(g) Microbial management. The control of the conditions that allow or encourage microbial growth should be a primary objective of building operations and maintenance. (1) Water intrusion. Damaged building systems or components that cause water condensation or water leaks in the building should be promptly repaired. Inspect the building for evidence of water damage and visible mold growth and promptly correct the problem. Areas that go unattended can soon become major problem areas. (2) Water damage. Porous materials that cannot be dried within 24-48 hours usually cannot be saved without great expense. Remove and dispose of water-damaged porous materials, such as sheetrock, fiberglass or cellulose insulation, carpets, mattresses, pillows, upholstered furniture, papers, and books. If water damage is from floodwaters that may contain sewage or from sewage backup, the water-damaged porous materials should be replaced and special cleaning is required for all hard surfaces. If large areas are water-damaged, desiccants and/or dehumidifiers may be necessary to remove excess humidity and prevent mold growth. (3) Cleaning/replacement. Promptly clean or replace materials contaminated with mold or other microbials. Contaminated porous materials should be replaced. Take precautions to prevent exposures to workers/occupants when cleaning and/or disinfecting with chemicals. When removing contaminated materials, handle the material carefully and gently to avoid dispersion of contaminant, and bag the material prior to removal from contamination site to prevent further contamination of adjacent areas. (4) Construction, operation and maintenance. To prevent microbial growth: exhaust the air directly to the outside in high moisture areas; prevent condensation on cold surfaces (i.e. windows, piping, exterior walls, roof or floors) by adding insulation, raising the temperature and increasing circulation; prevent water intrusion from rain and ground water by proper maintenance of the landscape, roof, and exterior structure materials; maintain relative humidity below 60%, preferably below 50%, at all times if possible; do not install carpet in areas where there is a potential moisture problem; and check the installation and operation of moisture barriers, weep holes, HVAC systems, roof, windows, and vents. (5) Water systems. Ensure that the following water systems are built, operated and maintained to prevent the growth of Legionella and other microorganisms that can become airborne: potable water systems, emergency water systems, heated spas, whirlpool baths, drip pans, architectural fountains, waterfall systems, cooling towers, fluid coolers, evaporative condensers, direct evaporative air coolers, misters, air washers and humidifiers. Treatment for these systems includes the use of chemicals, ionization and/or heat, depending on the system. Additional guidance can be found in ASHRAE Guideline 12-2000 "Minimizing the Risk of Legionellosis Associated with Building Water Systems."

(b) A school building must be properly ventilated and provided with an adequate supply of drinking water, an approved sewage disposal system, hand-washing facilities, a heating system, and lighting facilities that conform to established Standard of good public health engineering practices.