Assessment of level of contamination in soil and water involves using matrix of risk factors together with sensitivity and vulnerability aspects to determine corrective measures needed for effective decontamination

摘要

To determine the comparative measures to be taken in decontamination of soil and water, a matrix is drawn up showing the risk factors and vulnerability. The risk categories are arranged on a diagonal, giving the main diagonals for a medium risk level. The graduations of the risks are related to protection, and the graduations of the vulnerability are related to application. A classified risk rating is given for each contamination by its position in the matrix according to the risk factors. The comparisons are shown to avoid reductions in high and very high risk factors and lowering by more than one risk stage, and alterations within the low-risk ranges. Preferred Features: The risk factors are graduated into three stages in relation to effects related to protection, and sensitivity related to use. The graduation of the risk factors, for the protection of the soil and/or water is related to the relevant soil functions on the site and the protective materials for soil protection, and the water relevance for surface and ground water conditions. The decontamination of water takes the risk of the spread of hazardous matter and the sensitivity or vulnerability of the water resource value. To determine the tendency of the hazardous matter to spread, a mean determination of the reactive geogene complexes is taken by measurement of concentrations along the water flow direction of the contaminated water surface at least at two points in the ground water at a given point in time, to give the level of concentration value of ic according to the expression (i) together with the unit (ii) or without dimensions on standardizing the distance at 100 km. ic = (c2/c1)/(s2-s1) (i) ic = ((mg.l-1/(mg.l-1)/m) = (1/m) s1 = distance between the emission center and the first measurement point, s2 = distance between the emission center and the second measurement point, c1 = measured concentration at the first measurement point, c2 = measured concentration at the second measurement point. The process is repeated with two further measurements at a different point in time, and a further concentration level value is calculated. An objective assessment is made of the risk according to the spread of hazardous matter by space and time, and the resource value of the water, to form a decision matrix for the relevant risk categories. At least the second measurement point is on a theoretical line from the contaminated zone through the first measurement point, exactly on the water flow direction line.