2014.02.13
GERAS

Geo-Environmental Risk Assessment System GERAS-3 -Detailed model- (2010/4/20)

Abstract of GERAS-3 English version

We have finished to develop our original computer system, GERAS-3, for risk assessment of soil and groundwater contamination. This system is free for all users worldwide. Please utilize it for the proposes of risk management and risk communication, especially for site assessment. The following are abstract of GERAS-3 detailed model.

(1) Social background for the development of this model

Soil and water contamination can cause serious human health consequences. Mineral oil, volatile organic compounds (VOCs), and heavy metals, have all been identified harmful substances in groundwater aquifers. It is important to take measures for minimization of the soil contamination and to control the risk of soil and groundwater contamination in the places of business and urban areas; because the industrial activities always accompany the risk1). In April in 2010, Revised Soil Contamination Countermeasures Act will take to effect and the risk management of sites will be strengthened further. Therefore, it is necessary to evaluate the concentration, spatial scale, and the transport of soil contaminants using data obtained by observation and investigation of contaminated sites and to evaluate quantitatively the changes of risk with time and space. However, in Japan there are no standard tools to evaluate the risk of human health caused by the contamination of soil and groundwater. Current technological bases for the risk management of soil and groundwater are not sufficient.

(2) The progress of the development of this model

Motivated by the importance of risk evaluation described above, AIST has developed Geo-Environmental Risk Assessment System (GERAS) to evaluate scientifically the soil and groundwater contamination problems. Two models, screening model (GERAS-1) and site model (GERAS-2) have been opened to the public2)-9). These models can be applied to evaluate the health risk, the environmental impact by soil contamination and the effect of cleanup of contaminated soil. These models have been used by more than 800 factories and places of business. The new detailed model, GERAS-3, which can treat the multiple contamination of soil and groundwater caused by mineral oil, volatile organic compounds (VOCs), heavy metals, etc. has been completed and is made available to the public10)

(3) Subject of the research

GERAS is the evaluation system to calculate the amount of human exposure and human risk by chemical substances, which contaminate soil and groundwater. GERAS can easily be operated under the OS environment after Windows 2000. The detailed model, GERAS-3 is able to simulate the transport phenomena of contaminated substances from the soil layer to the aquifer as shown in Fig.1, and can quantify the change in human risk with time and space by contamination of multiple components based on the flow analysis considering the change of composition of contamination substances by the volatilization and diffusion, the dissolution to groundwater and the adsorption on soil. The degradation of contaminated substances by microorganisms can and should be taken into consideration. This model makes it possible to calculate the amount of human exposure and the human risk inside and/or outside of the contaminated field by taking into account the soil properties (soil characteristic, adsorptive property, permeability, clay components, etc) and the condition of human exposure. By combining databases of soil and groundwater characteristics in Japan, the physical properties and toxicity of contaminated substances, etc., this new model has been completed as a user-friendly computer system. Based on the research activities for development of this model, we have established the methodology to evaluate the human exposure and risk by multiple contaminants of soil and groundwater. We have also confirmed the validity of calculation formulas used in this detailed model through the evaluation by experts. GERAS-1 and GERAS-2 have already been made available to the public. In GERAS-1, we can determine the necessity for cleanup of the contaminated site by judging the level of the health risk of human. Using GERAS-2, we can understand the behavior of contaminated substances, which is typical of each site. By making proper use of these two models and the new detailed model, GERAS-3, it is expected that these three models can be applied for a wide variety of purposes such as the independent environmental risk management of factories and places of business, the risk assessment of mineral oil, volatile organic compounds, heavy metals, etc., non-regulated pesticides and persistent chemical substances, and the adoption of effective countermeasures to reduce the risk from soil and groundwater contamination. The newly developed model, GERAS-3 has following characteristics: With this model, the temporal and spatial distribution and the future transport of contaminated substances in soil and groundwater can be simulated and evaluated by inputting data of soil and groundwater measured by geological surveys at the site. As a result, this model can be applied not only to the post cleanup action for soil contamination, but also to design of preventive measures. GERAS-3 is a powerful tool both for the selection of the most suitable cleanup technology and for the reduction of cleanup cost and risk at the same time. In addition, the validity of this model is verified by comparing the analytical results and with the observation data at the site.

(4) Future plan

We are expecting to obtain the feedback of evaluation data from persons and/or organizations that have used GERAS-3 and this feedback will enhance the accuracy of the analysis of contamination in soil and groundwater environments. We will promote the technological transfer and distribution to industries and society for the purpose of independent environmental risk management by cleanup the soil contamination at places of business, etc.

(5) Contact for inquiries

Geo-Environmental Risk Research Group,
Institute for Geo-Resources and Environment
National Institute of Advanced Industrial Science and Technology,
1-1-1 Higashi, Tsukuba 305-8567, Japan
E-mail: geras-system@m.aist.go.jp
Fax: +81-29-861-8773

(6) How to get GERAS-3 system

GERAS-3 system is free for uses worldwide. Please identify the following information of user and send E-mail to the address of GERAS office.
E-mail: geras-system@m.aist.go.jp
Fax: +81-29-861-8773

User Name:
Organization: (company, university, institution)
Postal address: (street name, city, postal code, country)