"Phosphorus Removal Filter Performance in an Urban Watershed," Andy McCabe, PhD. Environmental Engineer, Barr Engineering, Minneapolis, Minnesota.

Lake Cornelia is a shallow urban lake (average depth of 3-4 feet) at Rosland Park in Edina, Minnesota. Lake Cornelia has a large urban watershed (975 acres) with highly impervious commercial areas. Average total phosphorus concentrations in Lake Cornelia typically exceed the Minnesota state standard of 60 micrograms per liter (µg/L). This has led to significant algal blooms (including cyanobacteria) and poor water clarity.

In collaboration with the City of Edina, the Nine Mile Creek Watershed District constructed a unique surface water filtration system at Rosland Park to address external phosphorus loading to Lake Cornelia. The filtration feature consists of a series of constructed concrete basins with an anthracite pre-filter for particulate removal and parallel up-flow reactive media filters for dissolved phosphorus removal. The filter is positioned in a park between a large upstream stormwater pond and Lake Cornelia. Water discharged from the pond is actively pumped to the filtration system for treatment. The advantage of this filter over a conventional passive iron-enhanced sand filter is that it can treat substantially more water while maintaining a relatively small footprint to preserve the park's green space. Construction of the filtration feature was completed in July 2022, and performance monitoring began in August 2022. 

This talk will cover the design of the filtration system, performance monitoring data through the 2024 monitoring season, operation and maintenance activities, and cost considerations.

The MWRD hosts a seminar series at the Stickney Water Reclamation Plant that is open to the public. These seminars are eligible for Professional Development Credits/CEUs.

In person: Stickney Water Reclamation Plant, Lue-Hing R&D Complex, 6001 West Pershing Rd., Cicero, IL. Reservations are required at least 24 hours in advance by emailing Dr. Heng Zhang at zhangH@mwrd.org or call 708-588-4264 or 708-588-4059.

Virtual: Visit Seminars on July 25 for the seminar link. 

The seminar is eligible for Professional Development Credits/CEUs.