Systematic planning of a site characterization project must be performed before any field activities begin by using a well-rounded technical team. With stakeholder input, the team determines the site decisions, which are clearly stated goals and objectives for the investigation. Once the site decisions are defined, the kind of information needed to support scientifically and legally defensible site decisions can be determined. From this, a Conceptual Site Model (CSM) can be constructed, and the types and quality of data needed to fill existing information gaps can be established.
When the data quality needs have been determined (i.e., establish DQOs), the analytical methods/equipment are selected that will be used to supply that data. If site decisions can be made with qualitative or semi-quantitative data, field methods can often be used. Even when quantitative data is needed, a wide variety of rugged field analytical equipment and methods now exist that permit the generation of high quality data at the site location.
On-site generation of data provides 'immediate' decision-making capability which can rapidly and efficiently guide characterization efforts by means of an adaptive sampling strategy, which uses the previous day's results to feed into the CSM and decision-making process to direct the collection of the next round of samples. This permits rapid location and definition of hotspots, guides the removal or treatment of contaminated media, and quickly identifies when enough information has been collected to address the site decision. It is then easy to minimize the collection and analysis of uninformative samples, to avoid unnecessary treatment, and to tell when the project is 'done,' thus saving time and money. The use of a dynamic workplan often allows projects to be completed in only one field mobilization.