Hydroelectric Dissolved Oxygen Monitoring

Project Overview

Dissolved oxygen monitoring site location

A large Midwest power utility operates a hydroelectric plant with a FERC (Federal Energy Regulatory Commission) permit requiring it to monitor nearby water quality. The permit specifies that water quality must be measured at certain locations upstream and downstream of the plant. NexSens Technology was contacted to help develop and set up a real-time system that would monitor the specified water quality parameters and transmit the data to the plant's office.

System Description

Secure sonde deployment

Near the upstream reservoir of the power plant, two YSI 6600EDS sondes are deployed at different depths to monitor water quality before flowing through the plant. Also deployed is an In-Situ T900 total dissolved gas sensor to monitor for supersaturated water. The probe measures TDG directly and reports it relative to atmospheric pressure. Mounted above flood stage, NexSens 4100-iSIC data loggers collect data from the sensors and send it via license-free radio telemetry to a nearby 4100-BASE radio base station connected to a PC.

Farther downstream, another YSI 6600EDS sonde and In-Situ T900 TDG sensor are installed within a PVC deployment pipe attached to a bridge. A 4100-iSIC data logger collects the data from the instruments at fixed intervals and sends it to the radio base station. At another bridge site farther downstream, an identical monitoring system measures the water's quality and transmits data to a nearby 4200-iSIC, where it is sent through a telephone line back to the base station PC running iChart Software.

With this system in place, plant operators instantly know if there are any inconsistencies in water quality after it passes through the plant.