m |
|||
Line 7: | Line 7: | ||
==TP and TSS credits== | ==TP and TSS credits== | ||
When conditions described in this section are met, applicable Up-Flo Filter w/Filter Ribbons systems are approved for the following removals for total suspended solids (TSS) and total phosphorus (TP). | When conditions described in this section are met, applicable Up-Flo Filter w/Filter Ribbons systems are approved for the following removals for total suspended solids (TSS) and total phosphorus (TP). | ||
− | *TSS: | + | *TSS: 80 percent removal |
*TP: Tier 1 | *TP: Tier 1 | ||
**Credit: 50 percent removal | **Credit: 50 percent removal | ||
Line 13: | Line 13: | ||
***Inspect manufactured treatment device a minimum of twice during year 1. Conduct inspections following manufacturer’s instructions/recommendations and any additional instructions [https://stormwater.pca.state.mn.us/index.php?title=Hydro_International_Up-Flo_Filter_w/Filter_Ribbons#Use_conditions listed in this section]. Use maintenance indicators provided by manufacturers to determine if maintenance is needed. Maintenance procedures should follow manufacturer’s guidelines. After year 1, follow manufacturers inspection, operation, and maintenance schedule and procedures unless otherwise required or unless year 1 inspections indicate a need for increased inspection and/or operation and maintenance. | ***Inspect manufactured treatment device a minimum of twice during year 1. Conduct inspections following manufacturer’s instructions/recommendations and any additional instructions [https://stormwater.pca.state.mn.us/index.php?title=Hydro_International_Up-Flo_Filter_w/Filter_Ribbons#Use_conditions listed in this section]. Use maintenance indicators provided by manufacturers to determine if maintenance is needed. Maintenance procedures should follow manufacturer’s guidelines. After year 1, follow manufacturers inspection, operation, and maintenance schedule and procedures unless otherwise required or unless year 1 inspections indicate a need for increased inspection and/or operation and maintenance. | ||
***Comply with [https://stormwater.pca.state.mn.us/index.php?title=Hydro_International_Up-Flo_Filter_w/Filter_Ribbons#Configurations appropriate configurations] and [https://stormwater.pca.state.mn.us/index.php?title=Hydro_International_Up-Flo_Filter_w/Filter_Ribbons#Use_conditions Use conditions] | ***Comply with [https://stormwater.pca.state.mn.us/index.php?title=Hydro_International_Up-Flo_Filter_w/Filter_Ribbons#Configurations appropriate configurations] and [https://stormwater.pca.state.mn.us/index.php?title=Hydro_International_Up-Flo_Filter_w/Filter_Ribbons#Use_conditions Use conditions] | ||
− | *TP: Tier 2 | + | *TP: Tier 2 - no Tier 2 credit at this time |
− | |||
− | |||
− | |||
− | |||
− | |||
*TP: Tier 3 - no Tier 3 credit at this time | *TP: Tier 3 - no Tier 3 credit at this time | ||
Up-Flo Filter w/Filter Ribbons is an engineered bioretention system designed to filter pollutants from stormwater runoff. It is classified as a manufactured treatment device (mtd).
This page provides information on pollutant removal credits for Up-Flo Filter w/Filter Ribbons, links to supporting information, and links to information on system design, inspection, operation, and maintenance.
When conditions described in this section are met, applicable Up-Flo Filter w/Filter Ribbons systems are approved for the following removals for total suspended solids (TSS) and total phosphorus (TP).
For more information on credits, see TP and TSS credits and guidance for manufactured treatment devices (mtds)
Applicable configurations (systems) include
To receive the full credit, Up-Flo Filter w/Filter Ribbons systems must comply with the following conditions.
Hydro International, Inc. Up-Flo® Filter Using Filter Ribbons]. Note that some information in this report is specific to Washington State and not applicable to Minnesota.
Credits apply only to the water being treated by a device. The applicable treatment volume must be determined using one of the methods described here.
The Tier 1 credit equals the TAPE-approved credits. Tier 2 and Tier 3 credits were determined by analyzing water quality data collected at Bellingham, Washington. The site consisted of residential land use with 0.4 acres of impervious draining to the device. The device was 4 ft by 6.5 ft, with a filter media depth of 1.8 feet and a ponding depth of 0.75 feet.
MPCA compiled data from Appendix K of the report TECHNICAL EVALUATION REPORT - FILTERRA SYSTEM PHOSPHORUS TREATMENT AND SUPPLEMENTAL BASIC TREATMENT PERFORMANCE MONITORING. Below are summary statistics for the device.
TAPE means and medians represent values meeting TAPE criteria for TP (inflow concentrations of 0.1 to 0.5 mg/L) and TSS (inflow concentrations greater than 20 mg/L). Of the 22 samples, TAPE medians and means represent 10 samples for TP and 18 samples for TSS.
The 95% boot strap LCL is 52% for all data and 69% for TAPE analyzed data. TAPE did not use data when TP inflow concentrations were < 0.1 mg/L. Of 22 samples collected, 12 had TP concentrations < 0.1 mg/L. TP removal decreases as the inflow concentration decreases below 0.1. However, if we consider only TP values > 0.05 mg/L, the LCL is 58.9 percent. TP concentrations of 0.05 mg/L or less are uncommon in Minnesota. Consequently, the recommended Tier 2 value is 59%. The median removal for all data was 67% and for TAPE-analyzed data was 78.5%. We therefore recommend a Tier 3 value of 60%, which meets a commonly employed regulatory threshold.
Phosphorus removal, as a percent of influent TP, decreased as influent TP concentration decreased below 0.1 mg/L and as the ratio of dissolved P:TP increased. For a discussion of effects of these factors on crediting, link here.
To link to the Excel spreadsheet containing water monitoring data click here
Meet the conditions specified for the appropriate TP and/or TSS credit.
Meet the following conditions, unless conditions for the appropriate TP and/or TSS credit are more stringent.