Aquasan treatment and holding tank

Status
Not open for further replies.
S

Sandy Squire

Hi Peggie We are in the process of building a 46 foot sailing catamaran which will have a head in each hull. One head is "public", the second is a private en-suite. We could 1. build in an integral fiberglass holding tank for each hull - they could be above the waterline (though this makes for a longer, rising inlet pipe from the toilet) to allow gravity flushing of the tanks. 2. build one holding tank by the "public" toilet and not use the en-suite toilet in restricted waters. 3. install a treatment system and holding tank (Aqua-San MSD, cost $AUD3000 = $US1650 ) adjacent to the "public" toilet and pump the en-suite toilet to it as well (up about 4 feet, across about 24 feet, down about 2 feet, aft about 12 feet = total around 42 feet!). I am asured that modern Tecma electric macerator toilets could handle this 'no problem'! (2.5 litres per flush) 4. we would probably need more holding tank capacity than 70 litre Aquasan - we could build in an integral glass tank to add volume and catch the overflow. The Aqua-San MSD oxidises and disinfects toilet waste and holds the waste onboard until it is possible to dispose of it properly. It consists of a kill tank (25 litres) working on the same principle as the Lectrasan (except it uses only a small amount of current - 1 amp/hr), and a holding tank (up to 75 litres) where chlorination continues. 99.98% kill occurs within 15 minutes, 99.9989% in 30 minutes. Effluent is pumped by an electric macerator toilet to the top of the kill tank and overflows from the bottom of this tank to the top of the holding tank. Each tank has a small overboard vent(about 1/4 inch)and each is flushed overboard by electric pump as required (or could be drained by gravity if above waterline). The web site is http://www.envirotreatmentsystems.com.au/default.htm - diagrams/photos/explanations etc can be viewed. We would appreciate 1. your opinion of this new system. It would seem it could not be vented with a big aerobic vent as this would allow all the chlorine to escape (though the integral overflow tank could be) 2. your thoughts & recommendations about the best way to install and manage the heads on our new cat. I am suspicious of 'complicated electrical technology' on an offshore cruiser and don't much like the idea of having heavy, 'electric only' toilets. Many thanks Sandy
 
P

Peggie Hall/Head Mistress

Interesting system...

I would not go with integral tanks--for several reasons...starting with, prob'ly more tankage than you really need. Also, any problems (leaks, cracks, blisters, etc) with the tanks becomes a structural problem too...and, integral tanks totally eliminate options for any future use of the space. Fiberglass hulls can last a century, and who knows what the future may hold for you or a future owner. At the rate the world is evolving technologically, anything is possible, 15 years ago, holding tanks were only just beginning to be required...15 years from now, treatment could entirely replace them, and may have evolved into something the size of a shoebox that needs no power...who knows? And another owner may want to convert the waste holding tank space to additional water or fuel holding. So go with removeable tanks. Although the it uses more power, I'd go with the Lectra/San plus a small holding tank and set it up this way: Lectra/San (which is a much less complex system) on the most-used toilet, with a y-valve that allows you to by-pass it to flush directly overboard at sea where power consumption can be an issue. Holding tank on the other toilet for use only in those "no discharge" waters where you can't discharge treated waste. A y-valve to allow you to flush directly overboard instead of going into the tank. Toilets: one each, manual and electric. Weight will be about the same. Electric macerating on the "public" toilet for convenience, ease of use for landlubber guests (just push the button), and clog prevention. Manual Lavac en-suite, where it will get the most use while at sea, eliminating concerns about power consumption. Doing it this way provides the most convenience, flexibility, and least maintenance. You can ALWAYS flush at least one toilet legally, with or without power. No "kill tank" chemicals to carry...and no holding tank issues caused by chemicals.
 
S

Sandy Squire

Peggie, thanks for your advice...

1. Do you consider the Lavac to be the best value as regards ease of use and low maintenance? Our cat is a family liveaboard cruiser - we don't really need an electric macerator push button job as everyone can learn to use a hand pump - the macerator was necessary if we used the AquaSan system. We could use 2 Lavacs with installed holding tanks - do we even need Lectrasan? 2. We will be a liveaboard family of 6 with occasional guests & can build almost anything at this point - is there an optimum volume/shape etc for holding tanks? 3. Can you recommend any Y-valves or skin fittings (preferably plastic) that would meet USA CG requirements for locking if in 'no discharge' waters? 4. Do you have any knowledge of the HeadHunter jet flush toilets re degree of maceration achieved, maintenance etc Regards Sandy
 
P

Peggie Hall/Head Mistress

Glad to help...

1. Do you consider the Lavac to be the best value as regards ease of use and low maintenance? Low maintenance, yes...because the pump is a diaphragm. Ease of use is arguable. For adults who are accustomed to a spartan lifestyle, anything on a boat becomes easy if it's what you're used to. For small children, it can be a bit intimidating...but then, so can a piston/cylinder toilet. Since the boat is to be your family home, I'd think you'd want as much creature comfort as the boat and your wallet can afford, not the least. 2. We will be a liveaboard family of 6 with occasional guests and can build almost anything at this point - is there an optimum volume/shape etc for holding tanks? Optimum volume depends upon whether you'll also have a treatment device, and if so, how much time you'll spend in "no discharge" waters. If you have only holding tanks, obviously they'll need to be larger. Optimum shape is whatever fits the space, as long as the tank depth doesn't exceed 20". Read the article "What Size Holding Tank Do I Need" in the HM forum reference library. In fact, if you haven't already done so, read all the articles in the HM forum library. Do you even need the Lectra/San? That depends. If you'll spend a lot of time in coastal waters, your only choices are a holding tank or treatment...you can't flush the waste directly overboard. If the boat has only a holding tank only, a family of 6 will fill it up VERY quickly. Are pumpouts readily available? Do you want to be forced to weigh anchor and either find one or head out to sea in foul weather that shows no signs of abating for the next 3 days? If it were my boat, with the power resources to support a Lectra/San...and I were in waters where a treatment device is legal, you couldn't pay me to use a holding tank instead...only in waters where I have no other choice. 3. Can you recommend any Y-valves or skin fittings (preferably plastic) that would meet USA CG requirements for locking if in 'no discharge' waters? You can drill a hole in the handle of any y-valve to run a wire-tie through it. For quality, I'd go with Whale. 4. Do you have any knowledge of the HeadHunter jet flush toilets re degree of maceration achieved, maintenance etc They're high quality toilets, but use a LOT of flush water compared to macerating toilets. The don't actually macerate, the force of the water splatters solids and paper...the end result is comparable to maceration. VERY expensive, VERY limited parts/service availability. The mfr is the only source in the U.S. Headhunters are "megayacht" toilets, and priced accordingly. If you want to spend that kind of money, go with the Raritan Atlantes. Best macerating toilet on the planet IMO and the pressurized water version can use as little as a quart of water...current draw is 11 amps, but only for 45 seconds, so actual AH consumed is actually very low compared to other macerating toilets.
 
Status
Not open for further replies.