Monitoring of indirect discharges in Põltsamaa

The munincipal wastewater treatment plant (WWTP) in Põltsamaa, Estonia, receives wastewater from the municipalities of Viljandi and Põltsamaa (22 300 PE) and from eight smaller wastewater collection areas (180-1 031 PE). The WWTP was established in 2003 and it is operated by Põltsamaa Vesi OÜ.

The company invested in a portable automatic water sampler to increase the wastewater sampling and monitoring capability in the WWTP with the view of achieving better and more efficient process control. As the sampler is portable, it can be used for monitoring wastewater in the whole catchment area.

Solution to which problem

Some of the industries operating in the collection area of the WWTP are carrying out activities, where either hazardous substances or sudden shock loads of nutrients can be found and can end up in the treatment plant.

As the company did not have monitoring capacity, the wastewater sampling and monitoring relied solely on external services provided by other companies. The situation caused several process interruptions, as the company was not able to react on the unexpected discharge in time.

The automatic water sampler enables the company to monitor its customers’ wastewater discharge with increased reliability in situ and hence helping the company to achieve better and more efficient process control.


In addition to the more accurate determination of the influent or effluent of the WWTP, the company can now identify harmful substances from the wastewater that may cause problems for the treatment plant’s processes. Combined with prior knowledge about potential emitters and communication with industrial customers, the sampler helps to locate the source of pollution. This in turn provides an opportunity to advise customers and, if necessary, to impose sanctions so that substances that damage the treatment plant's processes do not enter the wastewater.


The Põltsamaa Vesi OÜ has increased their wastewater monitoring precision and reliability. This investment is an example of a low cost and simple solution for municipalities to better control industrial wastewater discharge.

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