Effects of excess chloride from salt-chlorine pools in Minnesota’s Nine Mile Creek Watershed

Abstract

While the adverse effects of excess salt (chloride) in the environment are well documented, it is unknown how much salt-chlorine pools may contribute to this issue compared to other causes, such as winter salt use on sidewalks/roads and water softeners. The City of Minnetonka, along with the Minnesota Pollution Control Agency (MPCA) and the Nine Mile Creek Watershed District, proposed that salt-chlorine pools may become more prevalent in Minnesota communities. The city, alongside the MPCA and District, asked our team to research and analyze this unfamiliar issue, as a better understanding could inform policies to help control excess chloride and reduce negative environmental impacts. We started our research with a literature review, then interviewed city employees and pool installers. We collected additional data through an online survey of pool owners and city building permit data. Ultimately, our research found that the contribution of salt-chlorine pools (S-CPs) to excess chloride in the Nine Mile Creek Watershed (NMCW) is negligible. However, if S-CPs continue to rise in popularity, monitoring and possibly regulating the issue in the future may be advisable.