With environmental regulations on the rise for ranchers and farmers across the nation, it becomes increasingly important to look for alternative methods of controlling manure runoff, according to Chris Henry, extension engineer for the University of Nebraska-Lincoln. For generations and especially within the last 10 years, water quality has been a major concern among environmentalists. And with farms and ranches across the country bordering local waterways, U.S. livestock producers are even more closely regulated among governing agencies including the Environmental Protection Agency (EPA).
For beef and dairy cattlemen, the big worry comes in the form of manure runoff.
And while impoundments and holding ponds have been the traditional system used to regulate runoff from feedlots for several decades, Henry hopes to spark a different and rejuvenated idea in the minds of producers and regulators – a vegetative treatment system.
“A vegetative treatment system is an alternative option for controlling manure runoff for open feedlots,” said Henry. “Basically, you collect the runoff from the feedlot in a sediment basin, meter it out very slowly into a vegetative area instead of using a pond or impoundment.”
As simple as it sounds, according to Nebraska beef producer Doug Ferguson, 31, of Beatrice, it really is a simple and efficient system to operate.
“The biggest challenge for me in the beginning was letting go of my traditional ideas,” said Ferguson. “We started in 2005 and I have no regrets in doing this, we love it, it’s so simple and easy to maintain.”
How it works
The first step, he explained, is to collect the runoff from the open feedlot into a sediment settling structure, usually a basin in many cases. From that point, the runoff then flows into a Vegetative Treatment Area (VTA), where the soil treats and stores the runoff. On Ferguson’s ranch, his VTA consists of an old pasture area seeded to brome grass. Once the runoff saturates the soil, natural processes allow plants to further utilize the nutrients. For Ferguson’s 280-cow feedlot, the remaining workload centers around scraping dry solids in the lot and opening and closing the valves from the sediment basin as needed.
“Our system is gravity flow, the runoff flows out and we can close the valves when the soil becomes too saturated in one or more areas of the VTA,” Ferguson said, who also owns a 100-cow-calf business and registered 40-cow Angus and Maine Anjou herd. “We open and close the valves randomly depending on the moisture of the soil. Other than that, we clean out the solids from the pens and make sure the silt surrounding the outlet structure is clean.”
While Ferguson operates a traditional sloped or gravity-induced VTS, Henry assures producers there are several different designs of vegetative treatment systems. While a sloped VTA, generally using a 1 to 5 percent slope grade, is the most popular and simple of the VTS family, other options include a level VTA and vegetative infiltration basin, a terrace system, a sprinkler and pump VTA or dual and multiple VTA system.
The key for success in the design of a sloped VTS is to maintain a level area for the VTA and design berms that surround the vegetative area that range from 1 to 2 foot in height. According to Henry, the advantage in a bermed area is in it’s availability to contain and treat large runoff events caused by heavy rainfall.
Henry, who specializes in smaller feedlot VTAs from 300 to 1,000 cows, defined a terrace VTA as a serpentine broad base terrace that carries the advantage of having a long contact time. The drawbacks to this type of VTA is that in many cases it is more difficult to construct and often has to be twice as large as a sloped area for the same treatment area.
According to Henry, a VTA can be designed to suite nearly any size feedlot.
“The bigger the feedlot, the bigger the VTA, it just tends to be a bit easier with smaller herds,” he added. “For example, in a 300-cow feedlot, I would approximate a two-acre lot with a two-acre VTA. It’s about a 1:1 ration, that’s a good rule of thumb. It’s just not going to work with a five-acre lot and a one-acre VTA.”
However, expert researcher Robert Burns, an associate professor of agricultural and biological engineering at Iowa State University, said there is no one size fits all answer to the type, size and design of a VTA to fit a cattle operation, which can include either beef or dairy.
“It’s all very site specific and depends very much on the location,” said Burns, who is currently completing the third year of his three-year study funded by the USDA and the Iowa Cattlemen’s Association into the economics of VTAs in large confined feeding animal operations consisting of 2,500 to 5,500-cows. “Location is critical, meaning you need to have certain soil properties and a water table that is not excessively high in order for this system to succeed. You want well-drained soil, so that the water that is dispersed does not runoff or deep percolate.”
Another design of a VTA system includes constructed wetlands. Henry explained that constructed wetlands are shallow impoundments, usually three to four feet in depth that use the liquid surface to treat the nitrogen in the runoff water. The disadvantages in this type of system is that it is quite costly and does not completely clean the water, so it requires an additional VTA to be effective, he added.
One of Henry’s most interesting VTA designs includes a pump or sprinkler that uses a pump or mechanical device to convey runoff water to a distribution system, up gradient from the sediment settling structure.
“Many of the demonstration projects we do are the first of their kinds, the sprinkler VTA is an example you will only find in Nebraska,” said Henry. “This type of VTA distributes the runoff from the sediment basin evenly using a sprinkler system and is best for feedlots that are close to a water source.”
Finally, a dual and multiple VTA combines more than one vegetative system type and according to Henry will help improve the performance and efficiency of the total VTS system.
With so many options to choose from, a question on any producer’s mind is likely to be, ‘How much is this going to cost me?’
“A VTA can be built for as low as $30 a head, where a feedlot (bunks, fence, pad) can cost upwards of $250 a head,” said Henry, who indicated that his cost data shows that a VTA can cost a producer significantly less than a traditional impoundment or holding pond to hold runoff.
As a result, one of the major reasons producers are looking into this alternative system is because of its cost benefit.
For Ferguson, by building a VTA on his family’s farm, it enabled him to return home to the operation and continue the business by expanding the cattle herd in a sustainable and environmentally-friendly way.
“When I thought about it I quickly realized I was ready to abandon my old penning set-up,” said Ferguson. “One of the most important aspects leading to my decision was the growing environmental concerns. We found that this was going to be a good way to better protect our nature resources by building a berm around the vegetative area so that the (runoff) water could never escape and reach our creek bed.”
Unfortunately though, there is always a downside to every system, although according to Ferguson if he had to do it all over again, there is not a thing he would do differently.
“From a stockmanship aspect, the slope provided through proper feedlot design allows the lot to dry up fairly quickly and this translates to better productivity, rate of gain and a very healthy herd as a result,” he said. “The success that I’ve experienced I believe has been a direct result of how healthy my calves are. It makes a big difference and I could not speak more highly of this system.”
In Henry’s Extension work, the biggest downside with any VTS, is that “it requires event-based management, meaning when it rains you have to manage it more heavily so it doesn’t have discharge.”
You need to open (and close) the valves (from the sediment basin), change the gates (of the feedlot), so that the water gets uniformly discharged,” he explained. “With a holding pond, you don’t have to worry about that.”
According to Ferguson, a lot of planning must go into the construction of a VTA.
While most producers, including Ferguson at one time, want to utilize existing feedlots or areas, in many cases this is not possible.
“I wanted to build around what I already had set-up, but as we begin discussing options, I began to understand that we needed to design the waste management system first, then build the pens around that,” he said. “Once we got through that, it went up about as fast as I could build fence.”
Not all peas and carrots, Ferguson said, “I had never dealt with a VTA, it wasn’t a part of what I was used to doing everyday, so it was great to have Chris’s (Henry) team onboard to save me a lot of headaches.”
History of VTS
Henry began his research into VTAs in 2000 quickly, when he found out that Nebraska, at that time had no operations utilizing the environmentally-friendly system. Just five years later, Henry assisted Ferguson in the design and implementation of his vegetative system.
While VTS work first began in the 1970s when regulations started to develop for confined feeding operations across the country, according to Henry, it died off for a decade or so.
“The EPA updated their 30-year old permit program in 2003, and one of the changes that came about was the introduction of alternative performance, which provided another technology option to holding ponds,” he said. “This is when research really began to take off again.”
And while some questions still remain for Extension specialists such as Burns and Henry including the longevity of a VTA system, they collectively encourage producers to research VTS as an alternative to a traditional impoundment arrangement. Particularly, it will be a major issue for states with heavy feedlot regulations for CAFOs such as in Iowa.
“Iowa feedlots with more than 1,000 head are subject to regulations under NPDES (National Pollutant Discharge Elimination System),” Burns indicated. “Producers have to show less than a certain amount of discharge by monitoring flow and discharge of nitrogen and phosphorous. Despite it to say, our research (at Iowa State) is being very closely watched.”
According to Burns, Iowa is one of the few states that has initiated a separate set of regulations for vegetative treatment systems.
And while regulations in every state varies for livestock producers, one thing is certain, environmental regulations are on the rise for farmers and ranches with water quality and air emissions ranking amidst the most prevalent concerns.
Other opportunities for research into this alternative system can be obtained from two additional universities with considerable work with vegetative treatment systems – Kansas State University and South Dakota State University.
Vegetative Water Systems
Sloped and Leveled
A multiple Vegetative Treatment System (VTS) combines more than one VTA type. This image illustrates the combination of a sloped and level VTA.
A sprinkler Vegetative Treatment System (VTS) uses a mechanical device or pump to distribute the manure runoff evenly throughout the vegetative area, that is usually up gradient of the sediment settling structure.