Adding holding tank to Electro Scan

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Jan 31, 2023
Vessel Name
Last Meander
Vessel Make
Ta Chiao CT 35 Sundeck
We are getting ready to do the Great Loop bit our boat has the Electro Scan system. Can I lock off one head and plumb holding tank sharing Electro Scan water intake line? Any ideas how to do this? Things to watch out for?
Quick answer is probably yes. Electrosan discharge is not allowed in many boating areas these days. Most areas are no discharge and I wouldn't expect pump outs are that hard to find on the loop. When offshore in a legal area I run the macerator to empty the holding tank. Otherwise I pump out. I eliminated any setup that would flush a toilet directly overboard so there is no question if I am ever inspected. My electrosan is still inplace but decomissioned. I installed new toilets and switched to fresh water flush. So much nicer than using seawater. I put in a y valve on the toilet discharge hose so I could send to the electrosan or the holding tank but I suspect I will eventually remove the electrosan.
I just put a "Y" valve in line between the Electroscan and the overboard discgarge. That way I could go straight overboard from the Electroscan or to the holding tank.

When necessary, I would shut the overboard discharge thru hull and take the handle off.
Exactly what I would recommend. All the Great Lakes are NDZ so I would also close the thru-hull and remove the handle from any holding tank overboard discharge pump. You can use the ES on all the US navigable rivers (defined as interstate with access to the sea), but maybe not in some marinas on those rivers. Marinas are considered private property, so can make their own rules as long as they don't violate federal law.

I have what I think is the perfect setup.

Both heads feed into a holding tank.
The macerator pump connects the holding tank to my Electroscan which discharges directly overboard. The macerator pump is controlled by a Raritan Hold N Treat controller, which is controlled by a key switch.

If the key switch is in automatic the holding tank is kept near empty with all waste discharged is treated waste. This is perfect for areas that allow treated waste discharge.

If the key switch is in off then no discharge happens and I use the local pumpout service, or I wait until I am in a legal area.
I should’ve asked this before, now I’m almost done installing. Is there any reason this won’t work?
We are getting ready to do the Great Loop bit our boat has the Electro Scan system. Can I lock off one head and plumb holding tank sharing Electro Scan water intake line? Any ideas how to do this? Things to watch out for?
Does the Electro Scan perform a more detailed inspection of the contents than the Electro San model?
Why not continue to use both heads... Continue to use the ElectroScan where you can (just about everywhere but the Great Lakes and New's legal on the entire inland river system), put a y-valve in the other toilet's discharge line that lets you send flushes to the tank where you can't. There's nothing to be gained by sending flushes through the ES first...that won't make it legal to dump the tank inside the "3 mile limit."

I think you're asking if the ElectroScan treats to a higher level than the earlier LectraSan...the answer is no. The difference between them is in the controls. The ElectroScan controls are a lot more user friendly and provide actual information instead of requiring you to interpret blinking lights.

I'll be glad to answer any additional questions.

Next1 given that waste systems are prone to failures it looks like your solution is far from conventional and may be overly complex (increasing odds of failure). I cannot say for sure that it will not work but I don't think these 3 systems (4 if you count the holding tank) were designed to all work together. The vacuflush vac system is designed to work with a VF toilet. The VF system depends on establishing a vacuum to the toilet but that will not exist in your setup.

An Electosan has a panel at the toilet but a marine elegance has its own control panel. Both have timed parameters.

Finally I hope your pump out is drawn from a tube that extends down from the top of the tank and perhaps ends an inch or two from the bottom of the tank. If it really is as drawn from the tank bottom it might be prone to getting clogged with no easy way to clear it.

Good luck and let us know how it turns out.
Thanks for the info! I tend to make things more difficult than they need to be, lol. This is the the logic behind the set up.
I spend almost every summer weekend in a cove that is a no dump zone. On my way to, and from the cove, the Electric scan is accepted method of discharge.
So, my theory is, treat all of the waste before it goes into the tank so I can dump the tank on my return trip.
Is it illegal discharge the tank even if it is treated first?
I’ll be digging into the wiring this weekend, if I remember, correct, there to external trigger reports on the ES that can connect to the marine elegance. Hopefully between the chopper in the toilet and the chopper in the EC, the bottom won’t get too clogged, if so, I’ll replace the tank next season.
I should’ve asked this before, now I’m almost done installing. Is there any reason this won’t work?

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If you do that you will be defeating the purpose of the electro-scan.

The electro-scan kills 99%+ of the bacteria, etc... But not all of it.

If you plumb the effluent into the holding tank the bacteria will reproduce.
Is it illegal discharge the tank even if it is treated first?

Yes. The ElectroScan is a Type I MSD, all of which are USCG certified to discharge treated waste directly overboard. Once it goes into a tank it's no longer considered treated waste. Reason: Although it reduces bacteria count to less than 10/100 ml (1000/100ml is the legal limit), only one of the li'l buggers has to survive in the tank to multiply into a zillion..

I should’ve asked this before, now I’m almost done installing. Is there any reason this won’t work?
View attachment 154184
Your system is plumbed similar to mine, except we have two Elegance heads feeding into the Electrosan. I also have a "Y" valve to a separate through hull fitting or to the holding tank. My macerator pump vacates the HT the same way your system does, no "Y" valve, but simply a breaker switch. Usually we have the HT pumped out at our Club's facility. I did put in gauges in both heads to be sure to empty the tank when appropriate.

PS I did replace the circuit board to the ES (due to a power surge) and was blown away with the quality of service I received from Raritan. They are truly a customer service focused company!
The Propper way to plumb is all effluent goes into the holding tank. On the outbound side Plumbed to the discharge pump then to the elctrosan to batch treat the tank for discharge. It would be more difficult on the outboard side to bypass the electrosan since the pump is tied into the system and runs for a pre determined time ( batch size ) for the unit. You could simply just treat all waste being dumped overboard even in accepted dumping zones. Nothing wrong with that.

If you wanted to bypass the electrosan as an option a y valve and a second pump are required. Separate switch and control for 2nd pump.

The purpose of the lockout of the valve is to create a physical barrier between the holding tank and environment. So no leaks or accidental discharges occur.

What I dont understand is why is locking a head door compliant when is does not create the physical barrier.

The electasan hold and treat has a key system. If the key is "removed" Electrosan says it qualifies for meeting the lockout requirement . I was boarded once and they accepted it. But the key must be removed. I have on my new vessel installed key switches with the keys removed. for discharge pumps Have not been boarded yet. I still keep the overboard dumps locked out anyway.

I ran a electrosan hold and treat for a long time. everything went into the tank and then batch treated as needed to empty. I felt better about direct dumping of waste as treated all the time.


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Because the ES can only hold a max of 1.5 gal at a time, it would be wise, if not necessary to install Raritan's "hold 'n' treat controls" package if you want to empty the tank via the ES. It will meter out only as much as the ES can accept. And because the motor in the ES is not designed for continuous duty, it has to "rest" for about 15 minutes periodically to cool off. Call Raritan to get it. 800-352-5630.

We have an ES, a 75g holding tank and a Y valve in our aft SR. We have a composting head in the fwd location.

We did an 8yr Great Loop with this configuration.

When we were in NDZ's we would use the Y valve to switch the discharge from the ES to the holding tank. When we were in non-NDZ or open water we would discharge from the ES, its been treated to USCG standards, overboard.

The composting head was IF we got checked by the clearwater NAZIs then we'd be OK. We were never checked.

Any questions, PM me to let me know
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