What capacity should the sump tray have? Unfortunately, the answer to this question is “it depends”. The legal status in Poland regarding the safe storage of hazardous substances is still ambiguous in this respect. In the following article I will explain where this ambiguity comes from and what determines the capacity of the bathtub.
First, we need to define what will be stored in the berm:
List of differences resulting from the substance stored in a specific berm:
| The type of substance | Leading legal basis | The required capacity of the berm or drip tray |
|---|---|---|
| Liquid waste combustible |
Regulation of the Minister of the Interior and Administration of February 19, 2020 (…) | 25% of the total volume of liquid combustible waste stored.
110% of the capacity of the single largest package, unit container or portable tank – whichever is greater. Specific technical guidelines regarding the dimensions and construction of the sump. |
| Toxic and corrosive substances (UDT supervision) | Regulation of the Minister of Economy of April 16, 2002 (…) | Minimum 100% of the capacity of one tank: The leakage protection device should have a capacity not less than the capacity of the tank it protects.
75% of the capacity of two tanks, but not less than the capacity of a larger tank. 50% of the capacity of three or more tanks, but not less than the capacity of the largest tank. |
| Other hazardous substances | Labor Code
Regulations of the Minister of Labor and Social / Social Policy The internal security rules of the Company |
The employer is obliged to protect the health and life of employees by ensuring safe and hygienic working conditions with the appropriate use of the achievements of science and technology.
Good practice: not less than 25% of the total volume of substances stored in it or 110% of the capacity of the single largest container |
source: own study
In the case of storing liquid flammable waste as well as poisonous and corrosive substances in tanks under the supervision of the Office of Technical Inspection, the requirements for the capacity of the sumps are clearly specified. The remainder, possibly the largest group of employers, must rely on general regulations and “industry rules” when using advisory bodies – occupational health and safety workers or experts.
My many years of discussions with experts in the field of security design in enterprises indicate that the following principle can be adopted as good practice in general:
The net capacity of the sump tray container should be not less than 25% of the total volume of the substances stored in it or 110% of the capacity of the single largest package, unit container or portable tank – whichever is greater.
However, it should be remembered that ultimately it is the Employer who defines safety and determines whether the indicated capacity of the sump may be greater due to e.g. the frequency of verification of the condition of the containers, experience with failure rate and the number of packaging damage events, increased degree of chemical risk or environmental impact. An example is the refining industry, where the minimum sump capacity is often 150% of the volume of the stored containers.
The most important principle of selecting a sump is to increase the level of safety for employees and reduce the risk of threats resulting from unsealing of containers. Guided by this principle, let us choose solutions that will provide us with all this with their quality and functionality.
