There was oil traffic from Cork, Creedon mentioned it in his CBSC trilogy. It was brought to Albert qy by truck from the nearby esso depot and loaded in the yard, i'm pretty sure it was to do with the oil traffic to the Magnesite works in Ballincourty. As far as i remember it went via the city railway till it was transferred to another Cork depot (water street).
Seen as your layout is West Waterford based a lot of fertiliser traffic from Albatross New Ross to Cork & fertiliser from Net at Marino point could also be justified, the last traffic on the Cork city railway was from Albatross New Ross. Jbh posted up pics of both types of fertiliser wagons in Cork kent yard a while back. Suppose it would also be possible for earlier types of ammonia traffic to go via Waterford even though in reality it was the mid/late 1970's when it started.