The dispute in this case is about the state in which the defendants left the premises they leased from the plaintiff when they terminated their 26-year occupation and moved to new premises across the street. The tenant had operated a foundry in the building, after several industrial uses by others. After the foundry left, the landlord found tonnes of metal-laden dust in the crawl space, ceilings, walls and floor cavities. Some of the dust was leachate toxic for lead. The lease required the tenant to remove all industrial waste on termination of the lease, but allowed “wear and tear”. Although no government agencies required the landlord to cleanup the site, he investigated the contamination and removed much of it in order to re-lease the site. He sued for $200,000 in investigation and cleanup costs, costs of financing, lost property value, legal costs. The Supreme Court found it was an implied term of the lease that the property would be returned reasonably free from contamination. The tenant was required to take all reasonable steps to remove the dust when it vacated the site.