Sunlight and hot weather cause ground-level ozone to form in harmful concentrations in the air. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. Ground-level ozone also damages vegetation and ecosystems.

“Ozone levels tend to be higher in rural areas where there are less local emissions of nitrogen dioxides to destroy any ozone that has formed in the atmosphere.”

Ozone is formed when heat and sunlight cause chemical reactions between oxides of nitrogen (NOX ) and Volatile Organic Compounds (VOC), which are also known as Hydrocarbons. This reaction can occur both near the ground and high in the atmosphere.

Ground level ozone is the main component of smog and is the product of the interaction between sunlight and emissions from sources such as motor vehicles and industry. Ground level ozone is more readily formed during the summer months and reaches its highest concentrations in the afternoon or early evening.

Breathing ground-level ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ozone also can reduce lung function and inflame the lining of the lungs. Repeated exposure may permanently scar lung tissue.

Ozone is very reactive and corrosive, thus requiring corrosion-resistant material, such as stainless steel. Ozonation is not economical for poor quality (poorly treated) wastewater. Ozone is extremely irritating and possibly toxic, so off-gases from the contactor must be destroyed to prevent worker exposure.

However, ozone gas works faster, and it leaves no chemical residue in the water either. For home water, well systems ozone can be very beneficial and eliminate odors and kill bacteria as well as oxidize iron and manganese.