SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

16 April 1997 AGE-NC-95-0109 Page 2 of 3 • Ammonium nitrate includes both the reduced and oxidized forms of nitrogen. Both forms of nitrogen are used by the various bacteria which degrade hydrocarbons. The primary use of nitrogen is in the production of proteins for biomass. • A minor amount of harmless nitrogen gas (atmospheric NZ) is also produced through the degradation process. • Laboratory analyses of soil and ground water samples indicate no bioaccumulation of nitrogen. • Ammonium gas may be produced in anaerobic degradation processes. Anaerobic hydrocarbon degradation is significantly slower than aerobic degradation. The addition of hydrogen peroxide or oxygen will encourage aerobic degradation, therefore inhibiting the production of ammonium gas and increasing the rate of remediation. • No evidence of the production of ammonium gas has been observed at the site. • For the purpose of enhancing bioremediation at the site, hydrogen peroxide concentration in the water will remain below 0.1 per cent. Higher concentrations may be detrimental to the microbial populations present. Hydrogen peroxide is a weak base and therefore this addition should not produce a significant change in the pH of ground water. • The current monitoring program (revised monitoring and reporting program 93-701 dated 21 March 1997) includes the quarterly sampling of seven ground water wells and annual sampling of fifteen wells. Included in the requirement are pH measurements for each sampled well. Samples from two wells (MW-9 and MW-14) are analyzed for physicochemical properties on a quarterly basis. Semi-annual soil sampling is also performed near MW-14 to monitor soil remediation and nutrient concentrations.Nutrient addition will be concentrated near MW-14. • Monitoring will be performed to assure that the rate of nutrient addition does not exceed the rate of utilization. Nitrate nitrogen concentrations in ground water will be maintained at or below the regulatory limit of 10 mg/l (parts per million, ppm). As discussed, we would like to obtain a Waste Discharge Waiver for the addition of nutrients. Furthermore,we would like to begin the nutrient addition procedures as soon as approval is received. If you have any additional questions or comments,please contact our Stockton office at(209) 956- 0264 or Mr. A. Keith Kaufman at(310) 822-9385.