BVT-Merkblatt zu Abwasser- und Abgasbehandlung

Annexes
signed by the aforementioned environmental expert; this certificate is kept available for the perusal
of the supervisory official; a copy of the certificate will be forwarded by the operator to
the Environmental Licence Department.
§ 2. All containers must be provided with a permanent leak detection system. This obligation
does not apply for containers of reinforced thermoset synthetics or stainless steel located outside
a water abstraction area or a protected zone, and of which the individual water content capacity
amounts to less than 5000 l, or less than 10000 l if these containers are for the storage of
P3 and/or P4 products.
The leak detection system must detect a leak inside an interstitial space formed either by an
additional, solid or flexible impervious inside or outside casing, or by an impervious coat on the
walls and the bottom of the excavation, and must meet the corresponding provisions of appendix
5.17.3.
§ 3. For the installation of a metal container with an individual water content capacity from
5000 l, or for the storage of P3 and/or P4 products from 10000 l and the associated ducts:
1. in a water abstraction area or a protected zone type I or II, or
2. in an area surrounding electrical conductors where major stray currents can be present, the
corrosiveness of the soil and of the filling-in soil must be specified and categorised by an environmental
expert accredited in the discipline soil corrosion according to the method mentioned
in appendix 5.17.5.
Here the corrosiveness of the soil at the deepest point in the place where the metal container is
to be installed, or the filling-in soil is to be categorised as ‘barely corrosive’, ‘moderately corrosive’,
‘corrosive’ or ‘highly corrosive’.
The determining of the corrosiveness may not take place under extreme circumstances of
drought or frost.
The provisions of this paragraph may be departed from if the corrosiveness of the soil and filling-in
soil has already been determined during the last five years or when without a prior soil
corrosiveness investigation cathodic protection is applied. The application of this cathodic protection
must take place under the supervision of an environmental expert accredited in the discipline
soil corrosion.
§ 4. Cathodic protection:
1. if the result of the inspection mentioned in § 3 is ‘corrosive’ or ‘highly corrosive’, cathodic
protection must be applied
2. if the result of the examination mentioned in § 3 is ‘moderately corrosive’, it may initially be
decided to not install cathodic protection. In this case, corrosion monitoring on the basis of
permanent or periodic potential measurements must be provided for; with a potential measurement
more positive than -500 mV compared to a Cu/CuSO4 reference electrode, indicating
possible corrosion or stray currents, cathodic protection must be applied
3. if the result of the inspection specified in § 3 is ‘barely corrosive’ and the container is adequately
cladded, cathodic protection is not required.
The cathodic protection must bring the whole surface of the container, including the metal
ducts (if this proves necessary), to a potential of -850 mV or a greater negative value measured
with respect to a Cu/CuSO4 reference electrode. In anaerobic soils his potential must amount to
at least -950 mV.
§ 5. The containers must be covered by a layer of earth, sand or another adapted inert material
at least 50 cm thick.
Measures must be taken to prevent the passage of vehicles or the storage of goods above the
containers, unless these are protected by a non-flammable and sufficiently resistant floor.
384 Waste Water and Waste Gas Treatment