Spice is a place of taking water from layers of sand or gravel. The principle of its operation is to take the water flowing between the grains of sand by trapping the sand with the help of a sieve. The possible depth of the spice is 25m.
The spice consists of a water supply pipe and the spice itself (spice end or spice filter), which is a perforated pipe (a pipe with holes drilled or milled for the flow of water) surrounded by a sieve or other water-permeable but sand-retaining material. Its diameter and spice tip length can vary, depending on the pump used, water quantity or quality requirements, and soil characteristics.
The productivity of the spice depends on the diameter and shape of the sand grains in the respective layer, the saturation of this layer with clay or sludge, the water receiving surface of the spice (Spice tube diameter, perforation frequency, length and hole diameter determining the useful sieve area through which water flows), and from the water permeability of the sieve or other material used. Despite the potential productivity of the spice, the actual productivity is also affected by the vertical distance from the pump to the static water level in the spice, which is usually equal to the groundwater level. The smaller this distance is, the higher the water output of the pump.
Spice is the cheapest way to extract water from groundwater bearing layers. It is often also the most optimal, taking into account the cost of spices, equipment and purification filters, compared to the cost of other types of water extraction to the desired result - clean water. If the house has a centralized water connection, spice is an opportunity to significantly reduce the cost of water for garden water.
Most commonly, the water obtained from spices has an increased oxidizability, which indicates that surface water is entering the spice. Often, there is also an increase of iron, water hardness, and other indicators. To treat such waters, complex treatment equipment is most often used - with anionite and cation exchange resin fillings. Often, at very high iron content, in addition to this equipment, a water iron removal device is also required.
Spice cannot be made in the whole territory of Latvia. In most of the territory of Latvia, the upper soil layers are clayey, rocky, where water abstraction is not possible. A specialist with relevant experience should be consulted about the possibilities to make a spike, as well as about the expected water quality and quantity, as there is no centralized geological research on water-bearing layers suitable for spice. It is a misconception that extracting water from a borehole determines better water quality and volume than can be obtained with a spike. Often the difference in quality is only in the form of impurities in the water, where it is the type of impurities that determines the treatment options and the cost of the filters. But the amount of water can be achieved by the length, diameter, or number of spices connected together by the spice filter column.