Two Vegetable Wash Station Designs

Vegetable Wash Station Design 1

Based on design at One Step at a Time Gardens

This system is designed to provide a simple and effective method of hand washing fresh vegetables using materials commonly available from a large hardware/building material retail outlet at a modest cost.

Basic layout of the wash station (in order)

• Hand wash sink - see photo
• Shallow vegetable wash sink - see photo
• Rack for allowing vegetables to drip dry – see photo
• Wide tub sink (made from a 55-gallon food-grade plastic drum) for washing vegetables – see photo
• Another drying rack – see photo
• Deep vegetable wash sink – see photo

A drawing of the complete wash station, Wash Station.pdf, provides:

• Overall view of the wash station
• Water drain line and drop-down water delivery line
• Complete parts list for the drawings
• Drawing of the support-post layout
• Drawing of the base-line layout
• Drawing of the finishing construction details

Cost
The materials for this complete system can be purchased for a little under $1,000.

About the hand wash sink
This sink is not intended to be for ‘after bathroom’ use. This sink is for wash station operators to wash their hands prior to washing vegetables.

• NEVER USE the hand wash sink for washing vegetables.
• NEVER USE a vegetable washing sink for washing hands.

The best practice is to always wash your hands with soap prior to washing vegetables.  The hand wash station is located next to a roof support post, which is a convenient location to locate a soap dispenser and towel dispenser.

1) Selecting a site

• Select the site before beginning construction.
• Site needs to be level: 24 ft. in length and 3 ft. wide.
• Site needs to have ample workspace around it, roughly 6 feet on each side and around each end.
• Wash station roof requires overhead clearance of 9 ft. (plus a little more) along entire length of station.
• Locate near vegetable pack-out and cooler locations.
  Once the vegetables are clean and have finished drip-drying, it is helpful to minimize the transport distances to these two facilities, as they are the next step in the post-harvest process.

See site layout [PDF] of One Step at a Time Gardens.

2) Purchase materials for construction

• Lumber, roofing and sinks and drain line parts are readily available at hardware/lumber retail stores.
• Supplies for the water line and the blue tub can be purchased from a commercial vegetable irrigation supply company.
• For the blue tub use a 55-gallon, food-grade plastic drum, usually available from commercial food processing companies.
• Treated lumber required for wash station:
  • 3 - 12 ft. 4 x 4’s
  • 29 - 12 ft. 2 x 4’s
  • 2 - 8 ft. 2 x 6’s
  • 1 - 8 ft. 2 x 2’s
  • 1 – 4 x 8 ft. sheet of ¾-inch untreated plywood
• Recycled HDPE plastic lumber required for drying trays:
  • 9 - 10 foot 1 x 4’s

Note for organic growers:
If the producer is organic certified, the use of treated lumber may be in conflict with organic certification, so be sure to contact your certifying agency before purchasing materials. Metal poles with a poured cement base may be used as a replacement for the 4 x 4 roof supports, but alternative attachment procedures will be required. Contact your local lumber supply company for direction.

Similarly, untreated lumber may be used in place of the 2 x 2’s, 2 x 4’s, and 2 x 6’s. A food-grade water repellant should be applied to the wood surfaces, to provide appropriate outdoor protection of the wood surfaces. Keep in mind that this wash station is designed such that the vegetables do not come in contact with the wood surfaces at any point.

3) Build the wash station

• Install the three 4x4 support poles to provide stability for the roof. Dig holes so that each pole is 3 ft. into the ground.
• Construct individual components of the wash station. Each PDF below has a drawing of the component, a parts list and various drawing views to facilitate construction.
  • Steel sink
  • Drying rack (long)
  • Blue tub sink
  • Drying rack
  • Plastic sink
• When each component is completed, attach to the base-line layout, described in Wash Station.pdf.

About sinks and drain lines
It is helpful to attach each sink section with the side of the sink across from the drain slightly higher than side closest to the drain. A ½-inch elevation of the side away from the drain may be sufficient. This will facilitate smooth draining of the sink water after each use - see photo.

Once all components are attached to the base line, the drain lines can be assembled to fit individual sinks. Refer to Drain Line.pdf for specific details.

When constructing lines to individual sinks, they can be fixed drain lines as shown in the drawings, or can be made more flexible by installing 1 ½-inch flex PVC tubes. The flex tubes allow easier alignment of the drain lines - see photo.

Remember to create a slope in the drain line, starting with the hand wash sink (highest) to the exit end of the line. A 6-inch drop along this length will create sufficient gravity flow to drain the dirty wash water - see photo.

Attach a sufficient length of 3-inch layflat hose to the exit end of the drain line, to carry this dirty water to the drain field for the wash station.  A hose clamp works well to clamp the layflat hose to the 2-inch PVC drainpipe. This clamp easily can be removed to facilitate the removal of small root crops that may clog the drain line.

Supports for the drain line can be made by attaching 2 x 4 cross supports at four places along the drain line as shown in Drain Line.pdf and Wash Station.pdf.

• Attach water line support boards and roof support boards to the support posts.
• Construct roof trusses and attach to structure (see Wash Station.pdf and Roof.pdf) - see photo.
• Install water lines in the station (see Water Hose Line.pdf).

4) Build tray for air-drying washed vegetables.

This tray sits on the drying rack with the long side of the tray perpendicular to the length of the rack. Two trays can fit on each drying rack (see Drying Tray.pdf).

The bottom of the tray is made from plastic netting that has ¼-inch holes. The netting is cut larger than the bottom of the tray, and then each corner is cut on the diagonal to the dimension of the bottom opening in the tray. Fold the sides of the netting up onto the corners of the 1 x 4 sides of the tray and attach netting to sides of the tray by nailing ¾-inch stainless steel staples through the netting into the sides of the tray.

Construct as many trays as are needed (6-8 should be sufficient) to allow vegetables to be transported to the pack-out space in trays, while others are used to continue washing vegetables.

5) Make covers for each sink.

Covers help keep windblown leaves and dust out of sinks when the station is not in use.

Cut three pieces of ¾-inch plywood, each measuring 24 x 24 inches. They will cover the two stainless steel sinks and the plastic sink.

Cut a fourth piece, measuring 24 x 36 inches. This will cover the blue tub sink.

Apply several coatings of food-grade water repellant to all surfaces of the plywood sink covers. This will extend the life of the covers, which are exposed to outdoor weather elements.

Go back to Introduction

Continue to Part #2: Hoophouse Vegetable Wash Station