(a) The owner or operator of every commercial offsite multiuser hazardous waste disposal facility shall develop a proposed monitoring plan, in writing, for the monitoring of the ambient air downwind and upwind from the facility. The plan shall include all of the following:

1. (1) An identification of the constituents of hazardous wastes accepted in the past and present which will be monitored. These constituents shall be selected on the basis of pertinent factors, which may include degree of toxicity, relative and absolute volume, the potential for the constituent to volatilize or otherwise become airborne, and the method by which the constituent is or was handled, treated, and disposed.
2. (2) The type, procedures, and location of air sampling equipment and the type and procedures of analytical equipment.
3. (3) The duration of each sampling period in hours, and the number and time of sampling periods over a 12-month period.

(d) If the department determines that a hazardous waste facility which is required to develop a plan pursuant to subdivision (a) is the source of a substance in the ambient air which poses a significant threat to the public health or affects the quality of the environment in such a way that could significantly threaten public health, the department shall, pursuant to Section 25187, require the facility operator to do both of the following:

1. (1) Develop a corrective action plan and submit the plan to the department for approval or modification, within a schedule specified by the department.
2. (2) Implement the corrective action plan, as approved by the department, within the period specified by the department.