Red sand

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What is it?

Red sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm., also known as a "Minnesota Filter", is iron enhanced sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. designed to capture soluble phosphorus that generally passes through a typical stormwater management facility. Iron has an affinity for dissolved phosphorus, which will serve to bind and therefore remove a portion of the dissolved phosphorus from the stormwaterSurface runoff from at-grade surfaces, resulting from rain or snowmelt events.. [1] The sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. also filters the stormwater by removing a portion of the suspended solids and total phosphorus that may be attached to those particles.[1]

How is it being used?

The first retrofit in Ontario to incorporate a red sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. filter system was the George Richardson stormwater management pondA body of water smaller than a lake, often artificially formed. in Newmarket.[1] Red sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. was installed as the last part of a treatment trainStormwater management following the hierarchical approach: Source Control measures, Conveyance Control measure and End of Pipe treatment to achieve the water quality and water balance target for lot level development of the preferred strategy.A combination of lot level, conveyance, and end-of-pipe stormwater management practices. to function as a final polishing unit. The underground system was first lined with a bentonite liner to minimize groundwater exchange, with various layers of clear stone and red sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. sandwiched between nonwoven geotextiles. The water is distributed via a system of perforated piping covering the top layer of the underground system just above the red sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. filter mediaThe engineered soil component of bioretention cell or dry swale designs, typically with a high rate of infiltration and designed to retain contaminants through filtration and adsorption to particles., with collector pipes located near the bottom. The system is estimated to have a reduction in phosphorus of 23 kg/year. [2]

Another Ontario project was completed by the Upper Thames River Conservation Authority and Luckhart Transportation Limited, in which they retrofit an innovative wetlandA vegetated area such as a bog, fen, marsh, or swamp, where the soil or root zone is saturated for part of the year. treatment system to test a red sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. filter. This was the first of its kind for an agricultural application. In this project, a clear round stone was added to improve percolation and phosphorus retention.[3]

Benefits

Early data from the George Richardson site indicate a reduction in total suspended solids and phosphorus after going through the system.[2] "Average TPTotal phosphorus concentrations into the filter were 0.12 mg/L with a maximum of 0.54 mg/L as compared to an average outlet concentration of 0.052 mg/L with a maximum of 0.13 mg/L. Average OP concentrations into the filter were 0.01mg/L with a maximum of 0.031 mg/L as compared with an average outlet concentration of 0.007 mg/L with a maximum of 0.044 mg/L." [1] Poor orthophosphate removal was observed during hypoxic or anoxic conditions because the iron/phosphorus bond that facilitates the removal of orthophosphate can be broken under low oxygen conditions.[1]
  1. 1.0 1.1 1.2 1.3 1.4 Lake Simcoe Region Conservation Authority. Showcasing Water Innovation: Stormwater Performance Monitoring Report. 2013. http://www.lsrca.on.ca/Shared%20Documents/reports/swi_monitoring_2013.pdf. Accessed September 8, 2017.
  2. 2.0 2.1 Credit Valley Conservation. George Richardson Stormwater Management Pond Retrofit. 2013. http://www.creditvalleyca.ca/wp-content/uploads/2013/08/CVC-Case-Study-George-Richardson_Aug_2013.pdf. Accessed September 8, 2017.
  3. Upper Thames River Conservation Authority. Red Sand helps Protect Water Quality. 2014. http://thamesriver.on.ca/2014/11/11/red-sand-helps-protect-water-quality-november-11-2014/. Accessed September 8, 2017.