From the web for Information about Other DIY Medias:
Oyster Treatment Box Photo
Oyster Shells:
Oyster shells have been found to provide successful stormwater treatment in smaller scale applications, like treating runoff from parking lots or roofs (see Port of Seattle link).
Oyster Shell Catch Basin Retrofit, Mercer Island
Using oyster shells to clean up stormwater: a new pilot study
King County is partnering with the City of Mercer Island, with funding from the Stormwater Action Monitoring (SAM) program, to determine the effectiveness of treating stormwater with oyster shells from 2019-2020.
Study update
King County researchers collected samples during four storms in 2019 to test if stormwater in Mercer Island Town Center was cleaner after passing through oyster shells. Unfortunately, the results showed that the oyster shells were not reducing suspended solids and heavy metals in the stormwater and the study was halted in March 2020.
Oyster shells have been found to provide successful stormwater treatment in smaller scale applications, like treating runoff from parking lots or roofs (see Port of Seattle link ). The stormwater system at the Mercer Island Town Center is much larger. It’s likely that in this setting the ratio of oyster shells to stormwater was too small or the oyster shells were in contact with the stormwater for too short a time to provide sufficient treatment. The results suggest that this type of oyster shell treatment is not likely to be successful in larger stormwater systems like the Town Center area. For more information, please see the study report (coming soon!).
