Jump to content

Easy way to repurpose an unused black tank for grey water


Recommended Posts

Here's one way to use a black tank that may be available for other uses (e.g., a composting toilet installed).  Since the black and grey tanks share the same drainage pipe, an unused black tank is only good for holding extra grey water without major modifications to the plumbing.  It's pretty simple to put a cap with a hose connection on the end of the tank drain pipe and then use an inline hose pump to pump up to 15 gallons (in my case) of grey water into the black tank.

I never thought having extra grey water capacity would be important, but camping on the East coast involves pretty hefty fines if you are caught draining your gray water into nature.  I also assumed that camping with full water / electricity hookups meant unlimited, long hot showers in the Ollie (not the case!).  So, 15 extra gallons of grey water capacity could mean you don't have to tow your trailer over to the dump station in the middle of your camping trip because you have to empty your grey water tank.

Edited by NCeagle
spelling
  • Thanks 2
  • Like 3

John and Anita

2020 Oliver Elite II, Hull 688

Tow Vehicle:  2006 Silverado 2500HD Crew Cab.  6.6L Duramax

States Visited Map

Link to post
Share on other sites
On 3/22/2021 at 4:35 AM, NCeagle said:

Since the black and grey tanks share the same drainage pipe, an unused black tank is only good for holding extra grey water without major modifications to the plumbing.  It's pretty simple to put a cap with a hose connection on the end of the tank drain pipe and then use an inline hose pump to pump up to 15 gallons (in my case) of grey water into the black tank.

How did you do this, seeing as there is only one outlet for the grey and black tanks. 

2021 Oliver Legacy Elite II - Twin Bed - Hull 762 | 2018 F150 3.5L Ecoboost V6 w/ Max Tow package

Link to post
Share on other sites
4 minutes ago, SeaDawg said:

Jordanv, did you get the composting toilet?

Yes, we did. We are thoroughly enjoying it as well. We are on the borderline of boondocking currently (we have power and water but no sewer hookup) and we are glad we do not have to go into town to dump a black tank. Our host lets us drain the grey water into the ditch 👍

Edited by jordanv
  • Like 1

2021 Oliver Legacy Elite II - Twin Bed - Hull 762 | 2018 F150 3.5L Ecoboost V6 w/ Max Tow package

Link to post
Share on other sites
  • Moderators

Then , you don't even need to worry about his process .

I'm interested in more detail, as well.

 

  • Thanks 1

2008 Ram 1500 4 × 4

2008 Oliver Elite, Hull #12
 

 

Link to post
Share on other sites

Me too. I have a full grey water tank right now, almost, and am boondocking on BlM land. Not supposed to drain anything onto dirt. 

What becomes the inlet for the black water tank? Draining the grey water, and using a pump into the black water tank I understand, except what becomes the black water tank inlet, if the grey water tank is emptying?

      

2014 Toyota Tacoma 4x4

2021 Elite I #758       

      image.png.d972b5fc86270818b1e0f030bfaa433a.pngMap of Provinces I Visited

Link to post
Share on other sites

Transfer the grey water through a portable pump (with a good inlet filter) into the black tank rinse port (on the left side in front of the tires.)

A simple  solution indeed, except for keeping hair and food debris from clogging the filter. That could get tiresome....we need pictures please.

There is also the problem of venting, the tank connects to the 1.5” black vent pipe that goes out the roof, it tees into it under the sink. If the black tank should get too full, the water will flow into the sink, and then onto the floor, and back into the grey tank via the drain. Hopefully the blade valve is open! What a computer geek would call a waste water Infinite Loop . 😀 That could be very entertaining. Maybe it’s time to revive this thread... https://olivertraveltrailers.com/forums/topic/3213-grey-water-recycling/. It really is a shame that the black tank is several inches higher than the grey one, if they were level you could gravity feed one into the other quite easily.

John Davies

Spokane WA

Edited by John E Davies
  • Like 1

"Mouse":  2017 Legacy Elite II NARV (Not An RV) Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/

Tow Vehicle: 2013 Land Cruiser 200, 33" LT tires, airbags.

Link to post
Share on other sites
  • Moderators

A "relatively" simple solution would be to drain the bathroom sink water into the black tank. You could achieve this with gravity only. Pull the black tank valve to dump at any time. I would save 15 gallons of space in the gray tank.

  • Like 2

Steve, Tali and the dogs: Reacher, Lucy and Rocky plus our beloved Storm and Maggie (both waiting at the Rainbow Bridge) 2008 Legacy Elite I - Outlaw Oliver, HULL NUMBER: 0026 2014 Legacy Elite II - Outlaw Oliver, HULL NUMBER: 0050 2017 Silverado High Country 2500HD Diesel 4x4 

 

      ALAKAZARCACOCTDEFLGAIDILINIAKSKYLAMEMDMA       ABBCMBNSYTsm.jpg

 

 

Link to post
Share on other sites
  • Moderators
38 minutes ago, ScubaRx said:

A "relatively" simple solution would be to drain the bathroom sink water into the black tank. You could achieve this with gravity only. Pull the black tank valve to dump at any time. I would save 15 gallons of space in the gray tank.

I've  mentioned this several times, but definitely the "easiest " I  can think of. 

Many SoB trailers drain bath sink to the black. Relatively easy plumbing retro in an Ollie. 

 

 

2008 Ram 1500 4 × 4

2008 Oliver Elite, Hull #12
 

 

Link to post
Share on other sites
Posted (edited)
10 hours ago, John E Davies said:

Transfer the grey water through a portable pump (with a good inlet filter) into the black tank rinse port (on the left side in front of the tires.)

A simple  solution indeed, except for keeping hair and food debris from clogging the filter. That could get tiresome....we need pictures please.

There is also the problem of venting, the tank connects to the 1.5” black vent pipe that goes out the roof, it tees into it under the sink. If the black tank should get too full, the water will flow into the sink, and then onto the floor, and back into the grey tank via the drain. Hopefully the blade valve is open! What a computer geek would call a waste water Infinite Loop . 😀 That could be very entertaining. Maybe it’s time to revive this thread... https://olivertraveltrailers.com/forums/topic/3213-grey-water-recycling/. It really is a shame that the black tank is several inches higher than the grey one, if they were level you could gravity feed one into the other quite easily.

John Davies

Spokane WA

@John E Daviesis right on.  His description is how I did it.  I did NOT use a filter since we don't put any food / grease into our grey tank so it's soap and hair only - not a problem for the pump (as of yet).

I'm not sure what good pictures would do - I didn't take any - but it would show a hose coming out of the back bumper (connected to the black / grey drain pipe with this: Camco Durable Sewer Cap with Hose Connection- Caps the Sewer Connection to Prevent Leaks, Easy Install and Simple Use (39463)).  Then there's a pump like this Trupow 1/10HP 330GPH 115-Volt Mini Portable Electric Utility Sump Transfer Water Pump with Water Hose Kit that attaches to the drain hose and subsequently another hose to the black water flush port / inlet.  Hook it up, then pump in some grey water until the black tank is full.  Common sense provides the valve configurations...  when filling the black tank, the black tank valve must be closed and the grey must be open.

Problems can be avoided with the vent, etc. by not overfilling the black tank.  It's not that hard to be careful.  I timed how long it took my pump to transfer 15 gallons of grey water to a bucket before I tried this.  It took that pump listed above 3 minutes and 45 seconds for 15 gallons.  I ran the pump for 3 minutes and 30 seconds and then checked my black tank SeeLevel monitor and it was at 95%.  I figured that's close enough, so I can run the pump for 3.5 minutes safely.

There's no other way I can think of to easily use the black tank without plumbing modifications.  I wanted to preserve everything for resale just in case. 

It's also worth noting that we ordered the composting toilet with our Ollie, so the black tank is there but has NO hole in the top cut out.  If you upgraded to the composting toilet and you still have the hole on top of the black tank you would have to cover / seal the hole.

Edited by NCeagle
  • Thanks 1
  • Like 3

John and Anita

2020 Oliver Elite II, Hull 688

Tow Vehicle:  2006 Silverado 2500HD Crew Cab.  6.6L Duramax

States Visited Map

Link to post
Share on other sites

That pump looks interesting, can you buy replacement impellers and gaskets? It doesn’t have a switch, maybe adding a waterproof one would make it safer. Does it come with silicone grease? BTW we really like to look at pictures😀

Thanks.

John Davies

Spokane WA

  • Like 1

"Mouse":  2017 Legacy Elite II NARV (Not An RV) Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/

Tow Vehicle: 2013 Land Cruiser 200, 33" LT tires, airbags.

Link to post
Share on other sites
2 hours ago, John E Davies said:

That pump looks interesting, can you buy replacement impellers and gaskets? It doesn’t have a switch, maybe adding a waterproof one would make it safer. Does it come with silicone grease? BTW we really like to look at pictures😀

Thanks.

John Davies

Spokane WA

I've only used that brand of pump a few times now and it seems fine - comparable to others I've had in the past.  This particular one does have parts / kits available to repair it, but ones I've had in the past just had the motor die after a few years of pretty heavy use before anything else broke.  I use it for different things around the house.  Examples are transferring water from rain buckets to my pool (a lot) or getting water off of my boat cover when it caves in and turns into a pool 😁.  A rainproof switch with a permanent, long cord would be SUPER NICE (and smart too)  - right now I just unplug it from an extension cord coming out of the exterior 120V receptacle on the curb side.  Definitely don't want to be standing in a puddle!  It does get warm when I run it for extended periods - like 20 minutes or so transferring water from rain buckets - so I give it time to cool down when needed.

I didn't think pictures of this setup would be interesting, but I stand corrected!  Next time I have it set up I'll update this post with a few if someone doesn't beat me too it.  😉

 

 

  • Like 2

John and Anita

2020 Oliver Elite II, Hull 688

Tow Vehicle:  2006 Silverado 2500HD Crew Cab.  6.6L Duramax

States Visited Map

Link to post
Share on other sites

Could a valve like this one be screwed at the waste valve?  You open grey valve, once the tank is full, you open the black tank valve.  The water will fill the black tank.  When ready to dump, you open the added valve.  I saw a setup like this working in another RV.  Was wondering if it could be possible on a Ollie?!

image.thumb.jpeg.9df26940715131f8cb8a49ad8dabfb2c.jpeg

Link to post
Share on other sites
  • Moderators
16 hours ago, JoeSyl14 said:

Could a valve like this one be screwed at the waste valve?  You open grey valve, once the tank is full, you open the black tank valve.  The water will fill the black tank.  When ready to dump, you open the added valve.  I saw a setup like this working in another RV.  Was wondering if it could be possible on a Ollie?!

Not really - on an Ollie, the black tank is higher than the grey so you'd have to use a pump.

  • Like 2

Snowball • The world's only spherical Ollie

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...