In 2012 and 2013 the Federal Environment Agency study took at least two samples of groundwater at 48 measuring stations in four federal states (Länder) and tested them for 23 substances. There were none of these active substances traced at 39 of the measuring stations. However, sulfonamide was traced at seven measuring stations located in Lower Saxony and North Rhine-Westphalia. Whereas the maximum level among the samples of 11 nanograms per litre (ng/l) is very low, this compares to a groundwater limit value for active substances in plant protection agents that is ten times higher, that is 0.1 micrograms/litre, or 100 ng/l. The active substance sulfamethoxazole was traced at only two measuring stations in concentrations of more than 100 ng/l, which is above the limit value for plant protection agents or biocides in groundwater.
UBA's Vice- President Mr. Holzmann said, "We deliberately assumed a worst-case scenario in the study and selected measuring stations at which the likelihood of groundwater contamination with antibiotics was particularly high. It is reassuring that we only rarely made a find and that contamination is by no means widespread. Yet, entry into groundwater is possible and can be significant. This is why we must keep close watch of the situation. One way could be for the joint federal-Länder measuring network to sample and analyse specimens at regular intervals – at least below at-risk soils. The Länder could then take measures as necessary."
The following criteria, on which the UBA study also based its analysis, can serve to assess high risk to groundwater:
- intensive livestock breeding occurs in the region (catchment area of the measuring station) and large amounts of slurry are spread onto fields,
- nitrogen contents in groundwater are high, indicative of industrialised farming and evidence of significant substance discharge into groundwater,
- soils are sandy and permeable, that is, they provide little natural protection to groundwater,
- shallow depth to the groundwater table exists
- groundwater recharge or leaching rate is high.
The main risk for groundwater in Germany is the high rates of soil contamination by nitrate. This is a result of spreading fertiliser with excessive levels of nitrogen onto fields or originates from the slurry from fattening units and the fermentation residues from biogas plants. Whatever is not taken up by plants enters the organic substance of the soil or enters groundwater as nitrate. "About 50 per cent of all the groundwater measuring stations in Germany currently show elevated nitrate concentrations of over 10 milligrams/litre, and 15 per cent of the groundwater does not even comply with the quality standard of 50 milligrams/litre for groundwater. However, drinking water which is extracted from groundwater is uncontaminated nearly everywhere – only 0.08 per cent of drinking water samples tested in Germany showed levels above the limit of 50 milligrams/litre. It can be consumed without reservation“, said UBA’s Vice-President Holzmann. In the meantime, however, water utilities are having to go to considerable lengths to treat water. Some simply dilute excessively polluted groundwater with pure water, while more and more suppliers see the need to technically remove the nitrate from raw water because there is not enough uncontaminated groundwater available everywhere. This is an expensive undertaking and ultimately adds to the consumer’s water bill.
Background:
According to data from the Federal Office of Consumer Protection and Food Safety (BVL), some 1,619 tonnes of antibiotics were used by veterinarians in Germany in 2012, an amount about twice or threefold that of antibiotics use in human medicine (630 tonnes). The organism breaks down only a small amount of the antibiotic active substances, and about 60-80 per cent of the administered amount is excreted unchanged by the animals. It is spread in slurry onto soil and, under a few very unfavourable conditions, can leach into groundwater. Up to now no limit value for such substances has been established in Germany's groundwater legislation or the Drinking Water Ordinance.
The UBA has been responsible since 1998 for the assessment of potential environmental risk in the context of the approval of veterinary drugs. Conditions of approval may be imposed to protect the environment if an assessment indicates environmental risk. Guidelines issued by the European Medicines Agency have stipulated the standards of environmental risk assessment of veterinary drugs since 2005 and for human drugs since 2006. However, veterinary drugs which were “grandfathered”, that is were approved before the guidelines took effect, do not require a retroactive environmental assessment. A large majority of the veterinary drugs in use are grandfathered drugs. The impact on the environment of many of these drugs is largely unknown.
The research project Antibiotics and antiparasitics in groundwater under locations with high animal stock concentration was commissioned by the Federal Environment Agency and funded by the Federal Ministry of Environment (BMUB). The project was managed by the HYDOR Consult GmbH in Berlin and carried out in cooperation with Forschungszentrum Jülich GmbH and the INFU TU Dortmund in 2011-2013. The study report is available for download at „Antibiotika und Antiparasitika im Grundwasser unter Standorten mit hoher Viehbesatzdichte“ or may be borrowed from the Federal Environment Agency library (call number 001897).
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