Environmental Statistical Analysis Software Solution for Windows
ChemStat is the easiest and fastest application available for
the statistical analysis of ground water monitoring data at RCRA facilities. ChemStat
includes most statistical analysis methods described in the 1989 and 1992 USEPA
statistical analysis documents, USEPA Draft Unified Guidance Document, U.S.
Navy Statistical Analysis Guidance document, and other guidance documents
and methods documented in popular statistical
texts.
A unique combination of ease-of-use and innovative technologies
make ChemStat the value leader for environmental statistical analysis.
Browse the help system to learn more.
Download Animated Demonstration and Training Movies
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ChemStat Trial Version (Version 6.5 Now Available)
ChemStat Frequently Asked Questions
New Features for v. 6.5 (Available January, 2023):
- Upper confidence limit (UCL) calculations for all wells using a variety of statistical methods
- Improved user interface
- Improved support for the latest versions of Windows
New Features for v. 6.4 (Available July, 2016):
- New Shewhart-CUSUM Control Chart follows "non-standardized" method of USEPA Unified Guidance
New Features for v. 6.3 (Available December 20, 2010):
- Tarone-Ware Two-Sample Test - A non-parametric test comparable to the Wilcoxon presented in the USEPA Unified Guidance.
New Features for v. 6.2 (Available April 1, 2007):
- Non-Parametric Confidence Limit MCL Comparison.
- Parametric Prediction Limit (inter-well) with verification resampling
as described in USEPA Unified Guidance, for the following resampling
schemes:
- 1 of 2
- 1 of 3
- 1 of 4
- Modified California
New Features for v. 6.1
(Available March 25, 2006):
- Export Workbook reports and graphs directly into Microsoft Word.
- Improved Workbook printing to Acrobat PDF files.
New Features for v. 6.0
(Available July 23, 2005):
- New methods for compliance with USEPA Draft Unified Guidance:
- Rank von Neumann test
- Spearman's Trend Test
- Welch's t-test
- New features for adjustment of data (add/remove samples based on date
ranges, parameter names, well IDs)
- Improved Prediction Limits
- Improved Control Chart
- Improved Probability Plot
- Improved Graphs and Reports
New Features for v. 5.2:
- New Upper Confidence Limit (UCL) Methods
Including:
- Student's t-test UCL Method
- Chebyshev Inequality UCL Method
- Central Limit Theorem UCL Method
- Bootstrap Resampling UCL Method
- Jackknife Procedure UCL Method
- Improved Probability Plot for Censored and Detects-Only Plots
New Features for v. 5.0:
- Improved graph vertical axis scaling
- Method Selector Tree -- Hierarchical tree simplifies the
selection of the appropriate statistical tests.
- Poisson Prediction Limit not available as intra-well comparison
- New statistical methods, including methods from U.S. Navy
(1999) statistical guidance documents.
- Improved Parametric t-test
- Satterthwaite t-test
- Quantile Non-Parametric test
- Two Sample Test of Proportions MCL Comparison
- Slippage Non-Parametric test
- Improved Wilcoxon test for group comparisons (following U.S.
Navy Guidance)
- Discordance Outlier Test
- Enhanced parametric t-test follows U.S. Navy (1999) Guidance
New Features for v. 4.1:
- Parametric t-test analysis.
- Confidence interval analysis by Land's formula for log-normal
data.
- Two-tailed parametric tolerance limits
New Features for v. 4.0:
- Fully automated statistical analysis --
perform a complete statistical analysis of an entire data set with a
single command.
- Batch Processing -- Automated statistical analysis with scripts
(create a script of commands for a list of parameters and perform all
commands at once).
- Direct import of SanitasĀ® and DUMPStatĀ®
databases.
- Improved support for different parameter
units.
- Automatic elimination of outliers.
- Mann-Kendall supports testing for upward,
downward, or two-tailed trends.
New Features for v. 3.0:
- Easier File Importing -- File importing has been simplified.
Preview the file to prevent formatting mistakes.
- Summary List summarizes of all wells showing statistically
significant contamination for your project, showing parameter name, transformation, and
statistical method.
- More Transformations -- In addition to natural logarithm
transformations, you can choose log base 10, square root, or cube root transformations.
- Probability Plot Correlation Coefficient
ChemStat Features
ChemStat is powerful

Data set size limited only
by computer memory for most tests

Unlimited number of parameters

Unlimited number of wells

Unlimited number of sample dates

Unlimited parameter name and well label length

Easily exclude individual data points from analyses

Fast Performance

Full report and graph printing and print preview

Export reports to tab-delimited ASCII text file

Export reports to a word processor in rich-text format

Numerous choices for page headers and footers, page
left, right, and center

Choice of multiple fonts and colors in graphs and
reports

Highly customizable user-interface
ChemStat is easy to learn

Easily select parameter for
analysis from drop-down list

Complete on-line help with "what's this"
context sensitive help.
Advisor Window displays information about the
method and suitability of the method to the data set.

Method selector tree allows easy selection of the appropriate
statistical test for your data
Data Set Transformations

Quickly convert from
original data to log-transformed and back

Easily represent non-detects with 0, 1, DL/2 or DL for
any test

Accommodate
censored data with Cohen's or Aitchison's
adjustments
ChemStat Analysis Methods
Graphs

Box/Whisker Plots

Single Well Concentration vs. Time Plot

Multiple Well Concentration vs. Time Plot

Multiple Parameter Concentration vs. Time Plot

Probability Plots

Shewhart-CUSUM Control Chart for both Intra-Well or
Inter-Well Comparison

Exponentially Weighted Moving Average Control Chart for
both Intra-Well or Inter-Well Comparison
Parametric Methods

Parametric ANOVA with
Individual Well Comparisons

Parametric Prediction Limit (intra-well or inter-well
comparison)

Parametric Tolerance Limit (comparison to background)

Parametric Tolerance Limit (comparison to MCL)

Parametric Confidence Interval

Parametric
t-test

Satterthwaite t-test

Welch's t-test
Non-Parametric Methods

Kruskal-Wallis
Non-Parametric Analysis

Wilcoxon Rank-Sum Non-Parametric Analysis (intra-well
comparison)

Wilcoxon Rank-Sum Non-Parametric Analysis (inter-well
comparison)

Poisson Prediction Limit

Poisson Tolerance Limit (comparison to background)

Poisson Tolerance Limit (comparison to MCL)

Non-Parametric Prediction Limit (intra-well or
inter-well comparison)

Non-Parametric Confidence Limit

Gehan's
Test

Slippage
Test

Quantile
Test

Two Sample
Test of Proportions MCL Comparison
Distribution/Outlier/Trend Testing

Levenes Test for
Homogeneity of Variance

Bartletts Test for Homogeneity of Variance

Shapiro-Wilks Test of Normality

Shapiro-Francia Test of Normality

Coefficient of Variation Test of Normality

D'Agostino's Test of Normality

Skewness Coefficient Test

Dixon's Test for Outliers

Rosner's Test for Outliers

Discordance Outlier Test

Mann-Kendall Test for Trend

Spearman's
Test for Trend

Sen's
Slope Analysis for Trend

Seasonal
Kendall Analysis

Kurtosis
ChemStat Screen Shots
Click on an Image to View Full Size
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Among the methods for inter-well comparisons are the parametric
analysis of variance ANOVA as shown here, as well as Kruskal-Wallis and Wilcoxon
non-parametric comparisons.
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ChemStat include a powerful and highly customizable
Shewhart-CUSUM
control chart, for both inter-well and intra-well comparisons.
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Shown here is the multiple parameter time-series plot. Graph any
combination of parameters for a single well.
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Shown here is a multiple well time series plot. Graph any
combination of wells for a selected parameters. ChemStat spaces the date axis
proportional to the actual date value of the sample. ChemStat also plots multiple
concentrations for a single date.
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New: ChemStat 2.0 includes improved prediction
limits. Verification resampling is supported by allowing you to vary the number of samples
for each well compared to the prediction limit. Parametric prediction limit
calculations can follow USEPA (1989), Gibbons (1987) one-sided, or Gibbons (1987)
two-sided algorithms.
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Here is another view of ChemStat showing Skewness calculations,
probability plot, and the Workbook.
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The Workbook acts as a
repository for all your reports and graphs. Workbook items are saved with your data,
and will not change as you apply transformation to the data set. When you have
completed your statistical analysis, you can print the entire workbook, or selected items.
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ChemStat 2.1 adds the ability to easily exclude
individual samples from statistical analyses, and then add them back at a later
date. This is useful for removing statistical outliers, or reducing the size of the
data set for an individual well or background wells.
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New: ChemStat 5.0 adds the Method Selector Tree.
The method selector tree simplifies the selection of appropriate
statistical methods. Methods are grouped into a logical
hierarchy. Double-click a method to run the test.
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System Requirements:
Windows 7 or later, 8 GB RAM recommended minimum.
No "Per Facility" Fees
A Complete Data Management and Statistical
Analysis Package for Windows