Background
Ekeby is a small town located in Skåne, east of Helsingborg. Like many other catchments, the area has issues with extraneous water in their sewage system, which has resulted in frequent water level rises, both at their pumping station and wells. These backflows have been causing frequently floodings of cellars and in some cases also overflows to receiving waters. NSVA (Nordvästra Skånes Vattten och Avlopp) wanted an effective and economic method to trace the large amounts of extraneous water while also getting an indication of whether it was caused by inflow from drain misconnections or infiltrations. NSVA had previously tried to locate the extraneous water themselves with traditional flow measurements. However, it was not a scalable method due to high costs. NSVA chose Dryp’s wireless solution which is a price-effective tool that can track extraneous water in an automated way, even over long distances.
Ekeby
Located in the northern part of Skåne under the supervision of NSVA
3369
Inhabitants
100%
Of their sewerage system is separate sewerage.
60 km
Pipeline
Solution
Dryp’s wireless water level sensors make it possible to base the hydraulic analysis on real-time data from selected points in the water infrastructure.
An important part of the analysis is based on precise rain data, which typically show big local differences in the amount of rainfall.
The water level data is being converted to flow- and pump-activity, which is combined with tracking of precipitation and tracking of soil moisture.
Dryp installed 28 sensors to get a granular overview of the water levels. Furthermore, these sensors have access to NSVA’s X-band radar. This X-band radar has been connected with the rain gauges from Dryp, which has made it possible to get high-quality rainfall data.
The data will be collected over a period of one year to include seasonal variation. The final result of the project is therefore expected to be ready by the end of 2024.
The data
The project has been running for 5 months and there has already been collected useful data during various rainfall events. It is important to be able to distinguish between short and intense rainfall events and longer periods with a lot of small rainfall events. Throughout the past 5 months we have had both fall and winter, which has allowed us to see how the sewage stystem responds to both heavy and coupled rainfall events.
Knowledge we have obtained:
Value
The collected real-time data will allow NSVA to quickly narrow down problem areas over time and exclude areas that do not contribute to the overall amount of extraneous water, including water at the pumping stations. This will be of great value to NSVA, as it enables them to focus on the most crucial areas, thus extending the lifespan of the remaining pipeline network in Ekeby. In general, real-time data provides the opportunity to invest resources more efficiently.
Niklas Person, NSVA
What’s next?
The next step is to further collect key data, so that the areas can be compared with each other. Subsequently, we have the opportunity to narrowing down the areas further in order to quantify the contribution of extraneous water through conversion to flows, and by analyzing the development of the pattern of the water level over time.
This is done to assess whether or not specific distances are primarily affected by drain misconnections or infiltration.
This means that we split a big unmanageable task into smaller pieces, to prioritize the tasks in the right order.
When the project area has been narrowed down to the critical catchment areas, it allows us to monitor the water level further upstream in the sewage system to track down the source of the extraneous water in more detail.
In this process, it is crucial to know whether the extraneous water is caused by inflow from drain misconnections or infiltration. When the source has been found, the analysis can show an estimate of the location of misconnections or infiltration issues.