Garden residues to compost: Interview with K-Nord GmbH from Ganderkesee, Germany
Within the greenGain project, interviews with both local and European players along the value chains are conducted to learn more about the daily business and framework conditions of biomass from landscape conservation and maintenance work. The interviews address on the one hand the treatment of the biomass along the utilization chain and additionally also the legal aspects of its use. The local business know-how is an important contribution to listening to European experts and researchers.Zooming at the local level to find out how are the green residues treated in our own “backyard” led us to contact the company [k]nord Umweltdienstleistungen from Ganderkesee in Germany. The managing director Andreas Lange and the technical manager Andreas Melle introduced us their company and its business model.
Ganderkesee is a municipality in Lower Saxony with about 30 000 inhabitants. The company [k]nord is an environmental service provider and their activity comprises also compost production from organic and industrial waste in Ganderkesee. Further products are the construction and erection of green acoustic protection walls. The company has a long tradition in the region with more than 20 years of experience in waste management. Also the recycling yard and the hazardous waste collection point of Oldenburg County are located on the site of the composting plant. Household materials suitable for recycling can be delivered to this site. Paper, cardboard, glass, scrap metal, electric waste, corks and recycling bags of the Dual System Germany can be delivered free of charge.
Could you describe what types of organic waste and biomass do you process and where does it originate?
We take up residual garden material from local citizens, commercial garden keepers and public landscape management operations. Moreover we process industrial organic wastes like beverages or food whose expiration date has passed. The grass and pruning residues are processed for compost and the industrial organic waste is used as a substrate for the biogas plant.
How does the processing of the garden waste look like? Are there some specifics for this type of biomass?
We take up the garden waste from citizens and the commercial garden keepers for a gate fee. Therefore the biomass is first weighted and then shredded, mixed and composted in piles. The compost is regularly mixed and is ready after about three months. Then it is sieved and either sold as loose goods or packed into bags. The residual fraction from sieving is transported to a cooperation biomass heating plant for combustion.
The composition of the biomass and its quality varies widely. There are of course fluctuations in the moisture content and the composition of the material over the year. The personal at the gate inspects the quality of the biomass we uptake on content of litter or the like. But generally, the biomass from private garden is of a good quality and can be easily treated. By the uptake of the biomass from roadside maintenance we control the contamination by small particles and litter, which depends on the collection technology. There are annually 8 000 to 10 000 tons delivered and the supply radius is about 10 to 15 km.
What determines the price of the gate fee for the garden residues? How is the economic balance of the compost production?
The gate fee is the result of careful economic calculations of our incomes and expenses. The gate fee is the main income of the composting plant, as the compost selling price on the market is very low. The main cost component are the personnel cost for providing comfortable service for the costumers and high compost quality.
For example: local citizens pay for the garden residues a volume price which increases from 3 € for 200 litre up to 24 € for 2 m3. The gate fee has not been changed for almost nine years. Interestingly, even though the price slightly increased recently, the amounts of biomass collected did not decrease. Thanks to our recently extended opening hours the amounts even rose. This supports our notion, that the attitude of the citizens is decisive and the price plays rather a secondary role. The citizens who leave their waste on forest or road verges would probably still do it even if the prices would be lower.
Where does the compost go and what is your experience with the compost market?
We have long term experience with the compost market as we produce it since 1993. The biggest portion of the compost is sold to industrial companies who produce flower soil. In the future, the share of the compost in flower soil is expected to increase from 5 % up to 30 % while replacing peat, whose production in Lower Saxony will decrease due to a new legislation. Therefore the demand for compost in this sector is expected to increase. The potential of compost as fertilizer in agriculture is low, because of the high animal density specific for our region connected with oversupply of fertiliser.
From the start we had a certification for the compost to ensure the quality standards. We learned to optimize the products according to our costumers’ needs – for example the experience showed, that the local gardeners prefer smaller bags which they can easily manage rather than large bags, which we produced before. The local private costumers create about 5 % of our compost consumers.
Besides the certification, what is important for gaining the costumers trust and reliability?
It is crucial to ensure stable quality not only of the product but also of our service. We recently extended the opening hours, because it is decisive factor for the costumers. They appreciate if they can deliver their garden waste also in the evening after work. When the gates are closed too early, some people simply leave their waste in front of the gates anyway. The overall convenience of the delivery at the yard is also an important factor. This all means also higher personal efforts and therefore costs, which is something what we can ensure, but what would be impossible for smaller facilities. The same applies to the compost certification, because among others it requires exact documentation of the biomass origin and amounts.
Moreover, when you buy compost which was made from regional biomass and you use it in your garden, you somehow close the cycle. The gardeners contribute to the local circulation of nutrients and make the whole idea of recycling come truth. We cannot be a concurrence for big chain stores, but this experience is something what the costumer can appreciate.
The good reputation among the local citizens is for sure very valuable for the business, since spreading good word is the best advertisement. Did you face any problems in this regard during your long time activity?
Until 2011 we also composted municipal organic waste. The composting of this waste is difficult as it is often very wet and compacted. Occasionally an extensive smell occurred. We had to face the public disapproval and complaints. Important part of solving the problem was improving the treatment of the wastes but also good communication. We organized a site visit for the local people and explained the problem. The connection between us and the community remained and two contact persons were installed. For example once we had to open the facility because of some maintenance work which we knew could cause smell in the neighbourhood. We communicated it in advance to the contact persons and the inhabitants were informed. Subsequently, no complaints were received.
How do you see the future development possibilities?
We are open to new projects and new technologies and we have the possibility to extend our areal. We investigate also new technologies like hydrothermal carbonization for providing additional products and services. But the technology is not mature yet. Potential can be seen in big amounts of seasonal leaf-fall. Currently we process the leaf-fall for compost, but as its biodegradation is rather difficult, it requires relatively high amounts of time and space. I believe that the whole composting sector would appreciate if some cost-effective alternative would emerge.
Our business is strongly determined by current legal regulations, which have direct effect on us, therefore it is also important to follow the current trends in this area in order to estimate further development.
Author: Jana Žůrková