Turbidity

Form commonly found in stormwater:

Rock and soil fragments, dirt and debris from roads and vehicles, oil particulates.

Related constituents:

Total suspended solids (TSS) – measures the mass of particulates of varied origin suspended in a moving body of water.

Solubility in water:

The particulates causing turbidity are insoluble

Adverse human impacts:

High turbidity 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] Turbidity can also make streams less aesthetically enjoyable.

Adverse impacts on the environment:

Turbidity reduces visibility and absorbs 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]
The fine particles that cause turbidity 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 turbidity-causing particulates and can be transported into aquatic environments in this fashion.[v]

Stormwater Treatment to Remove Turbidity

Turbidity in Stormwater FAQs

What is turbidity?2019-07-26T16:40:28+00:00

Turbidity describes the amount of optical diffraction (the bending of light as it passes around an object) caused by particulates suspended in water. Measuring turbidity indirectly measures the number of particulates in the water.[vii] The particulates measured by turbidity can be either solid or liquid (i.e. oil droplets),[viii] however, the solid particulates are predominantly used in turbidity measurements. Turbidity is often used as a surrogate measurement for total suspended solids although no correlation between turbidity and TSS measurements can be made.[ix]

What causes turbidity in stormwater runoff?2019-07-26T16:39:11+00:00

Stormwater runoff can create turbid conditions in water when it picks up particulate debris from hard surfaces and transports it to water bodies. Turbidity in stormwater runoff is usually made up of rock and soil fragments, dirt and debris from roads and vehicles. [vii] TSS, a related pollutant, measures the mass of particulates of varied origin suspended in a moving body of water, with no direct relationship between turbidity and TSS measures. The particles causing turbidity are insoluble in water and will settle out of suspension with enough time.[viii]

Why should turbidity be removed from industrial stormwater runoff?2019-07-23T16:58:41+00:00

Turbidity should be removed from stormwater because its presence in drinking water sources has negative effects on humans and the environment.

The effects of high turbidity levels in water ingested by humans often mean 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]

Turbidity can also make streams less aesthetically enjoyable and can have negative impacts on plants and wildlife. Turbidity reduces visibility and absorbs light, which can increase stream temperatures and reduce photosynthesis.[ii] Resulting negative impacts of turbidity on plant and wildlife include:

  • interference with aquatic plant photosynthesis, reducing the amount of food, habitat and dissolved oxygen available for other species;[iii]
  • fine particles clogging and abrading fish and insect gills and tissue and interference with egg and larval development;[iv] and
  • pollutants such as pesticides and PCBs adhering to the surfaces of particulates and being transported through stormwater into aquatic environments.[v]
How is turbidity removed from industrial stormwater runoff?2019-07-23T16:58:55+00:00

Turbidity can be removed from industrial stormwater through a physical process of separation, absorption and enhanced media filtration typically found in a passive media filter. Our Aquip passive media filter offers an enhanced level of stormwater treatment for turbidity. Aquip can operate in-line after a gravity separator and before a polishing system. Find out more about the Aquip passive media filter.

Background:

Turbidity describes the amount of optical diffraction caused by particulates suspended in water indirectly measuring the amount of particulates in the water.[vii] The particulates measured by turbidity can either solid or liquid (i.e. oil droplets).[viii]
however, the solid particulates are predominant in turbidity measurements. Turbidity is often used as a surrogate measurement for total suspended solids although no correlation between turbidity and TSS measurements can be made.[ix]

U.S. EPA recommended water quality criteria: [vi]

None. EPA recommends water quality criteria for many of the constituents that cause turbidity.

See TSS for sources of turbidity.

Appendices

[i] U.S. EPA, List of Contaminants and Their MCLs, https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations (last visited July 26, 2019)

[ii] Lake Superior Streams, Turbidity and TSS, http://www.lakesuperiorstreams.org/understanding/param_turbidity.html (last visited July 26, 2019).

[iii] Lake Superior Streams, supra.

[iv] Lake Superior Streams, supra.

[v] Lake Superior Streams, supra.

[vi] U.S. EPA, National Recommended Water Quality Criteria, http://www.epa.gov/waterscience/criteria/wqctable/index.html#U (last visited July 26, 2019).

[vii] Wikipedia, Turbidity https://en.wikipedia.org/wiki/Turbidity (last visited July 26, 2019).

[viii] Fondriest Environmental Learning Center, Measuring Turbidity, TSS, and Water Clarity https://www.fondriest.com/environmental-measurements/measurements/measuring-water-quality/turbidity-sensors-meters-and-methods/ (last visited July 26, 2019).

[ix] Wikipedia, supra.

The Aquip® industrial stormwater filtration system uses an innovative enhanced media filtration process to effectively remove soluble and insoluble aluminum and other metals as well as oils, suspended solids, organics and nutrients from industrial stormwater runoff.

The Purus® Stormwater Polishing System provides the most advanced level of stormwater treatment, and is designed for challenging stormwater conditions or targeted polluant removal.

2019-07-26T16:40:35+00:00