How do YOU Dump YOUR Gray Water? (Safely, Easily and Legally – of course)

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February 26, 2011

There were six of us.  We were sitting around a campfire sharing stories and talking about most anything that came into our minds.

All of us had settled at a Corps of Engineers campground in Southside Virginia for a week of boating, fishing and swimming in Kerr Lake.

The campground was nicely laid out and offered both water and electric on our sites – but there were no sewer hookups.  The dump station was a considerable distance away, near the entrance to the park.

One of the guys looked up at the rest of us and asked, “What do you do with your gray water?”  “My gray tank fills up in a couple of days – I can go a full week with my black tank, but not the gray.”

Pete, one of the younger men in the group, responded, “I crack the drain valve after dark and let it slowly dribble out onto the ground.  Shucks, it ain’t poison – it’s just used wash water.”

Mike stared in stark surprise.  “That is against the law!”  “If you get caught they will write you a ticket and then kick you out of the  campground.”

George said, “I’ve got one of those blue tanks.”  “But, last time I tried to pull it to the dump station, a wheel fell off – so I just do what Pete does.”

We continued to exchange views on the dangers and possible benefits of letting gray water drain onto the ground.

Pros were watering the plants during a drought, keeping basically clean water out of the sewer treatment facilities, not having to fool with blue tanks, etc.

Cons were breaking the law, leaving food particles on the ground to attract insects and animals, bacteria from black water left in the drain that mixes with gray water, soap and cleaners that are not environmentally friendly, etc.

Ultimately, we all agreed that the proper thing to do was abide by the No Gray Water Dumping Law and the campground rules.

But, how do you get 40 gallons of gray water weighing 320 pounds from a low-lying campsite up a hill to the truck and from there to a dump station a mile away?  Hooking up a camping trailer that is set-up on a campsite and moving it to a dump station is an option, but a real time consuming hassle.  Even moving a motorhome that is parked and leveled takes a lot of extra effort and time.

Well folks, this is my solution.  It can be inexpensive, works every time, and is easy to manage.  The best part is you get to make it yourself.

I started by purchasing a 12 volt marine aireator pump.  The cost at the time was around $25.   Mine is a 750 GPH model 4370 pump.  It has been replaced with the  Tsunami 800 GPH Dual Outlet Aerator Pump. It should work just as well as the one I used, but one of the outlets will need to be capped off since it is a dual outlet pump.

You will also need an additional cap for your dump pipe.  They run about $2 at any camper supply store.


Pump, cap with hole, drill bit, nut and sealant needed to complete project.

You can attach the threaded stub on the inlet of the pump to a hole drilled in the cap with a regular 1-1/8″ spade type wood boring bit.   You may want to cut off part of the threaded stub on the inside of the cap once the nut is tight.

Run a bead of RTV (silicone) sealant around both sides of the connection to make it liquid tight and screw the supplied plastic nut onto the inside.

Allow the RTV to dry overnight before using.  You might want add a threaded PVC  “L” to the end of the pump and position it to point down to assure complete drainage in the camper outlet pipe.

Completed pump assembly with a small portable battery and clips on the end of the pump wires.

You can now put the cap with the pump on your gray water dump outlet.  Connect the pump wires to a portable battery or the camper battery, screw on a garden hose you use only for gray water, and pump all of your gray water uphill to a blue tank in the back of a pick-up  You then drive to the dump station and drain the tank.  No lifting, rolling, towing or broken wheels!

PLEASE, never try to empty a black tank with this pump!

Example of a PVC bag used for gray water transport.

Some campers prefer to use an old water bed mattress or air pillow rather than a blue tank.  This approach will reduce the space needed to carry a solid shaped tank in the camper or truck.  Connecting a drain hose to empty the bag may present a challenge if it does not have a garden hose fitting.

Being one afflicted with “Tinkeritus”,  I went a step further with the project and adapted a surplus 55-gallon plastic drum so that it has a 3″ camper dump valve.  This allows me to connect a 10′ sewer hose or even my new portable pump to the drum’s outlet at the dump station for emptying.  I fill the drum through the capable hole in the top.  If you have room to carry the drum with you when staying on no-sewer sites for more than a couple of days it can save a lot of grief getting rid of your gray water.  But, be forewarned, other campers that see what you are doing will want to “borrow” your equipment – which is easy to share.

So you see, it does not cost a lot to build up a gray water pump system to make emptying the tank a lot easier – and legal!  Obviously,  the 55 gallon drum project may be overkill.

If you are not into making things like this, you can always spend a few hundred dollars for a macerator pump system.  These work extremely well for both black and gray tanks since they grind solid waste and tissue into little pieces and discharge everything through a 1” plastic hose.  We now have macerator system that I purchased from RV Sani-Con .


Do you camp with a pet?  Please visit my No Pet Add-On Fees website at or by clicking on the blue highlighted and underlined text above for information regarding camping with pets in Virginia State Parks.

Private e-mails can be sent to:  RandynNancyageeatgmaildotcom (substitute a @ symbol for the bold at and a period . for the bold dot when entering the address into your e-mail program).

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  1. Or you can purchase a Sewer Solution which is a lot less complicated. According to the manufacturer, it will pump up to around 80' if I remember right

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  5. So many times I’ve seen campers without a good pumping system. Water accumulates over time causing mold to grow. After that mood could spread in other areas causing a lot of problems. Your post was very helpful.

  6. Professor95

    The project should work well for your needs. I am guessing you will be at North Bend Park and know the difficulty of getting gray water from a camper to the dump station. I remember filling a 20 gallon blue tank and then trying to lift it up by the handle to tow. That’s 160 pounds of water to lift and pull – it is a real strain on us old guys. WOW – a 32 gallon blue tank would be 256 pounds when filled. Even with wheels and a handle I would never be able to maneuver that much weight to a dump station unless I could put the empty tank in the back of the PU and pump water into it.. 20 gallons is a nice size to store and manipulate.


  7. We were contemplating this very same issue while making our camping plans for this year. We made reservations for a couple of weekends at Kerr Lake, but we usually don’t have a problem with running out of room in the gray tank for a weekend stay. Our concern is that we wanted to spend a week at Myrtle Beach State Park, without sewer. I budgeted for a 32 gal blue tote, but managed to find a 20 gal tote on Craigslist a couple days ago for $60. I’ll have to make more trips (and be careful about not overfilling the blue tote), but it’s worth a shot to see how well it works.