The Preparation of Mold Remediation Protocols: Part 2
The following is Part 2 of a 4-part series on the Preparation of Mold Remediation Protocols that discusses handling contents and preparing/maintaining a containment area. The goal of a Mold Remediation Protocol (MRP) document is to provide a guideline for the remediation contractor to complete the project in accordance with current industry standards and demonstrate that the building is safe to occupy.
The contents of an area scheduled for remediation activities are generally removed prior to beginning the work. Items that cannot be removed (i.e. a water treatment system) should be covered and sealed with plastic. All of the national remedial guidance documents provide good recommendations of the methods for identifying and decontaminating the contents. The MRP should include directions to the contractor on what materials are to be removed, how they will be cleaned after their removal (both the specific techniques and the possible use of a containment system), and where or how they will be stored until they are returned to the area. If some of the contents are to be disposed of as waste, those contents should be inventoried and possibly photographed. There should be no contents disposed of without permission by the owner. The MRP should state whether or not laboratory sampling of the cleaned contents will be part of the PRV process. The method of evaluating the laboratory results and acceptable thresholds for stating the item is clean should be agreed upon by the contractor.
The MRP should include the following specific items to describe how the contractor is to construct critical barriers:
Describe the exact locations for the critical barriers to create the containment area and separate the remediation activities from the rest of the building.
The number of plastic barriers (one layer or two) to be used and how it should be supported (i.e. the use of PVC tubing, zip poles, or other materials)
The type of plastic to be used to make the critical barriers (fire retardant, clear or translucent, fiber reinforced, 4 or 6 mil thick)
Indicate that the plastic that is used to construct the critical barrier is to be stapled and the seams sealed with duct tape. Note that the contractor may use a painters tape to prevent unnecessary damage to the wall as a result of using the duct tape. Spray tack may also be used.
State that the Contractor is to measure and calculate the volume of air inside the containment area and determine the number of negative air machines to remove a minimum of 4 air volumes per hour.
State that the Contractor may use an electronic recording device to monitor and print the differential air pressure between the area inside the containment area and outside. This equipment can indicate that the pressure is maintained between -0.1 and -0.02 inches of water column (based on 29CFR 1926.1101). Also, that the monitor can have an audible alarm that will signal the failure of negative pressure and that the site supervisor make notes on the printout as to the reasons why the pressure falls outside the acceptable range (i.e. torn seam along a side of the critical barrier). The monitor can also print the differential measurements to document that the pressure was maintained during non-business hours. The printout can demonstrate that proper negative air pressure was maintained throughout the project.
Indicate that the flow of makeup air should be controlled so that air enters the containment area on the opposite side of the negative air machines (NAMs).
Indicate that spaces of the building that has no potential for air flow will have air scrubbers or fans to create air turbulence. The NAMs should be located away from the egress chamber.
An egress chamber is attached to the entrance to the containment system.
Doorways in egress chambers should have zippers to control air flow.
State how the carpet will be protected or removed and when this should occur.
If remediation activities include the overhead floor joists in a basement, state the possible requirement for removing the return air systems of the HVAC that utilize the overhead joists to gain access to the enclosed spaces.
If the remediation activities consist of addressing a series of rooms that are adjacent to one another, then the use of positive air pressure after the cleaning process is completed in each room should be described
The use and location of air scrubbers should be presented in the MRP if the consultant feels this equipment is warranted.
During the remediation activities, the Contractor should be required to clean the HEPA filters in the NAMs each day.
In Part 3 of this series, we will discuss remediation techniques, waste disposal, and methods for