Challenge

Odor control was not a problem in Las Vegas, Nevada, in 1912, when the first wastewater treatment system ended on the outskirts of town with an 8-inch pipe discharging sewage directly into the desert.

Nor were odors a problem in 1931 when the first wastewater treatment plant began treating 1 MGD of wastewater at a site on the eastern edge of town.

Nor in 1955, when the flow increased to 7.5 MGD, forcing the City to purchase 160 acres of desert land for the site of the current Water Pollution Control Facility.

However, the City of Las Vegas has experienced unprecedented growth and escalation of property value over the last 20 years, and the WPCF now finds itself surrounded by golf courses and expensive residential developments.

Solution

A Major Plant Upgrade Was Unavoidable!

• Odor control was a primary concern of plant upgrade in 1998
• Eight 180-foot diameter trickling filters covered with domes to contain odors
• Contained odors treated by seven odor control scrubbers

The USFilter LO/PRO® odor control system offered several advantages over conventional packed towers, including:

• Factory pre-assembled units, enabling quicker turn-around time for delivery and installation
• Significant operating cost savings due to patented multiple stage design and chemistry
• Uniform size scrubbers, simplifying required parts and ease of operation and maintenance, and reducing engineering time

Results

Seven Model LP-7000 LO/PRO® scrubbers were installed and brought on line in late 1999, with outstanding results:

• Performed extensive performance testing at average and peak inlet concentrations of 10 to 20 parts per million
• Scrubbers tested independently for eight hours of operation
• All scrubbers comfortably exceeded 99.5 percent H₂S removal
• Even at peak concentration, no odors could be sensed at the scrubber outlet

Four more LP-7000 LO/PRO® scrubbers were installed at the new Northwest Water Resource Center, a 10 MGD reuse facility.

With eleven LP-7000 scrubber systems treating 269,500 cubic feet per minute of foul air in the Las Vegas Valley, the LO/PRO® scrubber system is playing a major role in helping the City of Las Vegas meet EPA requirements, optimize plant performance and be a good neighbor.