Groundwater monitoring Requirements

1. Groundwater monitoring Requirements

2. Comment on the differences between monitoring for surface and groundwater.

3. Groundwater’s Status Quo • Millions of m3 pumped every year: Monitored? Who? How? • 100’s of thousands of users: Registered? Controlled? • 10’s of thousands of wells/boreholes:Registered? Maintained? Info. about location, abstraction levels, water levels, water quality, formation, etc - • 1000’s of sources of pollution: Location, nature & quantity of pollutants? aquifer vulnerability? • Many governing departments/institutions: Joint management ? Coordination / cooperation?

4. General Introduction • Groundwater is: • an extensive, concealed and relatively inaccessible resource. • invisible..!

5. One way to make groundwater visible... • by monitoring it, e.g: Monitoring groundwater level shows a declining water table – which allows water managers to obtain an appreciation of the status of the resource. Year-wise depletion of groundwater

6. One way to make grdwater visible...(contd.) Some Consequences of GW abstraction Normal consequences of any groundwater pumping When pumping is further increased Excessive pumping

7. Groundwater Monitoring Systems by Function

8. Types of data for Groundwater Management

9. The Monitoring Cycle Mgt question & monitoring objectives, e.g.trends& changes, impacts & risks, etc. Mgt of info. & actions of Define actual info. needed, what for, wherefrom..? etc. needs static & dynamic water levels, water quality

10. When is groundwater monitoring considered cost-effective? • itis driven by a specific objective–monitoring for its own sake often leads to inefficient use of manpower and budgets • data collected is: • NOTonly used for the explicit purpose of the monitoring programme, but • Also systematically stored for future use – there are far too many cases of monitoring data being lost along the way.

11. Effectiveness of groundwater monitoring ....is improved by careful attention to: • network design • system implementation • data interpretation • data storage from past monitoring activities • accessibility of monitoring stations... • participatory monitoring amongst water users • interpretation and use of data to formulate management actions

12. Measuring GW Use &Aquifer Behaviour Primary goalof aquifer management is to: • develop groundwater resources on the basis of a policy plan. • monitor & control impacts of abstraction on groundwater systems. Thus, monitoring grdwater abstraction+aquifer water levels provides key information for management of grdwater resources.

13. Measuring GW Use &Aquifer Behaviour (contd.) Monitoring of: • grdwater abstraction, and • aquifer water levels combined with management actions – reductionof pumping –can contribute to more stable development of groundwater resources.

14. Establishment of baseline situation: Application of mgt actions, & monitor Example:Where historic data reveals over-abstraction.. Monitoring data

15. Is there any dedicated monitoring network in your country, or are existing production boreholes used? Questions Who is responsible for data collection, storage, interpretation and management? Which parameters are monitored, and why this choice?

16. Detecting Groundwater Quality changes Grdwater monitoring requires special sampling procedures as: • well pumping + sample handling may cause major sample modification through; • air entry • degassing +volatile losses need for appropriate sampling procedures.

17. Summary of sampling procedures and precautions for specific groups of groundwater quality parameters

18. In designing a monitoring network, what key steps would you take in terms of installation/selection of monitoring wells; data acquisition (who-by, frequency, etc.); data storage and interpretation

19. Early warning potential threats to Aquifer +Groundwater supply quality • a critical requirement for detecting any threats to groundwater quality Design of monitoring networks necessary, which... • relates to the spatial variation of grdwater flow + qualityof more recent recharge....

20. Early warning of potential threats to Aquifer +Grdwater supply quality (contd.) Detection of groundwater quality trends in aquifer replenishment in vicinity of a public-supply water well

21. Early warning of potential threats to Aquifer +Grdwater supply quality (contd.) Many cities have experienced rapid growth of urban & industrial waste disposal to the ground....

22. Early warning of potential threats to Aquifer +Grdwater supply quality (contd.) .....thus, necessitating a focused groundwater quality management monitoring, using sampling piezometers.

23. Early warning of potential threats to Aquifer +Grdwater supply quality (contd.) Some objectives of such sampling piezometers: • to facilitate early warning of the onset of groundwater pollution........ – to allow timely introduction of necessary control measures. • to provide advance warning of the arrival of polluted water at an important groundwater supply source and make provision for treatment or other mitigation.

24. What important natural or anthropogenic water quality problems are in your country? Who carries out the monitoring?

25. Basic rules for a successful groundwater monitoring programme - summary Network Design • objectives must be defined and program adapted accordingly • groundwater flow system must be understood • sampling locations and monitoring parameters must be selected according to objectives System implementation • appropriately-constructed observation + abstraction wells must be used • field equipment + laboratory facilities must be appropriate to the objectives • a complete operational protocol + data handling system must be established • groundwater + surface water monitoring should be integrated where applicable Data interpretation • data quality must be regularly checked through internal and external controls • decision makers should be provided with interpreted management-relevant datasets • program should be periodically evaluated and reviewed

26. Thank you for your attention