Environmental Pollution Exploration using Geophysical Equipment

Last update time : 05/09/2018

Author : zhang jie

Engineering geological exploration and pollution site survey

Site survey services

Overview:

The survey of environmental pollution sites, led by geophysical methods and regarding ERT electrical methods as the core, investigates the pollution status of typical pollution sources with the help of electromagnetic method and Ground Penetrating Radar. According to the physical and chemical differences between the pollutants and the surrounding media, the distribution of the physical sites is measured, and the distribution and migration of pollutants are deduced. The rapid, low-cost, non-destructive and systematic site survey techniques will provide a reliable basis for comprehensive site remediation and development in the future.

Scope of survey:

    • Environmental pollution site survey
    • Heavy metals, organic matters toxic substances
    • Geological exploration and geological hazard survey
    • Water exploration, mineral exploration, landslides, urban road collapse

 

Survey equipment:

  • Professional technical engineers and systematic instruments and equipment to guarantee efficiency and accuracy.
  • Co-use of rapid-detection instruments and equipment to ensure targeted and representative survey.

 

Technical features:

  • Non-destructive testing, less investment, high efficiency, all-sided space, in situ and fast speed;
  • Short acquisition time; real-time display and analysis of on-site data;
  • Flexible configuration and good scalability; suitable for a variety of unconventional tests and adaptable to conditions of 1D to 3D tests;
  • Good environmental adaptability, whether it is ground, underwater, or underpit;
  • Display of “linear, plane and spatial” information, rather than the traditional survey at certain “points”.

 

Environmental engineering site survey cases

Petrol station oil leakage survey

Objective: Delineate the leakage areas

Technical methods: GPR and ERT resistivity

Analysis and interpretation of survey results

Result maps of the GPR method with GPR-1 and result maps of the ground resistance image profiling method with ERT-1 (as shown below) indicate the same suspected leakage area

The test site didn’t have any impact on the premises, or cause any damage to the site environment (as shown below).

Survey of farmland heavy metal pollution in Baiyin

Objective: Identify the site distribution and depth of the heavy metal pollution

Technical methods: inductive electromagnetic method, ERT resistivity, and XRF fluoroanalyzer

Analysis and interpretation of survey results:

Inductive electromagnetic method: According to the survey results, in the result map, the red scale suggests high conductivity (low resistivity) and the blue-violet scale suggests low conductivity (high resistivity). It is assessed that the landfill in this area has been mixed with much leachate, resulting in a relatively high conductivity, and that the highly conductive area is associated with a large gathering of landfill leachate and may have formed underground channels for the landfill leachate. It is inferred from the analysis that the groundwater in the southwestern part of the site and the surrounding farmland may have been affected by the pollution of landfill leachate.

According to the result maps of the ERT resistivity method, it is speculated that the overall shallow strata is of low resistivity. At the same time, after analyzing the 3D distribution of low resistivity below 50 Ohm-m-80 Ohm-m, the results basically coincide with those of the inductive electromagnetic method, i.e., the heavy metal contaminated soils, large-scaled and deep, are mainly distributed in the west of the site. The 3D results show that the resistance is featured by downward extension; the average depth is analyzed as 1.2 to 1.8m and some low resistance even reaches 2.2 to 2.5m in depth. It is estimated that the heavy metal pollution in the west of the site reaches a deep degree of depth.

Survey of a landfill in Xiangyin

  1. Objectives: Underground landfill distribution of the landfill site; scope boundary, depth and volume of the area, characteristics of the landfill leachate; and stratigraphic status of the surrounding farmland.
  2. Technical methods: ERT resistivity and inductive electromagnetic methods
  3. Analysis and interpretation of survey results

Inductive electromagnetic method: According to the survey results, in the result map, the red scale suggests high conductivity (low resistivity) and the blue-violet scale suggests low conductivity (high resistivity). It is assessed that the landfill in this area has been mixed with much leachate, resulting in a relatively high conductivity, and that the highly conductive area is associated with a large gathering of landfill leachate and may have formed underground channels for the landfill leachate. It is inferred from the analysis that the groundwater in the southwestern part of the site and the surrounding farmland may have been affected by the pollution of landfill leachate.

ERT IP method: According to the survey results, the maximum depth is about 16 to 18m, and according to the results of geophysical survey, the average depth is 11.5 to 13.5m and the amount is about 300,000 to 350,000 cubic meters.

Survey of a printing and dyeing mill in Hangzhou

  1. Objectives: Detect the underground area of polluted soils in the site, and find out the soil thickness and pollution scope.
  2. Technical method: ERT resistivity
  3. Analysis and interpretation of survey results

As the resistivity is about 60ohm/m and the materials of the overall stratum presents ultra-low resistivity, it can be inferred that the site is seriously invaded by pollutants. According to the measurement results of the two arrangements, the high resistivity between 6-8 electrodes or the 5-7m section of the whole measuring line shows that there may be holes or pipes in the building structure. While, the lower part has resistivity values as low as few ohms per meter, so it can be concluded that the upper pipeline or the pollution accumulation has caused the diffusion of pollutants to the lower soils, resulting in a lower resistivity at the depth of 1m-2.6m underground. In addition, the measuring line also has abnormal areas at the 15-20m section, so the low resistance underground in the site is also caused by the pollution of accumulated waste.

Areas of high resistivity are inferred as building structures

Holes or pipes, with lower parts of low resistivity

Abnormal areas that may result from the leakage of pollution

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Last update time 05/09/2018

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