Black or Grey tank?

[Hialtitude]

    I've got a question into Adventurer about this picture and I was wondering if anyone on the forum might have the answer. Looking at this picture of the holding tanks on our 2019 EC1165 two (2) drains go into this lower tank. The smaller one on the right goes to the bathroom sink but the wider one behind the 2x4 bracing comes from the toilet. At this point I'm not sure now is it a grey water tank or black water tank? There is another tank that is further back but I can't tell what lines are going into it. Thanks for any ideas.

[testdog]

My first thought is that one of the pipes is a vent stack.
In the early days, Eagle Cap ran the sink drain into the black tank.
Speculation was that no one ever followed directions by adding the require two gallons of fresh water to the black tank after draining it.  Some water is required to be in the black tank - never completely empty.
Thus, EC had the bath sink drain into the black tank.
I don't know when or if they discontinued the practice.

[Hialtitude]

Thanks for the reply. I spoke with Adventurer and they said that the bathroom sink drains into the black tank

[testdog]

Thanks for the reply. I spoke with Adventurer and they said that the bathroom sink drains into the black tank

Thanks for the update.  Are you okay with that (draining into the black tank)?

(Your post will springboard a poll question about this issue.)

[Hialtitude]

You really don't have a choice.  Looking at the picture there is no way to get the sink drain back to the other tank.  As long as there is liquid in the sink elbow you should never have a problem.  Mixing grey water in the black tank also helps break down solids. I guess you just have to be good with it.  I was hoping to label each tank in case something comes up (excuse the pun).