For example, the installation of seepage could have an adverse effect on vertical barriers designed to prevent contamination from moving laterally as the increase in hydraulic pressure caused by the seepage will increase losses through barriers and reduce their effectiveness over time. Seepage may also interfere with a soil vapor extraction system commonly installed to reduce vapor pressure under buildings and evacuate any vapor hazards that may be caused by contaminants under the building. In this case, seepage can raise the water table, preventing the soil vapor extraction system from functioning properly and causing high volumes of condensation from the collected vapor, which is commonly contaminated (EPA, July 2013). When making decisions, all of these factors should be taken into consideration on a case-by-case basis