System solves waste treatment challenges for rural town

Problem: The 30,000-gpd wastewater treatment system in Section, Alabama (population 770), was designed to treat residential and commercial wastewater. The town needed an easy-to-monitor system with tight control.

Solution: The objective was to treat 30,000 gpd at 300 mg/L BOD and TSS and to handle average daily flow fluctuation over a range of 50 to 100 percent. ECOPOD units from Delta Treatment Systems were installed in poured-in-place concrete tanks with aluminum hatches. A 14,200-gallon flow equalization tank was installed before the treatment reactor tanks. This tank includes duplex pumps to ensure that flow surges do not reduce efficiency. A 19,190-gallon primary tank precedes the flow equalization tank. Effluent also passes UV disinfection. A drip disposal system includes an effluent pump chamber, headworks, tubing, controls and all necessary valves and fittings. A concrete building houses electrical controls and equipment.

Result: The system has performed as promised. 800-219-9183; www.deltatreatment.com

Analyzer helps track sludge blanket depth

Problem: Efficient secondary clarifier operation is critical for the Tres Rios Water Reclamation Facility in Pima County, Arizona. The facility’s continuous sludge blanket monitors were obsolete and failure-prone and led to periods in which blankets were not monitored.

Solution: The county installed an IFL 700 IQ sludge blanket level sensor from YSI, a Xylem brand, on 14 secondary clarifiers. A trial period proved the units were able to provide reliable data to enable process adjustments to minimize sludge blanket depth. The mounting was designed in-house to lift the sensor out of the water as the skimmer arm passes and to allow convenient removal for maintenance. The sensors were easy to install and set up and were programmed to ignore subsurface obstructions, including the rotating sludge rakes. 

Result: After five year, operators are pleased with the performance and durability of the sensors. The monitoring system is part of a solution that reliably produces clarifier effluent satisfying water reuse standards. 800-765-4974; www.ysi.com

Radar gets accurate level measurement in challenging lift station 

Problem: A wastewater treatment plant in New York’s Hudson Valley had tried for years to get accurate level readings in lift stations. Floats, gauges, pressure sensors and ultrasonic devices all eventually failed. Problems were caused by steam, high humidity, grease, rags and even an instance of spiders getting in the way. The stations needed a noncontact technology that would work in the harsh environment.

Solution: VEGA Americas provided the VEGAPULS WL 61 radar sensor, designed to make accurate measurements independent of the product, process and ambient conditions.

Result: Since the unit was installed, the plant has had no level measurement errors. Technicians can adjust the radar sensor to ignore certain structural components inside the lift station. The facility bought a second unit as a backup, removed all other level sensors from that lift station and purchased many more for other difficult situations. 800-367-5383; www.vega.com

Wastewater plant upgrades to cleaner and easier sludge level measurements

Problem: A wastewater treatment plant in St. Louis was measuring sludge blankets in primary and secondary clarifiers and digesters with 15-foot sampling tubes. Operators complained of getting wet, lifting awkward tubes overhead and being unable to get consistent, accurate sludge level readings.

Solution: Raven Environmental Products provided a portable SID Rotary Sludge Interface Detector for a six-month trial. The lightweight and portable unit uses a sensor that is lowered to the tank bottom like a fishing reel. As the operator reels in the sensor, a counter provides the sludge level in inches. There is no touching of wet surfaces and no overhead drips. The unit works with a base plate that is mounted on the railing and holds the unit over the tank for simple operation. The base plate provides a consistent sample point. A freestyle handle is available for tanks without railings.

Result: The operators are happy to measure sludge levels in all weather, day or night, knowing the procedure will be easy and clean and provide consistently accurate measurements for optimum process control. 800-545-6953; www.ravenep.com