Capturing more “free” water, containing runoff and reusing costly fertilizer are benefits of keeping nursery ponds in tip-top shape
Like all irrigation systems, nursery ponds require maintenance for continued smooth operation. In addition to routine inspection, testing and maintenance of pipelines, pumping plant components and other mechanical components, most ponds will require periodic cleaning, regrading and removal of sediment.
Making sure that nursery ponds are proactively maintained and operating at peak efficiency not only prevents negative water quality impacts, it also saves money in the form of water, fertilizer and environmental costs. Oregon has established laws to protect water quality, including laws that address agricultural activities that can negatively impact water quality.
“With droughts occurring with more frequency, having a backup supply of water is a big benefit to keeping a pond,” said Rod Park, owner of Park’s Nursery for over 40 years. “I only have 8,000 square feet of containers for growing liners, but if I lost that because I couldn’t irrigate, I’d lose a whole growing cycle, maybe more.”
While the benefits of having a pond are clear, maintaining ponds is a murkier matter.
“Nobody’s written a manual on how to maintain these ponds because a) no two ponds are built the same, and b) we’re in a bit of a legislative regulatory gray area,” said Chris Poulsen, an environmental engineer with Farallon Consulting.
Poulsen rifled off a list of maintenance questions every nursery owner should consider: “Is the pond adequately sized and does it function? Is there algae or an invasive species problem? Does the pond contain contaminants, whether that’s silt or pesticides or herbicides? Is there another issue that would prohibit the grower from reusing the water or discharging it?”
Keeping ponds clean
If one thing is certain, pools of algae are not what nursery ponds were intended to be. Neither were ponds meant to harbor built-up layers of fertilizer-laden sediment, the dredging and dispersal of which requires additional labor, time and money. Yet, those are issues that can occur when a pond isn’t maintained properly.
They’re issues Tom Fessler has managed to avoid at Woodburn Nursery & Azaleas in Woodburn, Oregon. Through various ways, starting with proper planning, through good stewardship and by using the latest technology, Fessler has figured out how to make ponds work for him and his operation, instead of the other way around.
“If you install [a pond] right, you don’t have to dredge the bottom or anything,” Fessler said. “The newer ones we line with rubber, and we have another clay-lined pond that collects runoff. We utilize shrubbery and a French drain to minimize silt, and we’ve also started using radio wave frequencies to keep the ponds clean.”
A nurseryman since 1968, Fessler makes nursery pond maintenance sound simple, but it’s water wisdom he’s gleaned over decades of constantly innovating, with radio wave frequencies being the latest technology he’s tapped into.
Adding chlorine to a pond is a common way to control algae blooms, but Fessler thinks he’s found a better way that doesn’t require adding more chemicals into the mix.
“We’ve started using radio wave frequencies,” Fessler said. “The cost was reasonable, and it’s proven to be a better option over chlorine. It keeps what fertilizer is there and helps with the disease and algae.”
Fessler is referring to the Agrimaxx ESP (Energy System Plus), an electronic device that can allegedly “restructure” water: “Water that passes through the controlled electrostatic field in the unit is treated by a patented wave which creates improved taste, reduced odor, scale reduction and reduction of other significant problems in water sources,” the manufacturer claims on its website (www.Agri-Maxx.com).
“We guarantee that Agrimaxx will save a minimum of 20% water and 20% fertilizer, and 20% increased yield,” said Mike Crist, president/CEO of Agrimaxx.
The Agrimaxx installs into a pond either via a frequency-transmitting box that floats on the surface of a pond or, less frequently, through electronic leads drilled into a pelican box residing within the pumphouse, where silt and other contaminants can build up over many seasons of use, clogging and corroding discharge pipes.
“We’ve found that the restructured water can actually descale the pumpback system,” Crist said.
Using radio wave frequencies to keep ponds and pumpback systems clean has also caught the attention of Ronald Tuckett, plant protection manager, at Monrovia in Dayton, Oregon, although more so as a curiosity than due to need. Another veteran nurseryman, Tuckett has overseen all irrigation systems, as well as pest control and landscaping, for nearly 30 years at the nursery. Fortunately for him, Monrovia’s ponds were well engineered and haven’t required more than occasional maintenance.
“Last year, we drained one of our ponds to work on a recycling pump that had gone out, but then after it was fixed, the pond filled right back up with rainwater,” Tuckett said.
Tuckett oversees seven ponds of various sizes at the nursery. All are man-made. One is an on-stream reservoir. The largest pond contains about 45-acre feet of water, with about 150-acre feet total.
“We collect rainwater during the winter as much as we can,” Tuckett said. “Last year, with the late rainy season up until May, we didn’t have to start pumping water from the river until June. It’s always good when we don’t have to pay for water.”
Tuckett said it would be nice to expand the water storage capacity of the ponds and thereby capture more “free” water, but space is an issue: “We just don’t have room to expand, and it’s expensive,” Tuckett said.
It’s cost-prohibitive to enlarge an existing pond for several reasons, foremost among them being the permitting process and navigating the regulations that govern bodies of water in the United States.
“Nurseries that are interested in upgrading a pond would first need to know whether it’s listed as a Water of U.S., which depends on how [the pond] drains and how it flows,” said Poulsen, who has engineered ponds for wineries, aggregate producers, manufacturing facilities and livestock operations.
“So, before you do anything, you have to get an approval from the Department of State Lands and Habitats. Then you’ll certainly be testing the quality of the sediment in the pond. If the sediment is contaminated, you’ll have to dispose it .…
“It’s quite a quagmire,” Poulsen said.
Adapting to change
Maintaining a pond to save water, reuse fertilizer and contain runoff makes perfect sense, but the practice is not that simple.
“The issue is that nursery ponds, for the most part, were created in a previous regulatory climate,” Poulsen explained. “Subsequent legislation, and a lack of clarity at the regulatory level as to who administers the provisions of that legislation, may nullify, or at least complicate, the nurseries’ ability to deal with their ponds as originally intended.”
Legislation includes the Federal Water Pollution Control Act, originally passed in 1972 and amended with the Clean Water Act of 1977 and amended again by the Water Quality Act of 1987.
On the state level, growers should also be aware of Senate Bill 1010, the landmark legislation that was passed in 1993 and established the Agricultural Water Quality Program. The program created 38 agricultural water quality management areas in Oregon, along with specific agricultural water quality management plans and rules designed to reduce nonpoint source pollution.
Senate Bill 1010 gave Oregon landowners the flexibility to address specific problems on their property. Sedimentation and retention ponds became common ways whereby growers could collect water for reuse while mitigating fertilizer-contaminated water runoff. If runoff does occur and results in potential pollution problems, ODA works with the landowner to resolve any violation(s).
“All our circumstances are different — that is one of the main points we made to DEQ,” said Rod Park, one of the architects of Senate Bill 1010. Park served on OAN’s Executive Committee alongside Clayton Hannon, then the executive director of the OAN; Park and Hannon partnered with Bruce Andrews, then-head of Oregon’s Department of Agriculture.
“We’ve had 30 years now of the system in place,” Park said. “Capturing excess rainwater is something we didn’t anticipate when the bill was created, but it’s turned into a really beneficial byproduct – ‘free’ water,” Park said.
Free comes with a price, however, and the cost of maintaining a pond can be attributed to changes in climate as well as regulations.
“There are now high-intensity summer rain events that occur and that cause problems for nurseries in the summer as well as winter,” said Kevin Fenn, Water Quality Program compliance leader with the Oregon Department of Agriculture. “Nurseries should have management practices in place that even when those big rain events occur, they have the capacity to handle them.”
Fenn emphasized that it is illegal to discharge contaminated wastewaters into designated Waters of the State. To mitigate runoff when large storm events do occur, nursery owners should plant vegetation along ponds and streams for bank stability and to filter surface runoff.
“Nurseries should have cover crops in bare root nursery areas, on steep ground, and areas that are not in production — anything that can be done to limit the nonpoint source runoff,” Fenn said.
Fenn also cautioned nurseries from using mapped streams as part of their tailwater recovery systems. “That is not in compliance with rules,” Fenn said.
Another maintenance tip Fenn recommended is emptying a pond before the stormwater season. “That way, when the runoff does connect to surface waters, it will have the potential to have less contamination in it. … The best sites have valves, so during the summer they can collect all their water through their tile lines and then pump the water back to their reuse ponds. Then during the winter, they can open those valves and let it go, because they can’t keep that stormwater on site.”
When in doubt, test the water. (For a list of analytical laboratories in Oregon, log on to https://Catalog.Extension.OregonState.edu/em8677/html).
“It’s always a good idea to sample your water and see if those nutrient levels are low,” Fenn said. “If not, run [the pond water] through some type of a wetland feature or create a field that you can apply that water to.”
Nursery owners who monitor water inputs and outputs will have a much better time maintaining their pond, and they’ll have less interaction with the ODA.
“Whether weekly or monthly or depending on the situation, making sure that every grower has some sort of testing schedule that they’re adhering to is crucial,” Fenn said.
Peter Szymczak, OAN publications manager, is managing editor and art director of Digger magazine.
From the March 2023 issue of Digger magazine | Download PDF