Holding tank volume

[iflypby]

Reviewing vessel specifications, it appears that the holding tank volumes are fairly small compared to the freshwater volume. It seems to average (on the vessels I am looking at) 40G holding tank to 400G potable water tank. Since there is not both a grey and black water tank listed, I am assuming that the one holding tank does dual duty. In my motor home, a 40G holding tank will last the wife and myself two days before needing to be emptied. Not a lot of time to swing on the hook unless you take a bath in the big tub outside.
What is the normal configuration, black water into the holding tank and everything else just dumped overboard?

 

[HeadMistress]

With the exception of a very few closed inland lakes, gray water may legally be discharged directly overboard in all US and Canadian waters ...so your holding tank only has to hold toilet waste.

If two days are all it takes to fill up a 40 gallon holding tank in your RV, you're using way too much flush water. The rule of thumb on most boats-which applies to RVs too--is an average of 3 gal/person/day, which should take at least 6 days to fill up a 40 gal holding tank--and that's without applying any flush water conservation methods.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

 

[Larry M]

We have a 30 gallon holding tank with a fresh water (single) Vacuflush head. We’re full time live a-boards (2) that get pumped out weekly. Seven days is no problem. Eight days I’m watching the tank level.

 

[DavidM]

We can go at least ten days, maybe more with judicious use of flush water and mostly overboard for me with 40 gallons of holding capacity.

With our RV which has about 33 gallons of black water capacity we can go a week or more.

David

 

[HeadMistress]

That doesn't sound like you're using enough flush water Larry...and it's too little flush water that's responsible for 99% of problems with VacuFlush. You should be leaving the peddle down at least 3-4 seconds after urine only, a full 10 seconds after solids and/or TP. Any less doesn't put enough water through it to rinse bits of paper and solids out of the pump and duckbills. If you insist on keeping on with the way you're doing it, at least flush a full bowl of clean water through it once a day. That's a small change, but will prevent problems...and prevention is always easier and cheaper than cure!

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

 

[tadhana]

Larry, we also find the it to be 2 gallons of black water discharge per day per person. our tank is about 45-50 gallons. After 9 years aboard, i guess we have had about 500 pump outs so we kind of know our tank and system. We pump out weekly. But can go 2 weeks.

 

[psneeld]

The pumpout guy in Marathon just quoted the stats for getting grants for pumpout facilities.

He said about 13 to 15 gallons for 2 persons aboard weekly. Or about a gallon per person per day.

Its an average so some might conserve better than others, or soend 5 days a week ashore working, etc...etc...

 

[O C Diver]

I have the luxury of an 80 gallon holding tank to 300 gallons of potable water tanks. Nice to be able to flush without conserving. Boat also has a Y valve for diverting gray water into the holding tank in the few restricted areas.

Ted

 

[iflypby]

Our motorhome only has one waste water holding tank so all grey and black water goes to this tank. What kills us is taking showers. Both of us like long hot showers. Should not be a problem if gray water is allowed to be dumped overboard. I am assuming that treated black water is no longer allowed to be dumped overboard, except in international waters.

 

[jleonard]

He said about 13 to 15 gallons for 2 persons aboard weekly. Or about a gallon per person per day.
..

That sounds about like our average. We can easily get two weeks out of our 35 gal tank.

 

[aboatman]

Our motorhome only has one waste water holding tank so all grey and black water goes to this tank. What kills us is taking showers. Both of us like long hot showers. Should not be a problem if gray water is allowed to be dumped overboard. I am assuming that treated black water is no longer allowed to be dumped overboard, except in international waters.

How is the black water being treated? Treatment systems are available but somewhat expensive and even their use is prohibited in some areas. For most of us, unless we are more than three miles offshore, we need to have the holding tank emptied on shore or by a pumpout boat.

As for long hot showers, that's what marinas are for. Shower water is commonly discharged into the waterway but you're not likely to have the fresh water capacity or the heating capacity for long hot showers.

 

[iflypby]

When I lived on the sailboat in South Florida, we had a wet head so mostly used the dock shower. That was fine when we were 25 years old but I am not interested in dragging my old bones down the dock to take a shower. Like drinking cheap scotch, I do not need to do that at this stage of my life. 400 gallons is enough for me, the wife can wait her turn or share! Instant hot water system or larger hot water heater.

 

[timb]

our old Marinette has a 15 gallon and although we tried to conserve space it would never last a weekend with two couples on board .and if we where there for the week we had to comeback to the dock and stay Wednesday so we would be there when the barge came by. we where on a lake
so the new boat has a 30 (we think) hooked to the front manual head. and the aft crown electric head has a lecta san that I don't know how to operate . or know the condition of . I am thinking of replacing the hand pump on the front one if I can find the parts is a Wilcox-Crittenden. and adding a 36 gallon tank in place of the lecta san(I have one I bought for the Marinette but never installed) . but then I will have two waste pump outs. would that be normal or strange? there is a 5$ pump out 50 yards away now. we are on the coast now.

 

[HeadMistress]

The pumpout guy in Marathon just quoted the stats for getting grants for pumpout facilities. He said about 13 to 15 gallons for 2 persons aboard weekly. Or about a gallon per person per day.
Its an average so some might conserve better than others, or soend 5 days a week ashore working, etc...etc...

His 13-15 gals/week estimate is about right for a weekend warrior couple and even for a liveaboard couple who are both away from the boat for about 10 hours/day, but 1 gal/person/day is waay off. The average adult uses the toilet 5x/24 hrs. The average flush including waste is .6 gals (flush water & waste combined)...that's 3 gal/person/day. A live-aboard, even if away from the boat 10 hrs/day is gonna use the toilet first thing in the morning, once when they get home and once before bed. That comes out to close to 2 gal/person/day. Using shore facilities 4 of the 5 trips most people make to the head each day is the only way to get down to an average of anywhere near 1 gal/person/day. And, in fairness, he may be factoring in use of shore facilities.

 

[HeadMistress]

...so the new boat has a 30 (we think) hooked to the front manual head. and the aft crown electric head has a lecta san that I don't know how to operate . or know the condition of . I am thinking of replacing the hand pump on the front one if I can find the parts is a Wilcox-Crittenden.

If you'd like to send me a PM, I'll be glad to help you sort out what you need--or whether you can even still get it...Theford bought W-C and discontinued the whole product line close to 10 years ago. Do you know which model W-C toilet you have? You may also want to consider replacing the Crown with one that draws less than 36 amps, needs a lot less than a gallon of water/flush, and doesn't make enough noise to wake the dead!

 

[psneeld]

I did say average for all boaters using at least pumpout boats, not sure if he included shoreside pumpouts.

0.6 gal per flush is assuming people flush every time and use that much water each flush....

Heck, even pretty well off people I know on islands where water is a premium dont flush every time.

On my boat I dial back the water used for each flush for liquid only flushes.

My last pumpout was 3.5 gallons for 2 people over a day and a half..

 

[ranger58sb]

I am assuming that treated black water is no longer allowed to be dumped overboard, except in international waters.

No; treated waste can be pumped overboard except in some inland lakes and in designated No Discharge Zones (NDZs). NDZs may or may not affect you. NDZ's usually don't apply to gray water.

Untreated waste can't be discharged overboard except outside the demarcation line, hence pump-out stations.

-Chris

 

[timb]

and for you viewing pleasure.

I think the fastest way to get something going would be to fix the manual. If parts are available. it leaks seawater at the handle I mean a lot of water. we may change it to electric later.
I saw the added in large cb for the crown it is loud and it must have a flush timer as it runs after you let off the button . I flusher some rv antifreeze down it.

and does any body have two holding tanks? one for each head.

 

[HeadMistress]

The Headmate is/was an inexpensive compact toilet with an average lifespan of < 10 years. You can still get a rebuild kit for it, but IMO a waste of time and money because as old as it is (W-C brought mfr'g back from Costa Rica 20+ years ago), a rebuild kit won't help much. Replace it if you want a toilet that's reliable and trouble free.

Two holding tanks are fairly common on larger boats.