TDS. This method quantifies solids in water or wastewater samples using gravimetric analysis following oven drying. Solids refer to matter suspended or dissolved in the water or wastewater and may affect water or effluent quality in adverse ways. Waters with high dissolved solids generally are of inferior palatability and may induce unfavorable physiological reactions in transient consumers. Solids analyses are important in the control of biological and physical wastewater treatment processes and for assessing compliance with regulatory agency limitations. The method has a detection limit of approximately 4 mg/L for TSS and 10 mg/L for TDS, TS and VSS. The results are generally reproducible within 10%.