With all the current demolition of existing structures making way for new buildings, I was considering how the hazardous material and "pest" problem is handled..
This is the City of Toronto demolition permit:
http://www.toronto.ca/building/forms/Demolition_Permit_Application_Checklist.pdf
It clearly states that concerning Enivormental Conditions, "The Occupational Health and Safety Act requires the identification of Desiganted Substances and Hazardous Materials on construction sites. Hazardous Materials are defined under the act to include a long and complete list of over 800 biological, radioactive, and chemical agents under the provisions of the Workplace Hazardous Materials Information System (WHMIS)."
At top howver, it states that: "It is often difficult for a building contractor to determine whether contaminated substances are present....The information requirements prescribed in The City of Toronto Municipal Code, Chapter 363, will be of assistance..."
This is The The City of Toronto Municipal Code, Chapter 363:
http://www.toronto.ca/legdocs/municode/1184_363.pdf
Interesting stuff with details about hoarding/fencing requirements, anti-vibration codes, designation zones, rights of entry etc, etc...
I couldn't find any mention of pest control and I highly doubt that a thorough check for all hazardous materials is conducted before demolition begins. I get the feeling that the "Rules" are only loosely enforced and that they focus specifically on structures that may have had a previous use where hazardous materials might have been present.
I suppose the rats, roaches and bedbugs just "move next door" so to speak.
Anyway, interesting stuff concerning the whole process and why sometimes the pre-construction/re-developement process may seem to drag on.