TSS, suspended solids
Rock and soil fragments, dirt and debris from roads and vehicles
Turbidity - a measure of the optical diffraction imparted by solids the water, no correlation of between TSS and turbidity units
Suspended solids are insoluble in water and will settle out of suspension with enough time.
Adverse human impacts: High TSS levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria, which can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.[i] Suspended solids can also make streams less aesthetically enjoyable.
Suspended solids reduce visibility and absorb light, which can increase stream temperatures and reduce photosynthesis.[ii] Impeding aquatic plant photosynthesis reduces the amount of food, habitat and dissolved oxygen available for other species.[iii] Fine particles may also clog and abrade fish and insect gills and tissue and interfere with egg and larval development.[iv] Pollutants such as pesticides and PCBs adhere to the surfaces of TSS and can be transported into aquatic environments in this fashion.[v]
None. EPA recommends water quality criteria for many of the constituents included in TSS.[vi]
Total suspended solids (TSS) describe particulates of varied origin, including soils, metals, organic materials and debris that are suspended in a moving body of water. Turbulence keeps the particulates suspended in water allowing the solids to be transported downstream.
Total suspended solids and turbidity are distinct measurements that provide similar assessment of the water quality. TSS is a measure of the mass of solids found in a volume of water that can be filtered by a 1.5 um glass fiber filter. Turbidity is a measure of the optical diffraction imparted by solids the water. Both can be used to assess the impact of solids on a water body.[vii]
The largest amounts of solids are generated from construction activities, agriculture, unpaved surfaces, and waste management. However, solids develop from less evident sources such as highways, parking lots, and air emissions.[viii] Wind and rain act as the predominant mechanism transporting solids into waterways.
Clara The StormwateRx Clara® is often used as pretreatment to the Aquip for removal of suspended solids. For industries with a heavy solids load, Clara is often the product of choice, especially if there are no other pollutants that require more fine particulate filtering or polishing.
Aquip The StormwateRx Aquip® industrial filtration system is typically used in a treatment train applications where Clara is used as pretreament. After the stormwater passes through the Clara, Aquip's enhanced sand filtration process effectively removes metals oils, organics and nutrients.
Purus The Purus™ Stormwater Polishing System (previously known as the AquiPlus) provides the most advanced level of stormwater treatment, and is designed for challenging stormwater conditions or targeted pollutant removal.
U.S. Air Force Reserve Station The U.S. Air Force Reserve Station in Pittsburgh, Pennsylvania was concerned that heavy metals, including lead and copper, from spent ammunition rounds was being washed by stormwater runoff into a nearby waterway. To address the risk, they installed a StormwateRx Clara® system. With the installation of the Clara settling system, munitions particulates are being captured and the site is limiting its exposure as a target for third-party litigation or potential fines from the EPA.
Washington Iron Works Washington Iron Works, is a leader in the Southern California architectural steel fabrication business. It installed a StormwateRx stormwater treatment system that includes Clara Plug Flow Separator installed in-line with the existing stormwater drainage lines for removal of TSS, and an above-ground Aquip system. Washington Iron Works has achieved excellent results removing sediment, oil, and heavy metals like iron that could impair waterways of the Los Angeles drainage basin.
[i] U.S. EPA, List of Contaminants and Their MCLs, http://www.epa.gov/safewater/contaminants/index.html
[ii] Lake Superior Streams, Turbidity and TSS, http://www.lakesuperiorstreams.org/understanding/param_turbidity.html (last visited Aug. 4, 2010).
[iii] Lake Superior Streams, supra.
[iv] Lake Superior Streams, supra.
[v] Charles River Watershed Ass’n, CRWA Water Quality Monitoring Parameters, http://www.crwa.org/water_quality/monthly/parameters.html (last visited Aug. 9, 2010).
[vi] See U.S. EPA, National Recommended Water Quality Criteria, http://www.epa.gov/waterscience/criteria/wqctable/index.html#U (last visited July 30, 2010).
[vii] Standard Methods [2-8, 2-55](Eaton, Andrew D., et al. eds., 21st ed. 2005).
[viii] Y. Feng, et al., Source apportionment of ambient total suspended particulates and coarse particulate matter in urban areas of Jiaozuo, China, 57 J. of the Air Waste Mgmt. Assn. 561-575 (2007).