Except in the case of an owner-occupied, single-family residence, the department shall within 30 days inspect all dwelling units in a dwelling when:
1. Lead poisoning found. A case of lead poisoning has been found in any dwelling unit within the dwelling; or
2. Lead-based substances. Lead-based substances have been found in any dwelling unit within the dwelling.
The department may, at its discretion, inspect an owner-occupied single-family residence whenever a lead-poisoned child has been identified as residing in or receiving care in that residence.