*3.3.1. Classification and monitoring parameters*

The development of the NLWQCS aims at providing a tool stakeholders and lake owners can use manage a lake or reservoir. NLWQCS applies to all lakes, reservoirs, ponds and wetlands. The proposed standard is divided into four categories, which were suggested as targets for the respective lakes to achieve [31] based on designated uses proposed by the respective author‐ ities. Categories A and B were criteria to be applied for lakes used for recreational environment: Category A for primary body contact such as bathing, diving, skiing and wind‐surfing activities, and Category B for secondary body contact such as boating, cruising and angling. Category A is the more stringent of the two and included criteria for parameters related to waterborne disease. The contaminant limits for certain parameters in Category A is more stringent than the raw water for drinking standard. Categories C and D were criteria to be applied for lakes that are productive and meant for fisheries and other economic activities: Category C for protection of aquatic health, and Category D for other limited uses. Category D is allowed to be more turbid, have higher concentrations of TSS and nutrients, and have lower transparency.

The main parameters identified for the different classes are categorized as (i) physical pa‐ rameters; (ii) nutrients; (iii) biochemical and microbial constituents and (iv) other toxicants. Only approximately 23 physical‐chemical parameters were identified to determine the cate‐ gories. Factors considered in parameter selection include simplicity of measurement, availa‐ bility of measuring devices and the reasonable cost of sampling and analysis [31]. Aesthetic parameters such as colour, odour, taste, floating objects, transparency, turbidity and sus‐ pended solids are emphasized in all categories for lake management. These parameters re‐ flect aesthetic values of the lake and most can be measured easily. Normal temperature was set at 28 ± 3°C [31]. Nutrient parameters relate to ammonia nitrogen, nitrate‐nitrogen and TP. Hardness, which influences heavy metals, is deliberated to be around 50 mg/l.

The proposed criteria for lake water quality are given in **Table 3**. The criteria in this work are based on established criterion found in the literature assuming similar health and aquatic life effects will be experienced when levels of water quality parameters exceeding the criteria. In terms of aesthetic parameters, floating objects, colour and odour are rarely reported on in the literature. Suitability for swimming has been associated with the clarity or the depth of light penetration into water. The clarity of Malaysian lakes mentioned in the literature range between 0.3 m and 5.7 m [2, 27]. This parameter is associated with the colour of the water, levels of turbidity, algae and suspended solids. Guidelines for water clarity or Secchi depth were set at 1.2 m and 1 m in Canada and South Africa, respectively as being the minimum visibility level for water to be suitable for swimming [17, 18]. In Australia and New Zealand,

the visual clarity level based on Secchi depth required to ensure swimmer safety in wadeable areas was recommended as 1.6 m [6]. A survey of perception for bathing in New Zealand found a Secchi depth of 1.5 m as the aesthetic consideration [32]. Currently, no survey has been carried out to measure perception for bathing in Malaysia. In the NLWQS, a lower threshold limit of 0.6 m was set following experience in Putrajaya. TSS in most lakes were generally found to be less than 20 mg/l, except in Sembrong and Aman Lakes which are known to experience algal bloom that can reach about 50 mg/l. DO concentrations in Malaysian lakes are highly variable and depend on the timing of the sampling. DO <5 mg/l is common for lakes located in peat swamp areas. In terms of nutrient parameters, TP was set to below <0.01 mg/l for primary contact and <0.05 mg/l for the other classes [31]. Nutrient values (specifically TP) were very high in many lakes and needed to be controlled to decrease eutrophication problems. Monitoring is necessary to ensure informed decision making regarding effective management measures to control nutrient inputs. These values are consistent with the limits set in Japanese regulations and at Lake Tahoe for bathing purposes, and are much more stringent than the PLWQS which specified higher TP value (0.05 mg/l) for its ambient recreational standard.

criteria suggested to change the classification into category as the four classifications were not based on ranking of parameters. Refinement was also made in setting the parameters, such as BOD, which is defined as BOD5 or BOD 5‐day test consistent with other standards

The development of the NLWQCS aims at providing a tool stakeholders and lake owners can use manage a lake or reservoir. NLWQCS applies to all lakes, reservoirs, ponds and wetlands. The proposed standard is divided into four categories, which were suggested as targets for the respective lakes to achieve [31] based on designated uses proposed by the respective author‐ ities. Categories A and B were criteria to be applied for lakes used for recreational environment: Category A for primary body contact such as bathing, diving, skiing and wind‐surfing activities, and Category B for secondary body contact such as boating, cruising and angling. Category A is the more stringent of the two and included criteria for parameters related to waterborne disease. The contaminant limits for certain parameters in Category A is more stringent than the raw water for drinking standard. Categories C and D were criteria to be applied for lakes that are productive and meant for fisheries and other economic activities: Category C for protection of aquatic health, and Category D for other limited uses. Category D is allowed to be more turbid, have higher concentrations of TSS and nutrients, and have

The main parameters identified for the different classes are categorized as (i) physical pa‐ rameters; (ii) nutrients; (iii) biochemical and microbial constituents and (iv) other toxicants. Only approximately 23 physical‐chemical parameters were identified to determine the cate‐ gories. Factors considered in parameter selection include simplicity of measurement, availa‐ bility of measuring devices and the reasonable cost of sampling and analysis [31]. Aesthetic parameters such as colour, odour, taste, floating objects, transparency, turbidity and sus‐ pended solids are emphasized in all categories for lake management. These parameters re‐ flect aesthetic values of the lake and most can be measured easily. Normal temperature was set at 28 ± 3°C [31]. Nutrient parameters relate to ammonia nitrogen, nitrate‐nitrogen and

TP. Hardness, which influences heavy metals, is deliberated to be around 50 mg/l.

The proposed criteria for lake water quality are given in **Table 3**. The criteria in this work are based on established criterion found in the literature assuming similar health and aquatic life effects will be experienced when levels of water quality parameters exceeding the criteria. In terms of aesthetic parameters, floating objects, colour and odour are rarely reported on in the literature. Suitability for swimming has been associated with the clarity or the depth of light penetration into water. The clarity of Malaysian lakes mentioned in the literature range between 0.3 m and 5.7 m [2, 27]. This parameter is associated with the colour of the water, levels of turbidity, algae and suspended solids. Guidelines for water clarity or Secchi depth were set at 1.2 m and 1 m in Canada and South Africa, respectively as being the minimum visibility level for water to be suitable for swimming [17, 18]. In Australia and New Zealand,

**3.3. Proposed lake water quality criteria and standards**

*3.3.1. Classification and monitoring parameters*

in Malaysia.

302 Water Quality

lower transparency.




**Parameter Unit Category A Category B Category C Category D Chemical Oxygen Demand (COD) mg/L 10a** 25a 25 50 **Chlorophyll‐a µg/L 10 3 – 15 15 25 Cyanobacteria Cells/ml 15000cf** 15000cf 15000cf 15000cf Faecal Coliform MPN/ 100ml 150fg <1000g 5000 (20000)\*a 5000 (20000)\*a **Total Coliform Counts/ 100ml 5000a** 5000a 50000a 50000a *E.coli* **cfu/100ml 100d** 1200g 3000h 3000h **Enterococci MPN/ 100ml 33d** 230c nvd nvd *Clostridium perfringens* **(including spores) ‐ ndi** ndi nvd nvd *Cryptosporodium* **sp. ‐ ndi** ndi nvd nvd *Giardia* **sp. ‐ ndi** ndi nvd nvd *Leptospira* **sp. ‐ nde** Nde nvd nvd Enteroviruses PFU/L nvd nvd nvd nvd Microcystin–LR μg/L 0 0 0 0

**Arsenic mg/L 0.05ai 0.1a 0.15d 0.4a** Aluminium mg/L 0.1ji 0.1ji 0.05i 0.05i Antimony mg/L 0.03i 0.03i 0.03i 0.03i Argentum mg/L 0.05k 0.05>k 0.05>k 0.05>k Barium mg/L 0.1g 0.1 1ai 1ai Beryllium mg/L 0.004i 0.004i 0.004i 0.004i Boron mg/L 1ai 1ai 1ai 1ai

**Cadmium mg/L 0.002i 0.01a 0.25d 0.25d** Chloride mg/L 250j 250 250 250 Chromium mg/L 0.05ac 0.025ac 0.05ac 0.05ac Cobalt mg/L 0.05c 0.05c 0.05c 0.05c Combined Chlorine mg/L >1.0 >1.0 >1.0 >1.0 Copper mg/L 0.02ai 0.02>ai 0.02>ai 0.02>ai Fluoride mg/L 1 1 1.5f 1.5f Iron mg/L 1ai 1 1 1 **Lead mg/L 0.05a 0.05a 0.0025d 0.05a** Magnesium mg/L 150k 150 150 150 Manganese mg/L 0.1ai 0.1 0.1 0.1 **Mercury mg/L 0.001a 0.002a 0.00077d 0.002a Nickel mg/L 0.05a 0.05a 0.052d 0.05a** Potassium ion mg/L 200 200 200 200 Silver mg/L 0.05ai 0.05 0.05 0.05 Sodium mg/L 200k 200k 200k 200k Sulphur mg/L 0.05ai 0.05 0.05 0.05 Zinc mg/L 3k 3k 5ai 5ai

1,2‐dichloroethane μg/L 30k 30k 30 30 2,4‐D μg/L 30k 30k 70ai 70ai

\*\*a

Calcium ion mg/L 200 200 \*\*a

*Heavy metals*

304 Water Quality

*Organics or pesticides*


*Notes*: Item in light grey—should be measured for categorization.

NV, not visible; NOO, no obvious odour; NOT, no obvious taste; nd, not detected; nvd, no value determined. a DOE [12].

b Health Canada [17].

c ANZECC [6].

d USEPA [24, 25].

e WHO [16].

f Ministry of Health, unpublished report.

g EPA Ireland [40].

h Conversion using USEPA ratio (126 *E. coli* = 200 faecal).

i Perbadanan Putrajaya [13].

j CONAMA [5].

k NDWQS.

\* maximum not to be exceeded.
