Total solids in water include total suspended solids, total dissolved solids, and volatile suspended solids. Dissolved solids consist of particles like calcium and chloride that pass through a small pore filter, while suspended solids include particles like silt, clay, and organic debris. Sources of solids in water include sewage, industrial discharge, road runoff, and soil erosion. Measuring total solids is important for controlling wastewater treatment and assessing regulatory compliance. The concentration of total solids is calculated by weighing solids in a water sample before and after drying.