Toilet-top hand washing basin


The Wash 'n' Flush Toilet Basin

What Is It?

The Wash n' Flush is a Humboldt State University environmental science 410 senior project implemented by Jeffrey Steuben, Annie Welbes and Tim Dower which is located in the downstairs bathroom at CCAT. This is a toilet modification that allows users to save water by utilizing the wastewater from handwashing to flush the Toilet.

If you think of this project as a way of doing a DIY version of an Aqus Toilet, you'd be mostly right.

These are also commercially popular in Japan.

Why Do It?

The goals of our project were:

  • conserve drinkable water by eliminating the use of clean, potable water to flush toilets.
  • break down social stigma around toilet water pre-use.
  • build awareness of creative water conservation.
  • make toilet modification replicable, accessible, and affordable to low income households.
  • conserve water at CCAT.

We thought about the fact that clean, drinkable water is being used to flush human waste down the toilet. We consider this to be environmentally and socially irresponsible. Therefore, we took action.

Step 1:

We are tracing the outline of the tank and the location of the overflow pipe.

Step 2:

This is the template we used to locate the overflow pipe, the faucet location, and where to place the brackets to secure the lid in place.

Step 3:

Using the hole saw to make a channel for the funnel to sit flush with lid surface, and a hole for the funnel drain through.

Step 4:

These brackets, attached to the underside of the lid, sit inside of the tank, holding the lid in place.

Step 5:

Don't forget to seal the lid with some sweet and low VOC paint! yeah!

Step 6:

The basin was placed on the lid to locate where the drain would be located. We drew a circle on the bottom of the basin through the previously cut hole in the lid, then used the drill with a molybdenum bit to remove the portion of the basin that would be the drain.

Step 7:

Here's Tim bending the copper tube over his knee to create a faucet-like effect. This technique is not recommended, as the pipe may kink during the process. Instead, use a pipe bending spring to keep the pipe open and bent.

Step 8:

Hey, look at that bent pipe! Now slide it into the hole in the lid and secure it in place.

Step 9:

Attach the small vinyl tube to the water inflow tube, then feed it through the copper pipe. This is where the water will come out of your homemade faucet. Note the two 32 ounce bottles in the toilet tank to decrease the amount of water used to flush.

Step 10:

Here you can see the larger vinyl tube attached to the bottom of the funnel. It runs directly into the overflow tube in the toilet.

Step 11:

We added this Star Trek-like panel to guide the water that was splashing onto the wall, back into the basin. This addition may not be necessary depending on your particular basin and water pressure.

Step 12:

Wear and tear

The Wash n Flush as of October 2013. It is well-used and complete with a bar of soap!

As of October 2013, the CCAT's water-saving-designed Wash n Flush is still fully operational. Here you can see it in proper working action!

According to a kind CCAT guide, the Wash n Flush provides "a lot" of water with which to wash hands! Indeed, the water from the Wash n Flush sink pipe flowed forth approximately another 20 seconds after the video ends--quite an ample amount. Though the fundamental functionality of the system has remained intact, time and usage has left its mark on the Wash n Flush. Below are the observable changes since its creation.

As of October 2014, the CCAT Wash n Flush toilet is still fully operational. The video below was taken on October 15th, 2014.

Although there are visible signs of wear and tear on the parts of the Wash n Flush toilet, the system is still functioning properly. According to an on-site source, the toilet gets used an upwards of 20 times a day, 7 days a week. Of the two people I interviewed at CCAT, neither of them reported any problems occurring with the system in the last 2 months since they had been present at the building. Not even a backup or broken flusher!


The Wash n Flush is a reliable water-saving system, but this model does require some basic upkeep.


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