Waste discharge

Even in the 70's we were very diligent about pumping bilges overboard, can't remember if we had OWS installed in mid-70's, but anytime the engineers pumped the bilges we posted a lookout on the bridge wing watching for oil. However, we were not that diligent with sewage and solid garbage.

Still recall doing rounds in port and observing ever increasing piles of garbage by the shell doors. Once 12 miles offshore, we made the call from the Bridge, the shell doors were opened and garbage discharged. Even between St Thomas VI & San Juan, we would go directly 12 miles off-shore, then head West the short distance to San Juan.

Even as recently as 2012, in Canadian waters, we were permitted to pump raw sewage overboard, provided we were moving. No minimum distance off-shore was required. We had the latest technology treatment plant, but it never worked from day 1. As Cheng pointed out they require a constant load, but on a 2 hr ferry, the system takes a hit when they board and again when they disembark. Therefore, many days we pumped raw sewage overboard, waiting until 1 mile off-shore and stopping 1 mile before reaching US waters. At 20 kts, this only provided 9 or 10 mins, so I believe the engineers pumped at max capacity.

Post 2012, Canadian Regs no longer permit pumping raw sewage, so the local vessels use holding tanks and pump ashore for treatment. All solid garbage and food waste is landed ashore for recycling or to the tip. Even water draining from the car deck scuppers goes through an OWS before going overboard.

Another interesting challenge in our refit facility on the Fraser River. To drain a potable (drinking) water tank containing city tap water, we could not pump this overboard. Any contents had to be pumped ashore into a tanker truck for disposal. Chlorinated tap water cannot be discharged overboard in the river.

Even in the 70's we were very diligent about pumping bilges overboard, can't remember if we had OWS installed in mid-70's, but anytime the engineers pumped the bilges we posted a lookout on the bridge wing watching for oil. However, we were not that diligent with sewage and solid garbage.

 

Still recall doing rounds in port and observing ever increasing piles of garbage by the shell doors. Once 12 miles offshore, we made the call from the Bridge, the shell doors were opened and garbage discharged. Even between St Thomas VI & San Juan, we would go directly 12 miles off-shore, then head West the short distance to San Juan.

 

Even as recently as 2012, in Canadian waters, we were permitted to pump raw sewage overboard, provided we were moving. No minimum distance off-shore was required. We had the latest technology treatment plant, but it never worked from day 1. As Cheng pointed out they require a constant load, but on a 2 hr ferry, the system takes a hit when they board and again when they disembark. Therefore, many days we pumped raw sewage overboard, waiting until 1 mile off-shore and stopping 1 mile before reaching US waters. At 20 kts, this only provided 9 or 10 mins, so I believe the engineers pumped at max capacity.

 

Post 2012, Canadian Regs no longer permit pumping raw sewage, so the local vessels use holding tanks and pump ashore for treatment. All solid garbage and food waste is landed ashore for recycling or to the tip. Even water draining from the car deck scuppers goes through an OWS before going overboard.

 

Another interesting challenge in our refit facility on the Fraser River. To drain a potable (drinking) water tank containing city tap water, we could not pump this overboard. Any contents had to be pumped ashore into a tanker truck for disposal. Chlorinated tap water cannot be discharged overboard in the river.