2. 1 - 3. 4.- CHEMICAL AND BIOLOGICAL VARIABLES 3.4.1. Overview

3. 3.4. Water quality variables 3.4.1. Overview Peter Kelderman UNESCO-IHE Institute for Water Education Online Module Water Quality Assessment

4. 3 CONTENTS Overview Biological monitoring Variables in the European Union Water Framework Directive

5. 4 CHEMICAL AND BIOLOGICAL VARIABLES Measure in water, particulate matter and/or in living organisms Physico-chemical variables Biological water quality monitoring Choice of variables: dependent on objectives, occurrence, impacts, resources. Also: water use (for irrigation? recreation?,..) determines variables’ choice.

6. 5 WHICH VARIABLES; HOW? See Course 2 & 3.6.3. Temperature (in situ): often large vertical variations in deep lakes Colour (e.g. humic acids); odour (e.g. H 2 S) TSS (total suspended solids; “turbidity”), especially in rivers: high values in storm floods (monsoon !) Electrical Conductivity (EC, µSiemens/cm): easy to measure and gives good idea of ions like Na +, Cl - ; typical value: 100-200 µS/cm pH (in situ); mostly between 6 and 8; otherwise waste discharges? pH > 9-10 during day-time in eutrophic lakes and reservoirs. Hydrological variables (flow, discharge) in rivers DO (mostly in situ). DO< 2 mg/L will kill most fish species. Large day/night fluctuations in eutrophic lakes and reservoirs.

7. 6 NO 3 -,mainly from agriculture; nitrite (NO 2 - ) as “intermediate” in reactions NH 4 +  NO 3 - and NO 3 -  N 2 Ortho-phosphate (PO 4 3-, HPO 4 2-..; “soluble reactive phosphorus”: SRP) as limiting nutrient for algal growth; total-P Ammonium (NH 4 + ) :indicator wastewater pollution. For pH > 9.5 mostly present as (toxic) NH 3. Also: Kjeldahl-N (organic N), total-N BOD (biodegradable organics); COD, see before Major ions (Ca 2+, Na +, Cl -, HCO 3 - SO 4 2- ….): often natural sources. For irrigation water, sodium adsorption ratio “SAR ” (ratio Na + vs Ca 2+ + Mg 2+ ) is important. High Na + gives bad soil permeability.

8. 7 Alkalinity, acidity: pH-buffering capacity for H + ; OH -. Especially by “bicarbonate” HCO 3 -. Reacts with added H +  H 2 CO 3 ; with OH -  CO 3 2- Sulphide (S 2- indicator anaerobic conditions. H 2 S: smell of “rotten eggs”) Fluoride (F - ;in ground water  Course 3.8. ) Arsenic (As), especially in groundwater  Course 3.8. Chl-a (chlorophyll-a) in lakes, as indicator of eutrophication E-coli and other microbiological indicators: helminths like round worm; viruses (hepatitis,. ) Trace/heavy metals, organic micropollutants: expensive; only if necessary ! Radioactivity...

9. 8 GEMS PROGRAMME Some 20 variables; see list Extra: BOD,COD (sometimes); some heavy metals.. “Minimum list”: temperature., pH, DO, nutrients, EC,.. Major ions often as “Quality control” (ionic balance); see later

10. 9 Netherlands: strong increase number of parameters

11. 10 BIOLOGICAL WATER QUALITY MONITORING Physico-chemical methods give “snap-shot view” of water quality; organisms such as algae, bacteria, plants, give more a “history” of the pollution Concentrations may be immeasurably low, but still have effect Various techniques: Biomonitoring (E coli bacteria, algae, macro- invertebrates…...) characterize “the” water quality. Also: toxicity tests  Course 2.4.: “Ecotoxicology” Bioaccumulation monitoring Early warning monitoring, using fishes, water flees, mussels,...

12. 11 MACRO-INVERTEBRATES (few mm’s) Especially used for organic pollution; water quality during whole life cycle. From top to bottom, the organisms can cope with less oxygen. Applicable all over the world Frequency: few times per year Disadvantages: dependent on substrate (stones, etc.) difficult to compare e.g. upstream/downstream

13. 12 BIOACCUMULATION MONITORING “Biomagnification” of micropollutants in the food chain; the relatively high values in “top predators” can easily be measured. Example: world-wide programme of monitoring heavy metals, pesticides, etc., in mussels, hung in nets in polluted waters (“mussel watch”) (http://ccma.nos.noaa.gov/stressors/pollution/n sandt/musselwatch/as_intl_mw_study.aspx )http://ccma.nos.noaa.gov/stressors/pollution/n sandt/musselwatch/as_intl_mw_study.aspx

14. 13 Go now first to Unit 4.2: Presentation on Biological water quality monitoring (by Diederik Rousseau)

15. 14 Biological water Quality in West Germany, 1970 (red = very polluted)

16. 15 Biological water Quality in West Germany, 1990 (red = very polluted)

17. 16 NETHERLANDS: AQUALARM SYSTEM Used for early warning in rivers Rhine and Meuse: Continuous, fully automated monitoring using: Biological systems (water fleas, algae) Physico-chemical variables (standard variables; radioactivity, pesticides, etc.). In case of alarm levels, warnings go to drinking water companies downstream, Water Boards, etc. Results can be followed via the Internet, in “real time”

18. 17 European Union WFD

19. CATEGORIES OF VARIABLES pH, alkalinity, EC, temperature, dissolved oxygen (not BOD/COD), TSS,.. Nutrients (SRP, P-tot, nitrate, ammonia, N-tot) Priority substances Biological/ecological water quality elements (plankton, fish, biomonitoring with macro-invertebrates,…) Hydromorphology, e.g. hydrology, variations in water depth river, presence of dams in rivers. 18

20. PRIORITY SUBSTANCES “ Pose significant risk to aquatic environment”; should not be discharged: Heavy metals (Hg, Cd, Pb,Cu..) Organic micropollutants (DDT, PCB, etc.) No definite list yet; >150 substances. Monitoring only for those that can be expected in the River Basin Alachlor, Anthracene, Atrazine, Benzene, Brominated diphenylethers, Cadmium and its compounds, C10-13-chloroalkanes, Chlorfenvinphos, Chlorpyrifos, Dichloroethane, Dichloromethane, Di(2- ethylhexyl)phthalate (DEHP), Diuron, Endosulfan, Fluoranthene, Hexachlorobenzene, Hexachlorobutadiene, Hexachlorocyclohexane (gamma-isomer, Lindane), Isoproturon, Lead and its compounds, Mercury and it’s compounds, Naphthalene, Nickel and its compounds, Nonylphenols, (4- (para)-nonylphenol), Octylphenols (para-tert-octylphenol), Pentachlorobenzene, Pentachlorophenol, Polyaromatic hydrocarbons, (Benzo(a)pyrene), (Benzo(b)fluoranthene), (Benzo(g,h,i)perylene), (Benzo(k)fluoranthene), (Indeno(1,2,3-cd)pyrene), Simazine, Tributyltin compounds (Tributyltin-cation), Trichlorobenzenes (1,2,4-Trichlorobenzene), Trichloromethane (Chloroform), Trifluralin...

21. 20 Europe’s Water Framework Directive - Quality Elements

22. 21 Water Framework Directive - Quality Elements Lakes

23. 22 Surface water status in WFD To be determined by “worst case” of chemical and ecological status: –Chemical status: concentrations of specific pollutants not exceeding specified levels  “good” or “bad” quality; “one out: all out ! –Ecological status: Ecological Quality Ratio based on biological indicator values related to reference conditions

24. 23 Bad statusGood status Bad status Poor status Moderate status (differs moderately from type specific conditions) Good status (slight changes from type spec. conditions) High status (close to undisturbed conditions) Chemical status Ecological status target status max. ecol. potential reference biotic elements abiotic elements Water-quality status = Chemical status + Ecological status Yardstick OVERALL ASSESSMENT