Do holding tanks have over-side overflow tubes?

[JonnyQuest]

I had emptied the holding tank just a short while back, but now today the holding tank must have filled up despite only three short dockside visits with the family--I am wondering if the fascination of a marine head has been keeping my young children entertained while we have been topside. :naughty:

While sitting in the cockpit this evening I noticed my son use the head and the flush, and immediately saw water jettison over the side near the head area. I had my y-valve permanently shut down so that we couldn't accidentally jettison overboard, so I am assuming that the tank must have filled and his flush was overflowing and jettisoning overboard. (I couldn't see the water-line well through the white plastic side-wall of the tank, especially at night, so I am assuming that this is what has happened and I will be visiting the pump-out station tomorrow)

So is that how holding tanks work when they get full?

Looks like I'll have to refresher course with the crew on water conservation as well.

 

[Calif. Ted]

So is that how holding tanks work when they get full? No
Some boats have the capability for direct overboard discharge when 12 miles offshore where legal, 3 miles offshore you may discharge waste macerated to less than 1/2 inch. Less then 3 miles offshore you may not legally discharge any waste.
Simplest explanation for what you describe is the direct overboard discharge is open, not closed.

 

[JonnyQuest]

So is that how holding tanks work when they get full? No
Some boats have the capability for direct overboard discharge when 12 miles offshore where legal, 3 miles offshore you may discharge waste macerated to less than 1/2 inch. Less then 3 miles offshore you may not legally discharge any waste.
Simplest explanation for what you describe is the direct overboard discharge is open, not closed.

Hmm. When I bought the boat about 1.5 yrs ago the y valve was frozen in the holding tank direction. Rather than replace the valve, the boat repair yard removed the y valve since I'd never be going far enough to discharge overboard. (or so they were supposed to!)

Haven't noticed any side discharge in the last 1.5 years until now. I'll double check things tomorrow to see just what is going on.

Thanks for clarifying.

 

[JonnyQuest]

And to add a short note, if the valve were in the overboard discharge position then the holding tank shouldn't be getting full, yet it does and I've pumped it out 2-3 times over the past year or so.

I'll have to check on this. Hopefully it was simply the electric bilge kicking on coincidentally at the same time, but I'll ned to make sure of what is happening here.

 

[Peggie Hall HeadMistress]

To answer your question...

Holding tanks do NOT have "overflow tubes." If what you saw was coming from the holding tank, your tank was overfull and overflowing out the vent.

Tank vents are very necessary, but only AIR should ever pass through one. Overflowing out the vent is one very good way to block the vent, which can have very nasty consequences...the worst of which can be a ruptured tank. So you might consider investing in a tank level indicator that lets you know how much is in the tank.

The Head Mistress forum is devoted entirely to sanitation and plumbing...and there's good information in the discussions there that can help you learn how to operate and maintain your system...you might want to spend some time reading some of 'em. The link in my signature goes to a comprehensive "marine toilets and holding tanks 101" manual that should help you learn how to prevent most problems. And I'm always glad to answer questions too.

Fwiw, unless you have a USCG certified Type I MSD (treatment device) installed, keeping your y-valve in the overboard position is illegal in all US coastal and inland waters....and has been for 30 years. You must be in open ocean (in your case, out in the Gulf) at least 3 miles from nearest point on the whole US coastaline to flush a toilet directly overboard or dump a tank legally. Getting caught flushing raw toilet waste directly overboard inside the "3 mile limit" can cost you BIG bucks in fines.

 

[Peggie Hall HeadMistress]

Not QUITE true, Ted...

You said, "Some boats have the capability for direct overboard discharge when 12 miles offshore where legal, 3 miles offshore you may discharge waste macerated to less than 1/2 inch."'

The Florida Keys are the only waters in the US where it's necessary to be 12 miles offshore to dump a tank or flush directly overboard...and even there, only on the Gulf side. In all other US waters, it's only necessary to be outside the "3 mile limit" (open sea at least 3 miles from the nearest point on the whole US coastline. US marine sanitation laws do not require that waste be macerated to dump a tank.

Less then 3 miles offshore you may not legally discharge any waste.

It's illegall to discharge raw untreated waste inside the "3 mile limit," but the discharge of TREATED waste from a USCG certified Type I or II MSD (treatment device) IS legal inside the "3 mile limit" except in waters specifically designated "no discharge." On your side of the country, that would make the discharge of treated waste legal in all coastal waters north of Santa Barbara. On the east coast, New England is a hotbed of "no discharge" waters...but there are none of any size between New England the FL Keys...and only two in the whole Gulf of Mexico--the Keys and Destin Harbor.

 

[Peggie Hall HeadMistress]

I'm having a hard time sorting out contradictory information

In your first post you said, "I had my y-valve permanently shut down so that we couldn't accidentally jettison overboard..."

Later you said, "When I bought the boat about 1.5 yrs ago the y valve was frozen in the holding tank direction. Rather than replace the valve, the boat repair yard removed the y valve since I'd never be going far enough to discharge overboard. (or so they were supposed to!)

And then you said, " if the valve were in the overboard discharge position then the holding tank shouldn't be getting full, yet it does and I've pumped it out 2-3 times over the past year or so.

So which is it...there is a y-valve that lets you flush directly overboard...or there isn't?

It's just occurred to me that if you leave the head intake seacock open when no one is aboard AND there's no vented loop in the head intake, it's entirely possible that a leaking wet/dry cam assembly is letting sea water fill up your tank....Very slowly if that IS happening, 'cuz if it were leaking fast enough to overflow your bowl, your boat would be sitting on the bottom of your slip by now.

 

[Donnybrook]

Peggy, not to pick nits, but in Florida the waste discharge zone is 9 miles on the Gulf side and 3 miles on the Atlantic side. Taken from myFlorida.custhelp. "Since October 1, 1994, boaters are prohibited from discharging untreated sewage into fresh or within coastal salt-water limits. Coastal limits are 9 nautical miles on the Gulf and 3 nautical miles on the Atlantic Ocean."

 

[JonnyQuest]

I appreciate the help here and need to get to the bottom of this. I'm going to check on it today.

To clarify, when I bought the boat the y valve was noted as frozen in the holding tank direction. I had the local repair yard do some work for me and they noted the stuck y valve. They told me that they did not want to try to unfreeze the valve as it could just break and that they would (from vague memory now) fix it so the discharge tube was no longer available. I do not recall what they said they would be doing, perhaps the repair receipt will have notes.

So perhaps they forgot to do that part of the job. But I'm not certain yet as the holding tank has been operating and filling up with occassional usage. Pumped it last time and believe I saw all the usual floaters etc.

Tank that's operational yet discharge off the side? Perhaps they did not remove or otherwise lock out the y valve and it is in a midway position allowing backflow to go overboard once the holding tank is full?

A theory to check on.

Thanks for the help as I figure out this issue. I hadn't planned on a tank gauge in the budget since it's a small boat (oday 27) and we just daysail, but with young kids perhaps it would be a good idea after all.

I'm looking forward to reading the forum entries and your guide, thanks for those initial pointers.

 

[RAD]

Johnny, you need to teach all on board that in the land of sun and sea we don't flush for pee and if it's brown flush it down you'll save a lot of trips to the pumpout.....also how big is your holding tank?? when I got my 32 Oday someone put a 9 gal tank in and that just wasn't going to cut it without a lot of pump out stations in my sailing area (its a lot better now) any way I studied the situation and was able to replace the tank with a 20 gal in the same space (a lot of other stuff had to be removed)

 

[RAD]

BTW my tank gauge is a light behind the tank on a momentary switch and the tank is opaque so I can see the waste and water tank levels pretty good

 

[Old Skool Neil]

Peggy, of course, is right. What you saw was coming out the vent.

Even if you were able to intentionally discharge overboard, the thru-hull is located below the waterline so you would never see it. If it were above the waterline there would be a permanent disgusting stain down the hull.

Maybe you should get the little cherubs involved in emptying the holding tank, make it their responsibility and see if their usage diminishes. I bet it will.

 

[JonnyQuest]

Peggy, of course, is right. What you saw was coming out the vent.

Even if you were able to intentionally discharge overboard, the thru-hull is located below the waterline so you would never see it. If it were above the waterline there would be a permanent disgusting stain down the hull.

Maybe you should get the little cherubs involved in emptying the holding tank, make their responsibility and see if their usage diminishes. I bet it will.

Hah! Neil, I like your thinking, truly "Old Skool." I will definitely get the little angels to do the dirty work today. (pray for me!)

I'm glad you mentioned about the waste thru-hull being below the waterline; I read about that last night and wondered if mine would have been set up that way too.

 

[Old Skool Neil]

I worked at several boat plants as far back as 1971 including Jensen Marine who acquired the O'Day line when they were swallowed up by the Bangor Punta conglomerate and I can say categorically I never saw a black water discharge above the waterline. Never.

 

[Peggie Hall HeadMistress]

A little math may help

The average flush from a marine toilet is approx .5 gal...the average person uses the toilet 5x in 24 hours. So each person continuously aboard will put approx 3 gal/day into a tank...less of course if you're only aboard for a few hours. If you want to know how fast your tank is filling up, do the math: multiply .5 gal/flush x X total flushes each time you're aboard. Four people each using the toilet twice will put four gallons into the tank in a day on the boat. If your tank is small, it doesn't take long to fill it.

I really doubt that you've seen any "floaters" go through the sight glass when you pump out, 'cuz solid waste dissolves very quickly in water. If you have seen anything that isn't liquid, it may be TP that doesn't dissolve or it may be sludge that's accumulated on the bottom of the tank. Switch to quick-dissolve TP (cheap, single ply, no name) and flush out your tank very thoroughly...that should be done at least 2-3 x season...the tank should be at least nominally rinsed after EVERY pumpout. You'll find discussions about both in the HM forum.

What's the make/model/age of your toilet? When, if ever, has ANY maintenance been done...the joker valve replaced at the very least? Marine toilets, unlike household toilets have moving parts that wear out, requiring either preventive maintenance or repairs. Preventive maintenance costs less and, because it gets done at your convenience instead of when something breaks--which NEVER happens at a convenient time, eliminates a lot of "head aches.

A Profile single tank "Solo" tank level indicator that lets you know how much is in the tank, not just when it's full, will only cost you $100. Profile Tank Monitors

Donny, your info is a bit old...when all the Keys went "no discharge" a few years ago, the enviro-zealots pushed through a 12 mile limit on the Gulf side and have been actively trying to do the same on the Atlantic side...so far without success...it's still 3 miles there. There are some places on the rest of the Gulf side of FL where the limit is 6 miles, a couple where it's 9...all south of Tampa Bay. The GOOD news is, the discharge or TREATED waste is legal everywhere on both sides of FL, including the ICW, except in the Keys.

Rad, if shining a light behind your tank lets you see how much is in it, it has to be translucent, not opaque. I'm not a fan of leaving urine in the bowl either...that's a good way to have urine splattered all over the head if you tack or jibe hard or even just encounter a really big wake. You won't fill up the tank any faster if you flush it using dry bowl, then pump once or twice in "wet" to bring in only enough water to rinse the bowl. And, you'll use much less water to flush solids if you add a couple of cupfuls of water from the sink to the bowl before use...'cuz you won't need as much water to rinse the bowl.

 

[mitiempo]

I would install a tank monitor of some kind. ABYC requires you to know when your tank is 3/4 full. And it is good to know.

 

[Peggie Hall HeadMistress]

It's federal law, not ABYC

It's 33 CFR 159.83 that requires a means of determining when a tank is at least 3/4 full. If a tank is readily accessible and made of a material that allows that to be determined by visual inspection, no gauge is required. But if not, law requires a gauge.

Neil, you've led a sheltered life...I've seen all kinds of boats that discharge waste above the waterline. Production boat builders put the thru-hull there because it saves 'em the cost of a seacock. And some equipment mfrs tried some really creative approaches around the time the marine sanitation laws requiring all boats to either hold or treat first went into effect in 1980. My favorite was a Jabsco combo pumpout/overboard fitting, designed to be installed in the side of a boat. (see photo)

The idea was to connect the pumpout line to the larger port (1.5") and the discharge from a macerator pump to the smaller 1" port. To empty the tank at sea, the macerator would literally shoot poop out the side of the boat. You would NOT want that side of the boat to be to windward while you were dumping the tank! The fitting allso dribbled, leaving a stain on the hull.

I don't know whether it was Jabsco's idea to try installing it in the side DECK instead of on the side of the hull, or badly misguided builder or yard's idea...but I did see one installed there (no longer operational). When the macerator was turned on to dump the tank, THAR SHE BLOWS! And wind direction was an even bigger factor in that installation! :dance:

Needless to say, the "Jabsco Poop Shooter" (my name for it) was not a huge success!

 

[Stu Jackson]

JQ, in addition to reading The Head Mistress posts, try this and then follow the pipes on your boat to figure out what you have installed.

http://www.westmarine.com/webapp/wc...1151&catalogId=10001&page=Heads-Holding-Tanks

 

[RobertLangdirect]

Toilet Paper? Out Dam Paper!

I had emptied the holding tank just a short while back, but now today the holding tank must have filled up despite only three short dockside visits with the family . . . is that how holding tanks work when they get full? . . .

My Pearson 31 has a topside vent that will "squirt" unpleasant sh** if:

a. The tank is full, or

b. The initial tank-held screen is full of toilet paper or other crap.

I learned about a. "The tank is full," over the years of having the boat. But I most recently learned about b. "The initial tank-held screen is full . . ." only last month while cruising with three women on the boat.

I pumped out the day of a two-day trip to another marina. The day after getting there, my vent was squirting, even though I did not think the tank would be full. So, over to the pump-out I went.

As we emptied the tank, the flow from the tank stopped rather quickly and we were vacuuming air. I asked a crewmember to go below and flush the toilet. As soon as they began pumping water, the station began sucking copious amounts of paper and freshly flushed water.

Seeing that, it made sense what I then dicerned happened.

The women, using more paper than the system could initially digest, filled the inside the tank initial screen full of paper. Once full, it acted as a dam for the rest of the pumped liquids. Once I was pumping the tank, the crewmember's adding of raw water to the basket washed free the debris, whish the pumpout staion was able to suck through the screen.

So, I would ask, do you know what the inside of your holding tank looks like? And while I usually add, please send a picture, maybe this time I will be happy with a general description.

 

[Peggie Hall HeadMistress]

The solution is both simple and obvious

1. Knock the screen out of the vent thru-hull...screens cause more problems than they solve.

2. Back flush the vent line every time you pump out and/or wash the boat to keep TP or anything else from clogging it.

3. Stop overflowing your tank. Add a tank level indicator if you don't have one.

However, if you can't prevent waste from spilling out the vent when the boat is heeled, it's a VERY simple matter to move the vent fitting to a location on the tank where that can't happen. Meanwhile, that makes it even more important to get rid of the screen and start making a habit of backflushing the vent line and STOP blaming your neglect on women's use of TP. :dance: