Waters that are designated as bathing waters must meet certain requirements with regard to their microbiological water quality. These requirements are formulated and laid down in Directive 2006/7/EC of the European Parliament and of the Council of the European Communities (EC Bathing Water Directive of February 15, 2006). In order to implement this directive, the state of Lower Saxony issued the Ordinance on the Quality and Management of Bathing Waters (Bathing Water Ordinance) on April 10, 2008. This defines the binding quality criteria for Lower Saxony's bathing waters. Compliance with the limit values is monitored by regular tests. The data collected is reported to the Federal Ministry for the Environment via the Lower Saxony State Health Office. The data is collected here and submitted to the EU Commission in a comprehensive annual report.

The public health department for the city of Salzgitter and the district of Goslar carries out bathing water sampling every 14 days during the bathing season. Water samples are taken at the respective bathing area for laboratory testing and on-site measurements such as depth of visibility, water temperature and determination of the pH value are carried out. In addition, an inventory is made of the local conditions at the bathing area, e.g. algae bloom, mineral oils, tar residues, coloration, surfactants, phenol odor, transparency, pH value, water temperature, rat infestation. Additional water samples are taken if there are any abnormalities. The samples are then examined microbiologically and, if necessary, chemically in a recognized laboratory.

The test results are sent to the public health department, from where they are immediately published on the Internet.

If the limit values for the parameters Escherichia coli and enterococci are exceeded, follow-up tests are carried out immediately. If the exceedance is confirmed in this follow-up test, a bathing ban must be imposed for the bathing area until further tests prove that the situation has improved.

The most important values in detail

As part of the monitoring process, Lake Salzgitter is also visually inspected for pollution, e.g. tar residues, floating objects (e.g. wood, plastic, bottles, glass, rubber) and other substances.

Escherichia coli "E-Coli" as well as intestinal enterococci are germs of the normal intestinal flora of warm-blooded animals (e.g. humans, waterfowl and grazing livestock). When monitoring bathing waters, they serve as indicators of massive faecal contamination, e.g. from liquid manure, sewage sludge, wastewater discharge or large numbers of waterfowl/km2 . With such a large amount of contamination, dangerous pathogens can also enter the water and represent a source of infection for humans. If no or few such germs are found, you can be fairly certain that there are no other pathogens that cause serious diseases that are excreted from the intestines in the bathing water.

Incidentally, the corresponding "entry" into the lake by bathing people or playing dogs or cats does not pose a health risk.

The new EC Bathing Water Directive 2006/7/EC stipulates that bathing water must be tested for blue-green algae (cyanobacteria) if necessary. In mass occurrences, they can form both allergenic and acutely toxic substances in effective concentrations. Samples are taken as soon as algae growth begins.

Do not feed waterfowl, as this increases the parasite infestation and thus the possibility of bathing dermatitis (cercaria dermatitis)!

Bath dermatitis is caused by cercariae swimming in the water. Cercariae are the larvae of sucking worms that parasitize in the intestines of waterfowl. The eggs enter the water with the birds' excrement. They hatch into ciliated larvae, which seek out an intermediate host, i.e. various freshwater snails.
So: the more food, the more droppings the birds produce.

However, cercariae also mistakenly target humans as a false host. The cercariae penetrate the human skin, where they die and cause skin infections.

Cercaria infestations in Germany are generally harmless to humans, but are unpleasant and annoying due to the skin eczema with severe itching.

Treatment is exclusively symptomatic with antipruritic and anti-inflammatory ointments, creams and lotions.

The occurrence of cercariae is not related to the hygienic water quality as a bathing lake.

The public health department does not carry out tests for cercariae, which are not required by the EU Water Directive. As cercariae diseases are not notifiable, we are generally not aware of any numbers. It is not possible to predict or "measure" an accumulation of cercariae in water bodies. As cercariae cannot be seen with the naked eye due to their small size, an increased occurrence of cercariae is only noticed when there are already cases of bathing dermatitis. During the swarming period of the cercariae, which lasts around a week, areas of the shore rich in plants should be avoided, as this is where the water snails and therefore most of the cercariae are found.

Recommended rules of conduct for bathers cannot completely protect against cercaria infestation, but they can reduce it:

• Avoid spending long periods of time in shallow water (children in particular are at risk)
• Preferably swim in deeper or gently flowing areas
• Change swimsuits after swimming
• Rub the body well with a towel (cercariae dry out quickly)
• As a preventative measure, rub the body with the following products: SPF 15 or SPF 30 sunscreen lotion, which also offers protection against jellyfish