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Water Table Issues

The water table is the depth at which the earth becomes permanently saturated with water. Typically, the water below the earth's surface is potable, does not affect surface structures and can be used in wells to provide water for cooking, cleaning, agriculture and industry. However, certain factors can affect the depth of the water table or the safety of the water below.

  1. Changes to Soil

    • Underground water in agricultural areas may become contaminated by runoff from chemical fertilizers. The soil then can become damaged when the groundwater evaporates, which may permanently inhibit crop production or the growth of natural vegetation. When the water table exists within a few meters of the soil, salinity is also a concern. If water near the surface isn't used by plants, evaporation can leave behind salts. This increases the salinity of the soil and jeopardizes the future health of the land.

    Drinking-Water Pollution from Sewage

    • In areas where sewer systems are poorly constructed or where connections between pipes have eroded, sewage can contaminate groundwater and make it undrinkable. In developing areas, such as some parts of Pakistan, poor-quality sewer pipes often leak. The contaminated water from these pipes mixes with the water at the water table's surface and carries contaminants deeper, spreading them to other parts of the subterranean water supply. The contaminated water brings with it industrial and medical waste products, including solvents, heavy metals, polychlorinated biphenyls (PCB) and cyanides as it sinks.

    Flooding and Water Damage

    • Excessive rain or melting snow combined with poor drainage can cause the ground to become saturated and the water table to rise. In a residential area with a high-water table, rising water can flood basements and cause water damage to interior walls and floors. Water damage can necessitate expensive repairs and cause unsightly stains. In addition to the aesthetic damage caused by water stains, moisture can accumulate within walls and contribute to the presence of mold. This can cause future respiratory problems for people living in the affected homes.

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