At various sites under remediation, we have reactivated or improved remedial system performance, provided operation and maintenance services, or brought system operations back into compliance with discharge permits. For example, we assisted the City of San Jose to rehabilitate a groundwater recovery and treatment system that operated at one of their closed landfill sites. The system was used to collect groundwater and leachate from beneath the landfill and treat the extracted liquid before discharge to a nearby stream under a National Pollutant Discharge Elimination System (NPDES) permit. Treatment included liquid/liquid separation, air stripping, and carbon treatment of water and air prior to discharge. We assessed operation of the system and enacted several modifications to streamline operation, simplify compliance with discharge permits, and save money. We eliminated the air stripping system, separated the leachate and groundwater streams, and eliminated liquid/liquid separation. Air stripping was eliminated based on an evaluation of cost for liquid-use carbon versus the cost of air stripping followed by liquid-use carbon; separation of leachate and groundwater allowed partial use of the sanitary sewer system; and liquid/liquid separation was eliminated because separate phase liquid was no longer being extracted with groundwater. The system was modified so that only liquid-use carbon treatment was used prior to discharge. The modification simplified compliance sampling, lowered power costs, and reduced operation and maintenance requirements.
At a pipeline fuel terminal operated by Chevron Corporation, a malfunction in a valve header allowed several thousand gallons of diesel to enter the site’s emergency spill retention basin. Once the diesel was recovered from the basin, it was discovered that diesel had leaked from the basin and was partially trapped between the basin liner and the earthen floor of the retaining basin. We mounted an effort to vacuum extract diesel from perforations made in the basin liner, investigated and found the leaking seem that allowed diesel to leak from the liner, and worked with a contractor to repair the liner. We also conducted an investigation to delineate the extent of diesel impact to soil and groundwater, and initiated remediation to remove diesel from strategically placed extraction wells. Recovered diesel was sent back to the refinery as transmix for recycling.
After a product pipeline was discovered to have impacted soils and groundwater Chevron Corporation relied on us to construct and operate a groundwater treatment system in Tracy, California. The system operated for 24 hour-a-day, and we remained onsite to provide day and night service. The system included thirty groundwater extraction wells with submersible electric pumps, conveyance piping, ten 20,000-gallon steel tanks, diesel transfer pumps, a 200-kilowatt generator, four 20,000 pound carbon vessels, and secondary containment berms. As part of the project, our staff received additional safety training to comply with Chevron standards. Water was treated and discharged according to cleanup standards and the pipeline was successfully repaired.
As part of pipeline maintenance, companies routinely hydrotest pipelines that are used to transport refined fuel products. Water used for hydrotesting becomes impacted with petroleum hydrocarbon fuel components and additives. To assist Chevron Corporation with disposal of hydrotest water, we devised a plan whereby impacted water would be routed to a pipeline terminal, stored for treatment in an unused product tank, treated using activated carbon, and discharged to the storm drain under a National Pollutant Discharge Elimination System (NPDES) permit. Treated water was contained in a storm water/emergency spill retention basin for verification testing prior to discharge. Methyl tertiary butyl ether (MtBE) posed a challenge for treatment and discharge. After treatment, trace levels of MtBE were detected in retained water and recent regulatory policy dictated complete removal of MtBE. We took advantage of the retention basin discharge pumping system to create a spray system that eliminated MtBE and kept the retained water from becoming an odor nuisance. The MtBE challenge was overcome and treated discharge was allowed to enter the storm drain.
The Charles Derby Small Bore Range was a 1-acre area located in Santa Cruz County. The range was located on a flat area within a ravine; a nearby intermittent creek directs drainage from the area into the Santa Cruz Municipal Harbor, which in turn drains into the Monterey Bay Marine Sanctuary. The range had operated since the early 1950s and was used by law enforcement agencies and private gun owners for rifle and pistol target practice. It was estimated that approximately 200,000 rounds per year of ammunition were fired at the range and until approximately 1990 all the ammunition was lead. We worked with the City of Santa Cruz Parks and Recreation to assess the gun range and develop site assessment and remedial action plans acceptable to the Department of Toxics Substance Control (DTSC), Regional Water Quality Control Board (RWQCB) and County of Santa Cruz Environmental Health Department (County). As part of the Phase II assessment, we drilled over one hundred soil borings and collected numerous grab-groundwater and surface water samples. Using the data, RRM prepared health and ecological risk assessments, developed remedial action cleanup goals, and prepared a Remedial Action Work Plan (RAW) for site cleanup. The RAW also included a soils management plan and site health and safety plan. The RAW was approved by the oversight agencies and successfully implemented. After completion of the work, the property was incorporated into the nearby county park.
To prepare for construction of a Lowe’s retail store in South San Francisco, previous improvements at the site were removed, and preliminary grading and trenching occurred. Analyses of soil samples from borings at the site revealed petroleum hydrocarbon impact and concentrations of California Code of Regulations CAM-17 heavy metals (antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, thallium, vanadium, zinc). We provided a health and safety plan addendum for the site that focused on exposure to heavy metals and conducted on-site air monitoring as part of plan implementation. In another case, we worked with a primary contractor to provided characterization of soils handled during a seismic upgrade to the Bay Area Rapid Transportation system. We coordinated with the stakeholders to pre-profile soils in place as an alternative to the original plan that called for off haul and disposal. Our pre-profiling sample plan resulted in on-site reuse for all soils, providing significant time and cost savings to the client.
The State Water Resources Control Board (SWRCB) requires industrial facilities, such as recycling yards, mining operations, and transportation facilities, to actively monitor the quality of their site storm water runoff that flows into nearby surface waters under a general discharge permit. At a transportation facility in San Jose that stores and maintains large tour buses, storm water runoff enters the San Francisco Bay from two point sources within the facility's parking area. Under the general provisions of the facility's discharge permit, monthly observation of each point source and samples of storm water runoff from each point source are required twice per year during a heavy precipitation event. Concentrations of oil and grease, gasoline, diesel, and other petroleum-based contaminants present within the samples must be within acceptable levels and the findings must be presented to the regional SWRCB in an annual report. The facility operators save time and limit cost by using our experienced monitoring and consultation services. They recognize we provide more efficient liaison with local and state regulatory agencies, efficient labor and materials costs, and discounted laboratory fees.
Chlorinated solvents were discovered beneath a San Francisco Bay Area dry cleaner during a Phase II investigation that was instigated as part of financing the property. We used shaft excavation to remove soil with high concentrations of tetrachloroethylene (PCE) from the interior of the dry cleaners building. An area approximately 20 feet by 20 feet was drilled down to 25 feet below grade using an excavator-mounted 24-inch diameter low-mast drill capable of drilling to a depth of 50 feet. The bore locations were staggered so that no two adjacent locations were drilled consecutively. Bores were back filled with a sand slurry control density fill and allowed to set-up over night. Areas surrounding the previously drilled and backfilled bores were then drilled out until the entire footprint had been removed. Over one hundred slightly overlapping bores were drilled and back filled within a week. Excavated soil was carted outside the building through an opening created for the work and placed into 20 cubic yard roll-off bins. The soil was disposed as RCRA hazardous waste; soil with extremely high concentrations required out-of-state treatment. Diesel equipment was outfitted with scrubber technology to minimize exhaust hazards and an extensive ventilation system was used to generate adequate fresh air exchange. This methodology allowed for deep indoor excavation of source material without the need for shoring.
We have worked at numerous petroleum hydrocarbon underground storage tank (UST) sites for small businesses and large commercial clients such as Chevron and Valero. When available, projects have been funded by the California Underground Storage Tank Fund (Fund), where we have been responsible for all facets of work including reimbursement from the Fund. Services included regulatory compliance; groundwater monitoring; remediation system design, permitting, installation, and operation and maintenance; all manner of reporting; verification monitoring including soil gas and vapor intrusion assessment; public health and environmental risk evaluations; site closure; and site redevelopment.