Monitoring and Remediation Optimization System (MAROS)

The Monitoring and Remediation Optimization System (MAROS) software was developed by GSI Environmental Inc (GSI) on behalf of the Air Force Center for Engineering and the Environment (AFCEE) in 1998 as a public-domain, data management and evaluation tool specifically designed to improve long-term groundwater monitoring (LTM) programs. MAROS provides both: i) optimization routines, to help determine the appropriate number of sample locations, sampling frequency, and laboratory analytes for site monitoring objectives, and ii) statistical analysis tools to evaluate the plume stability condition and remedy performance. The release of MAROS 3.0 includes several new and improved algorithms to review groundwater networks for optimized data collection.

MAROS v3.0 BETA Overview


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What’s New in MAROS 3.0 BETA

The current version 3 of the MAROS software is a Microsoft Access database application employing simple statistics and decision frameworks to prioritize data collection efforts and link data to defensible site management decisions. The flow of modules in the software is illustrated in Figure 1. MAROS 3 has been updated with the goal of providing the User more options to compare different network configurations. MAROS 3 is more interactive, allowing the User more options to remove locations and review the resulting plume stability and concentration uncertainty metrics. Results generated from the software tool can be used to develop lines of evidence, which, in combination with professional judgment, can be used to inform site management decisions for safe and economical long-term monitoring of groundwater plumes. The MAROS tool can be used to help design and calculate remediation performance metrics and as a tool to evaluate progress toward site remedial goals.

Unlike many other software applications, MAROS uses the full analytical dataset over time, including both spatial (x,y coordinates) and temporal (all analyses over the time period of interest) data to evaluate contaminant plumes. The software can analyze data for up to five COCs and from 6 to over 100 wells in one run. The software contains modules that prioritize constituents, calculate summary statistics, determine temporal trends at individual wells (using both Mann-Kendall (MK) and Linear Regression (LR) techniques), and calculate plume stability metrics and their trends over time (i.e. total dissolved mass, center of mass and spread of mass). Spatial analysis of well distribution is performed using a Delaunay Triangulation/Voronoi Diagram spatial geometry algorithm. Optimization analyses include identification of redundant locations using a nearest neighbor and a qualitative approach exploiting statistics for spatial geometry, and estimation of plume concentration uncertainty to recommend new well locations and a sampling frequency module to recommend optimal sampling intervals based on the rate of concentration change.



MAROS v3.0 BETA Features

    • Several features distinguish MAROS from other tools designed specifically to optimize networks:
    • Simplicity – the MAROS tool employs simple statistical metrics that do not require specialized training to perform or interpret.
    • Rapid results – once data have been imported into MAROS, results can be generated in an hour or less.
    • Small networks – while MAROS can generate data for networks up to 200 wells from 40 sampling events, the tool can be used to evaluate networks of as few as six wells and four sample events. MAROS is often used for small plumes, or limited areas of concern within larger plumes.
    • Ease of installation and operation – MAROS is an open-source application built on the MS Access platform and can be run from any computer running MS Office. The application is small, easy to download and does not require sophisticated add-ins to run. Data can be imported into MAROS as either MS Excel or Access files. No specialized data preparation or files are required.
    • Easy output - Results of a MAROS analysis can be printed in concise reports or exported in a database format that can be used to build tables and maps of relevant findings. MAROS output can be imported into ESRI or other software tools compatible with the database format.
    • Exit strategy – MAROS includes statistical metrics to identify when locations have achieved cleanup goals. Modules evaluate the quantity of data required to confirm or reject hypotheses on cleanup status.

New and Improved Features

  • Updated Graphical User Interface – Using richer controls allowing easy data manipulation outside of the MAROS application (easy copy & paste of data tables to Excel, copy & paste of graphs to Word ).
  • Improved Statistical Analysis Tools: MAROS 3 has added and expanded several summary statistics and data review tools for individual well concentrations. MAROS now includes calculation of summary statistics using the Kaplan-Meier method to account for higher numbers of non-detect results. Additional statistical tools include Dixon’s method for identifying outliers in datasets and the Shapiro-Wilk method of estimating the distribution of data as well as an estimate of 95% UCL’s.
  • Monitoring Objectives: MAROS 3 prompts the User to enter monitoring objectives for each well. Monitoring Objectives along with the results of individual well statistics are used to prioritize wells in the network.
  • Improved Plume-Level Analysis Options: In MAROS 3.0 the Plume-Level Analyses to estimate total mass, center of mass and distribution of mass have been modified to provide the User more choice in selecting wells, and sample events to use in the analysis.
  • Percentage Total Mass and Total Area: The Plume-Level Analysis includes an option to determine the percentage of total mass in the plume each well represents for each sample event. The software also calculates the total area each well monitors based on the Voronoi Diagram calculation.
  • Expanded Spatial Optimization Options: MAROS 3 calculates several statistics to assess the spatial distribution and concentration uncertainty between well locations. In addition to Slope Factor, the software calculates the relative prediction error between wells and the variability in prediction error. The software also identifies variability in the area each well monitors, recommending well removal or addition in areas that monitor too small or too large an area relative to the total plume footprint.
  • Expanded Sample Frequency Tools: MAROS 3 provides recommendations for individual well and plume-wide sampling frequencies.
  • Improved Options for Exporting Data: MAROS 3 allows the User to export results of analyses in multiple formats at several locations in the software. The User can choose to export resuts in Microsoft Excel Spreadsheets or Access databases or choose to print MAROS reports.

System Requirements

Microsoft Windows XP, Microsoft Windows Vista or Microsoft Windows 7 Microsoft Access 2007 or 2010 Microsoft Excel 2007 or 2010 Ability to enable macros in Microsoft Access and Microsoft Excel


The current BETA version available is MAROS v3.0 BETA R352 released 28-SEP-2012.

For MAROS 2.2 downloads and information please see the MAROS 2.2 web page.

Installation Instructions

Download the appropriate version of MAROS software for your version of Microsoft Office above. The download is a .ZIP compressed file. Extract the contents of the ZIP file to a folder. To start the MAROS 3 interface; open the MAROS 3.0 BETA.accdb database. Several other files will appear in the extracted folder. These files are required for MAROS to run.

Note: It is important that the .ZIP file is extracted and MAROS is not run from inside of the .ZIP file – this will cause errors when MAROS tries to access other files within the zip file. To extract the .ZIP file into a folder you typically will right-click on the .ZIP file and choose “Extract” from the context menu.

Training Documents

Technical Support

GSI provides the MAROS software free-of-charge and provides no technical support for its installation or usage. The MAROS FAQ is provided to answer the most common questions.