Adaptive mixers eliminate 99% of ditch settling problems for Clifton Sanitation District

The small town of Clifton, Colorado, is known for its outdoor recreational activities, proximity to local vineyards, and stunning views of the Colorado River. The Clifton Sanitation District (CSD) plays an important role in helping protect this precious water source for seven states. Each day, the utility treats 2.5 million gallons of wastewater through a multistage process that breaks down organic matter and removes contaminants to enable safe discharge back into the river.

When the aging drum mixers in CSD’s treatment tanks began to underperform, causing both operational and cost challenges, the utility took action – partnering with Xylem to solve the problem.

Reliable mixers play a key role in ditch treatment efficiency and performance

The Clifton Sanitation District uses one of the most common biological wastewater treatment processes: oxidation ditch technology. The activated sludge biological treatment process uses a method called fine bubble aeration to get rid of biodegradable materials by mixing pretreated wastewater and dissolved oxygen with bacteria and other microorganisms that consume harmful organic matter.

Mixers play an essential role in wastewater treatment. They keep solids from settling and maintain consistent composition in the tanks – critical for removing nitrogen and phosphorus, which can harm ecosystems and are tightly regulated by the government. When mixers are working properly, utilities can boost performance and stay in compliance.

Here’s the challenge: mixing is one of the most energy-intensive processes at a wastewater treatment facility, and when mixers are outdated or underperforming the costs can quickly add up.

Sludge buildup, expensive repairs and excessive energy use not only strain utility budgets but also increase emissions and risk noncompliance with environmental regulations.

There is a smarter path forward. By combining fine bubble aeration and adaptive mixing technology, utilities can achieve significant energy savings, improve system reliability, and ensure consistent oxygen delivery throughout the treatment process.

Intelligent controls eliminate 99% of settling problems

To solve Clifton’s drum mixer challenges, the utility turned to Xylem’s Flygt 4320 Adaptive Mixers. The large, three-blade mixers can adjust their speed in real-time based on conditions in the tank, delivering reliable, high-performance mixing while reducing energy use and operating cost. Equipped with an integrated control system, the mixers offer both manual and automatic operation. They continuously measure airflow resistance in the tank, allowing water managers to finetune mixing zones and adapt to changing process demands.

The mixers are now efficiently managing the nitrification/denitrification zone, ramping up and down as needed. In the past, incomplete mixing forced the utility to run their equipment at full speed. With Xylem Flygt Adaptive Mixers, CSD can operate at half the RPM resulting in more than 50% energy saving, while improving treatment and ensuring regulatory compliance for safe discharge.

“One of the biggest benefits we've seen is complete mixing on a scale that we were never able to achieve before. We were able to eliminate 99% of our settling problems in the ditch,” says Greg Lofstrom, Plant Operator, Clifton Sanitation District. The Xylem Flygt Adaptive Mixers “have just absolutely been phenomenal.”

See how adaptive mixers can generate energy and cost savings for your treatment operations.