UUES design criteria based on preventions preferability. In wastewater treatment systems the primary odor of concern is hydrogen sulfide gas (H2S). Industrial and manufacturing facilities have an impact on the environment, the community’s well-being, and plant worker’s safety and productivity. Many industrial facilities are now facing the challenge of meeting and maintaining compliance with ambient air standards driven by air pollution regulatory agencies and workplace health and safety enforcement organizations. If prevention is applicable, all our plants undergo thru a deep cycle of study, and analyzing possible scenarios of odor emission. Capturing and destroy odors before they are released to the environment is preferred. If prevention or destruction is not applicable, dispersion may help to avoid such problem.