Guidelines for Inland Surface Water Quality (G.N. No 188 of 1998)

Guidelines for Inland Surface Water Quality Government Notice No 188 of 1998 MINISTRY OF LOCAL GOVERNMENT & ENVIRONMENT Guidelines for Inland Surface Water Quality 1. The following guidelines are hereunder published for the information of the public with the objective of preserving the quality of the inland surface waters for sustaining aquatic life. 2. Inland surface water (a) includes water of river, watercourse, stream, lake, pond, dam or reservoir; (b) excludes (i) all ground water, (ii) water contained in any sewer, sewage disposal works, private drain or private reservoir used for irrigation purposes, (iii) water in any privately owned chamber, tanks or other container, and, (iv) sea water. 3.The public is requested to assist in the preservation of the quality of the inland surface water for the benefit of the community at large. 4.For the benefits of those concerned the under mentioned parameters could be adhered to. Parameters Maximum Limits Remarks (a) Inorganics Boron.............. 0.75 µg/1 Cadmium .................... 0.70 µg/1 Chlorine Residual .......... 2.0 µg/1 Chromium (total) ........... 2.0 µg/1 Copper ..................... 6.5 µg/1 Cyanide..................... 5.2 µg/1 Dissolved oxygen (lower limit) 6.0 mg/1 (at 25o C) Iron ......................... 1.0 mg/1 Lead ......................... 1.3 µg/1 Mercury ...................... 0.1 µg/1 Methyl mercury compounds 0.012 µg/1 Nickel ....................... 87.6 µg/1 pH ......................... 6.5 - 9.0 Selenium ..................... 1.0 µg/1 Silver ....................... 1.2 µg/1 Zinc ......................... 59 µg/1 Sulphide (H2 S).................. 2.0 µg/1 Phosphate .................... 25 µg/1 for a lake 50 µg/1 for streams entering a lake 100 µg/1 for streams not entering a lake (b) Organics Dieldrin ................... 0.0019 µg/1 Chlordane ................. 0.0043 µg/1 Pentachlorophenol 3.5 - 9.5 µg/1 for pH 6.5 - 7.5 DDT ........................ 0.001 µg/1 Endosulfan ................. 0.056 µg/1 alpha and beta forms Endrin ..................... 0.0023 µg/1 Guthion ................... 0.01 µg/1 Lindane ................... 0.08 µg/1 Oil and Greases ........ undetectable PCBs ....................... 0.014 µg/1 Suspended solids............ 10 mg/1 at background concentration <100 mg/l 10% of back- when background ground conc. concentration >100 mg/l(mg/1) Ministry of Local Governmen & Environment 23 January 1998