Printable version

Key Concepts

The Triad manages hazardous waste site decision-making uncertainty through systematic planning, dynamic work strategies, and real-time measurement technologies.

The Triad approach offers a new paradigm for addressing the uncertainties associated with hazardous waste site decision-making, and the design and implementation of sampling programs intended to support site decisions. This paradigm consists of three principal components:

• Systematic Planning. Systematic planning is a planning process that lays a scientifically defensible foundation for proposed project activities. Systematic planning usually includes identification of key decisions to be made, the development of a conceptual site model (CSM) to support decision-making, and an evaluation of decision uncertainty along with approaches for managing that uncertainty in the context of the conceptual site model. Systematic planning is important to the success of all hazardous waste site projects whether the Triad is embraced or not, but it is particularly critical for the Triad where the use of real time measurement technologies allow the CSM to evolve and mature as field work is underway.



• Dynamic Work Strategies. Dynamic work strategies are work strategies for contaminated site characterization, remediation, and monitoring that incorporate the flexibility to change or adapt to information generated by real-time measurement technologies. As information is gathered it is used to make decisions about what subsequent activities will best resolve remaining data and decision uncertainties, and/or meet cleanup goals. Dynamic work strategies are usually documented as pre-approved decision logic within appropriate planning documents.



• Real-Time Measurement Technologies. Real-time measurement technologies refer to any data generation mechanism that supports real-time decision-making (i.e., a dynamic work strategy) including rapid turn-around from a fixed laboratory (using either quantitative or screening analytical methods), or field-based measurement technologies. Real-time measurement technologies return results quickly enough to influence the progress of data collection and field activities.

The Triad approach emphasizes managing decision uncertainty, rather than simply analytical uncertainty. For example, the Triad recognizes that the contribution of sampling uncertainty to decision uncertainty often dwarfs the contribution of analytical uncertainty. Given this fact, the Triad focuses on data collection methods that can increase spatial coverage for an area without sacrificing sample representativeness or driving up total sampling program costs. The Triad uses a weight of evidence approach to decision-making where appropriate, based on collaborative data sets. Collaborative data sets can contain data from a number of sources, including quantitative and screening analytical methods.

A Triad approach can be applied equally effectively to either statistical or judgmental sampling programs. The use of dynamic work strategies and real-time measurement technologies allows data collection programs and field activities to adapt or adjust to site conditions and analytical results as they are encountered. This, in turn, focuses work on site decision-making needs, and provides a mechanism for responding to unexpected site conditions or data quality problems while the work is underway. This ultimately means that with a Triad approach data collection can continue until decision quality goals have been achieved and decisions confidently made.

From a sampling program perspective, the goal of the Triad is to produce effective or decision quality data (i.e., data that are of known quality, that are defensible, and that support the decision that needs to be made) in a manner that is as cost and schedule-efficient as possible.

Printable version