My "Sewer Solution"

A lot of RV owners use a product called the Sewer Solution to empty their holding tanks. It is an attachment for your sewer outlet that uses a stream of water to break up waste and pump it through a small 1" hose. It is based on the venturi effect of a high pressure stream of water. This is a great product and I would highly recommend it. However, I'm always looking for ways to build things myself (and also like to save money), so I set out to see if I could build a similar device using readily available components. I built this device for around $45 and it works great.

The device I built starts with:

3" PVC cleanout Tee (threaded in the middle and glue joints on the ends)
short pieces of 1" and 1/2" PVC pipe
a 1/2" brass pipe plug with a 1/8" hole drilled through it
a 1" shutoff valve (allows you to backfill your holding tanks for flushing)
12' of 1" clear reinforced hose
a backflow preventer. (This goes between your fresh water hose and the device. You can find it in the sprinkler section of your local Lowes for about $4.)
reducing bushings to reduce from 3" to 1/2" on one end and 1" on the other.
assorted 1/2" and 1" connectors
an RV sewer pipe connector 3" pipe thread to 3" bayonet connector (see picture below)

The key to making this work is to build a nozzle inside the 3" tee.

To do this, you must pass a 1/2" pipe through the reducing bushing on one end of the tee. PVC glue connectors have a lip on the inside edge to serve as a backstop. I used a Dremel tool to remove this lip so that the 1/2" pipe could pass through to the inside. The pipe was then glued into place. On the end of the pipe, I glued on a 1/2" connector and screwed in a 1/2" brass plug.

The brass plug has a 1/8" hole drilled through it. This makes the nozzle.

In the following picture, you can see how this looks when the assembly is inserted into the 3" tee.

The other end of the tee consists of a 1" shutoff valve that is glued into the reducing bushing using a short piece of 1" pipe. The combination of the reducing bushings and 1" valve forms a funnel on that end of the tee. This enhances the venturi effect when the device is turned on. Use a 1" hose nipple to attach the hose to the end of the valve.

The last piece to be added is the 3" thread to 3" bayonet adapter. You can get this from your local RV supply house.

Here is the finished product attached to our trailer. (Note the black plastic backflow preventer between the hose and the device):

Here is the assembly hooked up to the sewer cleanout at our home. Notice how the pump has to push the sewage uphill.

If you have ground clearance problems, you can tilt the unit as long as the water can still drain out the bottom. You may also consider installing the shutoff valve inline with your 1" hose.

That's it! It works great and the total cost was only about $45.

Tracy Oakley
Cabot Arkansas
toakley1@yahoo.com

A Water Powered RV Sewer Pump