On the November 2nd, 2013 our director Ms. Komali Yenneti, along with representatives from Federal Ministry of Education & Research (BMBF), Germany, had a fantasitc opportunity to visit one of the best practices of waste management sites in the world. Here in this blog, she shares her experience of visiting Georgswerder Energy Hill, in Hamburg, Germany, which was formerly a dump yard. Read about the best practice in our directors words.
The layers of Georgswerder landfill
Meadows, clay extraction, rubble pile, household reguse landfill, toxic waste basin, bulky waste, covering layers, vegetation cover, and renewable energy sources: the layers of the hill tell its story.
First rubble, then household and bulky waste were stored here on the Elbe island of Wilhelmsburg between 1948 and 1979, all generated post-world war. In addition around 200,000 tonnes of hazardous waste despoited here in basins for liquids and barrel storage facilities between 1967 and 1974. Several basins and a barrel storage facility are located at a depth of about 15 metres east. Some of this hazardous waste contained the extremely toxic “Seveso dioxin”. As dioxin detected in the leachate in 1983 at the foot of the waste mound, it became clear that the landfill was no longer safe and needed to be cleaned up.
As no mdels or reference existed, the question that arose was How can amount of waste be secured in the long term? In 1984/85, experts in the Hamburg authorities developed a remediation concept which combined securing and decontamination, working closely with residents in Georgswerder. At first, the landfill was covered. An enormous 2 to 3 metre cover system resembling a giant umbrella prevents rain waster penetrating the landfill body and flushing out leachate containing hazardous substance. The core elements of the multi-layerd cover system is a geomembrane of plastic with a thicknes of 1.5 to 2 mm. Simultaneously, gases and liquid which emerge from the hill are intercepted and cleaned to prevent environment pollution.
However, the danger lurked in leachate,as rain had penetrated the site and accumulated over the years to a depth of several metres mobilising the hazardous dioxin,toxic substances and oil out of the hill at the foot of the landfill. This was stopped by the landfill cover system which prevented all the posed dangers. Apart from preventing the leachate, groundwate below the landfill is collected with the aid of pumps and cleaned to prevent toxic substances spreading further. About 450 operating, measuring and monitoring devices including gas probes, leachate and groundwater measuring points, hydrants, and many more were found on the landfill, distributed across the site. Grasses, shrubs and valuable biotopes developed on the varied vegetation which encompasses endangered plant. bird and animal species represent the outer visible parts of the cover system.
Three turned into one
The best part that comes here is the use of alternative renewable energy forms on this site.
The first one is the intelligent use of the methane gas generated from landfill was to be used an energy source. Since, 1986 about 39 gas probes extract the gas and direct to a compressor station from where it is conveyed to the Aurubis copper smelting point. In the plant it is iincinerated during copper ore treatment and exploited for energy.
As the landfill rises over 40 metres above the landscape of the Elbe Islands, the idea for the exploitation of wind power was initially emerged in 1992. This led to the first installation of wind turbine in 1992, followed by three smaller turbines until 2004. These three smaller turbines was later replaced by ‘Hamburg Energie’, a lrge turbine which supplies three times the energy of smaller ones. It achieves a nominal capacity of 3.4 MW and supplies around 2,660 households with renewable energy.
This was followed by installation of solar photovoltaic (PV) on the southern slope of the hill. This solar PV plant is the largest freestanding PV plant in Hamburg! Following completion of the second building phase in 2011, over 4,000 PV modules with an overall area of 8,000 square metres which supply energy to over 200 households were erected.
From 1948 on, the site was a landfill and not freely accessible to the p ublic. Now the ‘Georgswerde landfill hill’ is once again accessible to the public, and again a part of Hamburg city. A 900 metre circular train with approximately 250 tonnes of steel and 800 LED lights provides a horizontal path to traverse through the hill. This path is the symbol of the Georgswerder Energy Hill and Hamburg’s ‘Renewable Wilheimsburg’ climate protection concept. It is enticing to see how an unaccessible dumpyard turned into a living location in a living urban district. The award that this project received such as ICONIC Award of the German Design Council in the category Architecture Special (winner) for the horizon footpath, attests its innovation.
Source: Data, information and statistics from IBA_Hamburg
Image courtesy: IBA Hamburg