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Texas Agriculture Archive

September 20, 2002

Watershed Solutions?

Farm Bureau, dairymen search for way to
maintain a healthy dairy industry...

By Mike Barnett
Editor

Texas Farm Bureau has been searching for a way to maintain a healthy dairy industry in the Bosque River watershed for the past three and one-half years.

Spurred by an antagonistic city of Waco/dairy relationship in the past, the state's largest farm organization is encouraged that both dairy and city are finally starting to move closer in incremental steps to finding solutions for excess phosphorus in Lake Waco, which the city maintains causes taste and odor problems in the city's water supply.

"Water quality is important to agriculture and to municipal interests. A viable dairy industry is important for the economic interests of other Central Texas agriculture. And the good thing is, technology is available to address dairy waste management," Texas Farm Bureau's Director of Commodity and Regulatory Affairs Ned Meister told the Urban Water Council of the U.S. Conference of Mayors recently in Waco.

Meister told the group of the state's largest farm organization's role in initiating a model dairy waste project to demonstrate to Bosque watershed dairymen they can do an even better job of waste control in an economical fashion.

With a feasibility study funded by a $50,000 grant from Philip Morris Companies, Farm Bureau has been deeply involved in both selecting a dairyman for a demonstration project and contracting with Cascade Earth Sciences, a water quality management and reuse firm, to design and construct a project.

"One of the things in doing a demonstration project, you have to find the right dairyman," Meister said. "Talk about changing minds and mind-sets, we wanted to find one whose mind-set is changed, and we did."

Cascade Earth Sciences principal hydrologist, Steel Maloney, told the mayors from cities across the United States that any policy regarding the Bosque watershed should be broad-based.

"The policy needs to be based on science, not just fear and politics alone," Maloney said. "We usually kind of forget those three go together. Is the scientific solution alone a good solution? I don't think so. A political solution not based on science? I don't think so either. And I always caution us not to let fear get in front of us having a good solution."

The solution Maloney has in mind is modeled to target phosphorus.

"Trying to reduce phosphorus is our primary goal because of the TDML (Total Daily Maximum Load) in the Bosque River," he said. "We're also going to reduce odor from lagoons. We're going to generate power. But the big stickler here is it needs to be economically viable for a single dairy.

"This has been done and can be done," the hydrologist continued. "There's also been many of them that have failed. It's not something that we can guarantee that every dairyman will understand and be successful."

The balanced approach Maloney advocates first involves determining the treatment system capacity. That means he'll take a look at the produced waste and subtract out what can be safely recycled on the land without overloading it. And in a normal situation, he would then subtract out what the TMDL would allow.

"But in this example I'm going to say the TMDL will allow nothing because phosphorus is already a problem," Maloney said.

After the recycling capacity of the site is determined, Maloney will look at the cooperator's dairy and utilize as much infrastructure as possible. Why?

"We're looking to do this without grant money," he said. "We're looking to use this without public money. We're going to the dairyman and asking, `What do you have in your dairy that we can utilize?'"

The final system will maximize on-site management of waste and produce by-products that are usable on- and off-site, and should cost no more than what dairymen now spend on waste control.

The premise of the system Maloney is proposing is nothing new. It's been proven in other applications including handling municipal waste, hog waste, slaughter house waste and other industries. The approach is a system simple enough that the operator can manage it himself.

The system would first send waste through a trash screen to remove larger materials like eartags and feed bags that don't belong in the system. The waste then goes to a floater and sinker separator, which pulls sand and straw out. Then it flows through an organic screen, which will move organic solids into the digester units. At this point water goes into the storage pond, and in the digester unit—where most of the action is—methane is collected, excess liquid is removed and biosolids (where most of the phosphorus is) are produced for compost.

The phosphorus-free water will then be recycled to the barns for flushing.

"It's somewhat of a closed system," Maloney said. "If there is excess water, which at times there will be, we will apply it on-site within the constituent of the land. This means no water to the river; no discharge. It means we're going to put the phosphorus into a solid form rather than a liquid form."

Simple enough? There are also by-products to deal with. One is compost: "There's more compost in America than America knows what to do with," Maloney maintained. One solution with this system will be to mix the compost with peanut hulls (to add fiber) and use it to replace the bedding the dairyman now uses. A majority of the compost will go back into the system. The excess can be land applied or transported off-site for sale.

The big challenge in the project, however, is to design a system that results in no increase in cost for the dairyman. The cash flow from the by-products has to offset the infrastructure cost. The majority of the cash flow, Maloney said, will come from electricity produced by the methane.

The new system will also be much less labor intensive.

"The dairyman we selected has a man out there eight hours a day, every day of the week, managing that system," Maloney said. "If we can save on that labor, then those resources can be turned the other way."

The key for future Bosque watershed dairy adoption of the technology is efficiency and economics.

"Most dairymen we talk to aren't really interested in managing this waste any way except the way they managed it in the past," Maloney said. "They're interested in having a solution. They want to be a good neighbor, I think, as much as anybody. But they also have a full-time job running their operation."