Help me put my head plumbing back right

[Apex]

My C&C 30 is currently set up with a bladder for grey water. Galley sink, and Head sink drains are pumped into the cockpit lazarette into a bladder. I would like to change the system BACK to it's original configuration MINUS head pumpout directly overboard. I do have a blackwater tank, but can do without the grey water bladder. In the great lakes, so no option for discharge of head overboard is preferred.

On inspection I found:
1) abandoned vent hose, 5/8" in diameter which is at the rub-rail in the head area. I believe the holding tank has another vent aft already.
2) empty pad, I PRESUME was where original Y-Valve was located
3) abandoned 2" thru-hull. Looks to be original toilet discharge.
4) IN-USE 1" thru-hull for toilet intake.
5) abandoned thru-hull which looks to be where sink (?and shower sump?) discharged

The pickup in the shower pan goes to a poorly installed ball valve (not original) thru a strainer, then to an electric pump mounted on forward bulkhead of the head compartment, which then runs through several adaptors and finally a T, and then to the pump for the bladder in the cockpit lazarette. Sink drains from basin into the T mentioned above, then to the bladder pump. I have used the sin, not the shower thus far.

I am confused as to original use of the vent, I am thinking it was the anti-siphon for direct discharge of the toilet???
How does the shower sump/pump drain overboard? Does it tie into the sink drain? Is there an anti-siphon for that somewhere?

Of course I will be pulling out Peggie's book, but inital glance into the current plumbing has me confused.

Thanks

 

[Benny17441]

Can't really picture what you are describing. The galley sink usually discharges directly through a thru-hull below the water line. The head sink usually discharges directly overboard through a thru-hull above the water line. The shower and the refrigerator drain directly into the bilge so it can be pumped out. The head system should operate in a separate plumbing circuit. Usually a bladder tank is used to replace an original tank that has cracked and is leaking. Have you figured out how that bladder is emptied? Find an owner's manual for your boat as it should have a plumbing diagram as it comes from factory.

 

[Apex]

@Benny17441 it is difficult to describe, because I am also having a hard time picturing it, even when looking at it!

Good call on the manual.

The boat had all sink and shower drains switched to plumb into a grey water retention bladder. The toilet still empties into a black water holding tank. Both bladder and tank are pumped out through a deck fitting, via Y-Valve.

I am trying to avoid shower water in the bilge, that is an invitation for stink. I know some setups do just that, others drain into a dedicated pan with float switch and pump. My shower pan is very shallow, and already has a pump to it, and a manual pull switch in the head. I don't know if they can be combined with a sink drain through the same thru-hull. If not, I can use the large 2" thru hull originally used for head discharge overboard. Closing and removing the large thru hull would be preferred.

 

[Davidasailor26]

I don't know if they can be combined with a sink drain through the same thru-hull.

This is how my shower sump is currently plumbed by Beneteau. I don’t know if they use anything special in the line to keep the pump discharge going out the thru hull. I presume it’s just pushed down by gravity the same as the sink discharge.

 

[sail sfbay]

Suggest making a list of all your below and above waterline thruhulls and hoses with a diagram, including diameter, valves and thru-hulls. Might check with these guys for an owner's manual. Some thoughts:

• Remove the grey water bladder
• Sinks drains.........route to a dedicated below waterline thru-hull valve............you already have one under the galley sink and it sounds like you also have an abandoned thru-hull valve for the head sink
• Shower drain.......route to an electric hower sump pump box then out through an above waterline thru-hull
• Toilet discharge.............route through a sanitation hose to the holding tank with hoses connected to a deck pumpout, above waterline vent and macerator pump then to a below waterline thru-hull valve, if you want that capability

 

[Peggie Hall HeadMistress]

For one thing, it's illegal to combine black water (sewage) and gray water (galley, bath, and shower water) in the same tank. It IS legal to flush gray directly overboard in almost all US waters. For another, USCG regs REQUIRE all waste tanks--black water and gray water--to be vented to the outside of the boat...making it illegal to use UNvented bladders as holding tanks.

I'll be glad to help you design a system that's legal and won't create more problems than it solves...send me a PM.

--Peggie

 

[Apex]

@sail sfbay : You are in the same mindset as I am for the sinks. Shower sump drain above waterline: got it. The current unused "vent" is at the rub rail, I assume that would not be appropriate for the shower discharge, albeit likely rare to never used shower.
My previous boat had the head sink above waterline (no shower). My concern is measuring sink in relation to waterline at heal angles, it may be close: I have measurements and can check next time out sailing in heavier air. Bottom of the sink is 26" below the deck.

@Peggie Hall HeadMistress : At this time I think I am ok. I am trying to undo what was previously modded, and most of the bits are there. First section in your book addresses what is legal to discharge, and shower water, nor sink drains fall under the "human waste" category. So I think I am on the right road there. The head system looks OK. I rebuilt the O'Day 28 recently, so that all still makes sense, although now that I think about it, I will need to check for the vented loop.

Vents: We have plenty, all are above the cove stripe, near the rub rail....ready?
forward water tank: vented stbd side, forward. SS cowl vent
stbd settee water tank: vented stbd side, just aft of fwd water tank. SS cowl vent
UNUSED head vent: vented stbd side, mid-ship plastic mushroom vent
holding tank: vented stbd side, aft near pushpit. SS cowl vent
bladder: vented stbd side, aft near pushpit as well. SS cowl vent within 6" of the holding tank.
Diesel tank: vented port side, mid-ship. SS cowl vent

 

[sail sfbay]

• The current unused "vent" is at the rub rail, I assume that would not be appropriate for the shower discharge ....I would drill a hole a few feet hole above the waterline, install a thru-hull and connect hose with a loop from the shower sump collection box & pump , located below the shower
• Head sink.........suggest installing new below waterline thru-hull and valve under the sink (my preference), run a hose to the shower sump collection box & pump OR consider another option discussed in this thread Plumbing sink drain to head intake | SailNet Community

 

[Peggie Hall HeadMistress]

You've obviously thought out everything...just couple of observations:

Although bladders are ok for water, they're not recommended for sewage holding for several reasons..1. it's almost impossible to put a bladder where there's NO chance of ANY chafing--which results in leaking--anywhere on it. 2. Because bladders are designed to "hug" the contents it's impossible to maintain the contents aerobically, which makes it impossible to prevent odor out the vent. 3.Cheap ones (Plastimo) can be highly prone to blowing out a fitting at the first indication of a blocked tank vent and 4. a good quality bladder (Nauta, Vetus) can cost a lot more than a similar size top quality hard plastic tank. But even the best bladder tanks only have an average lifespan of about 15 years...good quality hard plastic tanks last decades unless abused.

So before you commit to a bladder, check out Ronco Plastics.
They make TOP quality thick-walled water and waste tanks for a very reasonable price and have more than 400 shapes and sizes, over 100 of which are non-rectangular, and they install fittings in the sizes and locations specified by the customer when they make the tank. There are retailers who sell Ronco tanks, but Ronco sells direct for a much lower price...and they're great to work with. Ronco Plastics marine Tanks Their drawings are here: Ronco Plastics old marine catalog
When looking at drawings it's important to know that there is no top or bottom until the fittings go in, and YOU decide where they go. So rotate, flip in any orientation to find the tank that fit your space.

Re your link to a 12 yr old Sailnet thread:...it's a great idea that I began recommending immediately after learning about it in the mid-90s, but I dunno why some people--including at least one person here--are so determined to tee a second line into the head intake line to go to the sink drain--requring a whole bunch of unnecessary plumbing and often the need to access an inaccessible thru-hull to use the sink to supply fresh water to the toilet--instead of just disconnecting the head intake line from the thru-hull and re-routing it to a tee in the sink drain line, creating a much shorter toilet intake line. The head intake thru-hull can then be repurposed to use for a washdown pump or whatever else you want.

--Peggie

 

[Davidasailor26]

Because bladders are designed to "hug" the contents it's impossible to maintain the contents aerobically, which makes it impossible to prevent odor out the vent.

Just thinking out loud - If the bladders hug the contents and there isn’t much air inside, then when new effluent comes in wouldn’t it just expand the bladder rather than displacing any odor out the vent? Or does it just not work that well in real life and you end up with the worst of both worlds, just enough air to emit odors, and not enough for aerobic processes?

 

[Peggie Hall HeadMistress]

If the bladders hug the contents and there isn’t much air inside, then when new effluent comes in wouldn’t it just expand the bladder rather than displacing any odor out the vent?

New contents will definitely expand the bladder, but the pressure created by flushing new contents into the tank will force the gasses generated by decomposing sewage in an anaerobic environment out the vent. And because they're anaerobic gasses, they WILL stink!

--Peggie

 

[Apex]

New contents will definitely expand the bladder, but the pressure created by flushing new contents into the tank will force the gasses generated by decomposing sewage in an anaerobic environment out the vent. And because they're anaerobic gasses, they WILL stink!

--Peggie