Changes

Measuring the phosphorus concentrations in stormwater is important for performance evaluation/inspection and ensuring that outflow to the streams meets the mentioned concentration requirements. For performance evaluation, both inflow and outflow of a stormwater feature should be sampled. Sampling of just outflow reveals the concentrations entering streams and checks if they meet the requirements. There are several sampling methods, decision on the most appropriate method to use, depends on the sampling objectives and budget limitations.  

Measuring the phosphorus concentrations in stormwater is important for performance evaluation/inspection and ensuring that outflow to the streams meets the mentioned concentration requirements. For performance evaluation, both inflow and outflow of a stormwater feature should be sampled. Sampling of just outflow reveals the concentrations entering streams and checks if they meet the requirements. There are several sampling methods, decision on the most appropriate method to use, depends on the sampling objectives and budget limitations.  

#'''Grab sampling''' is the least expensive method and often does not yield accurate and representative results. Depending on the timing of the grab sample, concentrations may be too high or too low as they change quickly within a rain event.  

#'''Grab sampling''' is the least expensive method and often does not yield accurate and representative results. Depending on the timing of the grab sample, concentrations may be too high or too low as they change quickly within a rain event.  

#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 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.