How to Build an a Grey Water Filter

Gray Water Barrel

Building a gray water filter is an excellent way to reuse water and save on your water and sewer costs. Gray water is the water that comes from showers and the washing machine. All of the other drains are not suitable for recycling in this manner as they need more sophisticated forms of filtering. There are regulations governing the discharge of gray water, and you should check with your local district for their directives. Basically, it can be used for irrigation if you produce less than 400 gallons per day, and it can only be used on your yard.

Things You'll Need

• 55-gallon barrel
• Plastic spigot
• Hose clamp
• Nylon hose
• Sand
• Crushed stone
• Weed mat
• Gravel
• Garden hose

Instructions

1. 

   Follow the suggested Best Management Practices 13 steps to reusing gray water. Each of these steps are important to the safety of everyone involved and to reduce the chance for bacterial contamination. You may have to get a permit to use discharge water for irrigation, so check with your local county office. You can print out the list imaged here.

2. 

   Since most gray water comes from washing machines, the water must run through a course filter to remove all the fibers in the water. This can be done by clamping a mesh bag over the discharge hose. A simple nylon hose is perfect for this. Use a 3-foot section and clamp it onto the hose with a hose clamp. This will have to be changed every few weeks, depending on how frequently you wash clothes.

3. 

   Pour a 6-inch layer of stone into a 55-gallon drum with a spigot in the bottom. Place a sheet of weed mat on top of the stone, cut to fit the circular barrel. Pour in a 10-inch layer of sand on top of the weed mat. And finally, add a thin 1-inch layer of gravel to hold the sand in place. This will be the filtering system of your gray water.

4. Divert the water from the washing machine discharge hose into the prepared 55-gallon drum that has a hose attached to the bottom spigot. It will passively flow through the layers of sand and rock and will flow out of the hose. This water can be used immediately for watering plants or drained into another barrel for use later during the day.

5. Use the water as soon as possible as the bacteria present in the water will multiply quickly, leaving you with foul-smelling water not suitable for use on edible plants.

Resources

• Using Gray Water at Home