"Consumer Reports" for Treatment Plants

Terrence K. McMahon

The Instrument Testing Assn. (www.instrument.org) is a non-profit association of water & wastewater treatment facility operators, suppliers, and engineering and consulting firms established in 1984 to provide its members with independent appraisals of instrumentation products, especially water analyzers. Headquartered in Henderson, Nev., it's near Las Vegas as well as Hoover Dam and its low-cost hydroelectric power. In the 1950s, when titanium metal was a crucial material in the fabrication of the first supersonic jet aircraft, one of the world's largest titanium reduction plants was sited in Henderson. Tony Palmer, ITA's executive director, tells me the plant is still working.

 

Originally formed by water & wastewater treatment facilities throughout the U.S. and Canada to cooperatively conduct objective testing of environmental instrumentation, its goals include improved reliability and performance of instrumentation and automation systems. ITA's mission includes advancing the theory and practice of instrumentation and automation through the understanding, selection, improvement and cost-effective use of instrumentation and automation applications for monitoring and controlling water, wastewater and industrial systems.

 

Although ITA's membership has broadened to include instrument suppliers and other related firms, the leadership roles (board of governors) are restricted to end-user members.

 

A representative ITA field test report (released in 2001) concerned online ammonia analyzers for water & wastewater treatment applications. Conducted at the City of Houston's Beltway Wastewater Treatment Plant over a three-month period, the report rates nine online ammonia analyzers using three different analytical technologies (ion-selective electrodes, colorimetric, and UV absorbance). The test bed consisted of a wastewater secondary activated sludge aeration basin, mixed liquor suspended solids environment. The Beltway facility handles an average flow of 5 million gallons/day.

 

Average throughput characteristic included:

 

                                BOD                                                 500-1,500 mg/L

                                Total Suspended Solids                      3,220 mg/L

                                Total Dissolved Solids                        340 mg/L

                                Dissolved Oxygen                              2.1 mg/L

                                pH                                                    6.7