I haven't managed to get a copy of the approach plates for the island. However, I am still skeptical that anybody would put their gear down until they are over the water on Final. Certainly, even the opponents of the airport, Community Air, show the approach over the water on their website. Someone can correct me if I am wrong but I believe Porter only uses runway 08/26 which would put their approach almost exclusively over the water making it highly unlikely that they would be dropping ice from a wheel well over the Annex.
And that's taking into account the plausibility of that level of ice accumulation which if it were to occur on a regular basis would have likely resulted in a smoking hole in the ground by Porter somewhere in Southern Ontario. It would certainly be criminally negligent if the airline were conducting operations that pushed the weather envelope to that extent regularly, such that ice was impacting your property on a monthly or weekly basis.