There has been an interesting case on Environmental Impact Assessment (EIA) and Habitats Regs Appropriate Assessment (AA). This is the case of Champion v North Norfolk DC and Natural England. Although there are important differences between EIA and AA, those differences need not trouble understanding of the case so I'll use the word "Assessment" to mean both EIA and AA.
The development in question was the erection of 2 large silos for barley storage, a lorry park/wash bay and associated infrastructure. One of the key issues was the risk of pollution of the River Wensum. A package of standard mitigation measures was offered and on that basis, NNDC concluded there was no risk of pollution and no Assessment was needed. The advice from Natural England agreed with that conclusion.
Those measures formed the basis of proposed conditions which officers put before committee. At the meeting, however, although members were minded to approve, one member who had experience of relevant matters (through membership of the local IDB) argued for conditions which would require monitoring of water quality, with the developer taking "all reasonable steps" if water quality was found to diminish due to the development.
The decision (and the advice of Natural England) were challenged on the basis that if the condition had any purpose, it must be to deal with the risk of pollution. If there was risk of pollution then an Assessment should have been undertaken.
The Court found for this point and the permission was quashed - "it does not seem to me that the Council could, rationally, adopt both positions at once" said the judge.
The outcome might be seen as unfortunate - had it not been for the suggested condition, at committee, the point would have been found in favour of the Council. Natural England's advice was not quashed because they had applied the correct standard.
The form of the conditions was also set out in the judgement - but no comment was made on whether they achieved the desired result in any event. Conditions requiring ongoing monitoring with measures to be identified in the future are not easy to draft and care must be taken to ensure they are properly imposed.