DOE Water Quality Index Classification 
The rapid urbanisation and growth of the population has led to both the ever increasing demand forwater consumption and in tandem the levels of water pollution in Malaysia. Rapid development has produced great amounts of human wastes, including domestic, industrial, commercial and transportation wastes which inevitably ends up in the water bodies. A large number of rivers are so polluted that in some, the consequences are to the extent that the rivers cannot be rehabilitate. Consequently, access to clean and safe water supply has become a tremendous challenge for the water authorities to surmount. Recognizing this, conservative water quality monitoring programs and sustainable use of water are promoted. The major pollutants in Malaysian’s rivers and lakes are Biochemical Oxygen Demand (BOD), Ammoniacal Nitrogen (NH3-N) and Suspended Solids (SS). High BOD is contributed largely by untreated or partially treated sewage from manufacturing andagro-based industries. The main sources of NH3-N are domestic sewage, livestock farming and other liquid organic waste products, whilst the sources for SS are mostly earthworks and land clearing activities which the removal is generally achieved through the use of sedimentation and/or water filters. The pollution in rivers and lakes has made it necessary for the water providers to take measures toward securing a stable supply of tap water and supplying potable water. On the other hand, the main contaminants of the marine waters in the country are mainly suspended solids, Escherichia coli, and oil and grease, whilst for groundwater are solid waste landfills, radioactive landfill, etc.
2. River water
River water quality and pollution control need to be addressed urgently since 98 percent of the total water use originates from the rivers. 70% of the water resources in the country are for the agricultural industry.As river water pollution increases, concentrations of the existing pollutants increase. Consequently, it increases water ‘quantity scarcity’ since good quality water available for use decreases and higher water treatment costs due to the presence of new pollutants. Moreover, the ecological health of the water bodies and the surrounding eco-systems degrade, affecting aquatic lives and habitat, and recreational activities.
2.1. River water quality and status
The Department of Environment (DOE) uses Water Quality Index (WQI) and National Water Quality Standards for Malaysia (NWQS) to evaluate the status of the river water quality . The WQI introduced by DOE is being practiced in Malaysia for about 25 years and serves as the basis for the assessment of environment water quality, while NWQS classifies the beneficial uses of the watercourse based on WQI. In 2012, nine rivers within the Klang River Basin under River of Life Project were added to the national river water quality monitoring programme. The river water quality was assessed based on a total of 5,083 samples taken from a total of 473 rivers. Out of 473 rivers monitored, 278 (59 percent) were found to be clean, 161 (34 percent) slightly polluted and 34 (7 percent) polluted . Figure 1 shows the river water quality trend for 2005-2012.
In 2012, 34 rivers were categorized as being polluted, as shown in Figure 1. Out of these, 19 rivers were classified as Class III, 14 rivers as Class IV and one river as Class V. Classification of level pollution by individual pollutant follows the standard set by DOE, as shown in Table 1. Construction activities such as earthworks and land clearing appear to be the main contributor for the sources of SS, whilst the sources for BOD and NH3-N were mostly from agro-based industries and livestock farming, respectively. Pollution of river by untreated or partially treated sewage was also indicated in term of BOD and NH3-N. Besides pollution from organic pollutant, inorganic pollutant especially heavy metals also another crucial contribution. Mercury (Hg), Arsenic (As), Cadmium (Cd), Chromium (Cr), Plumbum (Pb), and Zinc (Zn) were analyzed. All Pb, Cd and Zn data were within the Class IIB limits of the NWQS. Meanwhile, 99.97 percent of the data for Cr were within the Class IIB limits of the NWQS followed by Hg (99.96 percent) and As (99.68 percent) .
|Ammoniacal Nitrogen||mg/l||< 0.1||- 0.3||0.3 - 0.9||0.9 - 2.7||> 2.7|
|Biochemical Oxygen Demand||mg/l||< 1||1– 3||3 - 6||6 – 12||> 12|
|Chemical Oxygen Demand||mg/l||< 10||10 – 25||25 – 50||50 – 100||> 100|
|Dissolved Oxygen||mg/l||> 7||5 – 7||3 - 5||1 - 3||< 1|
|pH||-||> 7||6 - 7||5 - 6||< 5||> 5|
|Total Suspended Solid||mg/l||< 25||25 - 50||50 - 150||150 - 300||> 300|
|WQI||-||< 92.7||76.5 - 92.7||51.9 - 76.5||31.0 - 51.9||> 31.0|
According to the National Water Quality Standards, surface water quality could be gradually improved/upgraded to a better water class based on the standard values of 72 parameters in 6 water use classes. Tables 2 and 3 illustrate the water classes and uses and the DOE Water Quality Classification based on WQI, respectively.
|Class I||Conservation of natural environment.|
Water Supply I - Practically no treatment necessary.
Fishery I - Very sensitive aquatic species
|Water Supply II - Conventional treatment.|
Fishery II - Sensitive aquatic species.
Recreational use body contact.
|Class III||Water Supply III - Extensive treatment required.|
Fishery III – Commonof economic value and tolerant species;livestock drinking.
|Class V||None of the above|
|Biochemical Oxygen Demand(BOD)||91 - 100||80 - 90||0 - 79|
|Ammoniacal Nitrogen(NH3-N)||92 - 100||71 - 91||0 - 70|
|Suspended Solids(SS)||76 - 100||70 - 75||0 - 69|
|Water Quality Index(WQI)||81 - 100||60 - 80||0 - 59|
2.2. River water pollution
The sources of water pollution can be categorized as point sources and non-point sources. Point sources of pollution are referred to the sources with discharges entering water body at specific locations such as discharges from industries, sewage treatment plants and animal farms, while non-point sources do not have specific discharge point such as surface run-off.In 2012, 1,662,329 water pollution point sources were identified, which comprised of 4,595 manufacturing industries, 9,883 sewage treatment plants (not including individual and communal septic tanks), 754 animal farm (pig farming), 508 agro-based industries, 865 wet markets and 192,710 food services establishments.
According to , there were three parameters of pollutant loading that have significant impact on the river quality, which include BOD, SS and NH3-N. The estimated BOD load of 848 tons per day in 2012 had decreased by 39 percent compared to 2011 (1,394 tons per day). On the other hand, the estimated SS load was 1383 tons per day, while the estimatedNH3-N load was 232 tons per day, in 2012. Based on the monitoring results in 2012by DOE , in terms of river basin basis, Klang River Basin received the highest BOD Load (142 tons per day), followed by Perak River Basin (State of Perak) 114 tons per day, Sarawak River Basin (State of Sarawak) 30 tons per day, Jawi River Basin (State of Pulau Pinang) 26 tons per dayand Muar River Basin (State of Johor) 24 tons per day. Klang River Basin also received the highest SS Load (360 tons per day) and NH3-N load (37 tons per day) among the river basins in Malaysia.
3. Lakes and reservoirs
A lake is an enclosed body of water (usually freshwater) with considerable size, totally surrounded by land with no direct access to sea except with a river or stream that feeds or drains the lake [3, 4]. Lakes are considered lentic systems or standing water compared to rivers which are lotic systems or flowing water . Generally, lakes have in-flowing and out-flowing water which makes them complex . Lakes have 3 main characteristics which make them so unique: long water retention time and complex response dynamics and integrating nature of water body . Lake may occur anywhere within a river basin as natural or man-made lakes [4, 7]. Natural lakes consist of wetlands, marshes, estuarine lakes, or naturally occurring lakes whereas man-made lakes can be referred as reservoirs, retention pond, ex-mining pond, recreational lakes  or as urban landscape elements. Generally, lakes are important source of freshwater which account only the very small part of around 0.01 percent of the global amount of water .
Lakes in Malaysia, natural or artificial, have multiple functions. Almost 90 percent of the nation’s water supply comes from the lakes and reservoirs . Lakes and reservoirs serves as the source of water for domestic, industrial and agriculture; hydroelectric power generation; flood mitigation, navigation and recreation [8, 9]. They are also home to a variety of biological species and freshwater fish industry , i.e. the Bukit Merah Lake in Perak is believed to be the only origin of its natural habitat for the exotic species, Malayan Gold Arowana,
There is no comprehensive inventory on all lakes in Malaysia [8, 9]. A preliminary assessment showed that there were over 90 lakes in Malaysia which covered an area of over 100,000 ha and contained more than 30 billion cubic meters of water [8, 9]. Table 4shows the lake inventory based on states in Malaysia . This list of lakes inventory did not, however include ox-bow lakes and ex-mining ponds over the nation. It was estimated that there were approximately more than 4,000 ex-tin mining ponds in the country with area of 16,000 ha . Besides, the inventory excluded new hydroelectric projects like Bakun Dam in Sarawak .Bakun Dam alone has 695 km2 of reservoir surface area with gross storage volume of 44 billion cubic meters .
3.1. Pollution and eutrophication of lakes and reservoirs
In Malaysia, water quality of a lake or reservoir can be influenced by external inputs entering the lake or reservoir from the watershed as well as the in-lake ecosystem, nutrients cycling and internal loading. External inputs can be organic and inorganic pollutants as well as nutrients which cause deterioration of water quality from point and non-point sources. Point sources include discharge from domestic and municipal wastewater, agricultural effluents and industrial wastewaters whereas non-point sources includes urban/stormwater runoff, agricultural runoff, septic tank overflow and construction sites runoff. Excessive input of nutrients such as phosphorus and nitrogen into the lakes and reservoirs will lead to eutrophication. Eutrophication is the process by which a water body becomes uncontrollably rich and abundance in aquatic plants such as algae and aquatic macrophytes (water weeds)  due to plant nutrients enrichment, especially phosphorus and nitrogen as dissolved solutes and as compounds bound to organic and inorganic matters  from natural and anthropogenic sources . Eutrophication will induce an undesirable disturbance to the balance of organisms present in the water and to the quality of water.
According to adesk study on the Status of Eutrophication of Lakes in Malaysia by National Hydraulic Research Institute of Malaysia, NAHRIM , 56 lakes or 62 percent of the 90 lakes and reservoirs evaluated were eutrophic while 34 lakes or 38 percent were mesotophic. These lakes were assessed based on the Trophic State Index (TSI) values, computed adopting the landuse and TP relationships. The lakes and reservoirs were graded as good, medium or bad based on allowable nutrient loadings which were corresponded to Carlson’s TSI values. Lakes graded as good had TSI values of less than 37.4 whereas TSI values exceeded 47.4 were graded as bad. TSI is not the same as a water quality index. The terms ‘good’, ‘medium’ or ‘bad’ refers to the state of lake in respect to its biological productivity and not ‘good water quality’, slightly polluted water’ or ‘polluted water’ as detailed in the water quality index. However, if the lakes are confirmed to be eutrophic, steps are needed to tackle the deterioration of water quality. Table 5shows all 90 lakes and reservoirs inventoried in Malaysia with their TSI values and lake status [14-15].
|Air Kuning (Perak)||Sg. Ranting/ Sg. Perak||W||n.a.||1.8||60.30||n.a.||n.a.||B|
|Bersia||Sg. Perak||H, F||5.7||70||60.30||n.a.||n.a.||B|
|Bukit Merah||Sg. Kurau||I, W||41||75||60.30||n.a.||n.a.||B|
|Chenderoh||Sg. Perak||H, F||25||95.4||75.44||n.a.||n.a.||B|
|Gopeng||Sg. Gopeng/ Sg. Perak||SR||n.a.||n.a.||50.00||n.a.||n.a.||B|
|Jor||Batang Padang/ Sg. Perak||H||0.5||3.9||60.30||n.a.||n.a.||B|
|Kenering||Sg. Perak||H, F||60||352||60.30||n.a.||n.a.||B|
|Mahang||Sg. Mahang/ Sg. Perak||H||0.1||0.4||50.00||n.a.||n.a.||B|
|Temenggor||Sg. Perak||H, F||152||6168||45.85||n.a.||n.a.||M|
|Kinta||Sg. Kinta/ Sg. Perak||Exm||n.a.||n.a.||68.24||n.a.||n.a.||B|
|Air Kuning (Selangor)||Sg. Air Kuning/ Sg. Damansara||Re||0.04||0.06||45.85||n.a.||n.a.||M|
|Batu||Sg. Kelang||F, W||2.5||36||45.85||n.a.||n.a.||M|
|Klang Gates||Sg. Kelang||W, F||2.25||28.51||45.85||n.a.||n.a.||M|
|Sungai Baru||Sg. Baru/ Sg. Klang||Re||0.05||0.15||45.85||n.a.||n.a.||M|
|Sungai Tinggi||Sg. Tinggi/ Sg. Selangor||W||n.a.||107.5||45.85||n.a.||n.a.||M|
|Sg. Selangor||Sg. Selangor||W||n.a.||235||45.85||n.a.||n.a.||M|
|Tasik The Mines||Sg. Kuyoh/ Sg. Kelang||Exm, Re||n.a.||n.a.||60.30||n.a.||n.a.||B|
|TasikTitiwangsa||Sg. Bunus/ Sg. Kelang||Re||0.125||n.a.||-||42.43||n.a.||M|
|TasikKundang||Sg. Kundang/ Sg. Selangor||Re||n.a.||n.a.||60.30||n.a.||n.a.||B|
|Sg. Batu||Sg. Batu||F, W||1.1||2.5||69.39||n.a.||n.a.||B|
|Anak Endau||Sg. Anak Endau||I, W||7.2||38||45.85||n.a.||n.a.||M|
|Pontian||Sg. Pontian||I, W||20||40||60.30||n.a.||n.a.||B|
|RepasBaru||Sg. Rengas/ Sg. Pahang||SR||0.05||0.4||68.24||n.a.||n.a.||B|
|Repas Lama||Sg. Bentong/ Sg. Pahang||SR||n.a.||n.a.||68.24||n.a.||n.a.||B|
|Sultan Abu Bakar||Sg. Sempam/ Sg. Perak||H||0.5||6.7||68.24||n.a.||n.a.||B|
|Chereh Dam||Sg. Chereh/ Sg. Kuantan||W||54||250||45.85||n.a.||n.a.||M|
|TasikBera||Sg. Bera/ Sg. Pahang||N||6||0.61||68.24||n.a.||n.a.||B|
|UluLepar||Sg. Lepar/ Sg. Pahang||N||4.69||18||60.30||n.a.||n.a.||B|
|Bintau||Sg. Kertau/ Sg. Pahang||N||0.25||n.a.||68.24||n.a.||n.a.||B|
|Bukit Kuang||Sg. Kuang/ Sg. Kelantan||I, W||4.04||14.3||68.24||n.a.||n.a.||B|
|Pergau (Kuala Yong)||Sg. Pergau||H, F||4.3||62.5||45.85||n.a.||n.a.||M|
|Bekok||Sg. BatuPahant||F, W||8.75||32||75.44||n.a.||n.a.||B|
|Juaseh||Sg. Juaseh/ Sg. Muar||W||n.a.||33.2||55.03||n.a.||n.a.||B|
|Labong||Sg. Endau||I, W||4.25||11.54||45.85||n.a.||n.a.||M|
|Layang (Lower)||Sg. Layang/ Sg. Johor||W||n.a.||11.63||68.24||n.a.||n.a.||B|
|Layang (Upper)||Sg. Layang/ Sg. Johor||W||n.a.||45||-||n.a.||100.00||B|
|Linggiu||Sg. Linggiu/ Sg. Johor||W||50||772||-||n.a.||57.73||B|
|Machap||Sg. Benut||F, W||9.09||12.3||75.44||n.a.||n.a.||B|
|Sembrong||Sg. BatuPahat||F, W||8.5||18||68.24||n.a.||n.a.||B|
|Pontian Kecil||Sg. Pulai||W||1.75||n.a.||45.85||n.a.||n.a.||M|
|Ahning||Sg. Ahning/ Sg. PdgTerap||W, I||n.a.||275||50.00||n.a.||n.a.||B|
|Padang Saga||Sg. Ulu Melaka||I, W||0.05||0.2||50.00||n.a.||n.a.||B|
|Dayang Bunting||Sg. Dayang Bunting||N||0.375||n.a.||45.85||n.a.||n.a.||M|
|Beris||Sg. Beris/ Sg. Muda||W||13.7||1224||50.00||n.a.||n.a.||B|
|Bukit Kuda||Sg. Bangat||W||n.a.||4.78||60.30||n.a.||n.a.||B|
|Air Keruh||Sg. Melaka||Re||0.5||n.a.||60.30||n.a.||n.a.||B|
|Durian Tunggal||Sg. Melaka||W||3.5||32.6||75.44||n.a.||n.a.||B|
|Jus||Sg. Batang Melaka||W||4||48||68.24||n.a.||n.a.||B|
|Kelinci||Sg. Kelinchi/ Sg. Pahang||W||n.a.||50||50.00||n.a.||n.a.||B|
|Pedas||Sg. Beringin/ Sg. Linggi||W||n.a.||0.525||50.00||n.a.||n.a.||B|
|Sungai Terip||Sg. Terip/ Sg. Linggi||W, I||2.25||48||-||n.a.||62.9||B|
|Upper Muar||Sg. Muar/ Sg. Pahang||W||n.a.||53||50.00||n.a.||n.a.||B|
|Gemencheh||Sg. Gemencheh/ Sg. Muar||W||n.a.||30.8||55.03||n.a.||n.a.||B|
|Air Hitam||Sg. Air Hitam/ Sg. Pinang||W||0.25||2.6||45.85||n.a.||n.a.||M|
|Mengkuang||Sg. Mengkuang/ Kulim/ Perai||W||0.625||23.6||75.44||n.a.||n.a.||B|
|Bukit Pancur||Sg. Kecil/ Sg. Kerian||N||0.061||n.a.||45.85||n.a.||n.a.||M|
|TimahTasoh||Sg. Perlis||I, W, F||13.33||40||-||n.a.||56.6||B|
|Batang Ai||Sg. Batang Ai||H||n.a.||2800||45.85||n.a.||n.a.||M|
|Sika (Bintulu)||Sg. Sika||W||n.a.||3280||45.85||n.a.||n.a.||M|
|Kenyir||Sg. Terengganu||H, F||369||13600||-||-||73.5||B|
|Puteri/ Bukit Besi||Sg. Paka||Exm, Re||1.8||n.a.||60.30||n.a.||n.a.||B|
|TasikPutrajaya||Sg. Chua/ Sg. Langat||Re||7.5||45||-||27.07||60.6||M|
3.2. Lake and reservoir water quality standards
In Malaysia, there is no specific national standard or index for lake water quality as of year 2014. Since lakes are located within a river basin (although lakes have their own lake basins), water quality standards and classification used are of surface water. Normally, analysis on lake water quality is executed based on the DOE’s WQI classification as shown in Table 1 , DOE Water Quality Classification based on Water Quality Index as shown in Table 3  and National Water Quality Standards for Malaysia . Although there is no standards and index for lakes in Malaysia, Putrajaya has developed its own standards as stated in Table 6 .
|pH||6.5 – 9.0|
|Temperature||°C||30°C, Normal ±|
|Taste||-||No Objectionable Taste|
|Odour||-||No Objectionable Odour|
|Floatables||-||No Visible Floatables|
|Dissolved oxygen (DO)||mg/l||5 – 7|
|Biochemical oxygen demand (BOD)||mg/l||3|
|Chemical oxygen demand (COD)||mg/l||25|
|Total suspended solid (TSS)||mg/l||150|
|Ammoniacal nitrogen (AN)||mg/l||0.3|
|Total Phosphorus (TP)||mg/l||0.05|
|Oil and grease (O&G)||mg/l||1.5|
|Aluminum||mg/l||<0.05 if pH <6.5 ; <0.1 if pH>6.5|
|Ammonia||mg/l||0.02 – 0.03|
|Carbon Chloroform Extract||µg/l||500|
|Oil & Grease (Mineral)||µg/l||-|
|Oil & Grease (Emulsified Edible)||µg/l||-|
Besides WQI, lakes and reservoirs in Malaysia can be classified based on their trophic state calculated using Carlson’s TSI involving parameters of chlorophyll-a, phosphorus or Secchi Disk depth. TSI classification of lakes and reservoirs is as shown in Table 7 .
|<30||<0.95||>8||<6||Oligotrophy: Clear water, oxygen throughout the year in the hypolimnion|
|30-40||0.95-2.6||8-4||6-12||Hypolimnia of shallower lakes may become anoxic|
|40-50||2.6-7.3||4-2||12-24||Mesotrophy: Water moderately clear; increasing probability of hypolimnetic anoxia|
|50-60||7.3-20||2-1||24-48||Eutrophy: Anoxic hypolimnia, macrophyte problems possible|
|60-70||20-56||0.5-1||48-96||Blue-green algae dominate, algal scums and macrophyte problems|
|70-80||56-155||0.25-0.5||96-192||Hypereutrophy: (light limited productivity). Dense algae and macrophytes|
|>80||>155||<0.25||192-384||Algal scums, few macrophytes|
3.3. Lakes and reservoirs management
The current management of lakes and reservoirs in Malaysia are fragmented with different management agencies or lake managers, each having different and often competing, sectoral agendas . There is no definite policy on lake management and it is neither binding nor mandatory . As such, series of initiatives have been taken towards sustainable management of lakes and reservoirs in Malaysia. In 2009, Academy of Sciences Malaysia (ASM) together with NAHRIM had embarked on the development of Strategies for the Sustainable Development and Management of Lakes and Reservoirs in Malaysia with emphasis on Integrated Lake Basin Management (ILBM) which was first articulated by the International Lake Environment Committee (ILEC). The Strategy Plan for the Sustainable Management of Lakes and Reservoirs in Malaysia was presented and was endorsed during the 7th National Water Resources Council (NWRC) meeting on 1 November 2012[8, 9].
Besides the development of Strategy Plan, initiative had been taken on the development of Lake Briefs based on the format by ILEC. The main objective of Lake Brief is to assist lake managers and stake holders in preparation for gathering information and data relating to lake sand reservoirs towards the development of effective lake basin management plan based on the context of ILBM. Three series of Lake Briefs have been developed in 2010, 2011 and 2012 involving a total of 26 lakes and reservoirs/dam [9, 20-21]. First series of Lake Brief entitled Managing Lakes and their Basins for Sustainable Use in Malaysia, published in 2010 by ASM with support from NRE and NAHRIM involving eight lakes whereas second and third series of Lake Briefs documented by NAHRIM in 2011 and 2012, involved eight and ten lakes and reservoirs, respectively. Lakes and reservoirs documented in the respective Lake Brief are as exhibited in Table 8 [9, 20-21].
|∙ Bukit Merah, Perak|
∙ TasikKenyir, Terengganu
∙ LoaganBunut, Sarawak
∙ TasikPedudanMuda, Kedah
∙ TasikPutrajayadan Wetlands
∙ TasikChini, Pahang
∙ TasikTerip, Negeri Sembilan
∙ TasikTimahTasoh, Perlis
|∙ TasikBera, Pahang|
∙ Paya Indah Wetlands (PIW), Selangor
∙ EmpanganBeris, Sik, Kedah
∙ EmpanganSemberong, BatuPahat, Johor
∙ Tasik Ringlet, Cameron Highlands, Pahang
∙ EmpanganChenderoh, Perak
∙ EmpanganKlang Gate
∙ EmpanganSg. Selangor, Selangor
|∙ Batang Ai, Sarawak|
∙ Empangan Bukit Kwong, Kelantan
∙ Durian Tunggal, Melaka
∙ Tasik Taiping, Perak
∙ Tasik FRIM dan Wetlands, Selangor
∙ TasikJor, Perak
∙ TasikPergau, Kelantan
∙ Babagon, Sabah
∙ TasikSubang, Selangor
∙ EmpanganLangat, Selangor
A systematic approach of lake management plan involving all stakeholders especially community participation to cultivate the sense of ownership should be established and implemented. The successful case of lake management is the Putrajaya Lake and Wetland. Putrajaya has a comprehensive Catchment Development and Management Plan for Putrajaya Lake (CDMPPL) which incorporates various management guidelines and studies, aim to achieve and maintain the high water quality objective set for Putrajaya Lake . The Putrajaya Drainage Master Plan 1996 was developed to preserve the urban ecological values within the wetlands and lake areas and to mitigate the runoff and pollutants exports to external catchments whereas the Putrajaya Integrated Stormwater Management Guidelines set strategies that include stormwater drainage, managing stormwater as a resource, protection of receiving water quality and protection of downstream ecological health .
4. Coastal, estuarine and island marine water
Malaysia is one of richest in marine biodiversity in the world where these marine resources are essential contributions to the livelihood and sustenance of its people. Major marine ecosystems in Malaysia include coral reefs, seagrasses, mangroves, mudflats and estuaries . However, these coastal, estuarine and island marine waters are increasingly impacted by pollutants and materials discharged from land-based activities due to urbanization, development and increase in population, resulted in the deterioration of water quality. These threats are generally from point or non-point sources. Point sources of pollutant include sewage and municipal wastewater as well as industrial wastewaters . Non-point sources are runoffs from urban, agriculture, land clearing and construction activities as well as deposition from atmospheric sources. Besides land-based pollution, the marine environment is exposed to threats from the shipping activities, offshore oil and gas exploration and exploitation activities .
In Malaysia, the marine water quality is monitored by the Department of Environment (DOE) in Peninsular Malaysia since 1978 and 1985 in Sabah and Sarawak. The aim is to identify the marine water quality status and to determine the degree of pollution from both the land-based sources as well as the sea-based sources that can pose threats to the marine resources which potentially contribute to the stability and diversity of the marine ecosystem [16, 25]. In 2012, there were around 168 coastal and 78 estuary monitoring stations and 76 islands being monitored with a total of 579 samples from coastal, 325 samples from estuary and 190 samples collected from island monitoring stations . Analyses on data were based on the newly developed Marine Water Quality Index (MWQI). As for coastal water quality, only 155 stations of 168 stations were analysed for MWQI . Figure 2illustrates the trend in terms of MWQI for 2010-2012 . It was observed that three stations (1.9 percent) were categorised as excellent, 32 stations (20.6percent) as good, 111 stations (71.6percent) as moderate and nine stations (5.8percent) as poor in year 2012. The number of excellent and good marine water quality stations had decreased, while the stations with moderate water quality had increased .
Of the 78 estuary stations monitored in 2012, only 69 were analysed for MWQI. The comparison of MWQI trend from 2010 to 2012 in Malaysia is as depicted in Figure 3 . It was observed that there was a slight improvement for the good stations as the good stations had increased from 8.7percent in 2011 to 11.6percent in 2012. Besides, moderate stations showed some decrements from 50 stations in 2011 to 48 stations in 2012, while excellent and poor stations remained the same for 2011-2012 .
As for the 76 islands monitored in 2012, 3 islands were classified as development islands, 32 island as resort islands, 29 stations as marine park islands whereas 12 stations were protected islands . Development islands are Labuan Island, Pulau Pinang and Langkawi, resort islands are like Sipadan in Sabah, Dayang Bunting in Kedah and Pangkor in Perak while marine park islands are islands such as PulauPayar in Kedah, Tioman Island in Pahang, Perhentian in Terengganu and Sapi in Sabah. Protected islands are like Pulau Talang-talang Besar in Sarawak, Pulau Arang in Negeri Sembilan, Kukup in Johor and Pulau Panjang in Kelantan . From 76 islands with 93 island stations monitored, 86 were analysed for MWQI . Figure 4 shows the comparison of MWQI for islands in Malaysia between year 2011 and 2012 . It was observed that there is a slight decrement of station with good water quality from 17 stations in 2011 to 13 stations in 2012. 18 stations (20.9percent) in 2012 were categorised as good, while 52 stations (60.5percent) as moderate and were almost the same as recorded in 2011. Stations with poor water quality were very least with only 3 stations in 2012 and 2 stations in 2011 .
4.1. Marine water quality standards
Water quality at the coastal areas, estuarine and islands are analysed based on the newly developed MWQI by the DOE. The Index is developed based on an opinion poll approach using the Delphi technique involving experts from various group of stakeholders including professionals, practitioners, academicians related to marine water quality management, specialists from marine resource management, marine ecosystems, legislations and regulations, consultants, marine biologist, hydrologist as well as experts from governmental and non-governmental organizations . The MWQI is used as a way to reflect the marine water quality status and category. The index was developed based on seven main parameters consist of dissolved oxygen, DO (0.2), ammonia, NH3 (0.16), faecal coliform (0.14), total suspended solids, TSS (0.14), Oil and Grease, O&G (0.13), nitrate, NO3 (0.12) and phosphate, PO4 (0.11) with corresponding weightages in parenthesis, reflecting contributions of the respective parameters to the overall water quality . The resulting MWQI is classified into four categories of water quality consisting excellent with index value of 90 – 100, good (80 - <90), moderate (50 - <80) and poor (0 - <50) .
Apart from MWQI, Malaysia Marine Water Quality Criteria and Standard (MWQCS) is also developed with four different classes (Class 1, Class 2, Class 3 and Class E) for four different beneficial uses as shown in Table 9 [16, 24]. Class 1 and Class 2 in the MWQCS require MWQI values equal to or greater than 80 and are categorized at least as ‘good’ water quality [16, 24]. The Class 3 waters of the MWQCS are generally within the moderate category of the MWQI [16, 26]. The application of MWQI to Class E waters requires the samples taken must correspond to a salinity of not less than 25 ppt .
|Beneficial Uses||Preservation, Marine Protected Areas, Marine Parks||Marine Life, Fisheries, Coral Reefs, Recreational and Mariculture||Ports, Oil & Gas Fields||Mangroves Estuarine & River-mouth Water|
|Temperature||≤ 2°C increase over maximum ambient||≤ 2°C increase over maximum ambient||≤ 2°C increase over maximum ambient||≤ 2°C increase over maximum ambient|
|Dissolved oxygen (mg/L)||>80% saturation||5||3||4|
|Total suspended solid (mg/L)||25 mg/L or ≤ 10% increase in seasonal average, whichever is lower||50mg/L (25 mg/L) or ≤ 10% increase in seasonal average, whichever is lower||100 mg/L or ≤ 10% increase in seasonal average, whichever is lower||100 mg/L or ≤ 30 % increase in seasonal average, whichever is lower|
|Oil and grease (mg/L)||0.01||0.14||5||0.14|
|Mercury (µg/L)||0.04||0.16 (0.04)||50||0.5|
|Cadmium (µg/L)||0.5||2 (3)||10||2|
|Chromium (VI) (µg/L)||5||10||48||10|
|Arsenic (III) (µg/L)||3||20 (3)||50||20 (3)|
|Ammonia (unionized) (µg/L)||35||70||320||70|
|Nitrite (NO2) (µg/L)||10||55||1,000||55|
|Nitrate (NO3) (µg/L)||10||60||1,000||60|
|Tributyltin (TBT) (µg/L)||0.001||0.01||0.05||0.01|
|Faecal coliform (Human health protection for seafood consumption) – Most Probable Number (MPN)||70 faecal coliform 100mL-1||100 faecal coliform 100mL-1 &|
(70 faecal coliform 100mL-1 )
|200 faecal coliform 100mL-1||100 faecal coliform 100mL-1 & (70 faecal coliform 100mL-1 )|
|Polycyclic Aromatic Hydrocarbon (PAHs) (ng/g)||100||200||1000||1000|
There are the freshwater in rivers, lakes and aquifers, and groundwater resources account for about 99 percent. Despite the abundance of groundwater, it only accounts for 3 percent of total water use for domestic, agricultural, and industrial sectors. Lack of information to indicate groundwater source, perception that the supply is non-sustainable and lack of local expertise on groundwater are factors of under utilization of groundwater resources. Furthermore, leachates from the disposal of waste in landfills pose a threat to human health and environment .
On top of that, costly installation of groundwater extraction system, plus readily water supply available to over 90 percent of the communities, groundwater development is said to be ignored. So far groundwater is only extracted through well for domestic use and irrigation in very rural areas. This situation continues until water crisis occurred in 1997. After the water crisis, DOE has taken preliminary steps to explore and determine the quality and distributions of groundwater through the national groundwater-monitoring programme.
5.1. Groundwater wells and quality
By 2012, 107 quality monitoring wells had been established, as shown in Table10. Selection of the sites were done according to the surrounding land uses which were agricultural, urban or suburban, rural, industrial, solid waste landfills, golf courses, radioactive landfill, animal burial areas, municipal water supply and examining areas (gold mine).
|Solid Waste Landfills||24|
|Ex-mining Areas (Gold Mine)||3|
|Municipal Water Supply||7|
|Animal Burial Areas||14|
According to , 361 water samples were taken from these monitoring wells for the analysis of physical, chemical and biological characteristics. These include total dissolved solids (TDS), pH, temperature, dissolved oxygen and conductivity for physical characteristic; volatile organic compounds (VOCs), pesticides, heavy metals, anions and phenolic compounds for chemical characteristic; and bacteria (coliform) for biological characteristic.The assessment of groundwater quality was based on the percentage of samples exceeded the National Guidelines for Raw Drinking Water Quality 2000 benchmark. In 2012, the results of monitoring showed that all stations were within the benchmark except for arsenics (As), iron (Fe), manganese (Mn), total coliform and phenol. Total coliform was categorized as exceeded the benchmark and in fact were recorded at all stations, followed by phenol, Fe, Mn and As .
5.2. Groundwater quality standard
The Ground Water Quality Standards for Malaysia is still not established, but considering potential of groundwater as an alternative source for surface water, DOE had started the National Groundwater Monitoring Programme to determine the groundwater quality status. The groundwater quality status was determined based on the National Guidelines for Raw DrinkingWater Quality, as shown in Table 11, as the benchmark .
|Coliform||-||Must not be detected in any 100 ml sample|
6. Drinking water
According to , Malaysia receives more than 25,000 cubic meters of renewable water per capita annually from its extensive river system that consists of more than 150 rivers. The amount of renewable water that Malaysia receives far exceeds that of many other parts of the world. Thus, over the past 200 years, consumers have the convenience of running water at the turn of a tap.
In Malaysia, the most tapped raw water sources are rivers, which are technically under the jurisdiction of the respective state governments. In the past, conventional treatment systems were employed to treat raw surface water. Typically, this kind of treatment system provides very basic treatment which includes screening, coagulation and flocculation, sand filtration, disinfection (chlorination) and fluoridation. As development becomes more rampant especially industrialization, river water quality becomes seriously deteriorated plus the water characteristic becomes more complex with the existence of new contaminants. At this time, conventional treatment system is not capable to remove these contaminants and as a result they might enter the distribution and supply network. To manage this problem, the Environmental Quality Act, 1974, prescribes more stringent regulatory compliance for wastewater discharging premises located upstream of a water intake point . In spite of this, not all contaminants are covered under the Act, therefore the risk of contamination cannot be totally eradicated.
6.1. Drinking water standard
In 1985, DOE has developed the Drinking Water Quality Standards for Malaysia, as shown in Table 12 below:
|Total Coliform||1||0||5000MPN/100 ml||0 in 100 ml||0|
|1||0||5000MPN/100 ml||0 in 100 ml||0|
|Turbidity||1||0||1000 NTU||0||5 NTU|
|Color||1||0||300 TCU||0||15 TCU|
|Free Residual Chlorine||1||-||-||0.20000||5.00000|
|Clostridium perfringens (including spores)||1||-||-||0||Absent|
|Colony count 22°||1||-||-||-||-|
|Anionic Detergent MBAS||2||0.00000||1.00000||0.00000||1.00000|
|Total organic carbon||2||-||-||-||-|
|Trihalomethanes - Total||3||-||-||-||-|
|Aldrin / Dealdrin||4||0.00000||0.00003||0.00000||0.00003|
|Heptachlor &Heptachlor Epoxide||4||0.00000||0.00003||0.00000||0.00003|
|Pesticides - Total||4||-||-||-||-|
|Polycyclic aromatic hydrocarbons||4||-||-||-||-|
|Tetrachloroethene and Trichloroethene||4||-||-||-||-|
|Gross alpha (α)||5||0.00000||0.1Bq/l||0.00000||0.1Bq/l|
|Gross beta (β)||5||0.00000||1.0 Bq/l||0.00000||1.0 Bq/l|
|Total indicative dose||5||-||-||-||-|
6.2. Drinking water treatment technology
In recent years, the pollution in rivers and lakes has become increasingly worse, and it has become necessary to take measures toward securing a stable supply of tap water and supplying good-tasting water. Generally, there are two methods used in water treatment, which are the conventional and non-conventional methods. Conventional method is water treatment which undergoes processes such as coagulation, flocculation, sedimentation, and filtration, as shown in Figure 5, while non-conventional method uses more sophisticated equipment.
In Malaysia, both conventional and non-conventional methods are employed. Generally, if the water is severely contaminated or there is a need for alternative water source, then conventional method is no longer viable for use. At present, Dissolved Air Flotation (DAF) and Actiflo are among the latest conventional technology in use.
In DAF float tank, suspended matter in the feed water is often flocculated with coagulant (such as ferric chloride or aluminum sulfate). These flocculated suspended matters are then floated up to the surface by the adhered bubbles and form a froth layer which is then removed by a skimmer. The froth-free water exits the float tank as the clarified effluent. The tiny bubbles are actually those bubbles that released from the pressure reduction valve when the mixture of clarified effluent and the compressed air are forced to flow through this valve (Figure 6).
One of the non-conventional methods used in Malaysia is membrane technology. Ultrafiltration process in this technology uses membrane modules (Figure 3) as filtration media as compared to sand in conventional filtration plant. At present, one water treatment plant in Bukit Panchor, Pulau Pinang  and two plants in Selangor  are adopting the application of this membrane technology. Ultrafiltration (UF) is a variety of membrane filtration in which forces like pressure or concentration gradients leads to a separation through a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained in the so-called retentate, while water and low molecular weight solutes pass through the membrane in the permeate. Among the advantages of using the UF technology is, it could produce clean water of high quality, lower operation cost, easily upgradeable system and space reducing compact system.
The progression and development of the water treatment technology are undeniably based on the deteriorating water source quality and current water demand over time resulted from the growth of population and industries. In addition, advancement in water treatment technology minimizes the space usage, increases production yield, more cost effective, and reduced labor.
The DOE uses WQI and NWQS to evaluate the status of the river water quality. There is no specific national standard or index for lake water quality analyses for the meantime. Since lakes are located within a river basin (although some say lakes have their own lake basins), the water quality standards and classification for rivers are used. On the other hand, the marine water quality is monitored by the DOE in Peninsular Malaysia since 1978, and 1985 in Sabah and Sarawak, with the aim to identify the marine water quality status and to determine the degree of pollution from both the land-based sources as well as the sea. Water quality at the coastal areas, estuarine and islands are analysed based on the newly developed Marine Water Quality Index (MWQI) by the DOE. After the water crisis in 1997, DOE has taken preliminary steps to explore and determine the quality and distributions of groundwater through the national groundwater-monitoring programme. Consequently, DOE had started the National Groundwater Monitoring Programme to determine the groundwater quality status. For drinking water, DOE has developed the Drinking Water Quality Standards for Malaysia since 1985. Selection of water treatment technology depends on the quality of water source. Among the technologies in use in the country are DAF, Actiflo and membrane technology.
The authors would like to express their sincere appreciations to the Department of Environment (DOE) Malaysia for their water quality monitoring work and comprehensive reports to make this book chapter a success. Special thanks are also extended to the other relevant Government’s agencies, departments and institutes for their information and materials to enhance the contents of this document.