Regeneration - Ground Conditions and Contamination

In the Environmental Impact Assessment it mentions that on part of the site there used to be a gas works with three gasometers (storage) and probably railway repair workshops associated with Seaton station, as well as 3 old electricity sub-stations. They mention potential contaminants such as Ammonia liquors, cyanides, pehnols, hydrocarbon fuels and pcb's - scary stuff. They say that contamination could be "moderate to high".

They mention that they took only five soil samples on the site (they don't say which part) which showed no evidence of contamination and that whatever contamination there is they think it is moving southwards (from the site towards the sea). They say that no ground gas investigations have been done. They say that they will do investigations later and decide on remedial works depending on the results of those investigations.

Is it usual to have an Environmental Impact Assessment that is so vague about possible contamination of a site? How can a district council make an informed decision about what and where to build on such a site if they don't have full information about it?

I don't know about Environmental Impact Assessments so I don't know if this is normal practice. Does anyone else know?

We have an organisation that will look at this Environmental Impact Assessment for us but it is still not available as a digital file. It is supposed to be available next week but until it is, they can't check it for us.

Anyone out there know how these things work?