The regulations take effect next year, 28 years after powers enabling design standards to be set for particular sources of water pollution were included in the Control of Pollution Act 1974. There were many official promises to apply the powers to oil stores, and a consultation paper finally appeared in 1996 - but still nothing happened.
Meanwhile, oil has remained one of the major water pollutants. Last year, it was involved in 6,215 of the 36,406 water pollution incidents reported to the Environment Agency - and in 26% of the most serious incidents.
Much of this pollution was caused by a lack of elementary precautions, such as bunds around oil tanks and alarms to warn of overfilling. These measures usually cost only a few hundred pounds per tank - whereas pollution clean-up costs and penalties often run to tens of thousands of pounds, and sometimes considerably more.
A recent example was a spill of 12,000 litres of kerosene at an oil products depot in Derbyshire which caused extensive soil contamination and some groundwater pollution, forcing the suspension of abstractions by a nearby milk products factory. The spill resulted from overfilling of a tank which had no bund or high-level alarm. The two companies involved, Total Oil and Halso Petroleum, paid £201,000 in legal penalties alone (ENDS Report 313, p 53 ).
The Government finally accepted last year that the argument was strongly in favour of regulation - and proposed controls which went considerably further than those of its predecessor. Even so, it concluded that the business and environmental benefits would be at least double the costs faced by business (ENDS Report 303, pp 41-42 ).
Most of last year's proposals have been retained. The regulations extend to England only, although similar measures are under consideration in Wales.
The regulations apply to storage of all kinds of oil in any "container" - a fixed tank, drum, intermediate bulk container or bowser.
However, certain kinds of installation are excluded. Among them are waste oil stores, underground tanks - which are to be covered by an approved code under the groundwater regulations (ENDS Report 319, pp 42-43 ) - containers with a capacity of 200 litres or less, or containers of up to 3,500 litres capacity serving private dwellings. Oil tanks on refineries, distribution depots and farms, which are covered by separate legislation, are also excluded.
The standards set by the regulations will take effect in three stages:
In addition, the Agency will be able to serve a notice requiring action ahead of these deadlines where it believes there is a "significant risk" of oil pollution. Notices will have to allow at least 28 days for compliance, and the regulations also provide for appeals against notices.
The technical provisions of the regulations set general requirements for all oil containers - notably the provision of secondary containment such as a bund or drip tray of sufficient capacity to retain all the contents of a container. Other provisions cover ancillary features of fixed tanks and bowsers such as pipes, leak detection and overfill prevention devices and pumps.
The Department for Environment, Food and Rural Affairs estimates that a "typical" business installing a new tank will face additional costs of about £500 to provide a bund. For existing tanks, costs will range from minimal where only bund repairs are needed to around £1,000 where a tank has to be replaced ahead of time.
On the benefits side, DEFRA estimates savings to a typical business of up to £30,000 for an oil pollution incident. It believes that the measures will reduce the number of incidents by around 2,500 per year from 2005.
Failure to comply with the regulations will attract a fine of up to £5,000 in a magistrates court, and an unlimited fine in a higher court.