To limit the probability that dispenser sumps will not meet proper standards, which could lead to such devices not performing in the way intended, which could lead to the spread of flammable liquids and combustible liquids from the dispensing unit due to internal leakage, which could lead to contamination of the soil, which could lead to contamination of the water table, which could lead to the accidental ignition of liquid or vapour from a nearby ignition source, which could lead to harm to persons.