1

ISMAIL C.MOHAMAD

GROUNDWATER

MONITORING

IN

MALAYSIA

OUTLINES

• Introduction

• Groundwater Monitoring Objectives

• Groundwater Monitoring Programme

• Monitoring Protocol

• Monitoring Wells

• Groundwater Monitoring Network

• Monitoring Parameters

• Results of Monitoring Programme

• Conclusion

INTRODUCTION

• One of the activities carried out by the Minerals

and Geoscience Department (JMG) is to monitor

the groundwater quality.

• Since the programme started in 1989 until 2009,

more than 400 monitoring wells were

established .

• It involves periodical monitoring of groundwater

levels and groundwater quality at the selected

wells on a periodic basis.

GROUNDWATER MONITORING OBJECTIVES

• Performed in a number of situations with varying

objectives.

• Generally, to determine the quality and trends of

water quality especially at public water supply

sources.

• Also to determine contaminants if they are

increasing, decreasing, or remaining in the same

range at contamination site.

• JMG objective: to acquire data for regional

groundwater management plans.

GROUNDWATER MONITORING PROGRAMME

• Initiated by the Geological Survey Department

(GSD) in 1989

• A network of monitoring wells was specially

designed and constructed to monitor the water

quality and water level changes in the alluvial

aquifer systems of Kelantan River basin.

• Programme was expanded as to include areas

where active groundwater pumping was being

carried out by state water supply authority, such

as in Terengganu, Pahang, Kedah and Perlis.

GROUNDWATER MONITORING PROGRAMME

cont..

• Monitoring was carried out using existing

JKR/JBA wells and supplemented by GSD's own

well where is possible

• In Kuantan-Pekan-Rompin area, the exploration

wells constructed during Regional

Hydrogeological Studies by GSD were used as

monitoring wells.

• In that time, Hydrogeological Unit, in Ipoh role

over all the monitoring programme.

• Previously, a total of 130 wells is monitored

regularly in Peninsular Malaysia

Location of Groundwater Monitoring Sites

A – Kota Bharu (Network)

B – Kg. Kepong, K. Terengganu

C – Kg. Sg. Ular, Kuantan

D – Kg. Padang, Kuantan

E – Nenasi Water work, Pekan

F – Kuantan – Pekan (Network)

G – Kuala Rompin

H – Kg. Pulau Manis, Pekan

I – Kg. Bohor Bharu, Temerloh

J – Arau, Perlis

K – Alor Semadong, Perlis

L – Chuping, Perlis

M – Rimba Mas, Perlis

N – Bukit Kemoja, P. Langkawi

O – Bukit Dundong, P. Langkawi

P – Teluk Datuk, Olak Lempit

STATETOTAL NOS.

OF WELLLOCATION

Terengganu 55 Besut, Kuala Terengganu, Kemaman, Setiu, Dungun, Kuala. Berang, Pulau

Redang, Pulau Perhentian, Pulau Kapas, and Pulau Bidong)

Kelantan 69 Bharu, Tumpat and Bachok

Pahang 16 Sg. Ular, Cherating; Kg. Padang, Kuantan; Pulau Manis, Kuantan; Nenasi,

Bohor Bharu (1994), Rompin (1991); Network Pekan

Kedah 15 Kuala Muda, Yan dan Pendang

Perlis 1 Arau

Pulau Pinang 3 Permatang Bongor

Perak 40 Pengkalan Hulu,

Selangor 40 Banting

Negeri Sembilan 12 Jelebu, Kuala Pilah, Rembau, Tampin and Sban

Melaka 6 Jasin and Alor Gajah

Johor 50 Johor Bharu, Pontian, Tinggi, Keluang, Segamat, Muar, Bat Pahat and

Mersing

Sabah 60 Sipitang, Beaufort, Kuala Penyu, Menumbok, Papar, Kota Belud, Kota

Marudu, Pitas dan Kudat

Sarawak 52 (JKR well fields) Kabong, Belawai, Paloh, Igan, Oya and Kuala Tatau,

(selected area) Kuala Sibuti, Kuala Nyalau, Rambungan and Bako

TOTAL 419

LOCATION OF MONITORING WELL SITES IN MALAYSIA

GROUNDWATER MONITORING PROGRAMME

cont.. • Groundwater monitoring programme carried out by

Department of Environment (DOE) has been

intensifically established since 1997.

• The groundwater monitoring programme was expanded

for Sarawak in October 2002 and Sabah in December

2002.

• To-date there are 122 groundwater monitoring wells that

constitute the DOE‘s monitoring network.

• Monitoring well sites targeted at areas potentially

vulnerable to contamination which based on landuse.

(eg. industrial, animal burial, rural, urban/suburban,

agricultural area; golf courses and landfills).

Groundwater Monitoring sites

- DOE

MONITORING PROTOCOL

• Involves twice-a-year measurements of groundwater

level and sampling

• Generally the field sampling campaigns are designed to

correspond, as far as possible, to the dry (August -

October) and the rainy seasons (January- March).

• In Kelantan, monthly groundwater level measurements

were carried out to monitor groundwater fluctuation by

pumping activities at public water supply well fields.

• Parameters such as temperature, conductivity and

dissolved oxygen were also measured in the field.

• Monitoring of ground subsidence at some critical well

fields such as in Kelantan and Selangor

Measuring Water Level

Water level meter

Groundwater Sampling

MONITORING WELL

• Generally, two types of monitoring wells are used which

is cluster type and individual wells.

• Cluster type represents as a multilevel-type of monitoring

system that permits sampling of groundwater from

several different depths.

• This type of well was constructed in monitoring well

networks at Kelantan (Kelantan River Basin), Selangor

(Langat River Basin) and Pahang (Pekan-Nenasi area).

• The individual wells are mainly exploration wells that

converted to monitoring wells.

TYPICAL MONITORING WELL DESIGN

Individual

TypeCluster Type

Kelantan River Basin

• Total 69 Nos. of monitoring wells (cluster and individual type)

• Constructed on 1989-1992

• Well depth ranging from 10m – 75m

Langat River Basin

• Total 24 Nos. of monitoring wells (12 shallow and 12 deep)

• Constructed on 1998-2000

• Well depth ranging from 5m – 50m

Kuantan – Pekan – Rompin

• Total 31 Nos. of monitoring wells

• Constructed on 1991-1992

• Well depth ranging from 6.1m – 119.5m

Groundwater Monitoring Network

17

Groundwater Monitoring System in Kelantan River Basin

Fence diagram of Alluvial Aquifer System of Kelantan River Basin

A

A'

B

B'

C

C'

D

D'

E

E'

PD2

PD1 PD5

PD43 PD44

PD42

PD40

PD35

PD37

PD34

PD26

KB20-21

PD32

KB48

PD52

KB28-30

PD55 PD14KB6-14 PD17

KB1-5

KB36

PD56

KB22-34

PD57

PD47

KB46

PD54

KB25-27

KB39

KB58

PD24 PD20

PD21

PD23

PD4

PD8

KB15-19

PD62

KB40

KB31-35PD22

KB57

WAKAF BARU

T. MAS P. CHEPA

SCALE

1000m1000m

40m

N

Aquifer (Sand, Gravel)

1 - Shallow aquifer2 - Deep aquifer

Aquitard (Clay, Silt)

Basement Rocks

(granite, metasediment)

Screen position of monitoring well

Screen position of production well

LEGEND

South China Sea

Kelantan River

Kemasin River

Kelantan Riverm. s. l.

m. s. l.

m. s. l.

Pengkalan Datu River

KB52

PD31

Kemasin River

Mean Sea level - m.s.l.12

Groundwater Monitoring Well(s) in Telok

Datuk-Olak Lempit area, Selangor

Kuantan

Tanjong Agas

Tanjong Batu

Kuala Rompin

Nenasi

S.K

uantan

S. Belat

S.Penor

S.PAHANG

S.Bebar

S.Merchong

S.R

om

pin

S.Pontian

Anak

Kg. Runchang

Song Cheng Enterprise (M)Sdn. Bhd.(Kolam Ternak Belut)

Laut China Selatan

KN 5

KN 1KN 2

KN 3-4

KN 9-10KN 6-8

KN 23-24

KN 27

KN 28

KN 11-12

KN 21-22

KN 25

KN 26

KN 19-20

KN 17-18

KN 16

KN 14-15

KN 13

103 15' T 103 30' T

Skala

0 2 4 6 8 10 KmKm

Pekan

245' U

300' U

315' U

330' U

345' U

245' U

300' U

315' U

330' U

345' U

103 15' T 103 30' T

Groundwater Monitoring Well(s) in

Kuantan-Pekan-Rompin area, Pahang

MONITORING PARAMETERS

RESULTS OF MONITORINGKelantan

• Generally, no serious adverse

impact on environment has been

noted at the present abstraction

• Groundwater in the shallow aquifer

is subjected to contamination with

nitrate from agricultural activities

• In Tanjung Mas well-field - a slight

chloride increase is noted due to

vertical leakage of brakish water

from overlying impounding layer

• Presently, no subsidence /

structural effect have been noted

RESULTS OF MONITORINGPahang

• Results from the monitoring programme shows that the overall

groundwater quality remain at the original state except in the

confined aquifer of Tanjung Batu and Nenasi areas, which

register increase in chloride content.

• A significant lowering of groundwater level also was indicated in

the confined aquifer in Pekan - Nenasi area due to large scale

groundwater abstraction in this area in 1996 until 2001. While, the

groundwater level for others areas remain high.

• Iron is also generally high and can even exceed 30 mg/l.

• Nitrate is generally low except in the Sungai Merchong area

where values between 10-20 mg/l are noted.

-24-

Variation of Groundwater Level and Chloride

Concentration at Nenasi Water works

-25-

Potentiometric Surface of Deep Aquifer System in Kuantan – Pekan –

Rompin Area – From 1990 to 2001

1990 1993 1996 2000 2001

-26-

Tahun 1993 Tahun 1996 Tahun 2001

RESULTS OF MONITORING cont…

Selangor

• From the initial observations made at the monitoring

wells, the quality of groundwater does not change much

as only some variations occur.

• The high values of chloride is found only at the western

part of the lower Sungai Langat basin closer to the coast.

• Only few monitoring wells show results which have some

influence on the pumping activities. The obvious drops in

water level is the monitoring well MWDI.

Potentiometric Surface - August 2008

O +2

-2

-28-

Land Subsidence

• In Langat River Basin, elevations of twenty shallow (20)

benchmarks were measured to monitor the land

subsidence.

• JICA reported on 2002, a total of eight (8) benchmarks,

namely BM3, 4, 7, 12, 14, 15, 16 and 20, indicate

continuous settlement.

• Consolidation by draining of peaty/clayey material that

are widely spread over the Basin may result in the

subsidence around the area.

29

RESULTS OF MONITORING

Land Subsidence Measurement

14 February 2006

Land subsidence measurement by 20 shallow benchmarks with corresponding deep datum

• Monitoring on ground subsidence, showing in 8 years period,

the ground subsidence is about 20-30cm

• Occur in area about 1 km from the active pumping activity

(Megasteel).

GROUND SUBSIDENCE CONTOUR

Sarawak

• Two areas that have significant change in groundwater quality is

Kabong and Igan. Other areas have little change in groundwater

quality. Changes in concentrations and trends of some ions such as

sulfate may be suggested that groundwater is being partly affected

by human activities such as agricultural activities.

Sabah

• Overall groundwater quality is good except of iron, manganese, and

nitrate slightly exceeded WHO standard.

Perak

• The general water quality is good, except of high iron content (well

No. 151 – 178)

32

RESULTS OF MONITORING

Kedah

• The general water quality at both the monitoring sites remains good,

and no significant change from the original quality is noted except of

high iron content

Perlis

• In Arau, Perlis, the chloride content is slightly higher than usual for

groundwater derived from a limestone aquifer due to mixing of

slightly brackish water from the overlying clay. ).

• Elevated of nitrate level (10-25 mg/l) found in groundwater sample

collected from Rimba Mas well due to anthropogenic activities

carried out from agricultural practices in the surrounding area.

Pulau Pinang

• Chloride content found exceeded WHO drinking water standard

content found in groundwater sample collected from Permatang

Bongor area..

33

RESULTS OF MONITORING

Negeri Sembilan

• The general water quality at both the monitoring sites remains good,

and no significant change from the original quality is noted except of

high iron content. High fluoride content found in groundwater sample

collected from Jelebu area.

Melaka

• No significant change from the original quality is noted except of

high iron content. Elevated fluoride level found in groundwater

sample collected from Alor Gajah area (MTW 32)

Johor

• The groundwater quality remains very good and no significant

changes.

Terengganu

• The groundwater quality remains very good and no significant

changes.

34

RESULTS OF MONITORING

CONCLUSION

• The overall groundwater quality remain at the original

state except in the confined aquifer of Tanjung Batu

areas of Pahang.

• Generally, iron and manganese content in groundwater

usually found exceeding the limits recommended by the

WHO especially in alluvial aquifer.

• However, due to rapid urbanisation and industrial as well

as agricultural developments, there is an increasing

threat of contamination to the groundwater

• Groundwater protection zone need to be established to

avoid contamination and sterilization of aquifers