VSP is a tool that helps ensure that the right type, quality, and quantity of data are gathered to support confident decisions and provides statistical evaluations of the data with decision recommendations. Developed with support from DOE, EPA, DoD, the Department of Homeland Security (DHS), the Centers for Disease Control (CDC), and the United Kingdom, VSP has more than 5000 users. VSP has many sampling design and statistical analysis modules focused on soils, sediments, surface water, streams, groundwater, buildings, and unexploded ordnance sites. Many statistical sampling designs are available including random, systematic, sequential, adaptive cluster, collaborative, stratified, transect, multi-increment, combined judgment/probabilistic, and rank set sampling. VSP is being recommended by many regulators for defensible sampling design and statistical analysis.
The underlying methodology employs statistically defensible approaches and has strong Data Quality Objectives (DQO) Process underpinnings. The objective is to ensure that the right type, quality, and quantity of data are gathered to support confident decisions.
It allows real-time evaluation of the tradeoffs between increased confidence in decisions and costs or number of samples required. VSP answers the questions of how many samples are required and where samples should be obtained. Designed for the non-statistician, VSP is organized around the possible data uses. Before developing a data-gathering plan, each user must determine what they will do with the data to support their decision-making process.
VSP currently supports the following sampling goals or objectives:
- Estimate or Compare Averages
- Compare Individual Sample Results Against Some Limit
- Do Transect or anomaly sampling/analysis for unexploded ordnance sites
- Evaluate Trends over time
- Develop a geospatial contaminant concentration map
- Evaluate Well Placement Redundancies or Inadequacies
- Explore Correlation between multiple analytes
- Estimate or compare proportions
- Assess whether the boundary around an area is contaminant free
- Develop a targeted, purely judgmental sampling scheme
- Sampling Items