Cost Analysis of Recycling Water in Greenhouses

Management of irrigation water is extremely important as fresh water continues to be depleted on a global scale and pollution is a big issue. In anticipation of regulatory restrictions, several businesses in New Jersey have implemented systems that disinfect and recycle their irrigation water.  A cost analysis of this investment was performed at five businesses in Southern New Jersey. This study compared the disinfection methods at two greenhouses and three nurseries. The disinfection techniques analyzed were ozone, chlorine gas, UV light, and copper. The data for this study were collected during on-site visits where the growers were interviewed. The Rutgers Office of Continuing and Professional Education filmed these interviews to produce educational videos. A partial budget analysis was performed to determine the economic efficiency of this investment. The most efficient disinfection technique could not be determined due to the variability between businesses and the many unquantifiable benefits of recycling water. A rubric was developed to compare the recycling systems to one another, and serve as a tool for growers that are interested in making this investment. A small-scale nursery would likely benefit from a small capital investment in a chlorine gas system; a high-end greenhouse would likely benefit from a large-scale investment in an ozone treatment system. A third option is for growers to reduce their runoff entirely by changing their water management practices.  One of the five businesses took this approach and does not recycle, but instead uses drip irrigation and strategic water management to produce negligible runoff.  This information was compiled into guidelines with recommendations that will be available to the public, along with the educational videos, to promote learning about new sustainable technologies in the field.