Application example: River water monitoring and enviLog Mobil

Area of application

Long-term monitoring of flowing waterusing multi-parameter probes and data transmission with a mobile GPRS data logger.

Application of YSI EXO1 multiparameter probes with ecoTech enviLog Mobil data logger in a river setting
Monitoring the influence of sewage treatment plant discharge on river water and examining the rehabilitation success downriver from the discharge

Background

The release of treated sewage into a river effects the natural properties of the water. Key physico-chemicalproperties can be impacted  over long distances, thusalso impacting  the aquatic biology of the river ecosystem.
The Schleswig-Holstein Department of Agriculture, Environment and Regions (Department 4 Waters, Dec-nat41 Rivers) is responsible for monitoring the rivers in Schleswig-Holstein as part  of the implementation of theEU Water Framework  Directive. To achieve this, the department carries out comprehensive  monitoring oflocal river systems and water quality. Their monitoring program includes water sampling for analysis and onsite monitoring. A further question examines the potentialinfluence of the treated sewage on the daily changesin the physio-chemical characteristics of flowing water.

Date collection

To collect data, three YSI EXO1 multiparameter probes were equipped with sensors to measure pH, temperature, conductivity, oxygen (optical) and water level. The probes were installed in flowing water for continuous measurement. The first probe was installed above the inlet of the sewage treatment plant to measure the "current state" (or control). The second probe was installed directly below the inlet, capturing the direct influence of the sewage treatment plant. The third probe was installed further downstream, after a section of rehabilitation work, and monitors the suspected improvement in water quality through rehabilitation works. The probes were equipped with an "enviLog Mobil" data logger and transmission device for rapid monitoring of changes. The data are transferred to the ecoTech enviWatch server and can be monitored, saved and graphically evaluated online.

With the exception of brief maintenance and calibration cycles, and extreme weather events, for example, risk of ground ice, the probes remain in the flowing water all year round and continuously provide data on water quality. The data are statistically evaluated and, together with the water quality tests, monitor the success of the river rehabilitation. Furthermore, the set-up facilitates analysis on the impact of treated sewage on the water.

Many thanks to Ms. Lukas from the State Office for Agriculture, Environment and Rural Areas of the State of Schleswig-Holstein for your detailed information and pictures on the use of the devices.

• Application report