Sustainable Development Goal for Water: Indicator 6.3.2 Stuart Warner UNEP GEMS/Water

Proportion of wastewater safely treated Target 6.3 By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally Indicator 6.3.1 Proportion of wastewater safely treated Indicator 6.3.2 Proportion of bodies of water with good ambient water quality The indicator allows countries to assess the outcomes and impacts of water quality management measures

Proportion of wastewater safely treated Target 6.3 By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally Indicator 6.3.1 Proportion of wastewater safely treated Indicator 6.3.2 Proportion of bodies of water with good ambient water quality The indicator allows countries to assess the outcomes and impacts of water quality management measures

Rivers, lakes and groundwater bodies What do we mean by “ambient” waters? Rivers, lakes and groundwater bodies Ambient water provides: A source of drinking water Fisheries for food Recreational opportunities Irrigation for crops Many other ecosystem services

What is “good” ambient water quality? Water quality that does not damage ecosystem function or present a risk to human health not severely impacted by human activities sewage wastewater discharges agricultural run-off supports a balanced ecosystem, including fisheries safe for recreational activities, such as water contact activities

General principles of indicator 6.3.2 “Good quality” is assessed in relation to target values for key ambient water quality parameters Countries set their own targets for good ambient water quality For baseline global reporting, five water quality parameters (DO, EC, DIN/TN, TP, FCB) have been recommended Monitoring data for selected parameters at each station on a waterbody are compared to target values to produce an index value Data are aggregated by temporally, and by waterbody to produce the country level indicator value

Choice of water quality parameters Dissolved oxygen: essential for aquatic organisms, low values may indicate organic matter pollution Nitrogen (DIN/TN): an essential aquatic nutrient but high concentrations often result from agricultural run-off or waste inputs Phosphorus (DIP/TP): an essential aquatic nutrient but high concentrations, often associated with agricultural run-off and sewage effluents, lead to eutrophication Electrical conductivity: a measure of dissolved substances, high values may suggest wastewater inputs Faecal coliform bacteria or E. coli: indicate presence of human and animal faecal matter and a potential risk for human Health Depending on national capacities and requirements, additional parameters can be included, and spatial and temporal intensity can be increased Internationally recognized standard methods should be used with appropriate quality assurance

Step by step approach Categorize and select representative waterbodies Select parameters and target values (baseline of five core parameters) Carry out monitoring and/or use existing monitoring data Past and present water quality monitoring data may already be available for many countries through the GEMS/Water Global Water Quality Information System GEMStat Calculate indicator at national level Use of GEMStat as an existing data portal and web services infrastructure for the global reporting

Examples of monitoring station locations on a single waterbody

Setting Target Values Different target values may be needed for different types of waterbody Natural fluctuations in parameters, e.g. seasonally driven, need to be considered before setting the target values Countries set their own target values – published examples can be used as a guideline Potential uses of the waterbodies may guide the selection of target values

Examples of published target values for core water quality parameters Unit Target type Remarks Reference Dissolved Oxygen 6 mg/l Lower* if average water temperatures >20°C Carr & Rickwood (2008)9 9.5 If average water temperatures ≤20°C Electrical Conductivity 500 µS/cm Upper* Dissolved Inorganic Nitrogen 50 as NO3- in drinking water WHO (2011)10 11 as NO3-N in drinking water 3 as NO2- in drinking water 0.2-2.0 as ammonia, toxicity to fish WRC (2016)11 Total Phosphorus 0.2 Class II “Good” quality OECD (2008)12 Faecal Coliform Bacteria 2000 No. per 100 ml Class II Suitable for treatment for drinking water and for recreational use * Target types are designated as “upper”, meaning the value should not be exceeded, or “lower”, meaning the value should not fall below

Suggested compliance levels for different standards of water quality Quality Designation Percentage compliance or index value Description Excellent 95-100 All measurements are within objectives virtually all of the time Good 80-94 Conditions rarely depart from natural or desirable levels Fair 65-79 Conditions sometimes depart from natural or desirable levels Marginal 45-64 Conditions often depart from natural or desirable levels Poor 0-44 Conditions usually depart from natural or desirable levels Good water quality requires compliance of 80% or higher with target values

Example calculation of the Indicator In the following example, a country has two waterbodies (it’s very small) with a total of five monitoring stations (2 at one and 3 the other) are we’re using the five core parameters to classify. Sampling values at each station are compared with their specific target values The compliance for each parameter is averaged over the accounting period The percentage compliance for all five parameters is averaged to give a station-level percentage and an indication of station-level water quality All stations in a waterbody are then averaged and finally all waterbodies in the country are averaged Result is an indicator value for the entire country

Parameter meets target value? Classification of each waterbody Parameter meets target value? Select water quality parameters according to intended step of monitoring ladder Select target values for each water quality parameter For each station of waterbody: carry out measurements or gather data and compare with target values Yes No Score = 1 Score = 0 Scores for Waterbody 1 over three years Station Date DO Score EC Score TN Score TP Score FCB Score 001 18.01.2013 1 04.08.2014 14.07.2015 002

Aggregation of station data to give Indicator 6.3.2 Aggregation Station 001 Aggregation Station 002 Site Date DO Score EC Score TN Score TP Score FCB Score 001 18.01.2013 1 04.08.2014 14.07.2015 Temporal aggregation 66.6% 33.3% 100% Station level aggregation Site Date DO Score EC Score TN Score TP Score FCB Score 002 18.01.2013 1 04.08.2014 14.07.2015 Temporal aggregation 33.3% 66.6% 100% Station level aggregation 59.9% Aggregation to SDG Indicator Aggregation Waterbody 1 Waterbody 2 001 002 003 Station-level 66.6% 59.9% 84.5% 75.0% 82.2% Waterbody-level 63.3% = Marginal = 0 80.6% = Good = 1 Country-level 50% waterbodies are of good ambient water quality

Proximity to Target The PTT scores are scaled to the range between 0 and 100 100 indicates the target is met, and decreasing scores indicate an increasing distance from the target Calculated over the accounting period e.g. 3 years If the target is the upper threshold as for electrical conductivity If the target is the lower threshold as for dissolved oxygen If the target is between and upper and lower threshold

Proximity to Target Waterbody 1 Waterbody 2 Station 1 Station 2 DO 75.24 75.54 100 85.52 65.52 EC 80.05 95 TN 62.45 75.94 85.54 85.25 TP 71.02 85.49 84.54 74.65 FCB 95.65 65.54 75.25 Station level 80.872 76.512 86.17 81.134 Waterbody level 78.69 = Fair 89.10 = Good National level 50 %

Topics for consideration Setting of country-specific target values Existence of, and access to, monitoring data on which to base target values Monitoring site selection and spatial coverage Capacity to measure core parameters in ambient waters Quality assurance of monitoring data Field operations, lab operations and data handling Data storage, indicator calculation and reporting mechanisms

Thank you for listening Stuart Warner UNEP GEMS/Water Capacity Development Centre s.warner@ucc.ie Training in best practice in all aspects of water quality monitoring activities is available through UNEP GEMS/Water