Plastic became so expensive on the world market a couple of years ago, that it became viable to open up and dig out old garbage
(rubbish) dumps and salvage it. It was cheaper to do this than to make new plastics of all types.
World prices have fallen steeply but it is still worthwhile for
companies to dig up and save this material until prices rise again.
This article explains the relatively new business of garbage mining and explains the
potential value of plastic waste which is very closely related to petroleum prices, since it is the core of plastic manufacture.
Plastic yogurt pots were actually worth more than their contents before the current world slump and they will rise again, so it is a wise move for previously buried plastic waste to be retrieved and saved. This process is an investment for the companies engaged in it.
The article goes on to explain that this procedure is not without its risks because the contents of some landfills and garbage tips are not always recorded and there is no way of knowing if unsafe chemicals were disposed of at these sites. There is also the problem of methane which is a highly volatile explosive gas which can remain active at these garbage dumps for up to thirty years.
The author of this article also touches on the potential treasure trove of plastics that could be retrieved from the world’s seas and the difficulties involved in recycling so many different types of plastic.