To control the impact of its activities on the local environment, CERN carefully monitors the relevant parameters, which include everything from air and water quality to soil or agricultural products. This monitoring is administered by the Environmental Management System (EMS), developed and implemented with the basic aim to continuously improve CERN’s environmental performance. EMS enables CERN to carry out and document its activities, conforming to environmental safety practices that are recognised worldwide.
CERN produces atmospheric emissions from the ventilation of accelerator installations and heating and cooling equipment. CERN minimises these using filters and has built monitoring stations in the surrounding area to measure the resulting air quality. Rivers receiving CERN water are regularly checked for water quality.
Noise barriers are erected around civil-engineering worksites and CERN facilities of concern to minimize noise and levels are monitored continuously.
CERN employs specialised companies to collect and transport special industrial and radioactive waste and follows Host States regulations in this matter. CERN is continuously improving the sorting and recycling of it conventional waste and strives to produce less on site.
To study the composition of matter, CERN uses particle collisions that generate radiation. The levels of radiation emitted to the environment by the facilities at CERN are very low. Even when the next big accelerator, the LHC, is operating they will be less than a few percent of the natural radiation level. The major part of radioactive material at CERN is not contaminating. All radioactive material is handled following the regulations in force, in particular the very small amount of other radioactive material used temporarily in some experiments. CERN adheres to the internationally accepted radioprotection system in which the optimization of facilities and practices that aims at dose minimization is a natural obligation. With this system, the real radiological impact remains well below regulatory limits.
To reduce the visual impact of new buildings on the landscape, plans are discussed with local authorities and CERN makes sure that additions to the existing landscape do not alter its overall appearance. Landscaping projects are adapted to each site with trees, bushes and grassy areas planted to ensure that the areas around the buildings remain indigenous to the area and natural.
CERN consumes the greatest amount of electricity when its most powerul accelerator, the LHC, is running. This amounts to 120 MW for the LHC (out of 230 MW for all CERN) which corresponds more or less to the power consumption for households in the Canton (State) of Geneva. Assuming an average of 270 working days for the accelerator, the estimated yearly energy consumption of the LHC in 2009 is just over 800 000 MWh. This includes the site base-load and the experiments.
A large fraction of the LHC electrical consumption is to keep the superconducting magnet system at their operating temperatures (-271.4°C or -268.7°C depending on the magnets). Thanks to the superconducting technology employed for its magnets, the nominal consumption of the LHC is not much higher than that of the Super Proton Synchrotron (SPS), even though the LHC is much larger and higher in energy.
The magnets are cooled using liquid helium. The exact amount of helium lost during operation of the LHC is not yet known. The actual value will depend on many factors, such as how often there are power cuts and other problems. What is well known is how much will be needed to cool down the LHC and fill it for first operation. This amount is around 120 tonnes.