Water intrusion throughout the law enforcement building envelope resulted in hidden mold in wall cavities and under flooring. Hidden mold is consistent with employee reports of musty odors, especially after rains, and health symptoms. The county has taken action to prevent further water intrusion through the foundation, including re-grading the ground to direct water away from the exterior building. The concrete slab will need to dry out and then be tested again for moisture before installing compatible replacement flooring. If the concrete slab moisture cannot be controlled, other options need to be considered including using breathable floor coatings or installing a moisture vapor suppression system. Mold and moisture-damaged materials should be removed or cleaned with appropriate containment to minimize exposure for remediation workers, building occupants, and unaffected sections of the building. The bat droppings identified in a wall cavity also should be removed, and the area cleaned. Inappropriate remediation can cause further problems and symptoms in occupants. The amount of fresh air delivered to occupied spaces within the building was originally incorrect, due to the elimination of planned outdoor airflow monitoring stations during HVAC system installation. However, the outdoor airflow rates were appropriately adjusted by Holistic Test and Balance, Inc. during their ventilation testing and balance assessment on February 4, 2019. If building spaces are renovated or repurposed for different uses in the future, new testing and balancing of the impacted ventilation systems should be performed to ensure appropriate outdoor airflow to those occupied areas. Temperature in occupied spaces should be maintained from 68.5 degrees F to 75 degrees F in the winter, and from 75 degrees F to 80.5 degrees F in the summer, while indoor humidity should always be maintained to provide a maximum indoor-air dew-point temperature of 60 degrees F. Implementation of a thorough HVAC preventative maintenance program and the creation of a comprehensive, written HVAC operation and maintenance plan for the facility would further help ensure proper HVAC system operation and indoor environmental quality. Establishing a team for improved communication and reporting of environmental or health concerns can help prevent future building-related health symptoms.