From composting to a circular economy business: the evolution of RETERRA
“Composting is a form of closed loop recycling that has been going on for centuries. In fact, it is the very first form of closed loop recycling that ever existed,” explained Barbara Junker. Her passion for her job is obvious. With her and others at the helm over the years, RETERRA has succeeded in turning this ancient form of recycling into a highly modern industrial sector. In a world where resource efficiency and sustainability are becoming ever more important, it turns out that one solution can be found, quite literally, on our own doorsteps – in our food and garden waste bins.
Founded back in 1991, RETERRA has transformed itself from a regional composting business into a nationwide biomass management specialist. “We have made big strides, further developing both our products and the technology we use. And we are bigger as well,” commented Junker, summing up.
“New areas of business have also been added to our portfolio, such as recycling sewage sludge, collecting and recycling food waste, and producing woodchips and fuel from old timber.”
Junker’s technical and scientific knowledge very much comes to the fore when she talks about the company’s development. Having studied engineering (she specialised in environmental and hygiene technology), she has a deep understanding of the complex processes used at her company. “When I joined the business, the plants were still using open composting areas. In the 90s, people thought this technology would continue long into the future – everyone was building large plants that were meant to last for decades.” But rapid progress was made in this field. Nowadays, the chain of systems used to process and recycle biomass is much longer and RETERRA operates a network of cutting-edge plants that can do far more than ‘just’ composting.
“Composting is a form of closed loop recycling that has been going on for centuries. In fact, it is the very first form of closed loop recycling that ever existed.”
Barbara Junker, Managing Director of RETERRA Service GmbH
From a waste product to a recyclable material
Just like its parent company REMONDIS, this firm’s philosophy is based on the idea of recovering valuable resources from waste. “Our composting plants are increasingly turning into biomass plants,” Junker explained. “We not only recycle organic and garden waste so the materials can be reused. We are also increasingly making the most of the energy potential of these materials.”
One focus here is on the production of bio-gas. “The biowaste is placed in a digester where we produce biogas that is then transformed into electricity,” she said, explaining the route that the majority of this type of waste takes. The company is planning to invest more in the production of biomethane, which can be fed into the gas network as a substitute for natural gas.
It is obvious just how committed Barbara Junker is to these topics. Her eyes light up when she starts talking about the advantages of compost: “We want to show that compost is an excellent fertiliser that stores both humus and water. This is particularly important – and especially for farmers – as we find ourselves experiencing ever longer periods of drought.” Her enthusiasm is catching and it is clear that she is well aware of how important her work is and the positive impact it has on both the environment and climate.
Challenges & innovations
Her sector faces a whole raft of challenges. One of them, for example, is continuously safeguarding the quality of the processes. “The amended Ordinance on Biowastes [BioAbfV] came into effect in May 2025,” Junker remarked. “This is the first time that binding numbers have been set for the amount of contaminants that may be present in biowaste. This has led to many processes having to be adjusted.”
Working together with her team, therefore, she has been looking at using both innovations and digitisation to achieve this. “We’ve been thinking about how we can use cam-eras and AI-based systems to further improve quality control,” Junker revealed. These can scan and analyse the incoming material to pick up contaminants at an early stage of the process.
A pragmatic person, she is not afraid of taking on technological challenges. She sees this as an opportunity to optimise the processes used by the company. This is also true for a further challenge that primarily affects the management side of the business: more and more local authorities and groups of local authorities are wanting to recycle their biomass.
“We not only recycle organic and garden waste so the materials can be reused. We are also increasingly making the most of the energy potential of these materials.”
Barbara Junker, Managing Director of RETERRA Service GmbH
The European context
Even though RETERRA primarily operates in Germany, the firm is also playing a growing role in other European countries. “We transport products to Belgium and to the Netherlands, too,” Barbara Junker explained. “These cross-border collaborations also underline our importance in the European circular economy and demonstrate how important cooperation is in the EU.”
Based in Erftstadt, Barbara Junker leads a team of around 180 employees at RETERRA Service in the Rhineland alone.
The future of the biomass sector
As far as Barbara Junker is concerned, all of these are tasks, not problems. She is very optimistic about the sector’s future. “Looking ahead, both biogas and biomethane production will play an even more important role,” she predicted. What’s more, she is also a pragmatist when it comes to the two biggest challenges of all: the regulatory framework conditions and ensuring these costly plants remain economically viable over the long term.
“There are signs that there will be more political support for biogas again.” This was not the case for a while. She stressed how important it is to have practicable guidelines in place so that businesses can respond to unforeseen events and developments. “Considering how technology is progressing, having restricted and rigid ‘guard rails’ in place could end up leading everyone in the wrong direction.” New regulations must be open – and remain open – to all things new.
A pioneer through and through
Barbara Junker’s path to becoming managing director of RETERRA is closely interwoven with the development of the company itself. She began her career at the firm in 1995 when she wrote her master’s dissertation and then continued working there following its commissioning of a composting plant in Erftstadt. Starting as a sales rep (the first for the field of waste and the first without a background in agricultural engineering), she gradually worked her way up the career ladder. She was appointed managing director after REMONDIS acquired the business in 2006.
Her university degree in environmental and hygiene technology gave her the foundations needed for her successful career in the environmental sector. Based in Erftstadt, she now leads a team of around 180 employees at RETERRA Service in the Rhineland alone; she also plays a key role in determining the company’s strategy and operational business across the whole of Germany.
There is one thing that is particularly noticeable when talking to Barbara Junker: she has her feet firmly on the ground and is close to her staff – perhaps because, as she described it succinctly, “Titles mean absolutely nothing to me.” She speaks highly of her team and stressed how important it is for them to all work together. “Our employees are our most valuable asset,” she said. “We would not be where we are today without their commitment and expertise.”
Junker’s dedication to sustainability and innovative biomass management solutions are also reflected in the posts she shares on LinkedIn. She has written, for example, about the new beehives at the company in Erftstadt, the new products in her sector and the successful competitions the RETERRA team have taken part in, to name just a few. She also posted greetings from the company at the start of Germany’s ‘fifth season’, the carnival season.
And so, Barbara Junker is full of the joy of life despite having a position of responsibility and a jam-packed diary. She laughed a lot during our meeting and talked enthusiastically about the progress that RETERRA has been making. It is obvious that her work is not just a job to her but a vocation. “I’m so lucky that my work is also a passion of mine,” she said. “Arriving at work every day and knowing that what we do is having a positive impact on the environment is simply a great feeling.”
Her positive attitude can also be seen in the way she talks about industry events and network meetings. “Talking with colleagues from my sector is something that is incredibly valuable,” she explained. “You always learn something new and you make important contacts.” Coming from the Rhineland, she finds small talk just as easy as negotiating and dealing with facts and figures.
About Barbara Junker:
Barbara Junker is not just a successful managing director. She is also a passionate sportswoman and a true child of the Rhineland, a so-called ‘Rheinländerin’. Her love of sport runs through her life like a thread. She played water polo in her youth and then spent 10 years boxing – “not in competitions; just to stay fit”. And she still makes sure that she remains fit today: she takes part in a challenging circuit training programme twice a week at a bootcamp in a park in Cologne. She did spill the beans, though, admitting that she turns into a couch potato on Sundays.
Despite her full diary – her daily commute is over two hours – Junker finds time for her hobbies. She and her husband like going on long bike rides with their electric bikes. And she likes spending time with her friends, at home and on holiday – and, of course, at the Rhineland carnival. This balance between her professional commitment and free time is probably the secret behind her energy, her great drive and her authenticity.
Heading towards the future of the circular economy
Under the management of Barbara Junker and her fellow managing directors, RETERRA has become one of the pioneers of the circular economy. “We’re heading in the right direction,” she said, summing up the situation at the end of our meeting. “But there’s still a great deal to do. The circular economy is not just vital for the environment; it is also a great business opportunity. I am proud that we are spearheading the way here.”
“The circular economy is not just vital for the environment; it is also a great business opportunity. I am proud that we are spearheading the way here.”
Barbara Junker, Managing Director of RETERRA Service GmbH
About the company:
Having enjoyed steady growth over the last 30+ years, RETERRA now has a network of businesses across Germany and is one of the leading companies in the biomass man-agement sector. A specialist in recycling organic raw materials, RETERRA transforms organic waste into high-quality products such as compost, substrate, soil coverings and wood-based fuel. The company serves a wide range of customers – from the food processing industry through to the agricultural sector – and handles around 2.5 million tonnes of organic and residual raw materials every year.
With a workforce of over 500 employees at its various branches in Germany, RETERRA offers an extensive portfolio of products and services that covers all stages of the supply chain – from collection and recycling through to production. By focusing on sustainability and recycling, RETERRA plays a valuable role in protecting the environment and preserving natural resources. The company is a fully owned subsidiary of the REMONDIS Group.
Image credits: © REMONDIS
