BS7750 leaves many important questions unanswered. One possible mechanism for achieving some consistency is the sector application guide (SAG). The Electricity Association is the first organisation to publish a draft SAG, covering both nuclear and large combustion plant in the power generation sector.1All of these processes are already regulated under IPC or radioactive substances legislation. As a result, the SAG does not raise significant expectations of additional measures. "For many of the major emissions", it says, regulatory controls "mean that economically achievable minima may have been reached...Thus it will frequently be the case that significant improvement beyond regulatory compliance is not practicable."
Such comments tend to make claims that BS7750 will be a framework for self-regulation ring a little hollow. However, there is no doubt that a management system that complies with the standard should ease the task of compliance.
One of the SAG's main aims is to provide guidance on the preparation of a register of "significant" environmental effects. These will "require appropriate management, within commercial constraints" - involving either a control programme, an improvement programme, or further investigation.
The SAG warns that the scope of effects is potentially vast, including fuel extraction and electricity use by consumers. It has limited itself to emissions which the organisation's management is "able to control or directly influence".
No mention is made of a generator's ability to influence the supply chain. One striking omission is the scope for purchasing decisions to favour cleaner fuels. This decision will have one of the strongest direct effects on the impact of a station, and is one of the few areas where BS7750 could, in principle, reach further than IPC. The issue may be addressed if a generator's purchasing department certifies to BS7750, though this is not considered in the SAG.
In assessing the "significance" of an effect, the SAG says that the susceptibility of the local environment should be taken into account. Regulatory requirements are "automatically significant".
Otherwise, the tests for significance are:
Emissions will be significant if their environmental concentrations exceed 10% of regulatory or recognised guideline levels. However, if environmental concentrations are already within 85% of the limit, any plant contribution is significant. Short-term effects are significant if they breach WHO or similar guidelines.
Finally, significance can be signalled by public concern, as evidenced by complaints or local or national media attention, or by "quantifiable effects" on nature reserves.
In practice, most of these effects should have been considered under an IPC application. The only exceptions are noise, building damage and the impact of fuel and waste transport. However, modelling of particulate and acid deposition should, the SAG says, be included - a significant advance, given that National Power and PowerGen managed to avoid all mention of acid rain in their IPC applications.
The SAG says that targets for improvement should be quantifiable and "direct effort to achieving the greatest economically practicable benefit". Where possible, they should be expressed as a function of plant output, as the rate of operation of a station is "not under the control of the plant manager or even the company".