D.16 SANITAS FOR GROUNDWATER

Approximate Cost: about $1,000 plus annual maintenance fee

Source:  Sanitas Technologies (www.sanitastech.com)

Current Version: v9.2

Operating System Needs: Windows 7 and 8, XP, Vista

Software Needs: Microsoft.NET version 4.0 Framework

Input Structure: Flat file or cross-tabular

Overview

Sanitas is a commercially available software package designed specifically for evaluating groundwater monitoring data, particularly at RCRAResource Conservation and Recovery Act Subtitle C and D facilities. Although earlier releases were less versatile, more recent versions allow for selection between USEPA (1992), California, Unified Guidance, or American Society for Testing and Materials (ASTM) standards, provide some user-defined treatment of nondetectsLaboratory analytical result known only to be below the method detection limit (MDL), or reporting limit (RL); see "censored data" (Unified Guidance)., and relax earlier input file restrictions. 

The software provides both interwellComparisons between two monitoring wells separated spatially (Unified Guidance). and intrawellComparison of measurements over time at one monitoring well (Unified Guidance). procedures for evaluating groundwater contamination, and employs parametricA statistical test that depends upon or assumes observations from a particular probability distribution or distributions (Unified Guidance). and nonparametricStatistical test that does not depend on knowledge of the distribution of the sampled population (Unified Guidance). approaches. You can select from several options for treatment of nondetects, outlier testing, data transforms and adjust for seasonality, low detection frequency, or trends in backgroundNatural or baseline groundwater quality at a site that can be characterized by upgradient, historical, or sometimes cross-gradient water quality (Unified Guidance).. Graphical analyses offered include probability plots, piper and stiff diagrams, control charts (Shewhart-Cusum), and statistical interval (prediction and tolerance) test results.

Add-Ins Available

None

Ease of Use and Data Import

The most recent (v9.0 and newer) versions of Sanitas software can run on any Windows version that supports the .NET framework; however, the older versions of Sanitas are not compatible with the newer Windows platforms. Older versions of Sanitas also require that the input data file be in cross-tabular format with some stringent formatting requirements; v9.0 and newer allow flat file input, but will also accept the earlier cross-tabular format.

The various statistical procedures available in Sanitas are all accessed from drop-down menus. You determine the general category of test, then choose more specific criteria from the menus. Depending on the number of sample points, collection dates, and contaminants monitored, each test may take several minutes to complete.

Although no statistical expertise is required to run Sanitas and the operational basics are relatively simple, as with any software, you should make sure that you understand the assumptions and input requirements for any statistical tests used in making decisions based on the output. Sanitas Technologies also offers training workshops at regular intervals for new users.

Type of Distributions

The Sanitas package includes distributions and distributional analyses such as parametric (normal, transformed normal, and Poisson-based distributions), nonparametric, Shapiro-Wilk normality, Shapiro-Francia normality, chi-squared, coefficient of variation normality, skewnessA measure of asymmetry of a dataset (Unified Guidance). and kurtosisA measure of whether the data are peaked or flat near the mean. High kurtosis would show a distinct peak near the mean and drop off rapidly to heavy tails (NIST/SEMATECH 2012)., and Levene’s test, equality of varianceThe square of the standard deviation (EPA 1989); a measure of how far numbers are separated in a data set. A small variance indicates that numbers in the dataset are clustered close to the mean..

Visualization

Sanitas includes graphics for data visualization, including customized graphs, powerSee "statistical power." curves, plots, and production of summary tables.

Primary Uses for Groundwater Data Analysis

Sanitas is a statistical application developed specifically for groundwater monitoring applications. Many of the statistical procedures needed for groundwater data analyses are included.

Benefits

• straightforward use
• unlimited number of users for each site license
• developed specifically for groundwater monitoring applications
• relatively inexpensive
• documentation is well-written and generally easy to understand

Limitations and Data Requirements

• Each site must be licensed independently (price reduction after several sites licensed).
• Evaluation of distribution is limited to normal and ladder-of-powers transforms.
• Configuration errors (for example, selection of nondetect treatment) may go undetected by the user.

 

Publication Date: December 2013