By Jerome E. Spear, CSP, CIH
Effective January 1, 2005, consultants who prepare mold management plans for buildings located in Texas must be licensed as a mold assessment consultant in accordance with the Texas Mold Assessment and Remediation Rules (http://www.tdh.state.tx.us/beh/mold/FinalRule.pdf).
According to the U.S. Environmental Protection Agency (EPA), mold has affected approximately 10 to 25 million workers and 800,000 to 1.1 million buildings. Mold spores are all around us and have been since the beginning of time. Actually, there are some benefi cial uses of mold (including cheese, beer making, etc.). However, mold growing inside of buildings can create indoor air quality issues; therefore, steps should be taking to minimize the potential of indoor mold growth.
The first step in preventing claims of mold is to develop a written mold management program. A mold management program outlines the operations and management procedures to prevent, control, and manage potential indoor water and moisture conditions and subsequent indoor mold growth. Since mold requires moisture to propagate, prudent building owners and managers have the basic philosophy that water intrusion incidents are inevitable and thus they must be prepared to promptly respond and correct the such incidents and excessive moisture conditions. Also, if seeking insurance for your building(s) that covers indoor mold contamination, your insurance carrier will likely request to review your mold management program to assess the effectiveness of your program.
A mold management plan should cover administering the program, defining roles and responsibilities, preventing water intrusion and mold growth issues, responding to water intrusion incidents, remediating indoor mold contamination, selecting qualified contractors, and training personnel. Elements of a mold management program are outlined below.
Program Administration
Administering the mold management program starts with defi ning the scope and purpose of the document. Since operations and maintenance procedures are critical components with preventing and managing water intrusion events and subsequent indoor mold growth, consideration should be given to integrating your mold management program with other existing programs, such as the buildingʼs operation and maintenance program.
Another critical aspect of administering the program is to define duties and responsibilities to all affected personnel. Like other maintenance and management programs, a program administrator should be assigned and understand his/her responsibilities. This person is generally responsible for the day-to-day activities involved in maintaining the building(s) in acceptable conditions with good indoor air quality. The program administrator should have knowledge and experience in mold prevention concepts and mold responsive actions.
Other critical personnel in the management and control of indoor mold contamination include the property manager, maintenance and custodial workers, building occupants and tenants, and contractors. In general, the property manager should have the overall responsible for minimizing and managing the risk of water intrusion and indoor mold growth and for allocating the necessary resources to implement the program.
Maintenance and custodial workers play a vital role in preventing water intrusion events and are a key link in the cleanup response chain. Finally, a certain level of education and communication should be provided to building occupants and/or tenants as these people are responsible for promptly notifying maintenance personnel of water intrusion incidents and maintaining their unit in an acceptable conditions. One way to delineate and communicate the tenantsʼ responsibilities is through the lease agreement.
Contractors should perform their scope of work as defi ned by their contract in a standard of care normal for their industry. However, specifi c requirements and specifi cations applicable to the project should be included in their contract. The Texas mold rules require the initial mold assessment to be performed by licensed mold assessment consultants (with certain exceptions). If remediation is warranted, the licensed mold assessment consultant is responsible for developing a written mold remediation protocol for the remediation contractor to follow. The mold remediation contractor is responsible for preparing a work plan (that is based on the consultantʼs protocol), submitting the work plan to the building ownerʼs representative prior to the start of work, and performing the work in accordance to applicable mold-related laws and industry standards.
Construction and Renovation Projects
Water intrusion efforts must be considered in the design and construction of a building. An owner representative who is experienced in construction methods should be involved with coordinating and overseeing construction and renovation projects to observe that the work is performed according to the ownerʼs specifications and according to the ownerʼs mold management program. Depending on the complexity of a project, it may be helpful to engage construction experts to review plans and provide their expertise during the design stage, which can minimize or eliminate costly changes during or after the construction phase of the project. During the construction phase, independent testing or observation may also help minimize the risk of water intrusion and/or further protect against the potential of claims of interior mold contamination.
There are many design considerations to moisture control. One is the proper sizing of the heating, ventilation, and air-conditioning (HVAC) system. If the HVAC system is “oversized,” the system will not run long enough to dehumidify the building. However, if the system is “undersized,” the system may run for long periods and still not be able to handle the moisture load resulting in condensation on interior surfaces. However, equipment is routinely installed with total capacities that are 50% to 200% greater than needed (Hourahan 24). Other design and construction considerations are outlined in Figure 1.
Preventive Maintenance
Preventive maintenance of equipment (such as the HVAC system) and regular inspections should be part of an on-going maintenance program. Equipment components should be on a scheduled maintenance program in accordance with the manufacturerʼs recommendations. The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) standard 62-2001 Section 8 contains maintenance recommendations for filters, air-cleaning equipment, humidifiers, dehumidifying coils, drain pans, air intakes, control sensors, and cooling towers. These provisions should be considered as minimum criteria. An effective system should be implemented to track and document preventive maintenance efforts.
One purpose of periodic inspections is to proactively identify areas that have previously experienced water damage and may have visible or hidden mold growth. Another purpose of periodic inspections is to determine the need for mechanical systems cleaning and maintenance.
Documented inspections should include the following:
- Ductwork, diffusers, and air vents
- Window frames
- Carpets
- Ceiling tiles
- Interior sources of moisture (such as decorative fountains, sauna areas, planters, pools, spas, bathrooms, and kitchens)
- Roofs
- Attics
- Basements and crawlspaces
- Crawlspace
- Weatherproofing components and flashings
- Building exteriors for potential moisture sources (such as sprinklers and drainage)
- Outside air dampers for nearby sources of contamination
- Drain pans
Interior moisture, humidity, and ventilation controls should also be incorporated into the siteʼs preventive maintenance program. Such controls may include periodically taking temperature and humidity readings throughout the buildings as well as evaluating the buildingsʼ ventilation rates to ensure it continues to meet ASHRAE 62-2001. Indoor humidity readings should be maintained between 30 and 50% relative humidity. ASHRAEʼs recommended ventilation rate in cubic feet per minute (cfm) per person depends on the type of indoor space. For offi ces, ASHRAE recommends 20 cfm/person of outdoor air. Consideration should also be given to automate building temperature and humidity controls such as the use of a humidistat. A humidistat is a control device that can be connected to the HVAC system and adjusted so that, if the humidity level rises above a set point, the HVAC system will automatically activate. The practice of shutting down the HVAC systems during unoccupied periods should be avoided as this practice may result in indoor moisture conditions that support mold growth.
For facilities with tenants, responsibilities pertaining to preventive maintenance of tenantoccupied spaces should be specifi ed in the lease agreements. Specifi c language should require tenants to notify the property owner/manager if water intrusion exists (such as leaking faucets, deteriorating ceiling tiles, etc.) or if mold growth is noted on surfaces (such as fl oors and/or walls).
Managing Water Intrusion Incidents
When a water intrusion or indoor moisture episode occurs, an effective system of communicating and reporting the condition(s) promptly should be established so that the situation can be corrected in a timely manner in order to prevent indoor mold growth. The EPA suggests that an “IAQ Complaint Form” be completed by the facility staff handling the complaint as well as an “Incident Log” to document each response (see http://www.epa.gov/iaq/largebldgs/ baqtoc.html). Feedback should be provided to the complainant(s) and a follow-up of the remedial action should be conducted to make sure the corrective action has been effective.
Since a prompt response to water intrusion is critical in preventing indoor mold growth, water restoration contractors should be pre-qualified and be prepared to respond immediately when needed. Water-damaged carpet and backing should be dried within 24 to 48 hours by using a water extraction vacuum, use of a dehumidifier, and use of fans to accelerate the drying process. Damaged ceiling tiles, fiberglass insulation, and cellulose insulation, should be discarded and replaced. Wallboard may be dried in place if there is no obvious swelling and the seams are intact. If not, they should be removed, discarded, and replaced. A water extraction vacuum should be used to remove water from impacted concrete or cinder block surfaces. For cleanup methods of other materials to prevent mold growth, refer to Table 1 in EPAʼs Mold Remediation in Schools and Commercial Buildings (see http://www.epa.gov/iaq/molds/mold_ remediation.html).
For facilities with tenants, the mold management program should include a system of educating tenants on the importance of addressing water intrusion incidents and reporting such incidents to the facility owner immediately. The tenantʼs responsibility of notifying the facility owner immediately of water intrusion incidents should be addressed in the lease agreement.
Mold Assessment and Remediation
If water damage cannot be cleaned-up within 24 to 48 hours or mold is present or suspected, the affected area(s) should be assessed by a qualifi ed person to determine to determine if mold remediation is needed. A detailed visual inspection of the impacted areas should be conducted by trained personnel. A borescope can be used to view spaces in ductwork or behind walls, and a moisture meter is useful in evaluating the moisture content in building materials, which may be helpful in identifying hidden sources of mold growth and the extent of water damage. Bulk and/or surface sampling may be performed to identify the presence of mold on surfaces and air sampling may be performed in an attempt to determine if there is an indoor amplification of mold spores.
Based on the assessment, a mold remediation protocol should be prepared and provided to the mold remediation contractor.
The protocol should include the following:
- Rooms or areas where the work will be performed.
- Estimated quantities of materials to be cleaned or removed.
- Methods to be used for each type of remediation in each area.
- Personal protective equipment to be used by remediators.
- Proposed type of containment.
- Proposed clearance procedures and criteria.
The mold remediation contractor should prepare a work plan that provides the specific means and methods in which the affected area(s) will be remediated. Some locations (such as Texas) have licensing requirements for performing mold assessments and mold remediation in certain situations.
Mold remediation guidelines (based on the size of the affected area) are available in Table 2 of EPAʼs Mold Remediation in Schools and Commercial Buildings (see http://www.epa.gov/iaq/molds/mold_ remediation.html). The guidelines include personal protective equipment requirements, cleanup methods, and containment requirements depending on the size of the remediation project. If contamination is in ductwork or HVAC system, the HVAC system should be shut down until the ductwork, HVAC system, and other impacted components are properly cleaned to prevent the spread of mold spores throughout the facility.
Mold assessment consultants and mold remediation contractors should also be pre-qualified and selected so that they can respond in a timely manner when needed.
Training and Qualifications
Maintenance personnel should be trained in the siteʼs planned and unplanned maintenance procedures and be trained in the siteʼs mold management program. Personnel responsible for performing mold assessments and/or remediation require more extensive training and may also be required to be licensed depending on local requirements. Occupants and tenants should be provided with tips on how to prevent indoor mold growth and to report water intrusion incidents immediately. Contractor prequalification and selection criteria should be formalized to ensure they have the necessary qualifications and expertise to perform their scope of work in an effective manner.
Finally, to ensure that the mold management procedures are kept up-to-date, the mold management program should be formally reviewed and updated on an annual basis. It is unlikely, that water intrusion or indoor mold growth will completely be eliminated. However, the cost of water intrusion incidents and subsequent mold contamination can be minimized by formalizing a detailed mold management program that includes defining roles and responsibilities, establishing communication procedures with occupants and tenants, considering moisture control measures during the design and construction/ renovation of buildings, incorporating water intrusion and moisture control in preventive maintenance procedures, establishing formal response procedures for correcting moisture conditions and mold growth, providing training to maintenance personnel, and educating occupants on reporting water intrusion incidents.
References
American Industrial Hygiene Association (AIHA). Recommendations for the Management, Operation, Testing, and Maintenance of HVAC Systems: Maintaining Acceptable Indoor Air Quality in Nonindustrial Employee Occupancies Through Dilution Ventilation (AIHA Guideline 2 – 2004). Virginia: AIHA, 2004.
American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE). Thermal Environmental Conditions for Human Occupancy (ANSI/ASHRAE 55-1992). Georgia: ASHRAE, 1992.
ASHRAE. Ventilation for Acceptable Indoor Air Quality (ANSI/ASHRAE 62-2001). Georgia: ASHRAE, 2001.
Hourahan, G. “Sizing and Selecting Equipment for Proper Humidity Control.” ARI Magazine. Spring 2003: 24-34.
U.S. Environmental Protection Agency (EPA). Mold Remediation in Schools and Commercial Buildings. March 2001. <http://www.epa.gov/iaq/ molds/mold_remediation.html>.
U.S. EPA. Building Air Quality: A Guide for Building Owners and Facility Managers. December 1991. <http://www.epa.gov/iaq/ largebldgs/baqtoc.html>.
