(One intermediate revision by the same user not shown) | |||
Line 30: | Line 30: | ||
*filter draw down within 48 hours of storm completion to avoid filter fouling and to prepare the filter for next storm event; and | *filter draw down within 48 hours of storm completion to avoid filter fouling and to prepare the filter for next storm event; and | ||
*the underdrain may consist of corrugated polyethylene pipe with slits not holes to prevent loss of sand and minimize clogging. If holes are used, the pipe should be covered with pea gravel. | *the underdrain may consist of corrugated polyethylene pipe with slits not holes to prevent loss of sand and minimize clogging. If holes are used, the pipe should be covered with pea gravel. | ||
+ | |||
+ | ==Best management practice with demonstrated mechanism for removing dissolved phosphorus== | ||
+ | Pollutant removal credits may be given to a best management practice based on one or both of the following, at the discretion of the MPCA. | ||
+ | *Sufficient documentation in the literature. Typically this will be peer-reviewed literature or published studies that follow acceptable protocol (see below). | ||
+ | *Monitoring that follows acceptable protocol (see below). Note that site-specific monitoring may result in credits for only that specific site rather than a specific class of best management practice. MPCA discretion will be used in determining applicability. | ||
+ | |||
+ | Monitoring protocol for establishing credits must be consistent with the protocol [https://stormwater.pca.state.mn.us/index.php?title=File:Monitoring_protocol_Version_1.docx described here], or other MPCA-approved protocol. | ||
+ | |||
+ | For an example of dissolved phosphorus credits given to a best management practice, [https://stormwater.pca.state.mn.us/index.php?title=TP_and_TSS_credits_and_guidance_for_manufactured_treatment_devices_(mtds)#StormFilter_using_PhosphoSorb_Media see here]. | ||
[[Category:Level 2 - Technical and specific topic information/soils and media]] | [[Category:Level 2 - Technical and specific topic information/soils and media]] | ||
[[Category:Level 2 - Pollutants/Phosphorus]] | [[Category:Level 2 - Pollutants/Phosphorus]] |
This page provides a summary of MPCA-approved mechanisms and values for removal of dissolved phosphorus from stormwater runoff. The discussion includes requirements for receiving the credit from the MPCA.
Two tiers for crediting dissolved phosphorus exist and conditions needed to meet the criteria are described.
An iron-enhanced sand filtration bench in a wet pond is essentially a wet extended detention pond with a permanent pool and a flood pool. The dissolved phosphorus credit for this practice is 40% if the following design features are implemented.
The outlet structure of the pond is designed such that the water in the flood pool during and after a storm event is held above the elevation of the iron-enhanced sand filter bench, thereby allowing water to filter through the bench. The basic design elements of an iron-enhanced sand filter basin include:
Pollutant removal credits may be given to a best management practice based on one or both of the following, at the discretion of the MPCA.
Monitoring protocol for establishing credits must be consistent with the protocol described here, or other MPCA-approved protocol.
For an example of dissolved phosphorus credits given to a best management practice, see here.
This page was last edited on 24 January 2023, at 18:25.