Total Suspended Solids (TSS) are measured by a test that assesses which of the following?

• A. The total amount of solids suspended in a sample
• B. The dissolved solids in a sample
• C. The settleable solids in a sample
• D. The volatile solids in a sample

Answer: (A)

Total Suspended Solids are measured by a test that determines the total amount of solids that remain suspended in a sample. In practice, a known volume of sample is filtered through a pre-weighed filter, the filter and its captured solids are dried and weighed, and the difference in mass gives the amount of suspended solids. Dissolved solids don’t get captured on the filter, so they aren’t included in TSS. Settleable solids are found by letting the sample sit and measuring what settles out over time, which is a different parameter. Volatile solids refer to organic matter that is measured by ignition, also a separate test. So the test for TSS focuses on the particulate matter that stays suspended, not dissolved or settled or volatile fractions.