Remedial Services Case Studies
Confidential Pipeline Company
Superior responded to a refined petroleum spill that leaked into a small creek near a bulk petroleum storage facility. Superior was tasked with delineating the extent of impact to minimize potential risks to the surrounding area and the general public.
Adverse site conditions restricted the use of conventional truck mounted drilling equipment, which could not navigate the terrain. To overcome the complicated site access issues, Superior mobilized two track-mounted Geoprobe® 7720 DT direct-push units to guide the initial site investigation. Due to the nature of the emergency response, this phase demanded long work hours that frequently involved drilling before daylight to well after dark each day. Through the use of the Geoprobes®, Superior was able to quickly identify areas where large-diameter recovery wells would need to be installed to intercept product from leaching into the creek. Each of the recovery wells was installed with Superior’s CME 1050 all-terrain vehicle (ATV) drilling rig, which could easily handle the muddy terrain and large-diameter augers. Due to the amount of product encountered while drilling the wells, a small, lined catch pit was constructed directly behind the drill rig. These pits allowed a vacuum truck to be stationed nearby to recover the product as drilling progressed. In total, over 100 wells were installed on the site during the response activities.
Due to the severity of the release and nature of the refined petroleum product, drilling activities were performed in Level C personal protective equipment. A heightened level of safety awareness was necessary to ensure safe operations while on-site. Through the use of Job Loss Assessments and tailgate safety meetings, each crew member participated in the accountability to mitigate the unique hazards associated with the drilling activities
Brownfield Redevelopment Site, Ohio
Superior was contracted to aid in the site investigation of a large property transfer covering half a city block. As part of a brownfield project, soil and groundwater assessment were the primary focus of this phase of work. The lithology in the area consisted of varying thicknesses of unconsolidated soils ranging between 5 to 30 feet below ground surface (bgs), which overlay bedrock consisting of sandstone and/or conglomerate formations. Groundwater was typically encountered within the bedrock at depths of up to 50 feet bgs.
To accomplish the scope of work, Superior used multiple drilling techniques to complete the borings. Conventional hollow-stem auger drilling was used to obtain soil samples in the unconsolidated formations and, upon reaching competent bedrock, a casing was installed and tremie grouted into place with portland cement. After sufficient curing, down-hole hammer (DHH) drilling commenced to complete the wells. DHH drilling is a specialized drill bit that is driven by compressed air. The 'hammer' is slowly rotated at the bottom of the borehole while a tungsten carbide bit repeatedly strikes the bedrock causing it to fracture the rock, much like a jackhammer operates. The drill cuttings are then blown up to the surface by compressed air and diverted into drums for disposal. In locations where relatively soft sandstone was encountered, the air rotary drilling method was used. This drilling method used a conventional tricone roller bit to create the borehole. By using a method that relies upon air instead of a bentonite drilling fluid to remove cuttings, water levels and contaminated zones can be immediately determined.
The investigation extended to depths of up to 60 feet below ground surface over multiple properties. Each individual boring location presented a unique challenge due to the need to perform assessment in congested areas that were surrounded by busy streets and sidewalks. The safety of the general public and drilling staff was a top priority, and hazards were identified and mitigated through the use of our Behavioral Based Safety program and procedures. Due to the experienced crews on the project, Superior completed another project safely and within budget.
Air National Guard Base
Superior was contracted to provide monitoring well drilling with hollow-stem augers, direct-push soil sampling, monitoring well abandonments, and test-pit excavation activities at secure locations throughout the base, including restricted areas along runways, aircraft aprons, and taxiways. Superior performed these activities over a 6-year period as part of an ongoing long-term soil and groundwater investigation for various hydrocarbon compounds and chlorinated solvents.
The majority of the monitoring well installation and direct push sampling was conducted in lithology comprised of thick, silty, and often saturated clay formations that are the predominate geological feature on the west shoreline area of Lake St. Clair. Many of the areas on the airbase contained perched aquifers that ranged from just below surface grade to over 20 feet in depth.
Superior used a variety of off-road drilling rigs, tracked direct-push units, and support equipment, such as skid steers and tractor backhoes to complete the varying tasks. Superior frequently had to be escorted through sensitive areas of the base. In addition, foreign object damage (FOD) was a constant concern. FOD are considered materials that can be pulled into turbine engines or blown about resulting in damage to the aircrafts on base. Superior employed a variety of measures to ensure safe operations for the crew and surrounding sensitive areas.
Superior was also tasked with the containerization, transport, and staging of investigative derived wastes (IDWs), some of which required off-site disposal as listed hazardous wastes. Transportation and staging of the IDWs were often challenging due to base regulations that dictated where the drums and roll-off containers could be stored, which often was greater than a mile away from the drilling work areas.
This attention to detail and dedication of Superior to provide the highest quality drilling program while maintaining a productive schedule under budget is another reason Superior maintains long-term relationships with their clients.