Groundwater Monitoring Leads to Remediation

Groundwater Monitoring Leads to Remediation

Sierra Piedmont® (Sierra) initiated groundwater monitoring at a gasoline/diesel station in Ballground, Georgia in March 2004. Multi-Phase Extraction (MPE) events were completed for recovery of phase separated hydrocarbons (PSH) on May 3, 2004 and January 5, 2005.  During the fourth monitoring event on April 5, 2005, Sierra observed that PSH remained.

The following corrective action hydrogen peroxide injection method was implemented beginning February 28, 2006.  The necessary safety precautions were taken prior to the injections such as:

A temporary containment pad for the hydrogen peroxide polytanks
A temporary fence around the polytanks
The work area marked with caution tape, permitting limited access only
Personal protective equipment including:  nitrile inner gloves, outer gloves composed of rubber, Tyvek suit, safety glasses, protective face shield, and steel toe work boots

Four newly installed injection wells and two existing monitoring wells were used for the injections. The initial injections consisted of a 17.5 % hydrogen peroxide solution. Temperature and pressure were monitored at the wellhead during the injection process. Second injections occurred in the same manner one week after the initial injections. Groundwater samples were collected from all permanent monitoring wells three weeks after the initial injections of hydrogen peroxide. During the injection process, it was evident that the reaction was working. Sierra will determine if the corrective action was effective after the receipt of laboratory analytical results.

The use of hydrogen peroxide to chemically oxidize the contaminants into mineralized products (carbon dioxide, salts, and readily biodegradable organic fragments) offers a number of advantages including the following:

Hydrogen peroxide is inexpensive, readily available, and has as its reaction products water and oxygen.
It is applicable to a wide variety of contaminants.
The process is easily applied and controlled.
The treatment occurs rapidly, lasting from a few hours to a few weeks.