WORK PLANS_PRE 2019 - Laserfiche WebLink

Home Browse Search

Stantec Work Plan for Amended Bioremediation Pilot Study BP Terminal 40T November 10, 2008 indicated that nitrate/sulfate injections may be able to remediate dissolved hydrocarbons at the site. The previous study indicated a decrease in petroleum hydrocarbon concentrations in monitoring well AR/MW-5A, which is located near the injection points. However, there were still variables that needed to be analyzed in order to fully evaluate the effectiveness of the technology. Following the recommendations in the Pilot Study Evaluation Report by URS, this expanded pilot study includes: • Re-installation of the bioremediation system • Installation of additional injection points; • Increasing the mass of sulfate injected; • Adding a tracer, such as bromide, to evaluate the rate of transport; and; • Modifying the baseline parameters at contingency point AR/MW-1A that are used to determine whether the nutrient injected into the groundwater is influencing the groundwater quality downgradient of the site. The specific scope of work is discussed below. Site Health and Safety Plan As required by the Occupational Health and Safety Administration (OSHA) Standard "Hazardous Waste Operations and Emergency Response" guidelines (29 CFR 1910.120), and by the California Occupational Health and Safety Administration (Cal-OSHA) "Hazardous Waste Operations and Emergency Response" guidelines (CCR Title 8, Section 5192), Stantec will amend the site-specific Health and Safety Plan (HASP) prior to the commencement of fieldwork. The HASP will be reviewed by field staff and contractors before beginning field operations, and will be in the possession of Stantec personnel while conducting work activities at the site. Permitting Stantec will obtain the applicable permits from the San Joaquin .Environmental Health Department prior to initiating field activities. Bioremediation System Re-installation Prior to starting the pilot study, Stantec will re-install the sulfate injection system discussed above with no changes to the design. Installation of Injection Points The results of the previous pilot study indicated that sulfate solution injections into treatment wells had a relatively small radius of influence; therefore, additional injection points are being proposed prior to the start of the expanded pilot study. The locations of the proposed injection points are represented in Figure 2. Injection points are placed in order to increase the area affected by the injection study. The proposed wells will be installed near monitoring wells with the highest levels of contamination. These wells will be screened to target the A-zone area of contamination. The number and required radius of influence for each well will be determined from tests on existing areas of the site. The new injection points will be installed using a 12-inch hollow stem auger and completed with a four-inch schedule 40 polyvinyl chloride (PVC) 0.010-inch slotted well screen from three ft bgs 40T Work Plan for Amended Bioremediation Pilot Study.doc 6