The Water Environment (Oil Storage) (Scotland) Regulations 2006

Type of Oils

The Regulations apply to any kind of oil including petrol, diesel, mineral oil, heating oil, lubricating oil, waste oil, vegetable and plant oil but does not include uncut bitumen as it was considered this material would solidify in the vicinity of any spillage. The storage of Agricultural Fuel Oil is now controlled by these Regulations and Regulation 8 removes oil storage from the Control of Pollution (Silage, Slurry and Agricultural Fuel Oil) (Scotland) Regulations 2003.

Uncut bitumen is specifically excluded from the definition of oil within the Regulations and is therefore exempt. Bitumen based products which are liquid at normal ambient temperatures e.g. bitumen emulsion, should be stored in accordance with the regulations.

The relevant provisions of Waste Management Licensing Regulations 1994 (as amended) will also apply to handling and storage of waste oil.

Who do the regulations effect?

The Regulations apply to any kind of container which is being used and which is stored on premises above ground, whether inside or outside a building. These include fixed tanks, intermediate bulk containers, drums (oil drums or similar containers used for storing oil) or mobile bowsers.

The range of premises covered by the Regulations is wide including land and mobile plant but does not include storage of oil in vehicles or vessels. The storage of oil on the following premises is included in the Regulations:

• industrial businesses: small manufacturing premises such as food processing, textiles, paper and publishing, engineering, bricks and ceramics, metals, chemicals;
  

• commercial businesses: such as shops, offices, theatres, hotels, restaurants, pubs, building and construction sites, motor garages, transport depots, bus stations;
  

• institutions (residential and non-residential): in the public and private sector, charities and voluntary groups. These include schools, hospitals, churches, prisons, libraries, public sector buildings, nursing homes, and occupiers of multi-residential dwellings whether, privately or publicly owned, blocks of flats or other dwellings where oil is supplied from communal storage facilities;
  

• farms: includes any oil used on the farm but does not include oil intended for use exclusively as a fuel for heating a farmhouse or other residential premises on a farm, which is stored separately from other oil and has a capacity of less than 2500 litres (see exemptions).
  

Exemptions

The following exemptions to the main requirements of the Regulations will apply:

• The storage of oil on premises used wholly or mainly as a single private dwelling with an oil storage capacity of less than 2,500 litres. New or altered tanks should comply with applicable Regulations under the Building (Scotland) Act 2003,
  
  

• The storage of oil in any container which is situated wholly underground (unless situated within a building underground),
  
  

• Where the oil is stored in accordance with;
  

1. an authorisation under Part I of the Environmental Protection Act 1990 in respect of a Part A process falling within the description set out in Schedule 1 to the Environmental Protection (Prescribed Processes and Substances) Regulations 1991; or
   

2. a permit under the Pollution Prevention and Control (Scotland) Regulations 2000 in respect of a Part A activity as defined in Schedule 1 to those Regulations.

• Premises used for the onward distribution of oil to other places i.e. oil distribution depots. This includes sites where operations such as blending and filling are carried out, but does not include fuel installations for transport companies.

When do the regulations come into effect?

The Regulations will come into force in 3 stages following. These stages are:

1. new tanks (i.e. facilities commenced after 1 April 2006) will have to comply within 6 months [by 1 October 2006],
   
   

2. existing tanks at significant risk (i.e. facilities that are located within 10 metres of any surface water or 50 metres of a borehole or well will have to comply within 2 years [1 April 2008]
   
   

3. remaining existing tanks will have to comply within 4 years [1 April 2010].

SEPA may also serve an enforcement notice under the Water Environment (Controlled Activities) (Scotland) Regulations 2005 on existing oil storage facilities, where it is considered that there is significant risk of pollution of the water environment, requiring compliance with all or part of the Regulations before the required date.

Key requirements of the regulations

The regulations set design standards for new and existing above ground oil storage facilities.

Where oil is stored in any portable container with a storage capacity of less than 200 litres, the container must be of sufficient strength and structural integrity so as to ensure that it is unlikely to burst or leak in its ordinary use.

Where the container has a storage capacity of 200 litres or more the regulations require provision of secondary containment (a ‘bund’ or ‘drip-tray’) to ensure that any leaking or spilt oil cannot enter the water environment.

The main controls introduced by the regulations are outlined below:

• The container must be strong enough to hold the oil without leaking or bursting,

• The oil container must be positioned to avoid damage (e.g. impact from any vehicular traffic), so far as is reasonably practicable,

• A secondary containment system (bund or drip tray) must be provided to catch any oil leaking from the container or its ancillary pipework and equipment,

• The container must be situated within a secondary containment system (e.g. bund, drip tray) of sufficient capacity to contain at least 110% of the maximum contents of the container. Where more than one container is stored, the bund should be capable of storing at least 110% of the largest tank or 25% of the total storage capacity, whichever is the greater (in the case of drums the tray/bund size should be at least 25 % of total storage capacity),

• Oil stored in mobile bowsers also require to be bunded,

• The bund base and walls must be impermeable to water and oil and checked regularly for leaks,

• Any valve, filter, sight gauge, vent pipe or other ancillary equipment must be kept within the bund when not in use,

• Above ground pipework must be properly supported,

• Below ground pipework must be protected from physical damage (e.g. excessive surface loading, ground movement or disturbance) and have adequate leakage detection. If mechanical joints have to be used, they should be readily accessible for inspection,

• SEPA has power to serve enforcement notices to minimise pollution risks during the transitional period before the Regulations come into force for all existing containers.
  

Key differences between Regulations in Scotland and England

Oil storage regulations are also in force in England under the Control of Pollution (Oil Storage) (England) Regulations 2005.

The requirements of the Regulations can differ with the following key differences:

1. Regulations in Scotland apply to domestic storage above 2500 litres and English Regulations are above 3500 litres.
   
   

2. Regulations in Scotland apply to storage of waste oil whereas waste oil storage is exempt under the English Regulations.
   
   

3. Regulations in Scotland apply to storage of oil in buildings whereas storage within buildings is exempt under the English Regulations.

4. Regulations in Scotland exempt storage of oil in any installation which is a Schedule 1 Part A Activity of the Pollution Prevention and Control (Scotland) Regulations 2000 or Schedule 1 Part A process of the Environment Protection (Prescribed Processes and Substances) Regulations 1991 and premises used as an oil distribution depot for the onward distribution of oil to other places. The English Regulations only exempt storage of oil at premises used for refining oil or for the onward distribution of oil to other places.
   

Information Note on Types of Tanks for Oil Storage

Introduction

There is confusion about the terms "double skinned", "integrally bunded", "twin walled" and "bunded" plastic and steel tanks in relation to above ground oil storage, and which are acceptable from an environmental protection point of view. Unfortunately manufacturers and suppliers of these tanks have used a variety of these terms with different interpretations.

Double Skinned Tanks

A Double Skinned Tank is just that – a primary tank with another "skin" placed around it with a very small gap (interstitial space) between the two; none of the pipework or ancillary equipment is contained. The risk of oil being lost from ancillary equipment and pipework is high; the Water Environment (Oil Storage) (Scotland) Regulations 2006 recognises this fact and require that tanks have all ancillary equipment such as sight gauges, taps and valves retained within a secondary containment system.

Double skinned tanks are not compliant with the Regulations unless additional secondary containment is provided for the tank and its ancillary equipment, such as an in-situ constructed bund (see SEPA /CIRIA Guidance notes on Masonry and Concrete bund construction).

Double Skinned Tanks are recommended for underground storage of oil/petrol etc because the interstitial space between the tank skins can be monitored for leaks. Underground installations should also have twin walled, non-corrosive pipework specified. See SEPA’s Pollution Prevention Guidance Note 27 – Installation, Decommissioning and Removal of Underground Storage Tanks, PPG7 – Refuelling Facilities (currently under revision) and the Scottish Executive Underground Storage Tanks for Liquid Hydrocarbons Code of Practice.

Proprietary Tank Systems

Proprietary Tank Systems come in a large range of designs and are produced by many different manufacturers who may make certain claims about the environmental performance of their products. Proprietary Tank System or just Tank System is the preferred generic term for tanks often referred to as integrally bunded or twin walled, to prevent the confusion described above. Some tanks systems may have adequate secondary containment to comply with Regulation requirements, but some may be regarded as "high specification primary containers" and would therefore be non-compliant without additional containment.

Some proprietary integrally bunded tank systems take the volume of the primary tank into account when calculating secondary containment capacity and provide additional secondary containment capacity of less than 110% of actual primary tank capacity. This is generally acceptable where, if there was a leak in the primary container, oil could find it's own level in both containers. In this instance the primary container contributes to the total containment capacity, which as long as it totals 110%, will be acceptable. A similar position is achieved in a conventional bund where the tank is situated low down.

The Regulations state that the secondary container "must have a capacity of not less than 110% of the containers storage capacity..." but this can be interpreted to mean that the secondary container must be "capable of containing 110% volume of the primary container and, where applicable, the volume provided by the primary container can be taken into account".

An important issue in determining if a tank system is acceptable is whether the ancillary equipment is adequately dealt with, such as being within the secondary container, which is where some tank systems have fallen down in the past.

To comply with the Regulations, tank systems must have containment to minimise damage from third party interference, prevent pollution incidents from overfilling, leaking primary container or ancillary equipment. They should be sited to minimise the chance of damage by impact or collision or protected by suitable physical barriers.

If well designed, manufactured, sited, installed, used and maintained correctly a tank system can be just as effective as a conventional in-situ bunded tank.

SEPA’s PPG2 ‘Above Ground Oil Storage Tanks’ gives some basic principles about the points to look out for when considering a tank system, products can be assessed against the check list. Please note that this guidance is currently being reviewed and will be updated to reflect the requirements of the Scottish Regulations.

Oil Storage Containers within Buildings

Storage of oil which falls within the Regulations and is stored within a building must meet the requirements of the Regulations.

Whilst SEPA would prefer use of ‘traditional’ tank secondary containment system, the 110% secondary containment requirements of the Regulations may be met within the building itself (e.g. 110% secondary containment may be provided within the building by forming a ‘lip’ on doorways and calculating the floor area capacity). All other requirements of the Regulations must still be met (e.g. additional requirements of the secondary containment system relating to impermeability, no drains etc).