Recent incidents concerning the water quality of the Seine River in Paris have sparked concerns, particularly with the upcoming Olympic events scheduled to take place in the city. These events have brought attention to the issue of pollution during rain events when the sewer system overflows, impacting the water quality athletes will be exposed to. However, this is not an isolated problem confined to Paris alone; all over the world sewage systems face similar challenges with overflow events into nature, during heavy rainfall.
So what's the issue actually ?
The root of the problem lies in the overflow system integrated into urban sewer networks. During heavy rainfall, the capacity of these systems is often exceeded, leading to the discharge of untreated sewage water into natural water bodies. This poses significant environmental and health risks, yet there is often limited awareness of the frequency and severity of these overflow events.
AFP news made a great video, showing how sewer overflows work, and what their impact is on the Seine river in Paris: https://youtu.be/9ognbk4N50Y?si=XcdZG2NM0bQxPnhp
How Paris 'solves' the issue by building an extra bassin
To address this challenge, Paris has implemented a quite basic solution: the construction of a large reservoir (content: 50.000 m3 or about 20 Olympic swimming pools) to temporarily store excess sewage water during rain events. While such measures are commendable, this is not a viable solution for most areas. Not all cities have an Olympic budget available to attack environmental issues.
In order to tackle the issues in a more structure way, it is important to understand where most overflow events happen, and especially to know what the impact of these events on nature is. Real-time monitoring and assessment of water quality during overflow events is key to gathering this information.
Online measurement of overflow events
Sewage water is often measured using samples and lab analysis. This gives a lot of information about the quality of the water, but is time consuming and very costly, making it only suitable for measurements on a few locations. Sampling also needs planning, while overflow events are generally hard to predict.
A better solutions would be a network of online measurements, giving a general indication of the water quality during overflow.
That's why we -at Olpas- have developed a new sensor to tackle this issue head-on. Our Total Suspended Solids (TSS) sensor is specifically designed for sewer systems, offering precise and reliable measurements of water quality during overflow events.
Thanks to our proprietary ultrasonic measurement technology our sensors boast extended maintenance intervals and minimal drift, ensuring accurate data collection even in these challenging conditions; in contrast to traditional optical sensors, which require frequent maintenance and are susceptible to drift,
For more information about our TSS sensor for water monitoring in sewers and overflows, see https://www.olpas.tech/product/water-monitoring-tss-in-sewers-and-overflows
Olpas TSS Sensor measuring during a sewage overflow event
By providing municipalities and environmental agencies with actionable insights into water quality, our technology empowers decision-makers to take proactive measures to mitigate the impact of sewage overflows on natural ecosystems and public health. Furthermore, it enhances our understanding of the dynamics of urban water systems, paving the way for more sustainable and resilient infrastructure solutions.