Profession～Technology～Integrity～Quality～Responsibility
Elisha said: Thus saith the LORD, I have healed these waters; there shall not be from thence any more death or barren land.
So the waters were healed unto this day. (2 Kings 2:21-22)
Principle
NAPL Ground Survey Technology (NGST) is performed by injecting pulse current into the aquifer through well electrodes or ground electrodes. And the distribution of current can be estimated by the magnetic distribution on the ground. When a site is contaminated by organic solvents, solvents with high electrical resistivity in the porous media seriously influence the hydrogeological characteristics of the site and form some obviously high electrical resistivity zones. When applying NGST, only a little current can flow through high electrical resistivity zones because of the accumulation of solvents. The image of the magnetic signal will present the contaminated zone by solvent.
When a chemical injectate is injected into an aquifer, the injectate will also change the hydrogeological characteristics. Therefore, the distribution of the injectate can be estimated by the magnetic variation received by the sensor on the ground.
NGST technology base on a sufficient academic theory and verified by peer-review journals of high quality. NGST also obtained the approval of several patents. If we well design its survey area and the survey grids, then professionally investigating and Interpreting these survey data, it can investigate the hydrogeology, the contaminant hot spot, and chemical injectate under the ground surface, just like the X-ray inspection applied on the human body.
Technical capabilities
Detectable depth:
It is estimated to resolve the signal generated at a depth of 100 m under the ground surface.
Detectable range:
The surveyable single area can be up to 600 m in length and 400 m in width.
Detectable pollutants:
(1) LNAPL: gasoline, diesel...etc.
(2) DNAPL: TCE, PCE...etc.
(3) Oxidants: persulfate, percarbonate ...etc.
(4) Heavy metals: heavy metals of high concentration.
NGST can be used to
find the contaminant hot spot, find the pollution source, estimate the remediation result, investigate the distribution of injected oxidant, survey the distribution of hydrogeology, analyze the aquifers, detect the leakage of landfills, perform the tracer test, detect the underground pipeline leakage, detect the storage tank leakage, investigate the site healthy condition...etc.
