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Mr. James Barton <br />April 14, 2004 <br />Page 3 <br />container of mixed dilute (1-5%) sodium metabisulfite solution will be kept on-site to neutralize larger <br />spills. The area will be well -ventilated and all sources of ignition will be removed prior to start of <br />work. <br />HYDROGEN PEROXIDE INJECTION <br />Hydrogen peroxide injection will consist of two treatments, one treatment per day. Each treatment <br />will consist of injecting approximately 20 gallons of 30% potassium persulfate solution through the <br />injection port on the EX -1 and EX -2 well caps, followed immediately by 400 gallons of 10% hydrogen <br />peroxide solution. The rate of chemical addition will average from 0.5 to 5 GPM. Addition of the <br />hydrogen peroxide solution will be slow initially to control water level, and increases in temperature <br />and well pressure. Technicians will monitor well water levels, temperature and well gas pressure <br />continuously during injection. As pressure in the well increases, additional pumping pressure may <br />be needed. Well pressure may need to be released during water level measurement. <br />Gas pressure increase will be monitored during hydrogen peroxide addition and flows will be <br />adjusted to keep well pressure as near 30 psi as possible. Pressure, temperature, injection volume <br />and water levels will be recorded at regular intervals. Well pressure will not exceed 30 psi by use of <br />an adjustable safety pressure relief valve and manual ball valve, so as not to damage the well casing <br />or cause injury. <br />POST INJECTION MONITORING <br />Contaminant concentrations in downgradient wells will be monitored at regular monitoring periods <br />following treatment to document trends in dissolved petroleum hydrocarbons. Post treatment <br />monitoring will be conducted approximately one month post treatment, followed by quarterly <br />monitoring thereafter. Persistent concentrations of petroleum hydrocarbons may require additional <br />peroxide injection treatments. <br />REPORTING <br />Results of the injection process will be included as part of the quarterly monitoring report prepared <br />after the initial injection. The results of hydrogen peroxide treatment and groundwater monitoring will <br />be included as part of the fourth post-treatment quarterly report. The report will include a summary <br />of the monitoring results, calculations of estimated mass destroyed, and estimates of the residual <br />mass flux emanating from the treatment well area. <br />I:\Chevron\95775\REPORTS\Peroxide Injection WP RevB.doc SECOR International Incorporated <br />