The owner has a duty to moderate the behaviour of any visitor or tenant on their property.
The way this works is that you have to identify a breach of the by-laws and the EC has to issue a Notice To Comply (which would say that they have breached by-law xx by making too much noise and disturbing other residents who have a right to the peaceful enjoyment of their lot).
You then write to the landlord and say that since this tenant has breached the by-laws, that means they are also in breach of their lease and the landlord not only has the right to evict them but has a legal duty to either do so or compel them to behave.
This puts the onus firmly back on to the landlord.
Another avenue you could explore might be a noise abatement order. Have a look at this fact sheet which has links to a lot of useful information.
Good luck