Sanitation Network Quality Monitoring

Real-time, remote detection and management of pollution episodes.

Challenge

Terrassa's municipal water supplier approved a by-law concerning the maximum concentration levels of pollutants permissible in wastewater discharges into the sewerage system.

The aim was to guarantee that the municipality's wastewater returned to the environment at quality levels required by environmental regulations. Secondly, they wanted to ensure that the network of collectors and the treatment plant (Terrassa WWTP), and in particular its biological reactor, worked adequately.

The by-law's preventive control measures included regular checks on activities considered critical or at risk and the processing of discharge permits. However, these proved to be insufficient in preventing problems and excess discharges into the sewerage system.

ADASA’s Solution

ADASA provided three automatic, continuous measurement stations, installing them in the primary collectors. Data harvested gave a 24-7 picture of the quality of the wastewater, permitting an assessment of its pollution load.

Each measurement station contains sampling equipment including a multi-parametric analyser, a BOD analyser, a hydrocarbon analyser and an ultraviolet analyser for organic matter. The stations transmitted fortnightly data on pH, temperature, conductivity, dissolved oxygen, redox potential, turbidity, BOD, hydrocarbons and flow rate to a data centre. This information is available in almost real-time from any location.

Alarm signals emitted from the stations facilitate operational decisions, helping to avoid possible damage to the environment and Wastewater Treatment Plants (WWTP). Samples collected automatically during contamination episodes make it possible to determine later the possible origin of the pollution.

ADASA's solution also included the integration of the council's sewage facilities into the remotely controlled network, including small treatment plants, pumping stations and spillways of the unitary sewage system. Our resolution made it possible to make changes from remote locations to treatment plant operations and pumping stations, as well as varying alarm ranges and activating sampling.

Result

Thanks to ADASA’s intervention, Terrassa’s water resources managers now have real-time details of the quality and quantity of the wastewater that flows through the primary collectors that converge at Terrassa's WWTP. Sensors detect variations in real-time, such as the presence of flows with peaks in pollutant concentrations and the possible origin(s) of uncontrolled discharges. Managers can also anticipate corrective measures to help avoid episodes affecting the sanitation system.
Today, Terrassa’s managers remotely manage their sanitation facilities, detect in real-time any mechanical or electrical problems in their equipment. Such data helps them efficiently organise preventive maintenance and repair work.

Client

Terrassa City Council is the administration in charge of the drinking water supply and wastewater treatment control within its municipality. In 1997, it began granting industrial activity permits to discharge wastewater into the municipal sewerage system, one of the first Town Halls in Spain to carry out this task itself. This register has increased progressively to now list more than 1,000 industrial activity discharge permits.