Drainage of the S86 route at the Agata junction,
Katowice,
Poland

The underground PEHD SN8 DN2500 retention tank with a length of 80 meters and a capacity of over 392 m³, together with a new pumping station, is one of the key elements of the drainage system for the "Agata Junction." This is due to the high frequency of stormwater inflow in the area of the road crossing located in a depression beneath the overpass. Once the new drainage system is operational, stormwater — rather than accumulating on the road, forming puddles, and causing traffic paralysis — will flow directly into the tank, which will be emptied continuously.
The drainage system has been designed so that the pumping mechanism ensures a consistent water flow at an optimal rate, preventing excessive inflow into the receiver. From the retention tank, stormwater will be directed to the pumping station tanks and subsequently discharged on two sides into existing DN1000 and DN1200 collectors.
The tank’s construction, installation method, and the course of the installation were dictated by its planned location between the roadway on one side and a slope on the other as well as the high groundwater level. A more than 90-meter trench was excavated using a sheet pile wall technique and secured with temporary steel struts placed between the sheeting walls. To enable the tank’s installation, the subcontractor, Hamer Polska, left two 9-meter “pockets” between the struts. Through these pockets, prefabricated components of the tank, specially prepared at the Uponor factory in Kleszczów, were lowered into the trench and moved into their final positions. The tank components were then extrusion welded by Uponor’s service team.
Despite challenging soil and water conditions and the necessity of performing work adjacent to an active roadway, the installation was completed without disruptions.
 

The characteristics of PEHD technology and the production methods of PEHD Uponor pipelines and retention tanks make them exceptionally suitable for infrastructure applications, including water supply and sewage systems. PE products are flexible, durable, and resistant to corrosion, chemicals, and abrasion. The use of extrusion welding for assembly ensures 100% system tightness and the transfer of all axial forces.
As a result, Uponor Infra retention tanks are exceptionally durable and long-lasting, with functionality estimated at over 100 years. They can be installed practicall anywhere, such as alongside or beneath transportation routes, as well as in areas of mining damage.
An additional advantage of this solution is the material homogeneity (pipe/tank and joints), as well as the durability of connections under varying soil pH conditions and the stored medium. Increasingly, customers also appreciate the fact that pipelines and tanks made of polyethylene have a lower environmental footprint throughout the life cycle compared to similar products made of traditional materials like steel or concrete.