A draft planning policy guidance note (PPG) entitled 'Planning and pollution control' was issued in June 1992 and is likely to be published in final form shortly.

The PPG clarifies the relationship between planning controls and other forms of pollution control.

It examines the principal statutes which regulate the other pollution control systems and considers their relationship with the planning system.In Gateshead Metropolitan Borough Council v Secretary of State for the Environment and Northumbrian Water Group plc (shortly to be reported in [1993] 3 PLR) one of the first indications of how the courts are likely to interpret that relationship is given.The case concerns an unsuccessful challenge in the High Court by Gateshead Metropolitan Borough Council to a decision of the secretary of state to grant outline planning permission for a clinical waste incinerator in Gateshead.

The inspector who held the inquiry into the refusal of permission had upheld the council's decision.

The secretary of state, however, took the contrary view and granted planning permission.The planning application had been accompanied by various environmental statements.

The inspector accepted that the maximum emission limits specified by the appellant accorded with the appropriate standards and also agreed that it would be possible to design a plant to perform within those limits in routine operation, as well as to design 'stand-by' systems such that the number of emergency releases could be reduced to a reasonable level.

Although some visual detriment to the locality would occur from the presence of the stack and some industrialists might be deterred from the locality, this alone was not sufficient to justify refusing permission.He accepted, however, that background air quality was ill-defined and urban air standards for the area gave an incomplete picture.

In addition, discharges of chemicals such as cadmium, although within the limits, were unacceptable in rural/agricultural areas.

There were public concerns regarding dioxin emissions, although the discharge data was only theoretical and insufficient practical exper ience was available for forecasts to be credible.He concluded that while the plant could be built to meet the relevant standards, the fact that the impact on air quality was insufficiently defined and also that there were public fears about environmental and dioxin pollution, meant that planning permission should be refused.After consideration of the inspector's report, the secretary of state concluded that the proposal was not in conflict with development plans for the area, but as a special industrial use it would have to satisfy certain criteria set out in structure plan policy EN 16 (SPP EN 16).The secretary of state took the view that all aspects of that policy had been met by the proposal, save for the environmental impact of emissions into the atmosphere.

He noted that the limits proposed by the appellants were part of the plant description and that the limits were considered by Her Majesty's Inspectorate of Pollution (HMIP) to be a valid starting point for the authorisation procedure required under pt I of the Environmental Protection Act 1990 (EPA), although he could not predict what emission limits would eventually be imposed.Although the inspector had concluded that these emission limits were not acceptable in semi-rural areas, the secretary of state considered that this had to be weighed against the fact that if planning permission were granted, emission limits would be determined by HMIP under the authorisation procedure.While the planning system must determine the location of facilities of this kind, the secretary of state did not consider that it was the role of the planning system to duplicate controls under the EPA and, while it was necessary to take into account potential emissions and their impact on the surrounding area, control of emissions was regulated by HMIP.

Although an application for an authorisation had been made at the time of the inquiry, it had not been determined.

Nevertheless, the secretary of state was confident that emission controls available under the EPA were such that there would be no unacceptable impact on the adjoining land.

Thus all the criteria in SPP EN 16 were now met.

Planning permission was granted.When the matter came before the High Court, the council argued that the secretary of state had not disagreed with the inspector's conclusion that there was insufficient data on air quality on which to judge the proposal, nor had he disagreed with the inspector's finding that there would be an unacceptable impact on the rural/agricultural area by reason of discharge of chemicals such as cadmium.

(Against that, the secretary of state had accepted that there was public disquiet as to dioxin emissions and that those concerns could not be sufficiently allayed.

However, he had concluded that these matters could be dealt with by the controls available under pt I of the EPA.)The council's view was that leaving the emission controls to the EPA authorisation was unsatisfactory and an abdication of planning responsibilities.

There was no evidence that controls under the EPA would be adequate and thus the secretary of state could not be satisfied that the proposal would comply with SPP EN 16.

The council also argued that HMIP would be bound to issue an authorisation even if the emissions would be harmful.It was accepted on behalf of both the secretary of state and Northumbrian Water Group plc that the environmental impact of the emissions into the atmosphere from the plant was a material consideration for planning purposes, and that there was a degree of overlap between planning and poll ution control.

Reference was made to the consultation draft PPG which makes it clear that the pollution implications of a development may be material planning considerations, although the line between pollution and planning controls is not always clear cut.They argued, however, that HMIP was not bound to issue an authorisation as the EPA gives it the power to refuse an authorisation if it considers that the release of a particular substance would cause harm as defined in the Act.

It also has extensive reserve powers relating to authorisations and enforcement.The respondents also argued that the secretary of state was entitled to reach the conclusion that the remaining matters which were of concern to the inspector could properly be left to the EPA regime.

This was a question of fact and degree in each case.

The inspector was not concluding that the proposed incinerator would give rise to unacceptable pollution; he was merely saying that there was insufficient data.

The inspector had applied policy guidance to the facts of the case and the secretary of state had explained why the inspector's remaining concerns could be addressed by the EPA process.Jeremy Sullivan QC, sitting as a deputy High Court judge, concluded that without doubt the environmental impact and emissions to the atmosphere were material considerations at the planning stage.

It would not be lawful for the secretary of state to adopt the policy of hiving off all considerations such as environmental effects in their entirety to the EPA regime.However, the existence of a regime under the EPA for preventing or mitigating the impact and rendering any emissions harmless was, he considered, also a material planning consideration and there may be a point in a planning appeal process where the secretary of state is entitled to be satisfied that, having regard to the existence of the EPA controls, there was no reason to refuse planning permission.

A difficulty is capable of being overcome with the result that whether the point has been reached is a question of fact in each case.The judge stated that there would be cases where evidence at the planning stage demonstrates that potential pollution problems could be left to the EPA authorisation process.

Equally, there would be other cases where evidence of environmental problems is so strong that there was no point in trying to resolve those problems through the EPA process.

However, a range of cases between these two solutions would make it necessary for the secretary of state to decide the issue as a matter of planning judgment.In this case, the secretary of state had understood that the controls available under the EPA were adequate for the proposal.

The inspector's concerns related to incomplete data regarding air quality, a matter clearly relevant for planning but capable of being satisfactorily addressed by HMIP.

The same applied to the residents' concerns over dioxin and cadmium emissions.

While environmental pollution is a material planning consideration, so too is the system of authorisation under the EPA.The secretary of state was entitled in this case to conclude that the controls available under the EPA were adequate to deal with emissions from the proposed plant and the risk of harm to human health.

The application was therefore dismissed and planning permission allowed to stand.In the UK, the powers and duties in relation to environmental protection are spread over a variety of organisations, some exercising policy-making functions and some regulatory ones.

Planning and other pollution control authoriti es must have at least a working knowledge of how the controls interrelate so that the respective regimes operate successfully.Although the environmental impact of the proposals is a material planning consideration, it will be up to local planning authorities and planning appeal inspectors to decide as a matter of subjective planning judgment in each case whether potential pollution problems can be safely left to the relevant pollution control authority or whether evidence of environmental problems is so weighty that planning permission must be refused.