The Omaha District requires a multiparameter sonde that measures sonde depth, conductivity, temperature, pH, ORP, optical dissolved oxygen, turbidity, chlorophyll-a, and phycocyanin.  Data collected from this sonde will be used in various applications including reservoir depth profiling and inflow and power plant grab sample measurements.  These measurements will be used to assess Project water quality, identify water quality exceedances, and further develop and calibrate CE-QUAL-W2 models.  This task is for the purchase of the multiparameter sonde only.  

This requirement has been determined as single sourced to the manufacturer.  Single Source for the Brand Name YSI (Xylem) is required for the purchase of the YSI EXO2 Multiparameter Sonde due to technology limitations.  While there are a couple brands that manufacture multiparameter sondes for the purpose of water quality monitoring, YSI is the only brand that currently has easily removable wet-mate swappable sensors that can be  exchanged or sent in for potential repairs.  This results in efficient maintenance of the unit.  YSI, compared to other manufacturers, also has a more robust research and development program that is continually developing new sensor technologies.  As new sensors are developed, they can be easily added to the YSI EXO2 Sonde platform, further improving the Districts water quality monitoring program.  Recent sensors that have been developed and used in other YSI sondes by the Water Quality team include fDOM and UV nitrate sensors.  These sensors are unique to only YSI (Xylem).