Some clean-water plants have trouble finding land to apply their biosolids. That’s not the case at Fort Collins, Colorado. 

The city owns the 26,000-acre Meadow Springs Ranch, a cattle ranch near the Colorado-Wyoming border that’s 30 miles from the plant. Trucks haul biosolids to the ranch four to five days a week — roughly 2,300 metric tons per year.

The city began land-applying at the ranch in 2001 after 10 years of careful study in collaboration with Colorado State University, the U.S. EPA and the state Department of Public Health and Environment.

“We unload the solids directly on land, then spread them using a tractor with a spreading trailer or a wet spreader,” says Jason Graham, director of plant operations for the Water Reclamation and Biosolids Division.

The wet spreader can fling solids 60 to 65 feet and has flotation tires to minimize soil compaction and impacts on vegetation. “The biosolids improve soil structure and water retention and act as a slow-release fertilizer,” Graham says.

MULTIPLE RECOGNITIONS

All Fort Collins wastewater facilities are certified under the ISO 14001 international environmental management standard. The department has won commendations including a Gold Partnership in the Environmental Leadership Program from the Department of Public Health and Environment, a Platinum Peak Performance Award from the National Association of Clean Water Agencies, and Rocky Mountain Water Environment Association awards in sustainability and safety.

In 2019, the biosolids program achieved Platinum Level classification from the National Biosolids Partnership and the Biosolids Management Award from the Rocky Mountain WEA.

“The awards provide credibility for our ratepayers and staff that we are on the right track,” Graham says. He attributes the program’s success to his staff, especially the biosolids management program team: “They’re the ones who’ve done all the work.”

The biosolids team includes Jennifer Ward, Nate Ader, David Wiedeman, Allison Becker, Mark Patterson, David Coad, Nick Russell, Tracy Bane and Jerry Yakel.

CLEANING THE WATER

The city’s Water Reclamation and Biosolids Division includes an industrial pretreatment program, mechanical and electrical maintenance, plant operations, technical services and resource recovery staff. An on-site pollution control laboratory and SCADA engineering team ensure accurate process control decisions and smooth operations.

The Drake and Mulberry Water Reclamation Facilities have a combined design capacity of 29 mgd and combined average flow of 19-20 mgd. Both use a three-stage biological nutrient removal process followed by UV disinfection (WEDECO - a Xylem Brand).

All solids are treated and stabilized at the Drake facility using four mesophilic anaerobic digesters to generate Class B biosolids. Only three digesters operate at any time; the other is reserved for use during maintenance and cleaning. A pair of Centrisys/CNP centrifuges yield cake at 19% solids.

Digester gas fuels process and building heating year-round; the excess is flared off in summer. The utility is developing a cogeneration project and expects to complete it by the end of this year. Three city-owned tractor-trailers equipped with tarps transport biosolids to the ranch — typically 10 to 12 truckloads per week, or more than 580 loads per year. 

The hauling presents budgeting and maintenance challenges, and weather can be a factor. “Trucks are not cheap,” Graham says. “We can get about 19 years of service out of a vehicle before we have to go to a new truck.” The trucks and spreading equipment are part of the utility’s asset management plan; the use of city-owned equipment is cost-effective.

GREAT FOR GRAZING

The Meadow Springs Ranch sprawls over rolling grassland on the Front Range of the Rocky Mountains just off Interstate 25. Elevation is about 5,500 feet, precipitation is moderate and temperatures can vary widely between summer and winter. Summer droughts are not uncommon.

The biosolids augment soil that supports grazing land. “The biosolids are nutrient rich,” says Ward, a technical services specialist with 25 years of knowledge and regulatory expertise. “They act as fertilizer in the short term and as a soil amendment in the long term.

“We really believe in what we’re doing. It’s good for the land.”

Along with Ward, four resource recovery specialists staff the ranch. Ader is the resource recovery chief, responsible for the operation; Karl Watkins and CJ Ellis are resource recovery technicians; and Wiedeman is in charge of biosolids hauling.

Meadow Springs Ranch is a working cattle ranch, leasing cattle operations to the Natural Fort Grazing Association. “We use the local Natural Resources Conservation Service expertise to determine annual grazing plans,” Ward says. “Application sites are determined by ranch staff. Then each plot is mapped using GPS and, weather permitting, truckloads are deposited directly on the land. A front-end loader is used to load the spreaders.”

One load covers 1.34 acres; the application rate is calculated at about 3 to 4 dry tons per acre. The staff also makes sure the ranch is using all its water rights, interacts with the public and assesses forage to determine how many animals to pasture.

HOME TO WILDLIFE

The ranch is also a habitat for the pronghorn antelope and the site for the National Black-Footed Ferret Conservation Center. The utility works with the U.S. Fish and Wildlife Service and the Colorado Parks and Wildlife department to reestablish the ferrets, a species related to badgers and weasels that is native to the area but on the endangered species list. It’s the first and only project of its kind in the country.

While there aren’t many neighbors in this plains-to-mountain region, there are some, and the utility takes good relations to heart. “Fencing is always an issue,” Graham says. “Dust, traffic and occasionally odors can present problems. We try to maintain an open dialog with our neighbors. We have a flyer, and we post information on our website. We’re also planning an open house. But sometimes it’s just best to have conversations with them.”

That’s one of the lessons learned at Fort Collins, according to Graham: “Communicate with your neighbors, and pay attention to odors.”

CAREFUL ATTENTION

Since the start of the program, testing and all biosolids practices have been directed by members of the biosolids management program team. The cross-functional team meets once a month, paying attention to the whole biosolids value chain.

They review the impact of pretreatment and the effects of cake application on the environment. Team members also monitor metals, nitrogen and phosphorus, establish standard operating procedures, provide training and set goals such as feed rates to the digesters and percent solids coming off the centrifuges.

They maintain contact with jurisdictional emergency response teams for quick response if anything were to happen during transportation or on the ranch. Recognition of the team’s contribution is another lesson learned: “Value the individual talents each member brings to the table, especially those employees in remote areas,” Graham says.

It’s an ethic that permeates civic activities in Fort Collins. In 2017, the city won the Malcolm Baldrige award, a prestigious national honor recognizing leadership, strategy, customers, measurement and analysis, workforce, operations and results.

Those sound exactly like the standards Graham, Ward and the team apply daily to the Fort Collins biosolids program.