Solids refer to matter suspended or dissolved in potable, surface, and saline waters, as well as domestic and industrial wastewaters. Solids may adversely affect water or effluent quality in a number of ways. Waters with high dissolved solids generally are of inferior palatability and may induce an unfavorable physiological reaction in the transient consumer, so a limit of 500 mg/L dissolved solids is desirable for drinking waters. Highly mineralized waters also are unsuitable for many industrial applications. Waters high in suspended solids may be aesthetically unsatisfactory for bathing and other purposes.
Solids analyses are important for controlling water and wastewater treatment processes and assessing compliance with regulatory requirements.