What is a Soil Survey?
A soil survey is conducted at sites where contamination is detected and there is a suspicion of soil contamination. The objective of the survey is to clarify the type of contaminants, the concentration of the contaminants, the physical scope of the contamination, the risks involved and the possibilities of treating and restoring the site.
Soil contamination in Israel is largely caused by industrial activity and the fuel industry activities. Pursuant to data issued by the Ministry of Environmental Protection, so far some 1,250 soil contaminated sites have been detected in Israel and it is estimated that many more such contaminated sites exist. The main contaminants are fuel, metals, oils and chloro-organic compounds. In those cases where the capacity of the soil to absorb large quantities of fuels is great, the contamination is only detected at an advanced stage, when a large quantity of fuels has already leaked out into the soil.
Contaminated soil is liable to be hazardous to human health and to the environment in the wake of exposure to contaminants, which is caused by direct contact, the breathing of ground gas released from the soil, and contaminated soil and dust particles. Furthermore, the contaminants are liable to enter water sources (mainly ground water).
A ground survey is carried out by means of a series of boreholes, and includes the gathering and sampling of ground gas. In designing the survey, the methods of measurement are selected, samples that will be sent to the laboratory for analysis are selected, the appropriate analysis process to identify the contaminants is selected and the manner of drilling boreholes and the manner of sampling are selected.
A ground survey consists of a number of main stages:
Initially a historic review is conducted, the objective of which is to gather all the existing information regarding the potential contamination of the site and various parameters that typify the site (such as infrastructure, leaks, etc.). At this stage, a comprehensive examination is conducted in conjunction with Government Ministries and Authorities, a tour of the site is conducted and photographs and maps of the site are consulted. A hydrological review of the state of the ground water table is carried out and a geological cross section is made to differentiate the ground strata
At the subsequent stage, in order to identify the focal points of the soil contamination, ground gas is collected and the components thereof are analyzed (when the case in point is volatile and semi volatile fuel components).
Pursuant to the soil sampling and the results of the analytical analysis of the samples in a laboratory, is it possible to assess the scope of the contaminated ground and to contain it.
Thereafter, the ground survey itself is conducted, which includes a series of boreholes and a determination of the concentration of the contamination.
Besides the concentration of the contaminants, (fuels, oils and metals), additional parameters are checked, such as the level of acidity of the soil, the percentage penetration into the water, electrical resistance, etc. Accordingly, the expected costs of the treatment and the duration of the ground restoration process are estimated.
Finally, the restoration program for the site is coordinated and the optimal technology for the treatment of the problem is selected. In a case where the contamination constitutes a public health hazard, the excavation, removal and internment of the soil, or in situ handling, is recommended.
The current awareness of ground contamination is growing, and regulatory steps and enforcement actions are being taken. The Ministry of Environment Protection obligates the following steps: Conducting a historical ground review and an examination of the current state of the soil, determining the ownership of the land (the owners responsible for handling and preventing the contamination), drawing up the budgets required for treatment, and estimates of the changes in the fiscal value of the land. A bill was formulated in 2008 regarding the prohibition of ground contamination and the obligation of periodic tests that obligate the testing of land suspected of being contaminated and the treatment of those found to be contaminated.
The conducting of a ground survey is necessary at sites for which a toxins permit has been issued, or when a severe contamination of the ground water table / the soil has been detected. It is also recommended to conduct a survey to detect the presence of contaminants in real estate deals and in the transfer of ownership in land, prior to consummating the deal.
The Easytop Company conducts ground surveys and historical reviews through experts in soil contamination and by using the analytical services of laboratories approved by the Ministry of Environment Protection.
Written up by the Easytop Company – Technological Solutions for Environmental Quality