Cutting Remediation Costs But Not Cornersby
Original Publication Date: January 1996
Remediation procedures and techniques are becoming increasingly more specialized and more costly for business and property owners. However, many of today's remediation costs can be minimized, without jeopardizing effectiveness, by gaining a better understanding of remediation procedures and the various options available at the different stages in the process. The following guidelines provide a concise yet comprehensive overview of the leading factors that can impact the cost of remediation for soil or groundwater contamination at each phase of a "typical" program. More importantly, the treatment of each cost factor also includes a review of frequently available alternatives that can dramatically reduce the ultimate cost of a remediation program without detracting from its effectiveness.
The first step in any remediation process is the proper analysis and identification of the contamination problem, both its exact nature and extent. The more thorough the initial analysis the less likely that costly surprises will surface at a later stage. The techniques employed to make these determinations will depend on the magnitude of the problem. For example, on large sites requiring extensive sampling it is often more cost effective to conduct an on-site analysis using a mobile laboratory, especially if plant operations must be shut down during this sampling process. Although bringing a mobile lab on-site is not inexpensive, in certain situations (such as those requiring shutting down operations) it can be very cost effective by reducing the amount of down time. The alternative is to ship samples to an off-site lab and wait for results to come back, which can add days or weeks to the process depending on the size of the site and the number of samples required.
A more focused initial site investigation by the environmental consulting firm will also help to keep costs to a minimum. If the consultant concentrates the site investigation on only the issue or issues that compelled the property owner to seek assistance in the first place, then there is no need to undertake broad screening and very costly investigative procedures, such as a priority pollutant analysis. If an analysis is capable of identifying traces of more than 100 different compounds, it is quite likely that some other contaminants will be found. While this generates additional work for the consulting firm, it only creates unanticipated and often unnecessary added costs for the owner.
Once the magnitude of the problem has been identified, the next step is the development of a remediation plan which includes a feasibility analysis. This analysis is intended to determine the most technically feasible and cost effective method for remediating a particular site and should be carefully reviewed by the property owner since it often presents several available remediation options. A well prepared feasibility analysis should include a discussion of the proposed remediation's impact on the business beyond just the capital costs. It should weigh such factors as the trade-off between time and cost and an analysis of the sensitivity of cost estimates. For example, should a business delay or draw out the remediation process and costs over several years, if possible; and can the process be financed from corporate capital or will it require bank financing?
A well designed feasibility analysis will typically take into consideration such factors as:
Type of soils. Certain soils respond better to particular remediation techniques. For example, if the soils on a contaminated site are primarily sandy, then certain remediation methods such as vacuum extraction or bioremediation might be appropriate depending on the type of contaminant. On the other hand, if the soil has a high clay content, then excavation and disposal, thermal desorption or incineration may be better suited to the task.
Contaminant location. The location of the contamination relative to surface features, such as buildings, utilities, etc., may limit the available remedial options. For example, soil contamination located under a building may make an in-situ method much more cost effective than excavation and ex-situ treatment.
If the contamination is located at or below the water table, a combination of remediation techniques (vacuum extraction, air sparging and pump-and-treat) may be required to accomplish the remediation. Or, on the other hand, the nature of the contaminant (e.g., PCBs) may be such that de-watering and excavation and disposal is the only feasible option.
Nature of the contamination. Some contaminants such as hydrocarbons, including gasoline and diesel oil, generally can be dealt with easily and inexpensively. If necessary, they can even be dug up and moved to a Type 2 landfill. Other contaminants, such as chlorinated hydrocarbons, however, cannot be hauled to a landfill without costly pre-treatment. Similarly, some remediation methods are better suited to certain types of contaminants. For example, bioremediation has proven to be very effective with petroleum gasoline hydrocarbons such as diesel fuel and heating oil products, but less effective with chlorinated solvents and PCBs.
Amount of contaminated material. Some remediation techniques are more cost effective for larger volumes of contaminants, such as bioremediation or low temperature thermal desorption. With bioremediation, contaminants are consumed or detoxified by micro-organisms, which are either naturally occurring or genetically engineered. Since this method typically is employed on the site, it eliminates the cost and liability of transferring contaminants from one location to another. Low temperature thermal desorption is another on-site remediation technique, but is best suited for petroluem hydrocarbons. Utilizing a unit resembling a modified asphalt plant, the contaminated soil is heated and volatile compounds are driven off and captured in the vapor stream where they are destroyed. Since the decontaminated soil is returned to its original site, this process also eliminates the liability issue and the need to bring in clean fill dirt. Other methods, such as excavation and disposal are generally more cost effective for smaller scale projects than for sites with large volumes of contaminated soils.
Time required to remediate the site. If the contaminated site is also the location of an operating industrial plant or other business which may be disrupted by the clean-up process, then the time required to accomplish remediation becomes a critical element in the decision as to which technique to adopt, assuming that several alternatives are appropriate. Often the more expensive remediation option can be the most cost effective, if it requires the least down-time. Conversely, the least costly remediation method could prove to be the most expensive technique, if it necessitates shutting down or disrupting operations for extended periods.
Although the actual time required for various remediation techniques is highly site and contaminant dependent, some of the more commonly used procedures can be ranked according to the following typical time requirements (going from least time to most time): excavation and disposal - days to several weeks; vacuum extraction - months to years; low temperature thermal desorption - days to weeks; and bioremediation, which may require years at a minimum.
In a situation where only one remediation technique is feasible, business owners can sometimes still reduce costs if they can take steps to modify their operations to facilitate the remediation, which in turn could minimize the time and expense of a clean-up procedure.
Time of year. In Michigan, the time of year can also impact the cost of remediation because of the state's Frost Laws. These regulations place weight restrictions on the size of a load that a truck can haul during the Spring thaw. During a six to eight week period usually in March and April, trucks are limited to hauling only partial loads which can add to the time and expense of any remediation procedure requiring the removal and transfer of site materials. Savings achieved by delaying the transfer process a few weeks until the Frost Laws have expired can often compensate for the added inconvenience.
Use of remediation specialists. For more specialized remediation techniques such as bioremediation, vacuum extraction or soil vitrification it can be more cost effective to retain a firm that specializes in a particular procedure. By bringing in a specialized remediation provider with extensive knowledge and experience rather than taking time to become familiar with new equipment and procedures, the lead consultant on the project can save the client time, money and grief. After all, it is always less expensive to remediate a site correctly the first time than to go back and correct oversights.
A good environmental consulting firm will include the foregoing factors as well as others in their feasibility analysis and provide the property owner with various remediation options, if applicable, and recommend the approach that is most cost effective. But the final decision ultimately must be made by the owner. If he or she is aware of the remediation options available and how they may effect day-to-day operations, the less costly that decision will be.