Capacity of black water tank?

[rls8r]

I'm in the process of putting in a 16-gallon holding tank. I am pressed for space also - and I didn't want to sacrifice storage area in the V-berth to accommodate a 35 - 40 gallon tank like others with my model of boat have done.

So - I'm installing the holding tank between the hull and the wall behind the toilet in the head. I'll use the Raritan "Hold and Treat" approach, but with using my own holding tank. That way, I can store wastes in the tank when I'm in a No Discharge Zone. Then, I can either have them pumped out at a marina - or treated by the Type II MSD (Raritan Electrascan) unit when I'm out of the No Discharge Zone and discharged overboard. I'm also plumbing it so I have the option to release wastes directly when I'm outside of the 3 NM limit.

I have a Marine Elegance toilet, which allows two flush volumes - 1 gallon per 'large' flush and about 1/2 gallon per 'small' flush. Having that toilet and the Electrascan unit allows me (I hope) to have a smaller holding tank than is normal for other setups. I hope to be able to spend about a week in a No Discharge Zone before having to pump out - or leave the area.

[gonesail]

mine is 20 gallons for a 30' boat. it's in the keel so all liquids flow downhill .. not needing much flush water. small but doable for 1 or 2 people.

[NorthCoastJoe]

Every boat I have had I removed the holding tank and all the stuff that goes with it. I have used an AirHead in 4 boats. I am against carrying around the weight of sewage. Salt water is 8.54 pounds per gallon times 40 equals 341 pounds of waste water not counting the weight of the tank and hose.

That 341 pounds can be better used for fresh water, food, toys, tools, anything but sewage.

For those who have a problem dumping the compost: Much easier and cleaner job than going to a pump out and dealing with that stink. No valves to clean, stinky hoses, pumps. Seems to me you have to be crazy not to have a composter.

Wah Wah Wah .... You have to dump the pee bottle once a day. Or have a drain fitting on the pee bottle to a holding tank if you desire. But that puts you back at the pump out, without the poop at least.

We have an Airhead for restricted areas and a Lavac for when allowed to pump overboard.

Oh I loved doing the pump and hose change on the Lavac, far easier to maintain the Airhead.

[SailingHarmonie]

Originally Posted by NorthCoastJoe

Every boat I have had I removed the holding tank and all the stuff that goes with it. I have used an AirHead in 4 boats. I am against carrying around the weight of sewage. Salt water is 8.54 pounds per gallon times 40 equals 341 pounds of waste water not counting the weight of the tank and hose.

That 341 pounds can be better used for fresh water, food, toys, tools, anything but sewage.

For those who have a problem dumping the compost: Much easier and cleaner job than going to a pump out and dealing with that stink. No valves to clean, stinky hoses, pumps. Seems to me you have to be crazy not to have a composter.

Wah Wah Wah .... You have to dump the pee bottle once a day. Or have a drain fitting on the pee bottle to a holding tank if you desire. But that puts you back at the pump out, without the poop at least.

We have an Airhead for restricted areas and a Lavac for when allowed to pump overboard.

Oh I loved doing the pump and hose change on the Lavac, far easier to maintain the Airhead.

So why not just pee in the lavac all the time?

[Mirage35]

Ours is 90 liters (some number of gallons depending on your definition of a gallon). I find it more helpful to think of it as eight person-days.

[coopec43]

Originally Posted by Mike OReilly

A composter solves all your problems (but creates new ones ).

One note though, at least in North American, having the urine plumbed as direct discharge would mean you could not venture into any No Discharge Zone area, nor travel within 3 nm of land. I don't know the laws in Australia.

Yes I think the laws are exactly the same in Australia. Maybe that is because both countries are signatories to the MARPOL treaty?

The International Convention for the Prevention of Pollution from Ships (MARPOL) is the main international convention for addressing ship sourced pollution.

I've also read that some marinas won't allow you into the marina unless the toilet discharge thru hull is padlocked?

[coopec43]

Originally Posted by leecea

We'd struggle to live with 10 gals. Ours is 30 gals.

I see the advantages of a composting head but don't understand how we could use one. It must be very dependent on what access you have for disposal. I can't think of a place we've been where we'd be comfortable doing that.

Maybe we should BOTH read this thread?

https://www.cruisersforum.com/forums...-229529-4.html

[Mike OReilly]

Originally Posted by coopec43

Yes I think the laws are exactly the same in Australia. Maybe that is because both countries are signatories to the MARPOL treaty?

Yes, I believe this is where the 3nm limit comes from. It's an arbitrary limit which was designed for large vessels. I have never seen any scientific basis for it to apply to small recreational boaters, but I understand the practicality of applying one regulation to all.

Originally Posted by coopec43

I've also read that some marinas won't allow you into the marina unless the toilet discharge thru hull is padlocked?

I've never heard this. Do you have a reference? It's true that in NDZ, such as the Great Lakes, the law states you need to have any direct discharge valves "disabled", but I've never seen that applied for marina entry. Nor have I actually seen it applied for the Great Lakes, but I was mostly cruising the Canadian side, where "poop" enforcement doesn't seem to be the issue that it is south of the border.

[peghall]

MARPOL only applies to commercial vessels, notably cruise ships. Recreational vessels aren't subject to it.

Australia's marine sanitation laws are bit different from US laws and--unlike the US--can vary with the province.

As for marinas, in the US they're considered private property, so can make any rules they want to as long as they don't violate federal law. It makes sense to require holding tanks unless the marina is in watrs where the discharge of TREATED waste is legal. Treated waste is far cleaner than the water in most marinas due to runoff from their parking lots, bird poop, bilge water, cleaning products, fuel spills while refueling etc. Marina operators who require ONLY holding tanks pat themselves on the back believing they're "doing the right thing" by requiring holding tanks inside their fiefdoms.

As for my take on composting (actually only desicating) toilets, I wouldn't want one, but to each his own.

As to the "right" size holding tank size for your boat...that depends on the number people aboard and how long you want to carry the contents around before pumping out. This can be a pretty good guide if you use a little basic math: The average adult uses the toilet 5x/24 hours. The average liquid deposit from most marine toilets is +/- 2 liters depending on the amount of flush water needed.

--Peggie

[coopec43]

Originally Posted by Mike OReilly

Yes, I believe this is where the 3nm limit comes from. It's an arbitrary limit which was designed for large vessels. I have never seen any scientific basis for it to apply to small recreational boaters, but I understand the practicality of applying one regulation to all.



I've never heard this. Do you have a reference? It's true that in NDZ, such as the Great Lakes, the law states you need to have any direct discharge valves "disabled", but I've never seen that applied for marina entry. Nor have I actually seen it applied for the Great Lakes, but I was mostly cruising the Canadian side, where "poop" enforcement doesn't seem to be the issue that it is south of the border.

Apparently the US Environmental Protection Agency has that requirement? Maybe the marinas were upholding the laws?

How do I comply with a no-discharge zone?
While operating in a no-discharge zone, overboard discharge from marine sanitation devices is generally prohibited. To secure a flow-through device (i.e.,. Type I or Type II marine sanitation device), vessel operators must do one of the following:

• Close the seacock and remove the handle;
• Padlock the seacock in the closed position;
• Use a non-releasable wire-tie to hold the seacock in the closed position; or
• Lock the door to the space enclosing the toilet(s) with a padlock or door handle key lock.

See 33 CFR 159.7(b)-(c) for the relevant statutory language.

https://19january2021snapshot.epa.go...uestions_.html

[Fore and Aft]

Coopec 43 if you have one of these valves you can simply padlock it in the correct position. But then who holds the key until you are out of the no discharge zone? Australia is fairly slack with enforcement, most holding tanks I see are hardly used and are more just to tick a box.
Cheers

[coopec43]

Originally Posted by Fore and Aft

Coopec 43 if you have one of these valves you can simply padlock it in the correct position. But then who holds the key until you are out of the no discharge zone? Australia is fairly slack with enforcement, most holding tanks I see are hardly used and are more just to tick a box.
Cheers

My manual toilet (now converted to electrical) empties the toilet bowl into the holding tank. I can the empty the holding tank through a "Y" valve into the ocean using a diaphragm hand operated pump. Otherwise I can use the "Y" valve to have it sucked out through the deck outlet.

You wouldn't want to lose the key would you?

[GILow]

Every state in Australia has a different set of rules. I’m currently in South Australia and I think it has the most restrictive.

Last I checked the majority of states required simply that there be clear printed and laminated instructions on board that showed the appropriate position of the Y valves (if fitted) to prevent overboard discharge. A lock was not required, but I last checked this stuff over five years ago, so things may have changed, and probably have.

In a bid to future-proof our new boat (I’m sure the regulations will only get tighter everywhere we travel) the blackwater tank is about 300 litres and the gray water tank is about 250. Neither will be fitted with Y valves, all plumbing to go direct to the appropriate tank. Saves arguments with the authorities about the correct position of valves. Both will have deck-fitted pump-out points and an electric discharge pump fitted with a lockable shut-off valve, in case the lock becomes a requirement. (Maybe it has already in some states?)

In principal I agree with the increased regulation. I don’t want to sit in an anchorage and fear putting a toe in the water. My only gripe with the regulation is that here in Adelaide, South Australia we have one (ONE!) public pump out point for a city with a population over over a million people and it is broken more often than not. My marina has a fortnightly free pump out service but the old boat’s 70 litre holding tank was only good for about ten person-days so careful planning was required.

[more]

Originally Posted by Mike OReilly

A composter solves all your problems (but creates new ones ).

One note though, at least in North American, having the urine plumbed as direct discharge would mean you could not venture into any No Discharge Zone area, nor travel within 3 nm of land. I don't know the laws in Australia.

please explain as dump people how goverment know i piising in sea,thanks.
in Croatia is law more restrict 12 nm forbidden discharge any water,3 nm only clean water.
if come police you tell policmen,cost guard don't ask me nothing call my layer for all question. or show me court order for question.
a clear example of passing laws without the possibility of implementation

[Dockhead]

Originally Posted by GILow

. . . In principal I agree with the increased regulation. I don’t want to sit in an anchorage and fear putting a toe in the water. My only gripe with the regulation is that here in Adelaide, South Australia we have one (ONE!) public pump out point for a city with a population over over a million people and it is broken more often than not. My marina has a fortnightly free pump out service but the old boat’s 70 litre holding tank was only good for about ten person-days so careful planning was required.

It's not regulation, but civilized behavior, which makes the difference. And regulation which is unscientific is counterproductive.


In Norway, for example, with some of the most pristine waters in the world, holding tanks are not required, and you are reasonably asked to not discharge closer than 300 meters from shore. People are much more law-abiding in countries with reasonable laws, and so you can swim with confidence in Norwegian anchorages (if you don't mind the cold water).



I am always afraid to swim in U.S. anchorages shared with other boats, because I know we are a nation of scofflaws, and all the more when the law is irrationally formulated and hard to comply with.