Depth to water

Migration pathways (i.e., soil type, depth to water table, utility trenches) ... 

Baildown test results do not always conform to the theoretical response anticipated. This is evident from Figure 6.12, which shows much fluctuation as a result of borehole effects. In these instances, maximum theoretical values can be determined by subtracting the static depth-to-product from the corrected depth-to-water. Thicknesses provided in this manner are conservative in that true thicknesses must be less than or equal to these values and, thus, this method overestimates the actual thickness by an amount equal to the thickness of the capillary zone. 

Since the water table as measured in the well is depressed by the weight of the hydrocarbon, a corrected depth to water is calculated ... 

A correction factor is then applied for capillary fringe effects. This factor can be empirically derived reflecting the corrected depth to water as shown below ... 

Each recovery site has its own individual site-specific characteristics. Subsurface stratigraphy and other geologic considerations, depth to water table, hydraulic conductivity, aquifer(s) thickness, size of product pool, physical characteristics of the... 

Soil. Harris (1969) studied the mobility of 11 insecticides, including heptachlor, in two soils (Hagerstown silty clay and Lakeland sand) using a standard column system. The depth to water in the soil column was decreased. Given that the concentration of heptachlor did not change with depth, the author concluded this insecticide is not mobile. 

Site permeability, clay content, depth to water table, and organic content can impact technology performance. 

The technical factors that must be considered include (1) volatility of pollutants, (2) lateral and vertical concentration of VOCs, (3) soil types and properties (e.g., structure, texture, permeability, stratification, and moisture content), (4) emission control requirement, (5) schedule for cleanup, (6) position and length of screened interval, (7) blower type, and (8) site factors (e.g., depth and contaminated extension area, depth to water table). 

Second, it is almost impossible to quantify the terms fast arrival and slow arrival of contaminants. In some vulnerability maps the legend is divided into intervals of arrival time (e.g., within 3 years, within 20 years, and later than 20 years). Third, the nature of the infiltration setup (depth to water table, porous or fissured medium) varies on a small scale, and there are no hints to it in geological maps. The information has to be derived from other sources, which are rarely at hand. 

Qualitative evaluation of water table aqnifers vulnerability we have conducted considering the depths to water-table from land snrface and thickness of poorly permeable soils in aeration zone. According to this method following types of soils have been distinguished in the cross-section of aeration zone ... 

Table 1 presents numerical scores assigned to depth to water table and to poorly permeable soils in aeration zone based on their thickness. 

Soil conditions moisture, aeration, nutrient status, microbial activity, heterogeneity, depth to water table Land forms topography, slope length and steepness,... 

Typical applications of GPR surveys include, mapping depth to bedrock, and mapping interfaces including changes in soil type, geologic formations, and depth to water table. Buried objects and excavations may also be located and in some cases identified, as well as buried cultural features including pipes, cables, and conduits (13). 

Depth to Water. The water table is the expression of the surface below the ground level where all the pore spaces are filled with water. Above the water table, the pore spaces are filled ri.th water and air. The water table may be present in any type of media and may be either permanent or seasonal. Depth to water refers to the depth to the water surface in an unconfined aquifer. Depth to water does not include saturated zones which have insufficient permeability to yield significant enough quantities of water to be considered an aquifer. 

This document also can be used to evaluate unconfined aquifers. For purposes of this document, depth to water refers to the top of the aquifer where the aquifer is confined. In this case, depth to water may include saturated zones above the top of the aquifer. 

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