MASON CITY, Iowa – Discolored water in a tributary of Chelsea Creek has been traced to a McDonalds’s distribution center in Mason City.
The Iowa Department of Natural Resources says employees at Martin-Brower said they had hosed a spilled milkshake ingredient into a stormwater drain on Monday morning. The DNR says the pollutant traveled underground through the city’s stormwater system and appeared in the tributary on the southwest side of Mason City.
DNR staff say they took samples at the site, which is a couple of hundred yards long and runs along a popular walking and biking path. Based on field tests, the DNR says it does not think the milkshake ingredient poses any immediate threat to anyone coming in contact with the water.
State officials say Martin-Brower must clean up the affected part of the steam.