Changes

#'''Automated samplers''' used to collect water from a rain event at given intervals (time or flow volume) are generally the most popular sampling method and involve compositing rain events to estimate an even mean concentration (EMC). For further information on sampling methods refer to the [https://sustainabletechnologies.ca/events/webinar-real-time-water-quality-monitoring-guide/ STEP Real-Time Water Quality Monitoring – How-To Guide]. The collected samples should be tested by a verified laboratory and handled based on laboratory instruction.

#'''Automated samplers''' used to collect water from a rain event at given intervals (time or flow volume) are generally the most popular sampling method and involve compositing rain events to estimate an even mean concentration (EMC). For further information on sampling methods refer to the [https://sustainabletechnologies.ca/events/webinar-real-time-water-quality-monitoring-guide/ STEP Real-Time Water Quality Monitoring – How-To Guide]. The collected samples should be tested by a verified laboratory and handled based on laboratory instruction.

Measuring phosphorus concentration in soil or LID media, is important for assumption and/or verification inspections. An LID media contains some amount of phosphorus in support of plant growth; however, the amount of phosphorus should remain low to avoid substantial nutrient contribution to nearby receiving waters. The organic matter in the media, as well as deceased plants can decompose and release both organic and inorganic phosphorus. This can increase concentrations in outflow, rendering such LIDs an exporter of nutrients instead of a treatment feature (Bratieres et al. 2008<ref>Bratieres, K., Fletcher, T. D., Deletic, A., & Zinger, Y. A. R. O. N. (2008). Nutrient and sediment removal by stormwater biofilters: A large-scale design optimisation study. Water research, 42(14), 3930-3940</ref>). Therefore, it is important to measure the phosphorus content of LID media and/or bulk materials such as [[compost]], and [[topsoil]] and ensure that it is within appropriate design specification range. Extractable phosphorus is the portion of soil phosphorus that is easily available to organisms like plant and algae and is of immediate concern to water quality in large amounts. The levels of phosphorus in media can also be evaluated and discussed as '''Phosphorus Saturation Index (PSI)'''. PSI is the proportion of extractable phosphorus to extractable aluminum and iron in the soil sample.

Measuring phosphorus concentration in filter media and growing media, is important for assumption and/or verification inspections. Such media contains phosphorus to support plant growth; however, the amount of phosphorus should remain low to avoid substantial leaching and nutrient contribution to nearby receiving waters. The organic matter in the media, as well as deceased plants can decompose and release both organic and inorganic phosphorus. This can increase concentrations in outflow, rendering LID facilities an exporter of nutrients instead of a treatment feature (Bratieres et al. 2008<ref>Bratieres, K., Fletcher, T. D., Deletic, A., & Zinger, Y. A. R. O. N. (2008). Nutrient and sediment removal by stormwater biofilters: A large-scale design optimization study. Water research, 42(14), 3930-3940</ref>). Therefore, it is important to measure the phosphorus content of LID media and/or bulk materials such as [[compost]], and [[topsoil]] and ensure that it is within appropriate design specification range. '''Extractable phosphorus''' is the portion of soil phosphorus that is easily available to organisms like plant and algae and is of immediate concern to water quality in large amounts, so should be included in the parameters tested.  '''Extractable phosphorus''' testing is commercially available from soil testing laboratories servicing agricultural and horticultural industries. The level of phosphorus saturation in a filter or growing media can also be evaluated as Phosphorus Saturation Index (PSI). PSI is the proportion of extractable phosphorus to extractable aluminum and iron in the soil sample.

==Limiting excess phosphorus==  

==Limiting excess phosphorus==  

===Chemical control===

===Chemical control===

For infiltration practices an 'amendment' or chemically reactive 'additive' can help to retain even more phosphorus.

For infiltration practices an 'amendment' or chemically reactive 'additive' can help to retain even more phosphorus. Typically these components would make up 5 to 10% by volume of the filter media mixture.  

{{:Additives}}

{{:Additives}}

==Phosphorus testing in media==

==Phosphorus testing in filter media==

To help ensure LID BMPs sustain healthy vegetation cover while not contributing substantially to nutrient loading of receiving waters, the quantity of extractable (i.e., available) P in the soil component needs to be measured and compared to design specifications or acceptance criteria.

To help ensure LID BMPs sustain healthy vegetation cover while not contributing substantially to nutrient loading of receiving waters, the quantity of '''extractable (i.e., available) phosphorus''' in the filter media or growing media (i.e., soil) component needs to be measured and compared to design specifications or acceptance criteria.

{{:Phosphorus testing in media}}

{{:Phosphorus testing in media}}

The levels of phosphorus in media can also be evaluated and discussed as Phosphorus Saturation Index (PSI). PSI is the proportion of extractable phosphorus to extractable aluminum and iron in the soil sample.

The levels of phosphorus saturation in a filter or growing media can also be evaluated and discussed as Phosphorus Saturation Index (PSI). PSI is the proportion of extractable phosphorus to extractable aluminum and iron in the soil sample.

==Design and maintenance considerations==

==Design and maintenance considerations==

==Additives for enhanced phosphorous removal==

==Additives for enhanced phosphorous removal==

Particulate phosphorus is removed to a good extent in LIDs due to the sedimentation and filtration mechanisms offered by these features. To further improve the removal of total phosphorus, the removal of dissolved phosphorus is targeted. As explained in the previous section, adsorption is the main removal mechanism for dissolved phosphorus and aluminum and iron are the main sorptive elements.  Therefore, including [[Additives| additives]] in filter media blends can enhance phosphorus retention.  Examples of such [[Additives| additives]] are [[Iron filings (ZVI)|iron filings]] or zero valent iron, iron-enriched or [[red sand|“red” sand]], and [[water treatment residuals]]. Other [[Additives| additives]] that enhance filter media sorption capacity are [[biochar]], [[Bold & Gold]], [[Smart Sponge]], and [[sorbtive media| Sorbtive Media]].  See [[Additives]] for further details and links.

Particulate phosphorus is removed to a good extent in LIDs due to the sedimentation and filtration mechanisms offered by these features. To further improve the removal of total phosphorus, the removal of dissolved phosphorus is targeted. As explained in the previous section, adsorption is the main removal mechanism for dissolved phosphorus and aluminum and iron are the main sorptive elements.  Therefore, including [[Additives| additives]] in filter media blends can enhance phosphorus retention.  Examples of such [[Additives| additives]] are [[Iron filings (ZVI)|iron filings]] or zero valent iron, iron-enriched or [[red sand|“red” sand]], and [[water treatment residuals]]. Other [[Additives| additives]] that enhance filter media sorption capacity are [[biochar]], [[Bold & Gold]], [[Smart Sponge]], and [[sorbtive media| Sorbtive Media]].  See [[Additives]] page for further details and links.

Determining when additive enhanced filter media needs replacing or maintenance represents a new challenge for stormwater asset managers, as there are no suitable visual indicators.  Erickson et al. (2018) suggest effluent sampling and laboratory testing to identify when enhanced filter media pollutant retention is waning, or periodic sampling and batch (laboratory) testing of filter media to directly measure its capacity to retain the targeted pollutants.<ref>Erickson, A.J., Taguchi, V.J., Gulliver, J.S. 2018. The Challenge of Maintaining Stormwater Control Measures: A Synthesis of Recent Research and Practitioner Experience. Sustainability. 2018, 10, 3666. https://www.mdpi.com/2071-1050/10/10/3666 </ref>

Determining when additive enhanced filter media needs replacing or maintenance represents a new challenge for stormwater asset managers, as there are no suitable visual indicators.  Erickson et al. (2018) suggest effluent sampling and laboratory testing to identify when enhanced filter media pollutant retention is waning, or periodic sampling and batch (laboratory) testing of filter media to directly measure its capacity to retain the targeted pollutants.<ref>Erickson, A.J., Taguchi, V.J., Gulliver, J.S. 2018. The Challenge of Maintaining Stormwater Control Measures: A Synthesis of Recent Research and Practitioner Experience. Sustainability. 2018, 10, 3666. https://www.mdpi.com/2071-1050/10/10/3666 </ref>