D.2 CARStat

Approximate Cost: $4,000

Source:  Discerning Systems Inc. (www.DiscerningSystems.com)

Current Version: 2.1.9

Operating System Needs: Windows XP (has been successfully installed and used on Windows 7 32-bit and 64-bit; 64-bit requires the Microsoft Virtual PC and XP mode)

Input Structure: ASCII (text) flat file; one data row per measurement; comma-separated values (CSV) file; delimited, or fixed column, flexible column order

Overview

CARStat is a statistical analysis system that automatically performs a complete analysis of all sampling locations, groups of locations, and contaminants for compliance, assessment, and remediation. This program was originally designed for the analysis of industrial plants, disposal facilities, brownfield sites and other installations requiring detailed investigation. CARStat statistically analyzes data for soil, groundwater, surface water, air and waste streams for assessment monitoring and corrective action programs and performs comparisons to backgroundNatural or baseline groundwater quality at a site that can be characterized by upgradient, historical, or sometimes cross-gradient water quality (Unified Guidance). and to regulatory standards, as well as performing a natural attenuation analysis. This program extends DUMPStat’s assessment monitoring capabilities with more sophisticated statistical techniques.

Monitoring locations can be combined and analyzed and graphed as Potential Areas of Concern. All statistical processing balances false negativeIn hypothesis testing, if the alternative hypothesis (Hᴀ) is true but is rejected in favor of the null hypothesis (H₀) which is not true, then a false negative (Type II, β) error has occurred (Unified Guidance). and false positive rates for the entire facility. Results are presented in graphical and tabular formats and all intermediate calculations are shown in worksheets.

Add-Ins Available

None

Ease of Use and Data Import

CARStat merges structured ASCII (text) files into its environmental database. Spreadsheet and database files such as Excel and Access can export data into an appropriate format for import.

To use this program, select the monitoring network and contaminants for analysis, and specify statistical options. These selections persist as new data are added, so that you can perform subsequent analyses easily.

The program makes all decisions on the most appropriate methods to use within the parameters of the statistical analysis settings, which guide the processing automatically so that large quantities of environmental data can be analyzed. You can set up a series of zones so that multiple areas of a site (whether they are related physically or statistically) can be batch processed differently from other zones without re-entering the monitoring network and statistical options.

CARStat provides separate viewers for the graphical and tabular results and for worksheets, which show the individual statistical calculations in detail. Use a dedicated Print Results screen to print all output from one place with options for grouping and ordering of the results.

Types of Distributions

Normal, log normal, Poisson, and nonparametricStatistical test that does not depend on knowledge of the distribution of the sampled population (Unified Guidance). distributions are available for data analysis.

Visualization

Specific options for data output include prediction limit graphs, confidence intervalStatistical interval designed to bound the true value of a population parameter such as the mean or an upper percentile (Unified Guidance). charts and powerSee "statistical power." curves. The graphs can be cut and pasted to move into other applications.

Primary Uses for Groundwater Data Analysis

CARStat is used by engineers, environmental scientists, regulators, consultants, owners and operators to comply with state and federal regulations at industrial plants, waste disposal facilities and Brownfield sites. The program monitors the progress of corrective action, demonstrates clean closure, and helps parties transferring real estate. The statistical analyses are also consistent with USEPA Subtitle C and D and American Society for Testing and Materials (ASTM) Standard D7048-04 requirements for landfill detection monitoring.

Benefits

• CARStat imports, stores, and manages large amounts of environmental data. Data can be edited, aliased, reviewed, and printed. Units can be converted.
• Flexible data import works with many laboratory data file formats and qualifiers.
• Statistical options and user adjustable time windows provide a means to custom tailor analyses while maintaining batch processing for fast, automated results.
• The program maintains a database of regulatory standards organized by state, matrix, and land use, which can be shared among facilities.
• Correct application of statistical methods can minimize the cost of remediation.
• Centralized analysis and printing speeds report generation.
• Powerful display and filtering options for output highlight important results.

Limitations and Data Requirements

• Cost
• CARStat does not interface with other programs for graphical output, it is limited to cut and paste into other applications.

 

Publication Date: December 2013