Are Total Dissolved Solids and Sulfate Rising in North Dakotas Aquifers?
In some areas of North Dakota, concern has been raised over rising salinity and total dissolved solids (TDS) concentrations measured in water samples from some wells. In most cases increasing TDS has been composed of sulfatic salts, including calcium and magnesium sulfate, and in some cases sodium sulfate. Increased salinity in water can be of concern to users of water. For irrigators sufficiently large salinity can decrease crop water use efficiency and crop yield. Soil salinization problems can result in needs for special management, such as increased water application for flushing salts from the soil profile. If sodium is present, substantial soil damage through slaking and loss of soil structure can occur. Increased salinity is also undesirable from the standpoint of drinking water, where EPA has suggested a maximum TDS guideline of 500 milligrams per liter (mg/L). Sulfate, which is a primary component of most of the increased salts, is not toxic, although large sulfate concentrati
