​The French capital Paris is one of the most popular destinations for travellers in Europe. Despite all the beautiful things to discover in this iconic city, hot summer days can get very exhausting. Parisians have experienced a series of extreme temperatures over the past couple of summers, and places to cool down are limited. But the challenge of tackling rising temperatures is not the only thing Paris has in common with other big cities around the world.

​The city has taken a number of measures to provide relief for citizens suffering from the summer heat, such as breaking up sealed concrete surfaces and sacrifice parking spaces to plant trees. Paris has also joined other big cities like Berlin or Rotterdam to make their local rivers swimmable again.

​In a long-term effort, the city´s administration has completed a lot of projects, aiming to improve the water quality in the Seine to such a degree, so that in 2024, the Olympic and Paralympic swimming competitions were taking place in the river.

​One year later, in 2025 three public beaches opened up during July and August, welcoming locals and tourists to take a dip and cool down in the Seine, after public swimming was officially banned in 1923 due to pollution and river traffic hazards.

​Safe, sustainable, and reliable disinfection

​In order to achieve compliance with the bathing water directive, the second biggest wastewater treatment plant in Europe, which is treating an average of 600,000m³ of wastewater per day, was carefully investigating solutions to introduce an additional disinfection stage, before releasing the treated water into the river. After a four year evaluation period, Kemira´s performic acid based solution KemConnect^® DEX was chosen due to its high efficiency, low environmental impact, and superior performance compared to other disinfection methods. Ever since the system is reliably performing to meet regulatory requirements and contribute to enable safe swimming in the Seine.