Division of Labor

A Nebraska treatment plant superintendent partners with the local Extension agriculture educator to advance his city’s biosolids land application program
Division of Labor
Dodge County extension educator Dave Varner, left, observes, “We couldn’t ask for a better partner than Keith.”

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Keith Kontor and his team know how to produce high-quality biosolids. Dave Varner knows how to explain the product’s benefits to farmers. Together they have built a highly successful biosolids land application program around Fremont, Neb.

The program supplies both Class B dewatered biosolids and a Class A composted product to corn and soybean growers within about 30 miles of Fremont in Dodge County. The materials are applied at agronomic rates on about 450 to 500 acres per year.

In his 11 years with Fremont, Kontor has worked hard to improve both farmers’ and neighbors’ perceptions of biosolids. He gives considerable credit to his team at the treatment plant and to Varner, Dodge County Extension educator.

“I don’t have an agriculture background,” says Kontor. “If I went to farmers and asked them to put biosolids on their land instead of the fertilizer they had been using for years, what are they going to tell me? That’s why I chose to work with Dave. He has the knowledge, and he has the trust of the producers. It really works out well.”

The respect goes both ways: Earlier this year Varner presented Kontor with an Award for Outstanding Contributions to Dodge County Extension Agriculture Education Programming, on behalf of the University of Nebraska-Lincoln Extension.


Marks of success

Kontor looks with pride on a variety of achievements in the biosolids program. He says the city has never received a complaint from the public about odor or other issues at application sites.

Demand is strong, helped by field test data showing the products’ effect on crop yields. In 2011, for the first time, the city charged farmers for the materials — $7 per ton plus $1 for each 10-mile increment in delivery distance. As a result, the program generated $42,000 in revenue, recouping about two-thirds of the city’s costs for hauling and application of Class B material at 25 percent solids and compost at 50 percent solids.

All told, the program saves the city about $200,000 per year over the pre-2001 practice of land-applying liquid material at 1.5 percent solids.

“The program is recognized as one of the best in Nebraska,” says Varner. “The growers love it because it’s one-stop shopping — we deliver and apply the product, and we take care of all soil testing. The farmers collectively benefit from $75,000 in savings on commercial fertilizer, plus any yield enhancements from the product.

“We couldn’t ask for a better partner than Keith. He has been willing to learn the needs of the farming community, and he has concentrated on making quality products that are easy to market. In 2001 when Keith came here, we were lucky to find two farmers willing to accept the material. Now we have a list of growers who want it. Since we began charging for it last year, demand has not dropped off a bit.”


Deep experience

Kontor came to Fremont (about 25 miles northwest of Omaha) with strong experience in wastewater treatment and biosolids. He began his career as a utility worker in Wilber, Neb., a community of about 1,700, and received a promotion to wastewater treatment operator in 1988.

After eight years there, he worked four years at a pork processing plant as a wastewater operator. When he arrived in Fremont (population 25,000), the city was completing a $20 million upgrade to the wastewater treatment plant, including major improvements to the biosolids process.

Today the plant has an 11 mgd design flow and 4.5 mgd daily average flow. The headworks is followed by a diffused air flotation process to remove grease from a local meat processor. Next come primary clarifiers, trickling filters to reduce BOD, and extended aeration activated sludge secondary treatment. Final effluent is UV disinfected before discharge to the Elkhorn River.

The heart of the solids process is an egg-shaped digester with mechanical mixing, supplied by CB&I. It provides thorough mixing that keeps the material in contact with microorganisms to maximize biogas production. The methane feeds boilers that heat the digester complex.

Upstream of the digester, primary and waste activated sludges pass through a thickening centrifuge from GEA Westfalia Separator. After digestion, another GEA Westfalia centrifuge dewaters the material to about 25 percent solids. In total, the plant processes 80,000 to 100,000 gallons of sludges per day and produces 2,500 to 3,000 dry tons per year.


Dramatic changes

Taking over Fremont’s program in January 2001, Kontor drew on his experience in Wilber, where he had worked successfully with the local Extension educator to market a liquid biosolids product. At the time, Fremont was applying liquid material on just one farmer’s land.

Kontor got permission from Fremont Utilities general manager Derril Marshall to seek a similar arrangement with the Dodge County Extension office. Varner embraced the idea. By August 2001, the new digester and centrifuges were online. Kontor and his team mixed the dewatered biosolids with yard waste from the local recycling station to reduce the concentration of molybdenum, which at the time slightly exceeded EPA 503 regulations.

Meanwhile, Varner went to work recruiting farmers. Initially, he sought to show growers that biosolids would meet their crop nitrogen requirements and deliver the yields they expected. He helped them conduct replicated on-farm research tests comparing commercial fertilizer with biosolids.

“We would calculate their nitrogen requirement based on soil tests and apply the product at the appropriate rates,” he says. “The growers met or exceeded their expected yields in almost every instance.” Data from those tests has helped the city’s marketing program significantly.

In 2004, Kontor and his team began composting biosolids on a 300-foot-square permitted site on the treatment plant property. Windrows of biosolids and yard waste are mixed by a Wildcat windrow turner (Vermeer).

“Probably 60 percent of our biosolids is now composted,” says Kontor. “It’s a seasonal operation, usually from about April until we get frozen out in November.” Farmers have come to prefer the compost product because it spreads more uniformly, Kontor observes.


Running smoothly

Today, the program runs with barely a hitch. The Class B biosolids product contains about 5.2 percent nitrogen and 4.3 percent phosphorus; the Class A product is somewhat lower in nitrogen and higher in phosphorus. Both products contain other essential crop nutrients, including zinc, sulfur and iron, that add fertilizer value.

Varner acts as the point man in the field. “He works with these producers day to day on how they can increase yields and what types of fertilizer to use,” says Kontor. “We have so many different kinds of ground here — sandy soils, gypsum soils, clay soils. That is Dave’s profession — helping the producers grow the best crops they can.”

In recent years, Varner’s outreach efforts have focused on land with soils low in phosphorus. Other selection criteria include suitable distance from residential developments and from floodplains, and farmers willing to be patient, as wet weather can cause delays in product delivery and application.

“The first thing Dave does is sample the ground,” says Kontor. “If he finds a site that’s low in phosphorus, he meets with the farmer to further explore the prospect of applying biosolids. Producers who are willing must apply to Dodge for a permit. As part of the process, notices are sent to all the neighbors within 1,000 feet of where we’re going to apply the material.”

Neighbors are invited to a public hearing; if they raise legitimate concerns, the permit application may be withdrawn. “We don’t want to fight a battle over public perception,” says Kontor. “There is always other ground we can go to.”

If all goes well, the county issues a permit that lasts five years, and the farmer is signed up to receive product the following year. Kontor and Varner try to permit 500 to 750 acres per year. “I feel it’s good public relations to let as many farmers as possible use the products and receive the benefits,” says Kontor.


Scientific process

The actual application is a rigid process designed to deliver nutrient value to match the needs of the crop. The products are stored at the treatment plant site, or on recipients’ farms if they have space available, until after harvest in fall. A contractor handles hauling and application.

Both the Class A compost and the Class B biosolids are applied using a tractor-drawn manure spreader with a vertical beater bar. “We have to weigh the spreader before we start to make sure we know how many tons we have on board,” says Kontor. “Then we calculate the necessary ground speed based on how much we need to put on per acre.

“The contractor has a GPS setup that tells exactly where he has hauled, so he won’t haul over the same ground twice. We use the same equipment to spread both materials. To change from one to another, all they have to do is re-weigh the machine and re-calculate the speed to make sure we’re applying at an agronomic rate.”

Over the years, the program built such credibility that it wasn’t difficult to transition to charging for the products. “Budgets of cities around the country are getting tighter and tighter, and we were asked how we could recoup or eliminate some of our costs,” says Kontor.

“We held a meeting with Dave and the producers — some with new land and some with land we had hauled to previously, and explained that we wanted to begin charging. We had 25 landowners at the meeting, and all 25 signed up.”

It’s all a credit to a good production, marketing and delivery process, and good teamwork. Varner observes, “Keith has maintained excellent quality control of the biosolids products and has done everything Extension has asked of him and more to accommodate area farmers. He has been instrumental in the program’s success.”


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