A step ahead

The management of irrigation water is becoming a top concern of ornamental growers who are affected by fresh water depletion, as well as the introduction of agricultural water regulations. Several growers in New Jersey have invested in recycling technology in anticipation of such regulations. This series highlights the costs and benefits of disinfecting and recycling irrigation water in large-scale container production. Look for more grower profiles in upcoming issues of Nursery Management.

As Ray Blew drove his pickup around his family’s Centerton Nursery in Bridgeton, N. J., he recalled the water runoff challenges that his family formerly faced. “We used to have to handle not only our own runoff, but also water draining off the nearby highway and neighboring properties. It was a major flood plain here after every storm.”

The Blew family began recycling irrigation runoff in 2009, and according to Ray, they now reuse more than 50 percent of the water on the nursery’s 230-acre container operation through a tail-water recovery system. Ray is clearly proud of the accomplishment. “Now we have the capacity to hold and utilize all of that water,” he says.

The nursery began as a 10-acre operation in 1975 and has been expanding ever since.

“My philosophy has always been that if you’re standing still, you’re dying. If you’re not moving ahead then you’re bringing down the business,” Ray says.

It was this mindset that propelled the growth of his business during the past 40 years. The Blew family now grows 1,200 varieties of plants and ships to 35 states. The nursery’s in-house machinery manufacturing and invention of new technology is a point of pride and has differentiated its operation from other growers. Centerton built the first automated potting machine in 1978, and it is still in operation today. Centerton Nursery has been a family affair since the beginning, with children learning the business from a young age and several generations presently involved.
 

Leading the way

The Blews took the first steps to controlling the runoff from their property in 2009, hoping to design a system that would contain all of their water. They wanted to design and construct a collection system on their own terms and before possible imposition of a deadline by the New Jersey Department of Environmental Protection (DEP.)

The family designed a tail-water recovery system that would feed into a pond at the low point on their property. But it took them several years to get approval for their construction plans. The DEP claimed that the area where the pond was going to be built was previously a wetland. However, the nursery had old maps showing that the area had been used as farmland for generations. The dispute was eventually resolved after Ray sought the intervention and assistance of several New Jersey politicians.

The Blews’ basic plan was to reuse the runoff for further irrigation, however they needed to find a disinfection treatment for the runoff. They knew that untreated water could spread disease throughout their operation. They decided that ultraviolet light was the best fit for their purposes after ruling out other disinfection techniques, including chlorine gas.

“One of the things that encouraged us to go with the UV light was the DEP in Trenton. They said they were going to eliminate chorine treatment in the state and they were adamant about it,” Ray says, but adds that to date, the DEP has not taken this step.

The Centerton tail-water recovery system carries runoff from the entire nursery to a pond at the low point of their property. The first step of filtration occurs when larger organic material sinks to the bottom of the retention pond. This water is pumped from the pond, filtered using fine mesh to the 80 micron level, and disinfected. To work properly, a thin film of water flowing very slowly is bombarded with UV light. Approximately 30 million gallons of water is pumped out of this system annually, making up 50 percent of the nursery’s total water use.

This type of treatment easily kills bacteria, fungi, and zoospores of water molds. But it can still be difficult to kill certain fungal pathogens and bacteria. Ray insists that “when you’re growing containers in the field you can’t get away with any pathogens.” He believes filtration is the most important step in the disinfection process. Ray recommends building the largest water reservoir possible so that large particles have the most time to settle out before the water goes through filtration and treatment.

“I would make my holding pond as big as possible if I could go back and do it a second time,” he says.
 

Costs and benefits

The initial investment for the tail-water recovery system was about $500,000, but the Centerton operation received 45 percent cost sharing from the National Resources Conservation Service, making the nursery’s out-of-pocket investment about $275,000. Maintenance costs include the replacement of UV bulbs, which last about 18 months and cost $3,000 each, and possibly filters, which could cost between $600-$2,000 each.

Centerton Nursery’s filtration process has required more investment than originally anticipated.

“There’s a lot of animal activity around the pond. There are frogs in there by the thousands,” he says.

These animals clog up the pipes and get caught in the screens and filters. These filters must be frequently replaced. He says the life of the filters is unpredictable because “you never know what’s going to happen. It seems like we have a problem three times in a row, and then not again for several months.”

The Blews introduced a water recycling system to minimize flooding on their property, but as it turned out, the investment also had some unexpected benefits. The recycled irrigation water has reduced the pressure on the aquifer, reduced fertilizer costs by 30 percent, and has been incorporated into the nursery’s marketing. The system “impresses people and they appreciate that we try to do the right thing,” Ray says.

The nursery has also avoided the expense of drilling two additional wells to maintain its current pump capacity of 50 million gallons per year.

Ray strongly encourages other growers to consider recycling.

“A key thing for any grower is to look at two, three, or four operations and see how they operate.”

There are many options when it comes to disinfection of recycled water, and each technique has unique costs and benefits. When evaluating the entire investment, Ray believes that water recycling “is not necessarily profitable, but it has to be done and more agricultural operations will be forced to stop their runoff in the future.”

Alyssa DeVincentis is a recent graduate from Rutgers University. She completed her honors thesis on water disinfection and recycling at horticultural operations throughout New Jersey, under the guidance of Robin Brumfield, Farm Management Specialist at Rutgers (Brumfield@AESOP.Rutgers.edu) and Paul Gottlieb (gottlieb@aesop.rutgers.edu).

Watch a video featuring Centerton’s water recycling and disinfection system at http://bit.ly/NM_Centerton.