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Advanced Drainage Systems, BaySaver Technologies BaySaver BayFilter with Enhanced Media Cartridge (EMC) 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 BaySaver BayFilter with Enhanced Media Cartridge, links to supporting information, and links to information on system design, inspection, operation, and maintenance.
TP and TSS credits
When conditions described in this section are met, applicable BaySaver BayFilter with Enhanced Media Cartridge systems are approved for the following removals for total suspended solids (TSS) and total phosphorus (TP).
- TSS: 85 percent removal
- TP: Tier 1
- Credit: 50 percent removal
- Conditions for receiving credit
- Inspect manufactured treatment device a minimum of twice during year 1. Conduct inspections following manufacturer’s instructions/recommendations and any additional instructions [ 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 appropriate configurations and Use conditions from TAPE.
- Comply with [ appropriate configurations] and [ Use conditions]
- TP: Tier 2
- Credit: 59 percent removal
- Conditions for receiving credit
- Must meet Tier 1 conditions.
- DP should be 25 percent or less of TP. For a discussion of conditions where DP is likely to exceed 25 of TP, link here. TP removal should be adjusted when DP fractions exceed 25%, as described at the link provided above.
- Inspect manufactured treatment device monthly during the frost free season for the first year of operation after construction. Conduct inspections following manufacturer’s instructions/recommendations. Use maintenance indicators provided by manufacturers to determine if maintenance is needed. Maintenance procedures should follow manufacturer’s guidelines. Determine future inspection and maintenance schedules from findings during the first year of operation.
- TP: Tier 3 - no Tier 3 credit at this time
For more information on credits, see TP and TSS credits and guidance for manufactured treatment devices (mtds)
Configurations
For a discussion of StormFilter configurations, [ link here].
Use conditions
To receive the full credit, BaySaver BayFilter systems must comply with the following conditions.
- Design, assemble, install, operate, and maintain BaySaver BayFilter systems in accordance with applicable [ manuals].
- The maximum flow rates through the devices are specified below.
- Systems are designed to treat a specified water quality volume or annual average runoff volume. The annual average runoff treated can be determined using methods that are specified here.
- Each site plan must undergo review before approval of the unit for site installation.
- StormFilter media shall conform to the specifications described in [ Specifications] and shall be sourced from with no substitutions.
- Follow maintenance procedures given in the most recent version of the [ Operation and Maintenance Manual].
- Install the BaySaver BayFilter in such a manner that flows exceeding the maximum BaySaver BayFilter operating rate are conveyed around the BaySaver BayFilter media and will not resuspend captured sediment.
- Discharges from the BaySaver BayFilter units shall not cause or contribute to water quality standards violations in receiving waters.
- When applicable, adhere to use conditions provided in Washington State Department of Ecology's report (Ecology's Conditions of Use) [ GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS) AND PHOSPHORUS TREATMENT For ]. Note that some information in this report is specific to Washington State and not applicable to Minnesota.
Data analysis
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 credit was determined by analyzing water quality data collected
MPCA compiled data from General Use Level Designation Technical Evaluation Report. Below are summary statistics for the device.
- Median TP inflow - mg/L
- Median TP removal (all data with concentrations > 0.05 mg/L) - %
- 95% lower confidence limit TP removal (all data with concentrations > 0.05 mg/L) - %
- Median TP removal (data meeting TAPE criteria) - %
- 95% lower confidence limit TP removal (data meeting TAPE criteria) - %
- Median TSS removal (all data) - %
- 95% lower confidence limit TSS removal (all data) - %
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 16 samples for TP and 17 samples for TSS.
Inspection, operation, and maintenance
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.
- 2 maintenance visits required annually if annual precipitation exceeds 30 inches; one visit annually if annual precipitation is less than 30 inches
- Spring visit to remove salts and sands and fall visit for sediment and leaves
- Maintenance includes removing trash, degraded mulch, and accumulated debris from the filter surface and replacing the mulch layer
Links