Protected by EPAS
The effluent of a wastewater treatment plant is usually characterised using physico-chemical parameters like COD, BOD, nutrients and other individual components. These parameters do however not give us an indication of the impact of the effluent on the receiving water (lake, river, etc..)
Tests on aquatic organisms
EPAS determines this ecological impact using several ecological tests on different aquatic organisms, like:
- Bacteria Vibrio fisherii
- Freshwater algae Pseudokirchneriella subcapitata
- Marine algae Phaeodactylum tricornutum
- Freshwater crustaceans Daphnia magna
- Freshwater crustaceans Ceriodaphnia dubia
- Freshwater crustaceans Thamnocephalus platyurus
- Marine crustaceans Artemia fransiscana
- Freshwater rofifer Brachionus calyciflorus
- Marine rotifer Brachionus plicatilis
- Brackisch copepode Acartia tonsa
A receiving eco-system is a complex unity, where different trophic levels are present.
A toxic effect on one part of the system can indirectly have an effect on the complete eco-system. Therefore, several organisms from different trophic levels are tested on the same effluent sample.
WET & TIE
EPAS provides an holistic ecological risk assessment combining classical physico chemical characterisation of plant's effluent, Whole Effluent Testing (WET) and Toxicity Identification Evaluation (TIE) and the quality and nature of the receiving environment.
Based in this combination, EPAS not only matches the treatment efforts with the ecological needs but also successfully negotiates site specific ecological risk based standards for treatment effluents.