Infilled land - industrial and household waste

ONEONEONE

Hello, 
Thanks in advance for your time and wisdom! I recently viewed a property which seemed great, at the top of a big hill and a friendly well-maintained estate. Very nearby (circa 50 metres poss closer) , is some open land for use by the public, mainly grass and scrub with lots and lots of manhole covers/ what seems like drainage systems. I couldn't work out what the land was, though I knew there was probably a quarry around at some point (name of roads suggests this). I searched and searched online for the name of the scrub land/previous uses of land etc and came back with a blank, figured if we got that far the property searches would explain things. Put an offer in on the property. In the meantime I looked for the planning permission docs for the estate (which I hadn't found prior), finally found out the name of the scrubland used to be a massive quarry which has since been infilled with 150 million cubic metres of industrial and household waste until around around 25 years ago. This is where I felt quite spooked! I also managed to then find a report from a company which looked like they monitored the land for the house builders and did some remedial works, they are responsible for the manhole covers which are basically pipes to pump out the methane as well as draining trenches/vents etc away from the houses. Not massively clear if the house I'm interested in is built directly on the infilled land or more quarry spoil, the maps/pictures of the area are quite unclear but it's v close to the infilled land regardless. I'm not clear whether the foundations of the houses take into account risk of movement etc though suspect as this is a modern development they might have.

 I'm feeling like passing on this as it seems like quite a big risk in terms of resale, also a bit worried about gas and safety etc. Would be great to get a second opinion, I don't want to progress up to searches/ waste anyones time if it's not right for me but at the same time is this a risk if modern development was given the go-ahead? 

Jadek

Do you know when exactly the land stopped being used as a landfill? There were a number of changes to permitting of waste sites in the 1990s so this site could either have been subject to certain requirements or it may not have been depending on the year. All waste sites require what are today known as permits, previously known as licenses. These days, when a landfill site stops being operational the operator is still required to manage the land until a point at which the EA (or other relevant regulator, dependent on country it would instead be NRW, SEPA or DAERA) deems the site to no longer be an environmental or human health risk. Operators are required to have a closure plan in place which includes a provision of finances to manage the site to this point, which will include the management of gases, leachate and so on, which in my (professional) experience is normally a number of decades (longer than 25 years, I know some sites that have plans for 60+ years from closure). If this site stopped accepting waste before 1996 then the operator would not have been subject to these requirements and likely will have surrendered its permit before the legislation changed, if it stopped accepting it after this date then it is likely it will still be permitted. If this is the case you can find details of its permit, including the owner / operator of the land, on the relevant regulators website. However, if it is no longer permitted then this simply means that management of pollution / contamination will have been left to someone other than the operator, likely to be the local council. It doesn't mean these hazards are not being managed.

Either way, it is highly unlikely that a site that only stopped accepting waste 25 years ago would have been given the go ahead to build houses directly onto, but my experience doesn't extend to what happens to land after it is fully remediated so there may be occurrences of this that I'm not aware of. But I know a lot of councils that have old landfill sites still in the remediation stage which are just kept as managed land at the moment. I think it's most likely that the house isn't built directly onto it, but from what you say it sounds like the open land is what constitutes the former landfill. From a safety perspective from living adjacent to the site then, as long as it is being managed properly, you shouldn't need to worry. Most of the post-operational issues are to do with ground and water contamination, gas is the main risk to human health. However I do agree that it could be something that puts people off thinking about resale, and I can't comment on whether it poses risk to the building itself in terms of ground stability.

martindow

Have you looked online for the planning documents when the estate was first built?  There should be information there on how the site was tested, etc. as part of getting planning permission.  Particularly for recent developments, there is a thorough environmental survey before PP is granted.

withaspritz

Most regs required a gas tight membrane to be installed to stop gases leeching through concrete foundations into the houses. Do you have any documentation on the planning portal relating to the required conditions and their discharge (usually towards the end of the development, when the builder submits "proof" to the council that they have done what they were told to by the inspectors up front - it'll all be on the planning portal depending on the age of the development