Wasenplatz

A Wasenplatz (from Wasen : moist lawn) is a place for the disposal of animal carcasses when the proper removal of animal bodies is overwhelmed.

Animal carcasses or parts of them that are not recycled are disposed of in animal carcass disposal facilities . In the event of a disaster, such as an animal disease outbreak , rendering plants can be overloaded. In such cases, it is necessary to bury the animal carcasses to prevent disease. For this purpose wasen places, which are kept by the responsible authorities. Wasenplatz are thus the modern successors of the earlier Schindäcker (also Schindanger ) near the village , on which knackers worked.

In order to find a professionally suitable Wasenplatz, it is advantageous to use white surface mapping today .

The State Office for the Environment, Nature Conservation and Geology Mecklenburg-Western Pomerania (LUNG MV) made the following recommendations in 2004 for the selection of suitable white areas and for operation. Adhering to the recommendations is intended to ensure that the harmful effects of a Wasenplatz are minimized, especially on the soil and groundwater.

Location selection criteria (white areas)

ground

Well-ventilated, rolling soil substrate
Ideal case: according to DIN 4022 fS - mS
tolerable: fS - gS, u, (h); tone-free in terms of DIN 4022

This promotes the desired decomposition. In the case of cohesive soils and the resulting waterlogging, the supply of oxygen is severely hindered and rot or wax formation occurs on the surface of the carcass, which prevents the organic matter from breaking down. This means that the dumped carcasses would be broken down over a much longer period of time. Coarse-grained substrates are to be rejected because their pores are too large as a substrate, through which gaseous decomposition products can escape and processes of mummification can be achieved. The locations can e.g. B. be tested according to MMK or GK25.

Groundwater level

Ideal case: more than 5 m below ground level
tolerable: the bottom of the pit is at least 1 m away from the highest expected groundwater level or 2.50 m from the currently proven groundwater level.

Locations with low groundwater levels but well-ventilated rolling soil can be adapted in individual cases by raising the terrain.

Distance to receiving waters

Since the organic material is mineralized during decomposition, there are high releases of nitrogen and phosphate-containing decomposition products, which are shifted with the seepage water and affect the groundwater and receiving waters .

Distance to the next body of water downstream :> 300 m
Minimum distance from drainage areas : 150 m
Distance to the next water extraction point in the downstream:> 500 m.

Since the use of Wasen places at least temporarily leads to harmful soil changes and influences the groundwater , any influence on the environment must be ruled out from the outset. Depending on the degree of protection of the aquifer used, it is therefore not permissible to create a water area between 500 and 2000 m in the inflow area of water intake points.

Protection zones

Prohibition in drinking water protection zones I, II, IIIa, in medicinal spring protection zones , in priority areas and precautionary rooms that serve to secure drinking water ,
in floodplains ,
Nature reserves as well as in
Core areas of biosphere reserves .

In order to protect the groundwater, it is not permitted to create water places in the areas. In the other protection zones, the main use is nature conservation, which would be negatively influenced by Wasenplatz.

Operation and monitoring

Before starting and operating the Wasenplatz, the following examinations should be carried out to monitor the environmental impact and operating instructions should be followed:

Groundwater monitoring

With a low to very low degree of protection of the uppermost aquifer, extraction points for chemical and possibly bacteriological monitoring of the groundwater over ten years after storage are required in the downstream of the Wasenplatz. The number and location of the measuring points must be determined on a case-by-case basis on the basis of a geological-hydrogeological site identification. For Wasen places with a total occupancy of more than 250 GVE , an outflow monitoring is necessary in any case. Zero sampling and analysis must be carried out before the burial begins. Monitoring must take place twice a year (spring and autumn) in the first five years after storage, and then once a year.

Analytics soil

Approx. Three ram core soundings (RKS) up to a depth of 5 m and their layer mapping are to be planned for each location . Soil samples related to the horizon are to be analyzed. Experience has shown that around five samples can be expected per RKS. The following analysis is recommended in order to evaluate the requirements mentioned under 1.1:

current pH value of the soil (with deionized water),
Grain analysis (dry sieving or sludge analysis according to KÖHN) with indication of the Kf value (e.g. according to BEYER),
Storage density (includes water content and residue on ignition ), substance and pore volume according to DIN 19683,
CaCO ₃ content according to SCHEIBLER.

The eluate analysis can be dispensed with.

The parameters listed here represent the basic analysis necessary for the suitability test of a site for the burial of cadavers. It must be carried out before the expulsion and is part of the documentation that the Wasenplatz fulfills the necessary principles of burial.

The pH value and the CaCO ₃ content also serve as a basis for decision-making for the required addition of lime when the site is used later.

The soil samples are to be kept. To do this, approx. 500 g per sample must be returned dry. An analysis in the sense of securing evidence of a protection objective (e.g. endangerment of groundwater) has not been carried out. As with large landfills, this can only be achieved by analyzing the water in question (generally groundwater, possibly receiving waters).

Analysis of water

Cadaver landfills certainly influence the uncovered and sometimes also near-surface groundwater at least temporarily. Therefore, if the groundwater is to be assessed as a subject to be protected or if the essential points mentioned under 1.1 are not met, the groundwater in the downstream area of the Wasenplatz must be analyzed in accordance with the hydrogeological conditions.

Important parameter groups as indicators for the influence of the water are:

a) Field measurements: pH value, conductivity , oxygen content, redox potential

b) Nutrients: ammonium content , nitrite content , nitrate , phosphate content

c) Organic exposure indicators : KMnO4 index, DOC

The parameter groups a) - c) are to be seen as the basic program. Further parameters such as trace metals (As, Cd, Cr, Cu, Pb, Ni, Zn) and hygienic-bacteriological parameters (e.g. Escherichia coli, coliforms ) should also be analyzed if there is a specific suspicion.

cover

Minimum coverage 1.5 m of rolling material

This protects the environment from harmful gaseous breakdown products and can lead to re-use through reforestation. The covering must be done with rolling material in order to promote oxidative degradation. The access of wild animals is largely excluded.

feed

Concentration of the carcasses to be stored

Max. Loading height 1 m
Max. Tilting width 3 m
Max. Length of the installation area: unlimited

Several defined installation areas can be parallel to each other. A minimum distance of 1 m between the areas must be observed.

After installation, the high concentration of organic matter in the pits will first cause putrefaction, as not enough oxygen can diffuse out of the pores . This creates a reducing microenvironment that is more stable the more thick the organic substance is as a layer. Only after some time (probably after several years) does a gradual change in the environment to the desired decomposition processes take place , which gradually mineralize the carcasses . In order to achieve the desired decomposition as quickly and completely as possible, the carcass layer must not become too thick. The undisturbed areas of at least 1 m between adjacent trenches support the diffusion of oxygen also over the sides and the floor area.

In order to absorb the liquid substrates during the rotting period, it is advisable to place an approx. 30 cm thick organic layer in the base area. Fine wood chips or sawdust should preferably be used for this . Due to its pH value, which can be between 3 and 7, peat can have an unfavorable effect on decomposition or the displacement of pollutants. Before using it as a sole material, the pH value of the peat should therefore be examined; sour peat must not be used.

The application of lime stabilizes the pH value in an alkaline environment and thus prevents the discharge of heavy metals when acids are formed during decomposition ( immobilization of pollutants), so lime should be incorporated. Since the upper floor areas are usually naturally decalcified, this should be seen as a preventive measure in order to stabilize the environment. The preferred locations in sandy areas of ground and terminal moraines also usually contain little carbonate. The use of germicidal quicklime should be determined by the responsible veterinary authorities if the carcasses are carriers of the disease . If a burial becomes necessary due to a technical catastrophe (e.g. major fire), it should not be done because quicklime hinders the decomposition .