Groundwater remediation in its simplest form is the process of using equipment to reduce oil-based compounds & chemicals in groundwater. Contaminated groundwater can work its way into the water table where it can travel to municipal drinking water system wells resulting in unsafe drinking water.

Utilizing ozone in groundwater remediation injects ozone into the groundwater to speed up the process of reducing oil-based compounds & chemicals. Ozone is an environmentally friendly treatment since it is not a chemical and reverts back to oxygen after reacting with contaminants.

The goal of utilizing ozone is to reduce on-site treatment time & costs. Typical treatment time can be reduced from 25-75% depending on site conditions. When utilizing ozone, total treatment costs can be reduced anywhere from 25-50%.

In virtually all states, a contaminated site or lot cannot be sold until the contaminant levels are reduced to state limits. It is in the owners, or insurance companies, best interest to quickly reduce contaminant concentrations so the land can be sold and developed. In large cities, plots of land worth millions of dollars are undeveloped because site contaminant levels are too high.

Ozone has been used since the '80s. However, ozone generation equipment was not very reliable and it slowly fell out of favor in the early '90s. Now, ozone generation equipment has improved and environmental regulations have tightened resulting in a resurgence of ozone implementation.

The variables one must consider for implementing ozone into groundwater are the following (this is not an exhaustive list):

Two primary treatment methods exist when treating ground water. They are Ozone/Air Sparging and Pump & Treat.

Ozone/Air Sparging is the process of injecting air & ozone into wells placed the ground in the contaminated zone. Air & Ozone is pushed from the equipment through ozone compatible tubing to multiple wells. The gases enter the wells and travel down to screens in the bottom of the wells. Well depths can vary from 10-70-ft. The gases permeate the screens there they come into contact with the groundwater and get absorbed into solution. Once in solution, the ozone reacts with the contaminants and reduces their levels. The reacted & unused ozone will revert back to oxygen within a few minutes. Ozone cannot be stored therefore it must continuously be generated onsite.

Pump & Treat is the method of pulling contaminated water out of the ground and treating it with ozone to reduce containment levels. If the contaminant levels are below those allowed by the state, the water may be reintroduced into the ground. This method is much less popular than the air sparging method since reducing contaminant levels before being reintroduced into the groundwater is very expensive. In some rare locations, the treated water cannot be reintroduced into the ground, even if it is perfectly clean, and must be transported off site.

A few of the challenges when using ozone for groundwater remediation are the following:

Below is a list of contaminants that are reduced with Ozone.

Most groundwater remediation sites are gas stations which require only 0.5-1 lb/day of ozone production. The next most common size is a 3-5-lb/day system to treat multiple injection points (5-10). The larges applications for ozone & groundwater can range into the 50-100 lb/day ozone generation capacity and typically involve 50-150 injection points.

Ozone has proven itself to be a valuable oxidant for groundwater remediation. If you are considering treating a site with traditional air sparging or pump & treat equipment, we encourage you to contact us at (712) 722-0337 to see how ozone can benefit you.