the pump would be the power behind using this water to irrigate the greenhouse and nearby crops.  Because we currently lease the land we farm, we didn’t feel comfortable excavating and installing a below-ground system.  Also, the cost of the solar water pump alone was over $2,000 and this did not include the solar panels.  We felt the cost far exceeded what savings we could generate by reusing the water.

Instead our system is primarily gravity-fed, with a back up small portable water pump when needed.  Once we have finished washing, two manifold lines are attached directly to the bottom spigots of the washing tanks.  These manifold lines lead directly to drip lines less then twenty feet away which water our greenhouse tomatoes and cucumbers.  If no watering is needed in the greenhouse on a given day the water can be transferred to either of our water storage tanks using the pump.  The manifold lines that attach to the 100 gallon washing tanks are easily attached and detached.  Once the water is drained, the silt is rinsed out of the tanks, which are then ready for their next use.  Produce is washed typically four days a week for about thirty weeks out of the year.  Sometimes emptying and refilling the washing tanks are necessary when produce is exceptionally dirty.  Therefore, about 24,000 gallons of water purchased first from the city are reused either in watering greenhouse plants or stored for later usage to irrigate field crops or watering livestock.  As our farm grows it will be easy to add additional wash tanks if necessary and incorporate them into our system.

Finally, the collection of the rainwater is the easiest aspect of our system.  Once the produce washing station was built a local handyman guttered the area.  The guttering leads directly to our 1,000 gallon water storage tank which is located right next to the washing station.  From there, we can irrigate the crops immediately surrounding the barn using low-pressure gravity drip irrigation.  Or, for produce further a field, another 500 gallon water storage tank and trailer were purchased.  We can both fill this tank directly during a rain storm by backing the trailer up to the barn to the guttering system.  Then, when empty, we can transfer from the 1000 gallon tank to the 500 gallon tank using a pump.  This portable 500 gallon tank allows us to capture those additional gallons during a heavy rainstorm and easily transport them to other areas of the field.  This includes hauling water to our six pigs which are pastured out in the field far from the barn.  The total surface area for rainwater collection is 832 square feet.  A rainfall of one inch yields 500 gallons of water. 

4. What results did we achieve?
In the end, we were unable to measure the results from our project.  The latter half of 2007 was spent finding a consultant and then deciding upon the design.  The early half of 2008 was when the wash station was built and rainwater and wash water collection systems installed.  However, 2008 ended up being the wettest on record.  We had an additional 23 inches of rain on top of the normal 36.  We had too much water to deal with!  It was easy to see the results of our rainwater collection system as a 500 gallon water storage tank was filled with every inch of rain.  But since we didn’t need to irrigate, some of the water was used our pigs, and we sometimes washed produce with it.  In the end, we couldn’t store or use all the rain water we would have collected; so much of it was redirected back to the ground.  Our greenhouse wasn’t built until early November 2008, so we were unable to see the savings from sending our wash water to irrigate those crops.  We most look forward to seeing results and savings from this aspect of our system in 2009.

We discovered a CATCH-22 with our system.  There is only so much water to store during a limited rainfall year, and when there is too much rain, there’s no need to store much of it because irrigation needs are met.  Storing rainwater can meet our livestock’s water needs and some irrigation needs.  However, where we can see the biggest impact is the recycling of our wash water and redirecting it towards our greenhouse, which always needs to be watered regardless of too much rain.  Financially, for this upcoming season, by reusing the 24,000 gallons of city water used to wash produce to water our greenhouse crops we will be able to save about $400 a year (we are charged $17 per 1,000 gallons).  This does not seem to be a huge financial savings.  What is less easily measured, however, is the possible erosion we are avoiding from disposing of so much wash water directly into the ground.  And, the slightly lesser demand we would be putting on a city water supply in a very dry year or several dry years by using what we do purchase to its fullest potential. 

In the end, I am unsure if tackling such a project so early on in a farm’s growth and development is a good idea.  The system we chose will grow as the farm grows, but only up to a certain point.  If our barn gets much bigger, or we add different technologies to washing produce, a different system will be needed.  I could see much larger benefits and savings for a well-established, well-infrastructured, high production produce farm. 

With that said, I am proud that we are taking steps toward sustainability, even if their end footprints are small.  If we had no city water source, then the rainwater we would collect from a normal rain year would be enough to for our livestock and produce washing water needs.  It feels good to know that ultimately we don’t need to rely on an outside water source; that Mother Nature can take us a long way. 

Stay tuned for results and photos from our 2009 growing season…

For further coverage on our project please visit the archives of www.agrinews-pubs.com.  In addition, our farm is profiled in the Reaping the Rewards of Our SARE Investment publication which can be downloaded at
http://web.extension.uiuc.edu/smallfarm/pdf/reaping_rewards.pdf.