Contamination is a phenomenon of introducing a harmful compound into the atmosphere of the earth, it could be in the soil, water, and air. There are lots of ways of contaminating the earth, and most common is to introduce waste chemical compounds from the industries.
Dry cleaning includes washing by various chemicals and bleaches, which after treatment are very harmful to dispose into the environment. About 80% of the dry cleaners use PERC as their main solvent and dry cleaning. The chemical contaminates the surface and gets a deposit in the soil. Also, it causes cancer recently studied by National Academy of Sciences.
Dry cleaners extensively use chemicals to wash clothes and chemical treat them. The chemicals then disposed of without treating because these dry cleaners lack the kind of investment it takes for setting up a disposing system that could treat the chemicals. The best solution is for going for cleanup after a certain period of time, which is funded by various trusts.
These dry cleaner contamination can be treated but the process is detailed and requires lots of knowledge about chemical handling and contamination removal. While removing the contamination, there are few things you should care for, firstly, the site which is about to get cleaned should be surveyed by certified trust who handles this kind of situations. While examining the site, things like how much work is required and what steps should be taken can easily be purposed.