Performance Monitoring Report - Geneva Bioretention Pilot Project
Reference:
Herrera 2026. Performance Monitoring Report: Geneva Bioretention Pilot Project Whatcom County, Washington. Prepared for Whatcom County, by Herrera Environmental Consultants, Inc., Seattle, Washington.
Herrera supported the County’s design of this regional facility treating 0.81 cfs using Ecology’s High Performance Bioretention Soil Media (HPBSM) with a passive dosing siphon that meters inflow, preventing continuous saturation and optimizing treatment within the media. Monitoring results show strong performance for phosphorus and bacteria reductions, consistently exceeding TAPE benchmarks. These results demonstrate that the County’s investment in regional treatment is advancing Lake Whatcom TMDL compliance.
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Technical Memorandum: 6PPDQ Roadway Runoff Stormwater Composite Sampling Protocol Recommendation
Herrera supported the County’s design of this regional facility treating 0.81 cfs using Ecology’s High Performance Bioretention Soil Media (HPBSM) with a passive dosing siphon that meters inflow, preventing continuous saturation and optimizing treatment within the media. Monitoring results show strong performance for phosphorus and bacteria reductions, consistently exceeding TAPE benchmarks. These results demonstrate that the County’s investment in regional treatment is advancing Lake Whatcom TMDL compliance.
2023-2024 Summary Report - 6PPDQ in Highway Runoff and BMP Effectiveness
Herrera supported the County’s design of this regional facility treating 0.81 cfs using Ecology’s High Performance Bioretention Soil Media (HPBSM) with a passive dosing siphon that meters inflow, preventing continuous saturation and optimizing treatment within the media. Monitoring results show strong performance for phosphorus and bacteria reductions, consistently exceeding TAPE benchmarks. These results demonstrate that the County’s investment in regional treatment is advancing Lake Whatcom TMDL compliance.
Design Guidance for Presettling Upstream of Bioretention Facilities
Herrera supported the County’s design of this regional facility treating 0.81 cfs using Ecology’s High Performance Bioretention Soil Media (HPBSM) with a passive dosing siphon that meters inflow, preventing continuous saturation and optimizing treatment within the media. Monitoring results show strong performance for phosphorus and bacteria reductions, consistently exceeding TAPE benchmarks. These results demonstrate that the County’s investment in regional treatment is advancing Lake Whatcom TMDL compliance.