Article courtesy of Adnan Adil | July 24, 2015 | Daily Times | Shared as educational material
The EPA survey found the value of sulphide in Rawal Lake to be four times the standard limit. This lake is an artificial reservoir that provides the water needs of the cities of Rawalpindi and Islamabad
There is little recognition of the fact that there are nine major lakes, natural and artificial, in six different districts of Punjab that are precious, scenic jewels of the country. However, they are suffering from severe pollution because of human activities in their catchment areas. These water assets provide drinking water to nearby communities and help keep the surrounding air clean. They are home to rare flora and fauna besides having aesthetic value. Natural lakes are believed to be one of the earliest formations on earth and possess an alluring charm. The nine major lakes include Kallar Kahar in Chakwal district, Ucchali, Khabeki and Jhalar lakes in Khushab, Namal in Mianwali, Malkana and Kohar Wala lakes near Trimmu Head Works in Jhang, Mangla in Jhelum and Rawal in Rawalpindi.
The BOD supports the chain of all marine life and indicates the amount of organic matter subject to putrefaction present in water. Therefore, a low BOD is an indicator of good quality water while a high BOD indicates polluted water. The DO is consumed by bacteria when large amounts of organic matter from sewage or other discharges are present in the water. The presence of sulfide in a water body causes ecological damage to aquatic and riparian ecosystems through fish kills, increased fish disease outbreaks, dominance of acid tolerant species, precipitation of iron, etc, effects on estuarine fisheries and aquaculture projects (increased disease, loss of spawning area, etc) and reduction in agricultural productivity through metal contamination of soils. The presence of TDS and total suspended solids (TSS) in water bodies has an effect on the clarity and taste of water, rendering it harmful for drinking for not only humans but also for animals.
Kallar Kahar Lake, situated in a beautiful valley in the southern mountainous area of Potohar plateau at an altitude of 1,500 feet above sea level, is a favourite recreational spot thanks to its stunning beauty and easy access but it tops the list of polluted lakes. There is a natural freshwater spring at the base of the hills that fills Kallar Kahar Lake up to a level and then overflows and makes a stream towards the north. The lake is not deep so a lot of natural vegetation can be seen all around it, even in the middle. Kallar Kahar Lake is a natural breeding sanctuary for many birds, so it is an ideal place for bird watching. Some migratory birds can also be seen in particular seasons. Wild peacocks can be seen wandering around the area.
The EPA survey found that Kallar Kahar Lake contains 10 times more BOD than the standard limit, which is 810 mg/l of BOD as against the standard limit of 80 mg/l. The lake contained 2,044 mg/l of COD as against the standard limit of 150, 6,860 mg/l of TDS as against the limit of 3,500, 2,302 mg/l of chlorine as against the limit of 1,000, 1,617 mg/l of sulphate as against the limit of 600 and 12 mg/l of sulphide as against the limit of one.
Ucchali Lake, situated just below the Sakaser Mountain, is a saltwater lake. The EPA study found BOD levels in the lake to be 23 times higher than the standard, COD 28 times, TDS nearly twice, chloride 2.5 times, sulphate 21 times and sulphide 16 times more than the standard limit.
Jhalar Lake is another picturesque lake in the Soon Valley of Khushab district. The lake is contaminated with BOD that is 1.4 times higher than the standard limit, COD 2.5 times higher, TDS twice the limit, chloride 1.5 times higher, sulphate twice the limit and sulfide 12 times higher.
Khabeki Lake, one kilometre wide and two kilometres long, is a salt-water lake in the gorgeous Sakesar valley in the Salt Range area of the Khushab district. This lake is the only spot in Punjab where flamingoes are found. Sakaser is a 1,522 metre high mountain in the Salt Range area and overlooks the plains adjoining the districts of Mianwali and Chakwal. According to the EPA survey, the amount of sulphate in the lake is twice as high and sulphide eight times higher than the standard limit.
The water of Namal Lake, spread over 5.5 square km, is located in one corner of the Namal Valley in Mianwali and was formed following the construction of Namal Dam in 1913, some 32 km from Mianwali city. There are mountains on its western and southern sides. On the other two sides are agricultural areas. In Namal Lake, the amount of sulphate is 3.5 times more and sulphide 12 times more than the standard limit, according to the EPA study.
The EPA’s samples from Kohar Wala Lake and the wet land near Trimmu Head Works in Jhang district indicate exceeding amounts of BOD (10 mg/litre higher), COD (1.76 times the limit) and sulfide (four times higher). Similarly, Malkana Lake and the wetland near Trimmu Headworks in the Jhang district were found to have values of sulphate (71mg/l higher) and sulfide (four times) exceeding the limit.
The EPA survey found the value of sulphide in Rawal Lake to be four times the standard limit: four mg per litre as against the standard of one mg per litre. This lake, located within an isolated section of the Margalla Hills National Park, is an artificial reservoir that provides the water needs of the cities of Rawalpindi and Islamabad. Korang River, along with some other small streams coming from Margalla Hills, form this artificial lake, which covers an area of 8.8 square km.
Given the significance of these lakes for a clean environment, there is a need to increase public awareness for the conservative use of domestic water. The installation of sewage treatment plants to properly dispose sewage water and to avoid agricultural soil contamination is a must. The EPA needs to direct industries to dispose their effluents after proper treatment. Industries should also be compelled to conduct third party audits occasionally and submit their report to the EPA Punjab for examination.
The unchecked pollution of these majestic water bodies will impoverish our environment. For the sake of preserving nature’s assets and a safe, healthy environment, urgent measures are needed. The government must control upstream pollution in these lakes, in particular the most polluted ones including Kallar Kahar, Ucchali and Jhalar lakes.