (Section 5) should include a possible emergency during delivery).
• Ensure the delivery point is clearly marked with the tank contents and maximum tank capacity, and secured when not in use.
• Where supervision is not provided, ensure that the driver has been specifically trained in dealing with an emergency at that location.
• Make pollution prevention equipment such as spill kits readily available and train staff in their use.
• Use non-return (check) valves and sealed connections where appropriate and protect filling points from overfill.
• Wherever possible, keep the length of the delivery pipe as short as is practicable. Tanker access should be considered when planning a new installation.

Accurate measurement of the volume of fuel stored and the available capacity at the time of delivery is essential to avoid overfilling of storage tanks. Filling the tanks to 90% of the total volume should be considered to allow for small discrepancies.

Provision should be made to contain any accidental spills or leaks which occur during deliveries and direct them to the appropriate drainage system (see Section 4). Where a tanker is used for deliveries, it may be necessary to provide additional protection to contain a potentially large-scale spillage during the delivery procedure. Containment at the delivery point can be achieved in a number of ways including the use of drainage grids, gullies, kerbs or drainage mats. Smaller losses can be contained using, for example, drip trays under delivery pipes; these should be checked after each delivery and emptied as necessary. Alternative methods may be appropriate depending on whether the delivery point is above or below ground or made directly into or offset from the storage tank.

(b) Dispensing
The fuel dispensing area should be impermeable and drained through an oil separator (Reference 8). Any damage to the surface should be repaired immediately to prevent fuels entering the ground and groundwater.

There are three main types of fuel dispensing systems:
• suction systems, which draw fuel through the pipes using a partial vacuum;
• pressure systems, which pump fuel using a high pressure pump;
• gravity systems (above ground only), which use the weight of the fuel in the tank to force fuel down the dispensing pipework.

A suction system is recommended. This is because, provided it is correctly fitted with a non-return (check) valve directly below the dispenser, it allows fuel within the pipework to drain back to the tank if a leak occurs, thus reducing the risk of pollution. These valves may only operate effectively on appropriate equipment and should be installed by an experienced contractor.

A pressure system should have adequate secondary containment and a leak detection system fitted. Losses can be significant, as the fuel is lost under pressure. However, leak detection can be relatively fast if operated correctly.

Gravity systems are not recommended, because it often impossible to achieve accurate measurement during dispensing. See Reference 3 if a gravity system is present or planned.

New dispensers should comply with BS 7117 Part 1: 1991 (Reference 19) or be of a similar acceptable level of safety. Where older dispensers do not comply with this standard, the provision of break couplings, drip trays and under pump valves may be required at higher risk sites. In addition, all fuel dispensing equipment must be protected against collision damage from vehicles and unauthorised use.

(c) Pipework
Historically, more fuel leaks are caused by failures and/or damage to associated pipework than by integrity failure of the storage tank itself. It is strongly recommended that pipework is installed above ground wherever possible. This enables regular maintenance checks to be carried out more easily and leaks to be identified earlier. The use of double-skinned or twin-walled pipework is considered good practice; the number of joints should be kept to a minimum as this is where leaks often occur.

9. References
1. Guidance for the design, construction, modification and maintenance of petrol filling stations. ISBN 0-85293-217-0: Association for Petroleum and Explosives Administration/Energy Institute, 1999. Energy Institute. Tel: 020 7467 7157 (under review by the Energy Institute during 2004/5)

2. Groundwater Protection Code: petrol stations and other fuel dispensing facilities involving underground storage tanks. Department for Environment, Food and Rural Affairs (Defra). Tel: 0870 1226 236 or www.defra.gov.uk/environment/water/ground/petrol/index.htm

Underground storage tanks for liquid hydrocarbons: code of practice for the owners and operators of underground storage tanks (and pipelines). Scottish Executive Environment Group. Paper 2003/27. Tel: 0131 556 8400 or www.scotland.gov.uk/publications

3. PPG2: Above ground oil storage

4. PPG26: Storage and handling of drums and intermediate bulk containers

5. Guidelines for environmental risk assessment and management. Department of the Environment, Transport and the Regions (DETR), Environment Agency and Institute for Environment and Health, 2000. TheStationery Office (Tel: 0870 6005 522) or www.defra.gov.uk/environment/risk/eramguide

6. PPG4: Disposal of sewage where no mains drainage is available

7. PPG21: Pollution incident response planning

8. PPG3: Use and design of oil separators in surface water drainage systems

9. HELA LACORS PETEL 65/45. Petrol filling stations surface water drainage: constructed wetlands.
www.hse.gov.uk/lau/lacs/m_s.htm#65

10. Pollution Prevention Pays – getting your site right. Available to download from the business area of the Environment Agency website.

11. PPG11: Preventing pollution on industrial sites

12. PPG18: Managing firewater and major spillages

13. PPG22: Dealing with spillages on highways

14. HELA LACORS PETEL 65/34. Leak detection in tanks and pipework. www.hse.gov.uk/lau/lacs/m_s.htm#65

15. BS EN 13160: 2003. Parts 1–7. Leak detection systems.

16. Wetstock reconciliation at fuel storage facilities. ISBN 1-844-32040. Environment Agency, 2002.

17. PPG27: Installation, decommissioning and removal of underground storage tanks

18. Waste management, the Duty of Care, a code of practice (revised 1996). ISBN 0-11-753210X: The Stationery Office, Tel: 0870 6005 522

19. BS 7117: 1991. Part 1. Metering pumps and dispensers to be installed at filling stations and used to dispense liquid fuel. Specification for construction.

20. Pollution Prevention: Major pipelines

21. PPG14: Marinas and craft

22. Pollution Prevention: Private, commercial and military airfields References 15 and 19 are available from the BSI Group (Tel: 020 8996 9001 or www.bsi-global.com). References 20 and 22 are available from www.environment-agency.gov.uk/ppg and www.sepa.org/guidance/ppg/ppghome.htm.

These notes are for guidance only and following the good practice described does not remove the reader’s obligation to ensure relevant legislation is complied with at all times and that their activities do not result in the release of polluting matter to the environment. Pollution of the environment is a criminal offence and compliance with one or more Guidance Note(s) is not a defence to such offences. It is recommended that references to other sources of guidance are checked to ensure they are still current.