Measuring Total Suspended Solids in Water

Total Suspended Solids (TSS) measurements quantify particles larger than 2 microns found in a water column. These can include inorganic compounds (gravel, sand, silt) or organics (algae, plankton, and decaying plant or animal matter). TSS contributes to the optical clarity or turbidity of water, but also includes solids that can settle at the bottom of a body of water.

Using standard EPA methods 2540C and 2540D, TSS can be quantified via gravimetric analysis1.2. A water sample is filtered through a pre-weighed glass fiber filter, capturing the solids larger than 2 um. Then, the filter is dried in an oven to remove remaining water and weighed again. The weight difference over the sample volume provides the TSS concentration in mg/L. An interesting technology advancement for TSS testing is offered in the WaterVac Filtration System. This vacuum filtration apparatus features two stainless steel filter holders for improved capacity when testing multiple water samples. And it features a built-in liquid pump which transfers filtered water directly to a waste container, eliminating the need for a separate vacuum flask.

Total solids (along with turbidity) give an idea of the overall health of a water system. When the concentration of total solids is too low, this can mean there aren’t enough nutrients in the environment to support aquatic life. Alternatively, overabundance of solids can indicate high turbidity, pollution, or eutrophication3. Water sources that are downstream of agriculture and mining can suffer from elevated levels of TSS that contribute to low water quality. This can greatly impact fish and other aquatic inhabitants, hinder the effectiveness of drinking water treatment, and render water unfit for recreational use.



References
NEMI Method Summary - 2540 C. (2019). Retrieved from https://www.nemi.gov/methods/method_summary/9818/
NEMI Method Summary - 2540 D. (2019). Retrieved from https://www.nemi.gov/methods/method_summary/9819/
Total Suspended Solids and water quality. (2019). Retrieved from https://www.state.ky.us/nrepc/water/ramp/rmtss.htm