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Home My WebLink About02a. ADS Ecostream GULD Passing August 2024 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), METALS & PHOSPHORUS TREATMENT For Advanced Drainage Systems, Inc. EcoStream™ Biofiltration System Ecology’s Decision Based on Advanced Drainage Systems, Inc. (ADS) application submissions for the EcoStream™ Biofiltration System (EcoStream), Ecology hereby issues the following use level designation: 1) General Use Level Designation (GULD) for Basic, Metals, and Phosphorus Treatment: • Sized at a hydraulic loading rate of no more than 3.125 gallons per minute (gpm) per square foot (sq ft) of media surface area. • Constructed with a minimum media thickness of 5-inches of Growth Media and 15-inches of Biofiltration Media. 2) Ecology approves the EcoStream at the hydraulic loading rate listed above, to achieve the maximum water quality design flow rate. The water quality design flow rates are calculated using the following procedures: • Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute off-line flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology- approved continuous runoff model and as described in section III-2.6 of the 2024 Stormwater Management Manual for Western Washington (SWMMWW). • Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute off-line flow rate as calculated using one of the three methods described in Chapter 6.5.1 of the 2024 Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual. • Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 3) This General Use Level Designation has no expiration date, but Ecology may revoke or amend the designation, and is subject to the conditions specified below. Ecology’s Conditions of Use EcoStream systems shall comply with these conditions: 1. Applicants shall design, assemble, install, operate, and maintain the EcoStream installations in accordance with ADS’s applicable manuals and documents and the Ecology Decision. 2. EcoStream Growth Media and Biofiltration Media shall conform to the specifications submitted to, and approved by, Ecology. 3. Applicants shall determine the minimum size filter surface-area for use in Washington by using the design water quality flow rate (as determined in Ecology Decision, Item 2, above) and the Hydraulic Loading Rate (as identified in Ecology Decision, Item 1, above). Calculate the required area by dividing the water quality design flow (cu-ft/sec) by the Hydraulic Loading Rate (converted to ft/sec/sq ft) to obtain the required surface area (sq ft) of the EcoStream unit. 4. ADS tested the EcoStream without plants. The GULD applies to the EcoStream whether plants are included in the final product or not. 5. Maintenance: The required inspection/maintenance interval for stormwater treatment devices is often dependent on the efficiency of the device and the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a “one size fits all” maintenance cycle for a particular model/size of manufactured treatment device. • ADS designs EcoStream systems for a target maintenance interval of 6 months in the Pacific Northwest. Typical maintenance includes raking, weeding, and general planting replacement as needed; removal of trash and debris from the inlet and top of the media bed; and removal and replacement of the Growth Media, inspection of the Biofiltration Media, and replacement of the top two 2-inches of Biofiltration Media. • An EcoStream tested at Lake Union Ship Canal Test Facility in Seattle, WA was on average able to treat 1.7 percent of a water year before needing maintenance. Monitoring personnel observed similar maintenance issues with other systems evaluated at the Test Facility. The runoff from the Test Facility may not be indicative of maintenance requirements for all sites. • Owners/operators must inspect the EcoStream systems for a minimum of twelve months from the start of post-construction operation to determine site-specific inspection/maintenance schedules and requirements. Owners/operators must conduct inspections monthly during the wet season, and every other month during the dry season (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to the SWMMEW, the wet season in eastern Washington is October 1 to June 30). After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections. • Conduct inspections by qualified personnel following manufacturer’s guidelines. 6. Install the EcoStream in such a manner that flows exceeding the maximum operating rate are conveyed around the Growth Media and Biofiltration Media and will not resuspend captured sediment. 7. Discharges from the EcoStream shall not cause or contribute to water quality standards violations in receiving waters. Applicant: Advanced Drainage Systems, Inc. Applicant’s Address: 4640 Trueman Blvd Hilliard, OH 43026 Application Documents: Technical Evaluation Report EcoStream™ Biofiltration System Performance Verification Project, Advanced Drainage Systems, Inc. July 2024 Quality Assurance Project Plan EcoStream™ Biofiltration System Performance Verification Project, Advanced Drainage Systems, Inc. September 2023 Treatment Performance Report EcoStream™ Biofiltration System, Advanced Drainage Systems, Inc. January 2023 Applicant’s Use Level Request: General Use Level Designation as a Basic, Metals, and Phosphorus Treatment device in accordance with Ecology’s Stormwater Management Manuals. Applicant’s Performance Claims: Based on field and laboratory testing, at a hydraulic loading rate of 3.125 gpm/sq ft, the EcoStream is able to meet TAPE performance goals for TSS, metals, and phosphorus. Ecology’s Recommendations: Ecology finds that ADS has shown Ecology, through laboratory and field testing, that the EcoStream is capable of attaining Basic, Metals, and Phosphorus treatment goals. Findings of Fact: Field Testing Herrera Environmental Consultants, Inc. conducted monitoring of the EcoStream at the Lake Union Ship Canal Test Facility in Seattle, Washington between September 2023 and February 2024. Herrera collected flow-weighted composite samples during 16 separate storm events. The system was sized at a hydraulic loading rate of 3.125 gpm/sq ft. • The average D50 of the influent PSD was 65 microns. • Influent TSS concentrations met the TAPE range for 16 of the storm events. For these events influent concentrations ranged from 28 mg/L to 341 mg/L with a mean concentration of 82 mg/L. All but three influent samples were below 100 mg/L so the results were assessed against the 20 mg/L effluent performance goal. The bootstrap estimate of the upper 95 percent confidence limit (UCL95) of the mean TSS effluent concentration was 15 mg/L. The single influent concentration greater than 200 mg/L (the upper end of the TAPE influent concentration range) was capped at 200 mg/L before performing the bootstrap analysis. • Dissolved copper influent concentrations from 16 storm events met the TAPE range and sample requirements. For these events influent concentrations ranged from 6.47 µg/L to 19.2 µg/L with a mean concentration of 10.8 µg/L. The bootstrap estimate of the lowe r 95 percent confident limit (LCL95) of the mean dissolved copper reduction was 35 percent. • Dissolved zinc influent concentrations from 16 storm events met the TAPE range and sample requirements. For these events influent concentrations ranged from 24.5 µg/L to 49.8 µg/L with a mean concentration of 32.7 µg/L. The bootstrap LCL95 of the mean dissolved zinc reduction was 61.1 percent. • Total phosphorus influent concentrations from 16 storm events met the TAPE range and sample requirements. For these events influent concentrations ranged from 0.11 mg/L to 0.64 mg/L with a mean concentration of 0.25 mg/L. The bootstrap LCL95 of the mean total phosphorus reduction was 62.8 percent. The single influent concentration greater than 0.5 mg/L (the upper end of the TAPE influent range) was capped at 0.5 mg/L before performing the bootstrap analysis. • The system needed to be maintained 4 times during the monitoring period: after 1.5 percent of a water year, 1.3 percent of a water year, 2.4 percent of a water year, and 1.2 percent of a water year. On average the system could treat 1.7 percent of a water year before needing to be maintained. Monitoring personnel observed similar maintenance requirements with other systems evaluated at the Test Facility. The runoff from the Test Facility may not be indicative of maintenance requirements for all sites. Laboratory Testing ADS conducted laboratory testing on an EcoStream System at the ADS Water Quality Laboratory in Mount Airy, Maryland. The testing was done following the New Jersey Department of Environmental Protection Laboratory Protocol to Assess Total Suspended Solids Removal by a Filtration Manufactured Treatment Device. • The testing evaluated the TSS removal capability of a 4’ x 4’ commercial sized EcoStream system with an effective filtration treatment area of 16 sq. ft. The unit was tested at a hydraulic loading rate of 4.125 gpm/sf, resulting in a 66 gpm design flow rate. • The test sediment used was a custom blend of commercially available silica sands and had an average d50 of 68 µm. • ADS evaluated TSS removal efficiency over 25 events. The influent concentration ranged from 192.5 mg/L to 211 mg/L with a mean concentration of 201.5 mg/L and a mean removal efficiency of 86 percent. • ADS estimated sediment mass loading over 26 events. Overall, a total of 315 lbs of sediment was loaded into the EcoStream and total mass captured was 270.8 lbs. Other EcoStream matters Ecology recommends that ADS address: Conduct hydraulic testing to additional information about the maintenance longevity and requirements. Complete testing by July 31, 2027. Technology Description: Download at https://www.adspipe.com/ Contact Information: Applicant: Joseph Chylik Advanced Drainage Systems, Inc. 4640 Trueman Blvd Hilliard, OH 43026 (866) 405-9295 joseph.chylik@adspipe.com Applicant website: http://www.adspipe.com/ Ecology web link: https://ecology.wa.gov/Regulations-Permits/Guidance-technical- assistance/Stormwater-permittee-guidance-resources/Emerging-stormwater-treatment- technologies Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 870-0983 douglas.howie@ecy.wa.gov Revision History Date Revision March 2023 PULD granted for Basic Treatment June 2023 Revised ADS Contact Information August 2024 GULD granted for Basic, Metals, and Phosphorus Treatment