Water use, discharge and effects on biotopes (EN8–9, 21, 25)
Vattenfall has performed a thorough analysis to assess the largest streams and impacts from the use of water in the Group. This analysis has resulted in the reporting of a total of ten water parameters, covering both water withdrawal and water discharge.
Water withdrawal 2008
Water discharge 2008
Use of water for cooling
The cooling process at nuclear power plants and combustion power plants requires water, and cooling water is taken from rivers, lakes and the sea.
The largest amount of cooling water is used in Vattenfall’s nuclear power plants in Sweden and Germany, and most of the water is taken from the sea. The temperature increase from discharges of cooling water is monitored and kept within specific limits for each respective plant. In terms of the plant’s environmental performance, the benefits of efficient cooling radically exceeds the small temperature increase that is the effect of discharging cooling water into a large water body.
Power plants with inland locations, using cooling towers, use significantly less water. For example, Vattenfall’s lignite power plants use state-of-the-art industrial cooling systems, with cooling towers and closed cooling cycles, demonstrating water consumption generally less than 2 m3/MWh.
Use of water in lignite mining
The water sources most significantly affected by withdrawal of water are around Vattenfall’s lignite mines in Germany: Jänschwalde, Cottbus–Nord, Welzow–Süd, Nochten and Reichwalde (no mining is currently being conducted at Reichwalde).
In 2008, approximately 411 million m3 of groundwater was removed to make fuel extraction possible. The removed groundwater is cleaned and thereafter used to cover the freshwater requirements of the nearby lignite-fired power plants, thereby sparing other water sources. Vattenfall’s need for freshwater is well below the amount of removed groundwater, and the treated excess groundwater is made available to nearby municipalities and industries. Even though Vattenfall and the surrounding municipalities and industries make use of the water, most of the cleaned groundwater is returned to rivers and lakes.
“Eco-water inlets” are used to support protected rivers and watercourses around the mines from running dry as a result of lowered groundwater levels during mining. About a fourth of the extracted mine water is used for this purpose.
To further limit the impact of lowering the groundwater when draining the mines, “sealing wall” technology has been developed by Vattenfall. Inflows from watercourses, valley plains or wetlands are sealed off by underground sealing walls on the periphery of the open-cast mine, when this is required depending on the geological and hydrological conditions. To date, Vattenfall has built sealing walls 7 km and 9 km in length along the Jänschwalde and Cottbus–Nord open-cast mines, respectively. In 2009, construction of a further sealing wall will be started at the Reichwalde open-cast mine, and in 2010 a sealing wall will be dug at the Welzow–Süd open-cast mine.
Hydro power
Vattenfall owns and operates hydro power plants in Germany, Sweden and Finland. In Germany, pumped storage power plants are used to store energy from other energy sources. River regulation and reservoirs for hydro power and pumped storage power have an impact on the natural water flow of rivers as well as on the surrounding landscape. For each hydro power plant, permits regulate how flows are allowed to fluctuate. In some cases, it is ecologically motivated to determine a so-called instream flow, or minimum flow, to ensure a continuous water perimeter. This means that the flow is never allowed to fall below a set minimum level. It can be adjusted over time so that it reflects the variations of the natural flow, but at a lower water level. A combination of instream flow, weirs and other physical adjustments can be very efficient at enhancing the conditions for aquatic organisms. The area of suitable fish habitat increases and the flow acquires a more diverse pattern, which benefits most aquatic life but also riverbank vegetation. Re-creating spawning areas is another way of promoting fish populations. These measures have been performed in some of the rivers where Vattenfall operates hydro power plants.
Hydro power plants have a significant impact on biodiversity in rivers and streams, especially fish spawning grounds and the ability of fish to reach them. For this purpose, fish ladders for salmon and trout have been constructed on some of the regulated rivers where spawning areas exist upstream of the power stations. Every year, Vattenfall Nordic plants more than 1.3 million fish in rivers and streams.
A number of initiatives and investments are taken to improve the efficiency and environmental standard of Vattenfall’s hydro power (for additional information, see www.vattenfall.se):
- Mobile environmental ambulances – an emergency response system for oil leaks in both flowing and still waters – have been developed by Vattenfall in Sweden together with Skellefteå Kraft and Statkraft. Three such ambulances are stationed along the Skellefte River and are equipped with absorption material, pumps, petrol-fuelled generators, inflatable dingies, outboard motors, etc.
- Expenditures on dam safety and improvement programmes amount to more than SEK 1 billion during the period up until 2013. Planned activities include modernisation and improvements of construction as well as installation of monitoring equipment.
- A research programme aimed at proposing socially and economically viable measures for improving environmental conditions for hydro power is currently being conducted by Vattenfall in co-operation with Swedish government agencies for energy, fishing and environmental protection and Elforsk, the Swedish electrical utilities’ R&D company.
- A new and improved fish passage is being built at Stornorrfors, and will be ready in summer 2009. The new ladder will improve both upstream and downstream migration of fish past the power plant. A large development project is currently studying the possibilities to further improve the conditions for fish populations as well as for recreational fishing in the area.
- At the Nordic hydro power plants, several projects are aiming to reduce the amounts of oil used to reduce the risk of oil leaks. When upgrading plants, one standard measure involves replacing oil-lubricated bearings with water-lubricated bearings. A pilot project in Älvkarleby in 2008–2009 will be testing the use of water and glycol in the hydraulic systems of dam hatches.
Biodiversity values of water bodies
Due to the diverse nature of Vattenfall’s operations and large number of sites, information on protected status and biodiversity values of water bodies is handled locally as it is most efficient. Information is therefore not gathered at the Group level.
Examples of activities to protect and support biodiversity have been provided in the sections “Use of water in lignite mining” and “Hydro power” above. A further example can be seen on the Vistula River in Warsaw, where Vattenfall operates CHP plants and discharges heated water into the river. This is a so-called Natura 2000 area, where Vattenfall is supporting a Life+ project initiated by the local government to protect biodiversity along the Vistula River.
