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
A unique combination of ease-of-use and innovative technologies
make ChemStat the value leader for environmental statistical analysis.
Download Animated Demonstration and Training Movies
All New ChemStat
Universal Converter now available. Free utility to convert MS
Access, MS Excel, tab-delimited text, and dBase files to ChemStat format.
ChemStat Trial Version (Version 6.3 Now Available)
ChemStat Frequently Asked Questions
Compare ChemStat to USEPA's
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
- 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
- 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.
- 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
- 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
- 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 Sanitas® and DUMPStat®
- Improved support for different parameter
- 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
- 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 is powerful
ChemStat is easy to learn
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
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
Highly customizable user-interface
Easily select parameter for
analysis from drop-down list
Complete on-line help with "what's this"
context sensitive help.
displays information about the
method and suitability of the method to the data set.
Data Set Transformations
Method selector tree allows easy selection of the appropriate
statistical test for your data
Quickly convert from
original data to log-transformed and back
Easily represent non-detects with 0, 1, DL/2 or DL for
censored data with Cohen's or Aitchison's
ChemStat Analysis Methods
Single Well Concentration vs. Time Plot
Multiple Well Concentration vs. Time Plot
Multiple Parameter Concentration vs. Time Plot
Shewhart-CUSUM Control Chart for both Intra-Well or
Exponentially Weighted Moving Average Control Chart for
both Intra-Well or Inter-Well Comparison
Parametric ANOVA with
Individual Well Comparisons
Parametric Prediction Limit (intra-well or inter-well
Parametric Tolerance Limit (comparison to background)
Parametric Tolerance Limit (comparison to MCL)
Parametric Confidence Interval
Wilcoxon Rank-Sum Non-Parametric Analysis (intra-well
Wilcoxon Rank-Sum Non-Parametric Analysis (inter-well
Poisson Prediction Limit
Poisson Tolerance Limit (comparison to background)
Poisson Tolerance Limit (comparison to MCL)
Non-Parametric Prediction Limit (intra-well or
Non-Parametric Confidence Limit
Test of Proportions MCL Comparison
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
Test for Trend
Slope Analysis for Trend
ChemStat Screen Shots
Click on an Image to View Full Size
Among the methods for inter-well comparisons are the parametric
analysis of variance ANOVA as shown here, as well as Kruskal-Wallis and Wilcoxon
ChemStat include a powerful and highly customizable
control chart, for both inter-well and intra-well comparisons.
Shown here is the multiple parameter time-series plot. Graph any
combination of parameters for a single well.
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.
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)
Here is another view of ChemStat showing Skewness calculations,
probability plot, and the Workbook.
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.
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.
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.
Windows 95/NT, 8 MB RAM recommended minimum.
No "Per Facility" Fees
A Complete Data Management and Statistical
Analysis Package for Windows 95/98/NT