Virus Fate and Transport (Virulo) Model
Model for Predicting Leaching of Viruses in Unsaturated Soils
Virulo is a user-friendly screening model that generates simulations of how physical, biological, and chemical factors might alter viruses so they become harmless or immobilized. Virulo was designed to help state regulators, utilities, and development planners with their understanding of the fate and transport of viruses in unsaturated soils, which is important for predicting the potential risk to human health from human and animal wastes.
Disclaimer: Any mention of trade names, manufacturers, or products does not imply an endorsement by EPA. EPA and its employees do not endorse commercial products, services, or enterprises.
Software, Compatibility, and Manuals
Virulo has been tested with Windows up to Windows 10. For a Windows installation, a Pentium-like grade processor is needed with at least 100 MHz speed and at least 32 MB of RAM. It should work without problems just as well on any other system that has a JVM with Swing component capability. (Operating systems: Windows and UNIX)
Software
| Date | Description |
|---|---|
| August 2002 | Virulo 1.0 - Windows Executable Version (EXE) (exe) |
| August 2002 | Virulo - Other Systems (zip) If you are familiar with Java, you can choose to run Virulo directly from this ZIP file. |
User's Guide and Report
| Date | Description |
|---|---|
| August 2002 | Predicting Attenuation of Viruses During Percolation in Soils – 1. Probabilistic Model Provides the conceptual, theoretical, and mathematical foundations for Virulo. |
| August 2002 | Predicting Attenuation of Viruses During Percolation in Soils – 2. Virulo 1.0 User's Guide |
Source Code Snapshot
| Date | Description |
|---|---|
| 2014 | Virulo 1.0 Code Snapshot (pdf) |
| August 2002 | ASCII text Java files (zip) |
| August 2002 | Class Documentation (zip) |
Disclaimer: Any mention of trade names, manufacturers, or products does not imply an endorsement by EPA. EPA and its employees do not endorse any commercial products, services, or enterprises.
Capabilities
Virulo is a probabilistic screening model for predicting leaching of viruses in unsaturated soils. It employs Monte Carlo methods to generate ensemble simulations of virus attenuation due to physical, biological, and chemical factors. The model generates a probability of failure to achieve a user-chosen degree of attenuation. It can be used based on limited information such as boring logs, climate data, and soil survey reports for a particular site of interest.
Virulo can be used to predict probability of leaching of viable viruses when the following assumptions can be used:
- The soil layer of interest is homogeneous in texture.
- Water flow in the layer is due to gravity only.
- The percolating water does not contain surface active agents.
- The soil layer does not induce preferential flow.
The particulars of these assumptions are described in detail in the model documentation.
Applications
Virulo can be used to analyze virus leaching from sorption sites in variably saturated soils and aquifer materials and predicts attenuation to total viruses as they pass through a soil layer. One use of the model could be to provide estimates of attenuation of viruses peculating through one or more layers of a particular soil type. The model has many another potential uses, such as predicting virus attenuation through land spreading of wastewater during groundwater recharge operations or for predicting the effects of short-term septic tank discharge on groundwater quality.
Related Resources
- Infiltration Models
- Methods, Models, and Tools for Water Research
- Microbiological Methods and Online Publications (bacteria, protozoans, viruses, and coliphage)
- Ground Water Rule