Physical & Quality Groundwater Monitoring Information for effective management Information for effective management Groundwater Management for Hygiene.

Physical & Quality Groundwater Physical & Quality Groundwater Monitoring Monitoring

Information for effective management Information for effective management Groundwater Management for

Hygiene and Sanitation IWSD – Harare June 2011

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?

GROUNDWATER STATUS QUOGROUNDWATER STATUS QUO

MONITORING: WHO? MONITORING: WHO?

• Who requires/requests for monitoring?

• Who determines priorities and expected outcomes?

• Who pays?

• Who implements the monitoring?

• Who owns/ shares the data?

GROUNDWATER USE AND QUALITY GROUNDWATER USE AND QUALITY MONITORING MONITORING

• Principles of groundwater monitoring

• Monitoring cycle and tools

• Monitoring resource use and aquifer response

• Groundwater quality monitoring

• Effectiveness, cost and quality control

• Examples

WHAT IS MONITORING NOT?WHAT IS MONITORING NOT?

PROVIDING IRRELEVANT INFORMATION TO ILL DEFINED QUESTIONSPROVIDING IRRELEVANT INFORMATION TO ILL DEFINED QUESTIONS

WHAT IS GROUNDWATER MONITORINGWHAT IS GROUNDWATER MONITORING?

Groundwater monitoring comprises the collection, analysis and storage of data

on a regular basis to provide information for effective groundwater management

to a variety of stakeholders.

Monitoring makes groundwater visible, if…….

SYSTEM BASIC FUNCTION WELL LOCATIONS

Primary(Referenc

e)

evaluation of general groundwater behaviour, e.g.: trends(variation in land use) and processes (recharge)

in areas withuniform

hydrogeologyand land use.

Secondary(Early

warning Protection

)

protection against potential impacts to:well-fields/springheads for public WSurban infrastructure (land subsidence)archaeological sites against rising WTgroundwater-dependent ecosystems

around facilities/areas/

features requiring

Protection.

Tertiary(Pollution impacts)

early warning of groundwater impacts from:• diffuse sources (intensive agr. land use)• point sources (industrial sites etc)

immediately down +

up-gradient from hazard

Compliance

(management)

Complying to requirements in a permit (abstraction rates, quality changes, water level decline)

Around groundwater well fields

Groundwater Monitoring Systems by FunctionGroundwater Monitoring Systems by Function

Object of protectionEarly warning

Pollution sourceImpact monitoring

Groundwater abstractionCompliance /management + early warning

monitoring

Impacts

Risks

Impacts

Risks

Trend monitoring

Purpose and function of monitoringPurpose and function of monitoring

Groundwater is invisible

Maputo 1984

Recharge estimations

So = 40 mm

Rainfall: 800-850 mm/year

Recharge: 165-185 mm/year

RECHARGE ESTIMATES MAPUTORECHARGE ESTIMATES MAPUTO

Monitoring for well field operaton- daily abstraction / pumping hours- well performance

Monitoring - water level fluctuations- water quality for purpose of use

Monitoring for resource mgt.- allocation / abstraction control- quality /pollution control- environmental flows- information sharing/ knowledge dev.- awareness /demand mgt.

Monitoring - linkage with other planning sectors.

Well field operation Industrial Drinking water Irrigation water

Monitoring well

MONITORING: DIFFERENT PURPOSE <> SAME MONITORING: DIFFERENT PURPOSE <> SAME DATA DATA

Groundwater is a hidden resource to which we have no direct access

Contrary to surface water, changes in groundwater quality and quantity are slow processes which cannot be determined by snap shot monitoring

Changes in groundwater quality are often irreversible

WHY IS GROUNDWATER MONITORING WHY IS GROUNDWATER MONITORING IMPORTANT? IMPORTANT?

GROUNDWATER USE AND QUALITY GROUNDWATER USE AND QUALITY MONITORING MONITORING

• Principles of groundwater monitoring

• Monitoring cycle

• Monitoring resource use and aquifer response

• Groundwater quality monitoring

• Effectiveness, cost and quality control

• Examples

THE MONITORING CYCLETHE MONITORING CYCLE

Management question Management question and monitoring and monitoring

objectivesobjectives

Definition of informationDefinition of information needsneeds

Collection of static and Collection of static and dynamic datadynamic data

Data storage, Data storage, interpretation and interpretation and

disseminationdissemination

Management information Management information and actionsand actions

• Trends and Trends and changeschanges

• Impacts and risksImpacts and risks

• Compliance Compliance

• Groundwater Groundwater specificspecific

• Water useWater use

• Supporting dataSupporting data

Information > data > information

Type of data

Static data (design phase, reference)

Dynamic data (monitoring changes)

Groundwater specific data

- existing data on grw. levels - existing data on grw. quality- tests on existing wells- information from new wells- aquifers tests

- monitoring observation wells (levels and quality)- monitoring existing wells- monitoring springs

Water use

- population registers- water use inventories

- demographic changes - monitoring water use

Supporting data

- surface water / springs- climate data- land use data- geological data (existing wells)

- surface water monitoring- rainfall /climate data- changes in land use

WHAT DATA DO WE COLLECTWHAT DATA DO WE COLLECT??

• Monitoring networks• Network density (hydrogeological and hydro-chemical

heterogeneity/complexity)• Location observation points (existing used wells,

abandoned wells, new observation wells, climate, surface water, water use)

• Monitoring parameters • Measuring and sampling frequency (instruments,

budget, monitoring program)

• Satellite images and airborne surveys • Statistics

Factors determining design• Budget, • Monitoring objectives

HOW DO WE MONITOR ? HOW DO WE MONITOR ?

MONITORING POINTSMONITORING POINTS

Climate

River water

Wadi Flows

Groundwater

Water use

GROUNDWATER USE AND QUALITY GROUNDWATER USE AND QUALITY MONITORING MONITORING

• Principles of groundwater monitoring

• Monitoring cycle and tools

• Monitoring resource use and aquifer response

• Groundwater quality monitoring

• Effectiveness, cost and quality control

• Examples

AQUIFER REPONSE: WATER LEVELS AQUIFER REPONSE: WATER LEVELS

•Historic data

Example: Water saving to reduce aquifer depletion

•Monitoring data

•Baseline data (reference)

MONITORING FOR RESOURCE USE & AQUIFER RESPONSEMONITORING FOR RESOURCE USE & AQUIFER RESPONSE

Monitoring of groundwater levels and groundwater use is needed to verify the predicted aquifer response for management scenarios.

Important issues: •knowledge of the reference situation: historic and baseline data•groundwater flow is related to the groundwater levels•water level response is related to the use

But: There remains always a certain uncertainty

HYDROGRAPHS: NYAMANDLOVU SST AQUIFER

Nyamandlovu SST Aquifer: BH Umgu-093 Hydrograph

1110.00

1112.00

1114.00

1116.00

1118.00

1120.00

1122.00

1124.00

1126.00

1128.00

1130.00

01/1989 Sep-90 May-92 Jan-94 Sep-95 May-97 Jan-99 Sep-00

Year

Wat

er L

evel

Alt

itu

de

(m)

•Direct monitoring- metering and regular inspection

•Indirect monitoring - energy consumption and average pumping rates- pumping hours and average pumping rate- population estimates and random tests (drinking water)- use of remote sensing information (irrigation water use)

MONITORING GROUNDWATER USE MONITORING GROUNDWATER USE

GROUNDWATER USE AND QUALITY GROUNDWATER USE AND QUALITY MONITORING MONITORING

• Principles of groundwater monitoring

• Monitoring cycle and

• Monitoring resource use and aquifer response

• Groundwater quality monitoring

• Effectiveness, cost and quality control

• Examples

MONITORING FOR GROUNDWATER QUALITY MONITORING FOR GROUNDWATER QUALITY

Sampling of production wells• cheap but often unreliable/not representative

• useful to determine the reference situation

Sampling of purpose- drilled monitoring wells:• Reference monitoring for natural water quality /natural recharge

• Offensive monitoring of pollution sources

• Defensive monitoring for groundwater supplies

• Evaluation monitoring for sites of known aquifer contamination

MONITORING STRATEGIESMONITORING STRATEGIES

Offensive monitoringEarly detection of incipient aquifer contamination by known pollution sources

Defensive monitoringProvide warning of pollution plumes threatening potable well fields or individual wells

WHERE TO LOCATE MONITORING POINTS ?WHERE TO LOCATE MONITORING POINTS ?

Physical parameters (indicators)- Electric conductivity /temperature

- pH

- DO

•Manuel and automatic recorders

Water sampling and analysis

parameters selected in the light of the quality objective and pollution hazard assessment: quality assurance and control

MONITORING FOR GROUNDWATER QUALITY MONITORING FOR GROUNDWATER QUALITY

GROUNDWATER USE AND QUALITY GROUNDWATER USE AND QUALITY MONITORING MONITORING

• Principles of groundwater monitoring

• Monitoring cycle and

• Monitoring resource use and aquifer response

• Groundwater quality monitoring

• Effectiveness, cost and quality control

• Examples

HOW ARE RESPONSIBILITIES HOW ARE RESPONSIBILITIES SHARED ?SHARED ?

Typical division of responsibilities• National level: basic reference networks/ climate stations

• Regional level/RBA/AMOR: regulation control + protection

• Contractors: contractual obligation for well testing

• Large abstractors: monitoring requirements in permit

• Local water users: self monitoring / awareness

Legal and regulatory basis required through water rights / water allocation plan /permitting system etc

+ Data collected by other agencies+ Data collected by other agencies

QUALITY ASSURANCE AND QUALITY QUALITY ASSURANCE AND QUALITY CONTROLCONTROL

Prevention (assurance) is better than cure (control)

• Starts with the observer: cross checks, keep your eyes open

• Guidelines: follow procedures (e.g. for sampling)

• Keep copy of field readings • QA/AC on chemical analysis• QC procedures for data entry in MIS• QC control in data processing

HOW ENSURE THAT MONITORING IS COST HOW ENSURE THAT MONITORING IS COST EFFECTIVE?EFFECTIVE?

• Monitoring by objectives

• Include cost-benefit analysis in project design

• Promote cost effectiveness and reliability by:• Defining clear information needs

• Use of data already collected in other programs

• Use of existing wells (abstraction wells and abandoned wells)

• Use of indicators: water level/temperature /EC (divers)

• Promoting self monitoring and self regulation

• Effective QC and QA system

Monitoring is considered expensive because the return on investment is generally not visible in the short run

GROUNDWATER USE AND QUALITY GROUNDWATER USE AND QUALITY MONITORING MONITORING

• Principles of groundwater monitoring

• Monitoring cycle and

• Monitoring resource use and aquifer response

• Groundwater quality monitoring

• Effectiveness, cost and quality control

• Examples

Groundwater fund used for:- Monitoring- Research- Training & manpower dev.

•Tariff 8.5 Bht

•Tariff 3.5 Bht

BANGKOK: REGULATION AND GROUNDWATER FUNDBANGKOK: REGULATION AND GROUNDWATER FUND

- Regulatory and economic measures

- Imposed based on monitoring information

CONCLUSIONCONCLUSION

WHAT IS THE HEIGHT OF

THAT TOWER IN METERS ?

I HAVE MEASURED IT WITH TWO DIFFERENT

MEASURING TAPES AND THE HEIGHT IS 26 +/- 2 METERS.

Monitoring makes groundwater visible if it:

• addresses well-defined management information needs (demand driven), is

• cost-effectively implemented providing

• reliable information

Thank you

Exercise: 3 Groups

1 Monitoring a dune infiltration system to protect a drinking water well field against seawater intrusion

2 Monitoring plan for an industrial site to prevent spreading of possible contaminants through the groundwater

3 Monitoring system for trend monitoring in a sedimentary shallow aquifer in river basin

Exercise: 3 Groups

• Define the monitoring objectives and basic design parameters

• What are the main benefits and who are the main beneficiaries of the monitoring

• Suggestions to make the monitoring plan cost effective

• How to assure sustainable financing?

• Who will implement the monitoring and how is the monitoring information handled to address the management objectives

HYDROCHEMISTRY: QA and QR !!!HYDROCHEMISTRY: QA and QR !!!

• Field measurements (EC and pH)• Sampling procedures • Ion balance• Extreme values (high and low) • Use certified labs• Contra expertise (5% of the samples)

GROUNDWATER SAMPLINGGROUNDWATER SAMPLING