Nikite Muller, Pearl Gola , Nosi Ketse , Andrew Slaughter, Tarqyn Human

1. Applying the DEEEP methods to managing environmental water quality: experiences with local effluents in the Eastern Cape Nikite Muller, Pearl Gola, NosiKetse, Andrew Slaughter, Tarqyn Human Unilever Centre for Environmental Water Quality Institute for Water Research, Rhodes University & Hesmarie Pearson ToxSolutions

2. Introduction • The context • Climate change and waste water reuse • Use of ecotoxicology in managing environmental water quality • Standardising toxicity test methods for managing environmental water quality

3. Introduction • Environmental water quality is about water chemistry, living organisms and their interactions • Integration of data and maximizing information: • > water physico-chemistry • > biomonitoring • > ecotoxicology

4. Introduction MANAGING ENVIRONMENTAL WATER QUALITY Resource Directed Measures: Setting and maintaining RQO Various national monitoring programmes Source Directed Controls: Control / manage impacts Meeting RQO DEEEP ECOTOXICOLOGY WATER CHEMISTRY BIOMONITORING

5. Introduction • Focus for this presentation was integrating and assessing data from various projects: • Biomonitoring assessments in order to establish environmental water quality conditions • In-stream toxicity testing, using standard organisms (contribute to NTMP) • Assessing effluent using methodologies in DEEEP policies: • addresses questions on implementation and methods available (e.g. kits vs laboratory cultures) • Assessing effluent quality using indigenous organisms: • development of new test methods and different species

6. The Bloukrans River: Grahamstown STW Tannery

7. The Buffalo River: King William’s Town STW Textile Zwelitsha STW

8. Methods • Standard methods were followed, either as provided in the DEEEP manual, the DWAF method for use of artificial streams for riverine invertebrates or newly developed in-house methods • Selected DEEEP toxicity tests: • Daphnia pulex 48hr test (toxkit and lab) • Daphnia pulex 21 day reproduction test • Pseudokirchneriella subcapitata 72hr microplate test (toxkit and lab) • Selected other toxicity tests: • Mayfly 96hr and 240hr exposure experiments • Caridina nilotica 96hr and 240hr exposure experiments • Daphnia magna 48hr test (toxkit) • Vibrio fischeri bioluminescent 15 and 30 minute definitive test (toxkit) • Indigenous algae, Scenedesmus bicaudatus, Chlorella sp.

9. Methods • 4 Effluents selected (based on biomonitoring data for nearby rivers:) • Waste water treatment works, tannery, textile and dairy • Sufficient sample needed to be collected to cover all the toxicity tests • Measurement of selected chemical parameters • Concentration ranges: • 100%, 50%, 25%, 12.5%, 6.25%, (3.13%) STW Textile Dairy Tannery

10. Results BD=below detection

11. Results +: growth stimulation nd / - : could not be determined, due to excessive mortality / insufficient mortality / non-monotonic mortality over the experimental exposure period

12. Results +: growth stimulation -: growth inhibition, but insufficient to calculate EC20/EC50 nd: could not be determined, due to excessive mortality / insufficient mortality / non-monotonic mortality over the experimental exposure period

13. Results

14. Results • Species differences in responses to effluents • Some differences between kit results and laboratory culture results • Are these real? (further testing and statistical examination) • Some effluents more toxic: • tannery>textile>dairy>municiple waste • Concentrations selected affected toxicity: chemical speciation?

15. Discussion • More questions than answers? • Not all tests were successfully carried out: • Requiring repeat testing: control mortalities, concentration ranges used • issues for implementation of DEEEP, especially with respect to training level of staff • Relevance of inclusion of indigenous species for more appropriate site-specific water quality management • Do we have the right selection of species, given the varied responses in toxicity?

16. Discussion • Issues associated with effluent: • Collection and storage of effluent: many tests required repeat testing, so important to collect sufficient effluent at the outset • Required 120L • Logistical nightmare for storage as samples needed freezing • Waste disposal, especially for the tests using recirculating streams • Colouration of effluent: interference with toxicity experiments • Algae and Vibrio tests, as well as counting of Daphnia

17. Discussion • Issues around methods • Methods manual: culture and experiment methods are well explained, but for chronic experiments, “things just go wrong” • Further refinement needed? Or just more practice? • Selection of concentrations • Acute and chronic tests • High acute toxicity, but what to do when no acute toxicity evident? • Basing chronic exposures on acute results not always successful: chemical speciation? • Repeated experiments with lower concentration ranges

18. Discussion • Where to from here? • Further testing: experience will allow refinement / improvements to current recommended methods and species • Resource development: human capital and laboratory facilities • Research questions: • Inhibition vs stimulation, especially for those effluents with high nutrient concentrations • Laboratory toxicity effect versus negative environmental consequences, especially if we really are talking about ecological effects potential • Use of biochemical biomarkers as early warning indicators of potential toxic effects requires urgent attention • Implementation: what do these results really mean for environmental water quality and ecological consequences?

19. Discussion Managing environmental water quality? • There is a role for toxicity testing: • Successful implementation of toxicity tests internationally to manage environmental water quality • Uncertainty of implications of effluent discharges on aquatic resources from climate change: • Site specific: • Uncertainty of rainfall patterns: amounts and timing • Implications from in-stream temperature changes • Increasing significance of waste water reuse: • reduce amount of discharge to environment • reduce water demands from aquatic resources

20. Acknowledgements • Unilever • Water Research Commission • ESKOM TESP • Staff and students of UCEWQ IWR: • Andrew Gordon, Alex Holland, Neil Griffin, Sukhmani Mantel, Fatema Morbi, Pumza Maseti