1. GROUNDWATER MONITORING REQUIREMENTS

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

3. Groundwater’s Status Quo  Millions of m 3 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. Groundwater is:  an extensive, concealed and relatively inaccessible resource.  INVISIBLE..! General Introduction

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

7. SYSTEMBASIC FUNCTIONWELL LOCATIONS Primary (Reference) Monitoring evaluation of general groundwater behaviour, e.g.:  trends resulting from land-use change + climatic variation  processes such as recharge, flow and diffuse contamination in areas with uniform hydrogeology and land use. Secondary (Protection) Monitoring protection against potential impacts to:  strategic groundwater resource  well-fields/springheads for public WS  urban infrastructure from land subsidence  archaeological sites against rising WT  groundwater-dependent ecosystems around facilities/areas/ features requiring Protection. Tertiary (Pollution containment) Monitoring early warning of groundwater impacts from: intensive agricultural land use industrial sites solid waste landfills land reclamation areas quarries and mines immediately down + up-gradient from hazard Groundwater Monitoring Systems by Function

8. Types of data for Groundwater Management DATA TYPEBASELINE DATA (from archives) TIME-VARIANT DATA (from field stations) Groundwater Occurrence & Aquifer Properties  hydrogeologic logs, grdwater levels, quality, etc.  well & aquifer pumping tests grdwater level monitoring grdwater quality monitoring Groundwater use  water well pump installations  Water use inventories  Population registers & forecasts  Irrigation energy consumption water well abstraction monitoring (direct/indirect) grdwater level variations Supporting Information  climatic data  land-use inventories  geologic maps/sections riverflow gauging meteorologic observations satellite land-use surveys

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

10. When is groundwater monitoring considered cost-effective?  it is driven by a specific objective – monitoring for its own sake often leads to inefficient use of manpower and budgets  data collected is:  NOT only 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 goal of 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. Monitoring of:  grdwater abstraction, and  aquifer water levels combined with management actions – reduction of pumping – can contribute to more stable development of groundwater resources. Measuring GW Use & Aquifer Behaviour (contd.)

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

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

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

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

23. 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. Early warning of potential threats to Aquifer + Grdwater supply quality (contd.)

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

25. Network Design  objectives must be defined and program adapted accordingly  groundwater flow system must be understood  sampling locations and monitoring parameters must be selected by 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 Basic rules for a successful groundwater monitoring programme - summary Network Design System implementation Data interpretation  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  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 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