Ambient Water Quality Standards and Guidelines for Raw Water
(What are they and what benefits do they bring)
What are they?
For a long time now, Zambia has been using water quality standards for drinking water to regulate the quality of raw water in natural water bodies. Though not recommended, the country has had no choice in the absence of not having ambient water quality standards specifically meant for raw water. This not only made the cost of doing business high but also did not help much in sustaining the aquatic ecosystem. Ambient water quality standards are the allowable amounts of materials, as a concentration of pollutants, in water. The standards are set to protect against anticipated adverse effects on human health or welfare, wildlife, or the environment, with a margin of safety in the case of human health. In Zambia, raw water which are in their ambient state (water in rivers, lakes, dams, groundwater), are usually measured against Drinking Water Quality Standards which are meant for processed or treated water. Limits for pollutants which can be discharged into water bodies and the environment by industries or mining activities are regulated by the Effluent Discharge Limits provided under the Environmental Management Act No. 12 of 2011. Therefore, the thresholds for ambient water quality standards are somewhere in between Drinking Water Quality Standards and Effluent Discharge Limits. This is the level of water quality required to keep a water body in its natural or ambient state. Ambient water quality standards have thus been developed to safeguard water resources from adverse effects arising from pollution through mining, industrial, agricultural, or anthropogenic activities. For Zambia, the Ambient Water Quality Standards were proposed to be Catchment specific. This meant taking into account the unique characteristics of each of the six catchments when developing the standards. This was important because catchments have varying water quality baseline levels and are impacted differently by industrial, infrastructural, or other developments in each of the Catchments. The standards are important to the Authority because they are meant to protect public health and the environment, and to maintain a standard of water quality consistent with its designated uses. Additionally, ambient water quality standards are important because if water is kept in its ambient state, the quality of water is sufficient to support natural habitats and preserve the integrity of ecosystems in water bodies in Zambia.
The Process
The Authority spearheaded a team comprising; Zambezi River Authority (ZRA), National Water and Sanitation Council (NWASCO), Zambia Environmental Management Agency (ZEMA) and the Zambia Bureau of Standards (ZABS) as the Secretariat in the development of ZS 1182 (Ambient Water Quality Standards) and ZS 1183 (Ambient Water Quality Guidelines). The process was done through a multi-stakeholder approach which involved over 350 key stakeholders. The six Catchment Specific Standards and one Guideline have now been Gazetted for use under Gazette Notice No. 88 of 2021. Benefits of the Standards and Guidelines
• Reduced cost of doing business – Good ambient water means industries which heavily rely on water for their process systems will have the cost of doing their business lowered because the water being supplied for industrial processing would not need as much treatment, cleaning or boiling as compared to using polluted water sources.
• Preserved Natural Habitat - Water kept in its ambient state is sufficient to support natural habitats and preserve the integrity of the ecosystem.
• Protection of Zambian Public from water borne diseases –Through promotion of public health and the environment.
• Effective regulatory framework for raw water -By providing water quality legislation in Zambia as a basis by which performance may be evaluated.
• Establishment of ambient water quality goals – The standards will serve as the regulatory basis for establishing water-quality-based effluent limitations, they will also provide a programmatic basis for water quality management and implementation.
• Improved water resources management – By promoting equitable access to water of acceptable quality for national development in Zambia. The general public is called upon to remain vigilant and report to WARMA any person or institution carrying out any activities that pose a threat of pollution to any water body in Zambia.