Guidelines for inland surface water quality | Guidelines for inland surface water quality, | ||||
| To maintain and improve groundwater quality, continued vigilance, sustainable land and water management practices, and investments in wastewater treatment and pollution control are essential. The protection of groundwater quality is vital not only for human health but also for the sustainability of agriculture and ecosystems on the island. |
| Unit |
| ||
Inorganics | |||||
Boron | ?g/l | 0.75 | |||
Cadmium | " | 0.70 | |||
Chlorine Residual | " | 2.0 | |||
Chromium (total) | " | 2.0 | |||
Copper | " | 6.5 | |||
Cyanide | " | 5.2 | |||
Dissolved Oxygen | mg/l | 6.0 2 | |||
Iron | mg/l | 1.0 | |||
Lead | ?g/l | 1.3 | |||
Mercury | " | 0.1 | |||
Methyl Mercury compounds | " | 0.012 | |||
Nickel | " | 87.6 | |||
pH | 6.5 - 9.0 | ||||
Selenium | ?g/l | 1.0 | |||
Silver | " | 1.2 | |||
Zinc | " | 59 | |||
Sulphide H2S | " | 2.0 | |||
Phosphate (for a lake) | " | 25 | |||
(for streams entering a lake) | " | 50 | |||
(for streams not entering a lake) | " | 100 | |||
Organics | |||||
Dieldrin | ?g/l | 0.0019 | |||
Chlordane | " | 0.0043 | |||
Pentachlorophenol (for pH 6.5 - 7.5 ) | " | 3.5 - 9.5 | |||
Dichlorophenyltrichloroethane (DDT) | " | 0.001 | |||
Endosulfan (alpha and beta forms) | " | 0.056 | |||
Endrin | " | 0.0023 | |||
Guthion | " | 0.01 | |||
Lindane | " | 0.08 | |||
Oil and Greases | " | Undetectable | |||
Polychlorinated biphenyl (PCB) | " | 0.01 | |||
Suspended solids (at background concentration <100 mg/l) | mg/l | 10.00 | |||
(when background concentration > 100 mg/l) | mg/l | 10% of background concentration | |||
| Source: National Environmental Laboratory, Ministry of Environment, Solid Waste Management and Climate Change 1 Water of river, watercourse, stream, lake, pond, dam or reservoir. 2 Lower limit at 25 oC. | ||||
