Domestic installers, page-19

Well, the people who might be affected are certainly considering the issue. The companies involved seems to be trying to pretend there is no issue - as companies usually do.

I am surprised in that case that there are not mitigation measures required. For example, huge fuel tanks have to be surrounded by a barrier that will retain the whole contents of the tank if it leaks. Partly this is a safety issue, but also partly environmental because you do not want oil or other fuels running into suburban drains or lakes. We should be able to expect similar levels of mitigation for any installation considering the local risks.