Remedial Investigation in the United States

Remedial Investigation/Feasibility Study (RI/FS) in Environmental Law

After an abandoned hazardous waste site has been listed on the National Priority List as a priority for federal cleanup, it moves through a procedure that leads to selection of the remedy. The phase of the process in which the site is thoroughly analyzed and alternatives are evaluated is called the remedial investigation/feasibility study, usually referred to by its acronym, RI/FS.

The RI/FS is a combination of an investigation and feasible alternatives evaluation, but the two overlap, with information from one looped to the other. For example, if data is needed about the type of waste at the site, it is obtained. Then that information is used to help select the methods of treatment, which may be tested in a pilot program. The pilot may result in additional knowledge about the characteristics of the site, which in turn may help fine-tune the remedial action.

These steps are required by the Superfund law (the Comprehensive Environmental Response, Compensation, and Liability Act) and the National Contingency Plan, the set of regulations that specifies how hazardous substances are to be addressed. The RI/FS may be conducted by one or more of the potentially responsible parties persons who have a legal responsibility to take care of the contamination or it may be done by a governmental agency or its contractors. If someone other than the government conducts the RI/FS, the government will oversee the work. The only part of the RI/FS the government prefers to do itself is the baseline risk assessment.

The components of the RI/FS include scoping, data gathering, community and state involvement, evaluation of alternative methods of remediation, limited studies, and treatability studies. The aim is to determine which remedial techniques will work. The governmental agency, usually the Environmental Protection Agency or a state environmental agency, then selects the methods to be used and publishes the selection in an official document called the record of decision, or ROD.

Much information is needed to properly evaluate the site. The initial effort is scoping the project. During the scoping, the overall plans are established. For example, the project manager gathers all existing information, develops a concept of the problems posed at the site, determines what questions must be answered, meets with the community and forms a community relations plan, starts identifying the state and federal regulations that may apply to the cleanup, and decides what technologies might address the contamination at the site. A baseline risk assessment is also completed by another governmental group, the Agency for Toxic Substances and Disease Registry, so the agency can establish cleanup needs.

The cost and amount of work done at a given site during the RI/FS depends on its complexity, previously gathered data, and the effectiveness of tested technology For a cleanup to be successful, all of the remedial activities must fit the conditions at the site. Thus, the RI/FS will result in a picture of the geology, topology, ownership, land use, waste volume and character, and anything else that is pertinent. The community will be consulted, interviewed, and informed about all proposed activities.

Alternatives for managing the site are identified early from among technologies. Technologies are broad categories of treatment, such as institutional controls, engineering, and treatment. Within each technology a number of variations may be screened, along with one alternative that must always be considered: the option of doing nothing. Screening of the alternatives identified takes place throughout the RI/FS. The specific type of remediation chosen is called a process.

Institutional controls include deed restrictions (to limit future use of the property) and erecting fences and signs (to limit access). Engineering includes installing drains to capture contaminated groundwater, placing an impermeable cap over a waste pile, and building a wall to cut the polluted area off from the rest of the site. Treatment includes digging up the waste and incinerating it, placing specialized microorganisms in the waste to accelerate decay, stabilizing it through a physical or chemical process, or aerating the ground to promote escape of gases.

If a technology is feasible, the RI/FS identifies it and its benefits and shortcomings for the site. Then representative processes are selected and screened. During the screening, studies may be done in a lab or at the site to determine how well the processes will work for the particular site being considered. Each process must be analyzed in detail. At the end of all the study and evaluation, a report is prepared that weighs all the options according to nine separate factors in three categories: threshold criteria, balancing criteria, and modifying criteria. After these criteria are considered, the processes are compared against each other and a proposed plan is recommended.

Unless they are waived, threshold criteria must be met by the processes being considered. Waivers are difficult to obtain, and it is easy to see why. The threshold criteria state that the remedy must provide overall protection of human health and the environment and meet all applicable or relevant and appropriate requirements, that is, any state and federal laws that apply. The next set of criteria is balancing criteria. They are short-term effectiveness; long-term effectiveness and permanence; reduction of toxicity, mobility, or volume of waste; implementability; and cost effectiveness. Balancing criteria actually weigh the projected success of the remedy. Finally, the modifying factors are a measure of acceptance of the proposed remedy. In addition to the lead agency’s approval, the state must be comfortable with the remedy. Even more important, the community should have confidence in it. If the community or state does not agree with the proposed remedy, it may be modified provided it still meets the threshold criteria and some of the balancing criteria. The remedy has been modified at some sites where the residents are strongly opposed to incineration.

The entire RI/FS process will generally take two years. The final product is the report that will recommend and influence the decision of the agency. A summary of the report will be included in the record of decision, the agency document that selects the remedy. See also bioremediation; cleanup technologies; Hazardous Ranking System; National Priority List; remedial design/remedial action.
Based on “Environment and the Law. A Dictionary”.