Hydrogeological conditions

Soil, climatic, and hydrogeological conditions vary widely between geographical regions. This variation occurs on a variety of scales and significantly affects agrochemical dissipation rates and fates in the environment. As a result, differences in... 

There are a number of critical parameters to be considered for the application of in situ soil flushing, including the hydrogeological conditions of the contaminated site, the type and properties of contaminants, the properties of the additives, and the treatability of the flushing solution.76 80... 

Requires characterization of subsurface hydrogeologic conditions, delineation and chemical characterization of LNAPL product pools, recovery of LNAPL product and overall aquifer restoration, and soil remediation... 

The time frames associated with the later two phases are dependent on the volume of residual hydrocarbon that remains following initial recovery, hydrogeologic conditions, among other factors, and are further discussed in Chapters 9 and 10, respectively. Important factors such as the presence and extent of residual hydrocarbons, and conceptual understanding of relative permeability and transmissivity as they relate to NAPL recovery, are further discussed below. 

FIGU RE 7.1 Idealized subsurface hydrogeologic conditions for use of a passive trench system. 

Geologic and hydrogeologic conditions (grain size distribution, packing density, hydraulic conductivity, etc.) ... 

Components of the pumping system reflect both practical aspects related to the characteristics of the site facilities and the subsurface hydrogeologic conditions encountered. The pumps selected are pneumatic, double-diaphragm suction-lift pumps. The advantages of these pumps include ... 

Hydrogeologic conditions such as flow rates and direction, water levels, number and location of injection and extraction wells under pumping conditions ... 

Evaluate hydrogeologic conditions Cradle-to-grave liability as generator High cost easy to overexcavate a>... 

Evaluate hydrogeologic conditions Emissions considerations Permitting can be difficult fD... 

Maintain documentation Confirm effectiveness Evaluate hydrogeologic conditions Requires dust control High costs but suitable under certain fD... 

Evaluate hydrogeologic conditions Requires total fluid collection May be used in association with ... 

Evaluate hydrogeologic conditions Soil must pass flash test Requires comprehensive understanding... 

Evaluate hydrogeologic conditions Requires regulatory acceptance Site specific... 

Selection of approach or combination of approaches to LNAPL recovery and ultimately aquifer rehabilitation and restoration is dependent on numerous factors as discussed in the previous chapters. The case histories presented below reflect different remediation approaches and strategies in response to varying geologic and hydrogeologic conditions, site-specific constraints, and regulatory environment. A variety of LNAPL recovery systems are first discussed, including ... 

A very similar process is used to calculate evapotranspiration in a hydrological catchment with well-defined hydrogeological conditions. Viewed over longer intervals (one or more years), 55 = 0 can be assumed. 7=0 can also be assumed because the area is hydrogeologically verified. Thus, it is easy to calculate evapotranspiration by carefully measuring the areal precipitation (cf. Precipitation ) and runoff. Care must be taken to ensure that all errors in the calculation of individual components of the water balance equation are reflected in the result, for example evapotranspiration. 

As shown in Table 3.4, acceptance criteria for stabilization parameters may have a range of recommended values. Because some are more stringent than others, they should be used with caution and be adjusted as necessary based on the knowledge of site-specific conditions. For example, the criterion for turbidity of + 10 percent may be too stringent for some hydrogeological conditions or for the conventional sampling method. On the other hand, this criterion may be easily achieved for wells with dedicated submersible pumps and non-turbid, clear groundwater. 

Geologic and hydrogeologic conditions are perhaps the most important factors in establishing the environmental suitability of the area for a landfill site. Data on these factors are required to assess the pollution potential of the proposed site and to establish what must be done to the site to control the movement of leachate or gases from the landfill. 

Stanfors R., Rhen I., Tullborg E. L., and Wikberg P. (1999) Overview of geological and hydrogeological conditions of the Aspo hard rock laboratory site. Appl. Geochem. 14, 819-834. 

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