The Duluth City Council met on Tuesday, May 27, 2025, at 6:00 PM in the Council Chamber. The meeting opened with a Committee of the Whole presentation on chloride reduction in city streams, followed by the regular council meeting. The council approved a large consent agenda, heard public comments on library funding, a rent repair ordinance, and other issues, and gave first readings to several ordinances. The meeting adjourned at 6:37 PM.
We will begin with our committee of the whole in one minute. We will begin our committee of the whole, the state of chloride in Duluth. And can we have our presenters come up to the lectern, please? Hi everyone. Right. Hi everyone. Sorry about that. Um, so like I said, uh, I'm a Minnesota Green Corps member. Uh, so my role at the city is uh researching and writing a chloride reduction plan to help outline some strategies the city can use to apply less road salt and um therefore reduce chloride pollution in the impaired streams. Uh, been taking some water samples in the impaired streams and doing some outreach and education events as well. So a quick recap. Um chloride uh road salt, you know, it works by dissolving in water, lowering the um freezing point of water, and um uh it stops working a bit uh after uh the pavement temperature hits 15 degrees Fahrenheit. Um when it melts um when it melts uh snow and ice um or if it gets hit by rain, it washes off as storm water and goes to the streams, causes pollution. Uh what's in those streams, it uh causes problems for fish and aquatic insects and uh vegetation in those streams. And another side of another effect of it is um damage to infrastructure and vehicles and uh uh vegetation. You know, we've all seen plenty of plenty of rusty vehicles and bridges and um damaged uh grass medians, that kind of thing. Uh it's also a permanent pollutant uh because of just how it works chemically. It uh there's no real way to remove it from water. So once it's in the water, it's there pretty much forever effectively. Uh and then chloride uh or excuse me, surface waters are considered impaired for for chloride at uh 230 milligrams per liter. Um if they test that that level uh twice in a three-year period, or if they test um once uh at 860 milligrams per liter in that three-year period. Uh and that's definition from uh the US EPA and was adopted by the MPCA as well. Uh the city uses about 13 and a half thousand tons of salt um per year. That's uh average from uh 2009 to 2022. So it's a pretty good picture of what's uh the average salt use is in the city. Next slide. Um the impaired waters in the city, so there are five impaired trout streams in the city. Uh so it's uh Tisher Creek, Miller Creek, Chester Creek, Keene, and Kingsbury. I know that map shows a few others. That's just uh those are impaired for other things, but that's just the map I was able to uh find from MPCA. So uh TMDLs, so a TMDL, that's the total maximum daily load. So that's the total amount of a given pollutant in uh this case chloride that can be uh that can enter into a surface water body. In this case are impaired trout streams, and uh remain below that 230 milligram per liter uh level. Uh so in the TMDL development for the city of Duluth, which is currently ongoing, uh it's been found that 93% of the chloride roughly in that's causing the uh impairments in the trout streams uh is due to road salt. You know, there's a few other sources, um water softening, fertilizers, and uh uh dust suppressants for gravel roads, but none of those are significant sources. You know, we don't have water soft that much water softening or fertilizer use and any of that kind of stuff. Um of that 93%, most of it is due to municipal street operations. You know, there's there's all of course there's also private contractors in the city and you know, people just putting salt on their sidewalks and uh driveways, that kind of thing. But most of it is due to municipal operations. Uh MPCA expects to complete this TMDL process by next spring. Uh it's gonna come with some new uh new requirements uh in the MS4 city's MS4 permit. Uh so it's gonna be a waste load allocation, so it's gonna be the total amount of salt that the city is allowed to put down in the given impaired watersheds uh in a given year. So it might be say a thousand tons allowed in the Tissure Creek watershed per year, and the city's gonna have to work out how they are going to uh conform to those regulations. Next slide, please. Uh some results. So I mentioned I did uh a bit of chloride uh monitoring, some sample collection throughout the season. Uh these are some of the results we've gotten. You can see all um four out of five of the uh impaired streams uh all tested well above um that 230 um milligrams per liter, and um uh all four out of five were all above that 860 figure um as well. Uh with the exception of uh Kingsbury Creek, which I believe is uh uh kind of uh proves the rule because I didn't get to uh Keene and Kingsburg as frequently as some of the others. So if I had to guess, it probably at least tested probably at least above that 230 milligram per liter level on probably one or two occasions.