Aggressive (corrosive) water – water actively engaged in chemical reactions leading to deterioration of different concrete and metal structures (e.g., mine working support) and equipment, to unfavorable consequences of water bodies flora and fauna due to salts and gases contained in such water. Aggressive water may be natural and production-induced (mining, discharges of chemical and metallurgical plants, etc.). There are the following types of activity of such water: carbon-dioxide, sweet-off, general acidity, sulfate, magnesia, oxygen. The aggressive water impact may be minimized by controlling inflows of surface and ground waters and of mine drainage water, by reducing the time for water contacting minerals, by controlling solution circulation rate and temperature.

The damaging effect of aggressive water on metal structures may be mitigated by using acid-proof and corrosion-resistant equipment and machinery with special alloying elements, films with higher loosening rate (restraining corrosion and improving metal durability), by introducing nitrogen into chrome steel. For mine water drainage with big volumes of aggressive water lined and fiberglass pipes are used, and for smaller volumes of aggressive water cast-iron, asbestos-shingle and asbestos-cement pipes are used. In oil and gas sector and for dumping industrial effluents well casing pipes are made of corrosion-resistant metal, and special cement grades with higher resistance are used in the annulus (with further lifting of cement up to the wellhead).