GA#441 Convention on Freshwater Shortages states:
6. Prohibits member nations or any businesses contained wherein from disposing hazardous waste into oceanic bodies, international waters, and the public drinking supply
The proposal in question states:
Prohibits the intentional disposal of hazardous waste, materials containing hazardous waste, or materials known to break down into hazardous waste, by governments or corporations, into oceans or water bodies that feed into oceans
The two clauses overlap in large part, constituting duplication. While there is some difference, such as that the proposal only prohibits intentional disposal while GA#441 prohibits all disposal, or that the proposal includes "materials containing hazardous waste" and "materials known to break down into hazardous waste" in addition to simply hazardous waste, it can still be seen the two clauses do duplicate. Although the proposal in question includes a definition for "hazardous waste" in its previous clauses while GA#441 does not, it would not be reasonable to interpret that the same phrase in GA#441 would cover entirely different things to the definition in the proposal in question.
As a further note, the following clause in the proposal in question
Provides an exception to waste disposed of in an effort to mitigate an acute unforeseen situation involving the potential for the immediate loss of life, massive property damage, or national security threat
would constitute Contradiction to GA#441, as GA#441 does not make provisions for any exceptions.