Modeling Subsurface Petroleum Hydrocarbon Transport
What was new a while ago....
 5222005 Estimates of chemical properties for petroleum hydrocarbons and oxygenated additives have been developed using the SPARC Performs Automated Reasoning in Chemistry (SPARC) calculator. These results were used in evaluating the potential environmental impacts from gasoline in the U.S. This data set can be searched for chemicals of interest at temperatures relevant for shallow ground water (5 ^{o}C to 25 ^{o}C).
 3202005 The diffusion coefficient estimator has been split into two parts. The first contains predefined input data for petroleum hydrocarbons and oxygenated additives. The second allows input of all parameters and can serve a wider range of chemicals.
 2142005 More datapoints can be entered into the gradient calculator and the coefficient of determination (R^{2}) has been added to the output.
 5262004 A forward calculation version of the JohnsonEttinger model has been added
 5152004 An online version of the JohnsonEttinger model for intrusion of contaminated vapors into residential buildings has been developed. The online implementation provides a simplified uncertainty analysis and automated execution of the model. Background on the model is provided on separate web pages and an explanation between different EPA versions of the model are given.
 4302004 The temperaturedependent Henry's Law Calculator has been updated to include data from EPA's Office of Solid Waste and Emergency Response(OSWER). This change greatly expands the number of chemicals included in the calculator, and gives provides an automated way of accessing the OSWER data and methods.
 2252004 Two modules have been added to the Modeling Subsurface Transport of Petroleum Hydrocarbons course: Introduction to fate and transport and phase distribution of waterimmiscible liquids. These are the first two modules that are available for usage. Information on how to use the materials is provided.
 12152003 Approximation of temperaturedependent effective solubilities has been added to OnSite. Along with background data and a Fahrenheit to Celsius calculator.
 12152003 Temperature dependence in the Henry's Law Constant for methyl tertbutyl ether (MTBE) has been added to the Henry's Law Coefficient Estimator
 6302003 Estimation of vertical gradients has been added to the online calculators
 6302003 A page on chemical property estimation has been added the Ecosystems Research site

 4302003 A calculator was added to estimate of Air and WaterPhase diffusion coefficients
 4302003 The mass distribution calculator has been enhanced to generate concentrations in all phases and the relationship between the effective solubility calculator has been made clearer.
 4302003 Uncertainty in transport model calculations can be assessed for a onedimensional model. A paper describing the model results, also defines bounding parameter estimates for various outputs of the model.
 4302003 A listserver has been established to keep up with information concerning OnSite and the web course.
 9242002 The Retardation Factor and 1D Transport from a Pulse Source calculators have been enhanced to include organic carbon partition coefficients compiled by EPA or certain State environmental programs. Contact Contact Us with requests for additional chemicals or data sets.
 9242002 A gradient calculator has been added to determine gradients from up to 10 wells.
 9192002 Corrections to the three pointgradient calculator
 1112001 New LatLong to distance calculators for degreesminutesseconds or decimal degrees
 1112001 Three point gradient calculator with out map scaling
 1112001 Reorganization of calculator list
 6272001 Addition of an environmental careers web site
 04252001 Error preventing calculation in the half life / rate constant converter corrected.
 01222001 New web address for the Web Course and Onsite:
 WebCourse  https://www3.epa.gov/ceampubl/learn2model
 OnSite  https://www3.epa.gov/ceampubl/learn2model
 02272001 Revision of the OneDimensional Continuing and Pulse Source Calculator. The calculator now calculates the first arrival time for a specified concentration and is intended to replace the travel time calculation previously performed in the seepage velocity calculator
 02272001 Replacement of the seepage velocity calculator
 02272001 Inclusion of tenths of inches in the gradient calculators.
 02272001 Correction of graphics problems throughout the site
 02092001 Complete removal of data storage in cookies
 02092001 New calculators:

 Averaging of borehole concentrations
 Three dimensional "Domenico Models:
Steadystate, centerline model
Unsteady model
 01222001 New Category of calculators: scientific demonstrations

 water flow through a onedimensional column
 02092001 flow in a onedimensional aquifer
 02092001 unsteady mass balance
 01222001 Corrections to the seepage velocity and gradient scaled from a map calculators. Corrections:

 gradient calculation with y coordinates in seepage velocity calculator
 gradient calculation with fractional portion of measurement units in gradient scaled from a map calculator
 Printer friendly page equivalents for each graphics and text only page
 October 5, 2000 Text only parallel site (subsequently disabled because of new EPA design: capability exists otherwise)
 October 5, 2000 New example site assessment with the OnSite calculators
 July 18, 2000 Steady State Plume Length Calculator
 7102000 Removal of data storage in OnSite.
 6192000 A new plume diving calculator and documentation. Unlike the rest of OnSite the plume diving calculator is implemented as a JAVA applet: therefore its download time may be longer than for the other calculator pages.
 6192000 Revision of the seepage velocity and onedimensional pulse source model to allow for user entry of the organic carbon partition coefficient K_{oc}.
 512000 New module showing pictures of field sampling and equipment.
 512000 New calculator for estimating Henry's Law Constants as a function of temperature.
 512000 New calculator for determining the gradient and direction from three points.
 512000 Revision of JavaScript Cookies for OnSITE calculators.
 512000 Expanded example of calculator usage including a review of fate and transport.
 512000 Revision of gradient calculators to eliminate unnecessary inputs.
 10111999 Control of significant digits and use of scientific notation where needed in all calculators
 10111999 Calculation of the gradient scaled from a map and unit conversion for flow rates
 9131999 Calculators for the gradient, moisture content and leaching from a NAPL source
 5191999 A calculator for calculating the effective solubility of BTEX and MTBE from petroleum fuels.
 5141999 Try out the calculators for
 Transport related formulas

 Ground water flow
 Retardation constants
 Half lives and rate constants
 Seepage velocity and travel times
 Effective solubility
 Unit conversions

 Henry's Law
 Hydraulic conductivity
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