Facts & Figures

 ClientPrzedsiebiorstwo Gospodarki Komunalnej i Mieszkaniowej
 LocationRyki, Poland
 Operation Start2015
 Project TypeGreenfield
 Process ConfigurationPre-treatment + Nereda + Effluent pond
 Nereda Design Capacity:
  • Dry Weather Flow6 MLD
  • Peak Flow465 m3/h
  • PE41,000 PE (PE = 60 gBOD/d)
 In the Media:waterworld.com

About the Ryki, Poland Nereda WWTP

Ryki WWTP is located in the Polish city of Ryki, in the eastern Polish province of Lublin.

The challenge

In addition to the usual considerations – such as increasing capacity due to population growth and new regulatory requirements – the WWTP in Ryki needed to be able to deal with very low process temperatures of 7 to 8 °C during the winter months. The plant also combined the treatment of different incoming sewages, such as domestic, septic tanks and industrial, and was required to handle extended industrial peak load periods.

Nereda WWTP Ryki, Poland

Image: Overview of the Ryki WWTP

The Solution

In 2012 DHV Hydroprojekt, a Polish division of Royal HaskoningDHV group, won the contract for the complete design of the new Ryki WWTP for Przedsiebiorstwo Gospodarki Komunalnej i Mieszkaniowej (PGKiM). The use of Nereda technology was the first time it had been implemented in Poland. Key to Nereda being selected was that it fulfilled certain important criteria, including low capital expenditure and low total operating costs. It also needed to be able to operate successfully in a variety of different temperature conditions. Skanska was the main contractor, with DVH Hydroprojekt as subcontractor responsible for the Nereda components, including design, supply and start-up of the installation. The Ryki Nereda plant is designed to treat 5,300 m³/day in dry weather, with peak flow of 430 m³/hour, serving a 43,000-population equivalent. The start-up of the plant was initiated in February 2015 and over a two-month period the treatment capacity was increased until the new installation was able to treat the total incoming sewage and the old reactors were decommissioned.

The Outcome

The works has successfully dealt with considerably lower wastewater temperatures than initially planned. The anticipated minimum design temperature was 12 °C. The biological process in the Nereda reactors was initiated in almost freezing conditions (approximately 4°C) and only three months later, at the end of April, the design temperature was achieved. The highest process temperature of 23°C was reached in summer 2015. Since then a strong negative trend has emerged and less than 8°C in the reactors was measured during most of January 2016.

The local benefits of the project

Nereda logo small Extremes of temperature conditions
Nereda logo small Low noise and odour
Nereda logo small Low capital expenditure
Nereda logo small Reduced operating costs
Nereda logo small  Superb performance in challenging location