Sustainable remediation practices can be used to reduce the adverse impact caused by spills of any size in any locale, even in middle of the ocean. The goal of every spill cleanup is to contain and control the spill, limit immediate impacts and minimize long-term cleanup efforts.
Selecting the sustainable response and short-term remediation options are only part of developing a sustainable spill response plan. Sustainability must be part of the planning and prevention process as well.
The first step to establishing a sustainable spill response program is to create a singular plan that complies with the various regulatory requirements for emergency response to spills and releases. The U.S. EPA and OSHA have stated that a single “emergency response plan” can be used to comply with both agencies’ requirements. Even local fire departments have accepted the Federal compliant emergency response plan as being compliant with their local requirements.
By having a single response plan, you reduce resources, paperwork and the amount of time needed to keep track of multiple emergency response plans. Employees have only one set of instructions, which simplifies the training process. Updates are made to a single plan and its associated copies. When a spill occurs, there is only one set of instructions to follow.
Most plans base response effort and disposal options on the size of the spill and what is spilled. Tipping over 1 quart of motor oil in the maintenance shop or treatment trailer requires less equipment and effort to clean up than responding to a crash on the highway or a collapse of a storage tank. Recovering 1 quart of motor oil for recycling or fuel blending may not be practical or cost effective, but recovering the contents of a railcar or storage tank for reprocessing or recycling could be. In fact, a portion of the escaping crude from BP Deep Horizon well was recovered and sent to a refinery for processing.
After combining the various plans into a single master plan, conduct a review of the clean up and disposal procedures for ways to increase recovery, recycling or disposal options other than landfilling. Look at what is used to contain and clean up the spilled material and impacted soils, sediments and waterways. How are the impacted media and used response equipment managed and disposed of? Are the guidelines for waste minimization and pollution prevention followed? Is recovery and reuse of the spilled material included as a disposal option? Can in-situ treatments be used?
The spill response plan should provide a list of options the on-site coordinator can select depending on the size, the location and cause of the spill and what is spilled. Most plans provide disposal selection guidelines based on amount of material generated during the clean up step and which disposal vendors have been vetted or issued a purchase order.
Sustainable selection criteria is usually limited to suggesting that the spilled material be recovered for site use if not contaminated, sending high Btu liquids to a fuel blending facility or thermal treatment of organic impacted soils. Note: sustainable disposal options for inorganic spill cleanup wastes and use of engineered absorbents are not discussed.
Most plans specify that absorbent pads, socks and booms be used to clean up a liquid spill. If there is a large amount of liquid spilled, kitty litter type absorbents are recommended and maintained as part of the spill response kit. The use of engineered absorbents as an alternative to kitty litter is part of the spill response plan.
Today’s engineered absorbents are not your father’s absorbents. Absorbent manufactures have developed low ash or biodegradable absorbents that can be destroyed through thermally treatment or composting. Other companies have developed in-situ products to minimize excavation and off-site disposal of contaminated soils and sediments for both organic and inorganic products.
Even if the composted or incinerated residue is landfilled, the treatment process has reduced the toxicity and quantity of the waste by 80 to 90%. Other absorbent materials are part of a system that can extract the absorbed liquid from the absorbent for reprocessing or recovery, especially for low Btu or inorganic liquids. Still others will neutralize corrosive liquids so they can be sent to a wastewater treatment system.
A web search for “oil absorbent vendors” identified venders such as The New Pig Corporation, Spill911, Absorbentonline.com, Gator International and a rough estimate of 100,000 additional sites that stock biodegradable or low ash absorbent products.
A similar search using “absorbent vendors” generated an equally large listing. Gather information; compare costs, benefits and ease of use. The final selection will be up to you and your company’s purchasing process. Stock these products on-site so they will be used when needed.
After selecting the absorbent materials to be used, the spill response plan must incorporate the recommended handling and disposal procedures from the absorbent supplier. Cleanup procedures may be as simple as picking up the overturned quart container, wiping down the exterior of the container and mopping up the spill. The used absorbents are placed in a plastic bag, the bag sealed tight and placed in a DOT approved trash drum, then the labeled drum is sent to a landfill.
If the bag is leaking, it must be placed in a drum containing an absorbent to solidify the liquids. Once all liquids have been solidified, the sealed and labeled drum can be landfilled. If the contents of the drum cannot be solidified, the drum must be sent to an incinerator or other disposal facility that can handle liquids.
As the spill gets larger such as overfilling the used oil storage tank, the ability to contain the spill within a shop floor or secondary containment unit becomes more difficult. Drain covers; containment booms and skimmers are needed and should be staged near the source of a spill on-site.
The selected equipment should minimize the amount of waste to be landfilled and complement the planned waste management option. On-site mobile systems such as thermal treatment, soil washing, bio-piles or chemical treatment can treat the impacted soil and sediments so they can be returned to the spill site as clean fill. The extracted material could be recovered for reuse or recycling. In-site treatment options that enhance biodegradation of organic compounds can eliminate the need to excavate.
Table-1 lists some of the response options for cleanup of common liquid chemicals using today’s engineered absorbents and in-situ or ex-situ treatments options.
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If recovery is selected, the containment system needs to isolate the spilled material without affecting it. If disposal is selected, the containment system must be compatible with the disposal option such as biodegradable if composting, have a high Btu and low ash content for thermal treatment or solidifies the liquids for landfilling. Disposal options are listed in Table 2 for generic liquids.
Once a spilled liquid reaches permeable surfaces such as soil, rocks or sediments or enters the sewer systems or local waterways, containment, cleanup and disposal options require even more preplanning and study. At this point, the spill begins to impact the public and coordination with local and state agencies is required. A website such as http://www.cameochemicals.noaa.gov/ can help identify pathways that need to be remediated without creating excess waste or injuries.
Excavation of the impacted soil for off-site disposal is the quickest solution, but not the most sustainable or cost effective solution. Depending on the amount of soil impacted, one sustainable solution could be on-site thermal treatment in a mobile unit from Clark Environmental or other vendors.
High Btu contaminants are destroyed and the treated soil can be used as backfill material instead of obtaining clean fill from an off-site facility. On-site thermal treatment becomes cost competitive when more than 5,000 cubic yards of soil must be remediated, especially if the nearest landfill is more than 100 miles away.
Other ex-situ processing such as soil washing, stabilization and bioremediation can be conducted in mobile units that can destroy the toxic organic or non-organic contaminants and allow the treated soil or sediments to be used as fill. These treatment processes become cost competitive with landfilling when processing over 2,000 cubic yards of solids.
To minimize long-term remediation and monitoring efforts, spray the sides and bottom of the excavation area with a chemical or biological reagent before filling in the excavation area. Chemical and biological reagents can destroy trace concentrations of organic contaminants remaining in the soil or sediments. Either can be sprayed on the side and bottom of the excavation using hand held spray systems available at home and garden stores.
If excavation is not an option for large-scale soil cleanup, modification of the chemical injection process has been used to destroy or recover the spilt liquid. URS developed a process using the Badger Injection System to push the spilled liquids towards a groundwater recovery system being used to remediate impacted groundwater. The recovered material was sent to a recycler for processing.
If mobile treatment systems cannot be considered for political or technical reasons, the sustainable disposal option is thermal treatment or destruction for organic contaminated solids or immobilization for inorganic contaminated solids. Corrosive liquids must be neutralized before being sent. Landfilling should be the last option and only used for waste streams that have no other viable treatment option.
If the spill enters a sewer system or waterway, sustainable cleanups become difficult to implement. The spill needs to be contained to minimize the extent of impact. If possible, recover the spilled material for reprocessing, reuse or destruction. Vacuum trucks, skimmers and oil/water separators can be used to collect the floating liquids. If recovery is not possible, consider using the sustainable processes approved for groundwater remediation.
The sustainable groundwater treatment technologies are not common practice even when cleaning up impacted groundwater. Regulators and elected officials are accustomed to seeing skimmers and absorbent booms, as well as, pillows and pads containing and collecting spilled liquids. Yet the justification for using chemical reagents to remediate groundwater impacted by historical releases is the same for remediating water impacts from current spills especially for large areas such as beaches and creeks.
Containment systems are needed to limit the distance the spill travels even if the source of the spill will not be completely plugged for some time. The goal of a recovery system attached to the containment system is to collect the spilled liquids at a rate equal to or greater than the amount being released. While recycling the spilled liquid is the preferred option, thermal treatment for organics and filtration for inorganics within the containment systems can reduce the adverse impacts caused by the release.
If petroleum sheens appear on the surface of waterways downstream of containment booms, consider spraying weak solutions of hydrogen peroxide or biodegradation products on the surface of the sheen to destroy the dissolved plume. These products successfully destroy the groundwater plume from historical releases and can help reduce the amount of spilled material washing up on the coast and riverbanks.
Once the source of the spill had been plugged and a short-term recovery and collection has been completed, the dissolved plume, if is still present, in the soil, groundwater and sediments must be addressed. Sustainable techniques used for cleaning up historical releases will work to clean up the areas impacted by the spill. The only difference is that the release is relatively fresh and the composition of the contamination will more closely match the composition of pure product.
The techniques and procedures used to implement sustainable remediation plans should be applied to the cleanup of a spill to reduce the need for a long-term remediation project. Equipment to facilitate recovery or in-situ destruction of the split liquids must be readily available and familiar to employees. If the spill cleanup cannot be completed within 30 days, the spill response plan can be converted into a sustainable remedial action plan that will complete the cleanup with minimal process changes, secondary impacts and regulatory delays.