What is Water Quality Standards?

Water quality standards are numeric values or narrative descriptions of water quality parameters that are meant to sustain the designated uses of a water body. Water quality standards involve not only the actual criteria associated with water quality parameters but how certain levels of those parameters negatively affect the use of the water for human and/or ecological purposes. Water quality standards consist of two different elements namely designated use and water quality criteria.

Water quality standards form an important aspect of regulation. Several approaches are used to maintain these standards. Regulatory instruments are compared with economic instruments.

Water quality standards are part of regulations. There are several sets of water quality standards, or guidelines for water quality standards issued by various agencies and authorities (e.g. United States Environmental Protection Agency (EPA), World Health Organization (WHO), European Union (EU), Federal Environmental Protection Agency in 1988 (now under Federal Ministry of Environment) intended to define the maximum acceptable limit of water pollution by various pollutants.

Standards for ambient water quality (quality objectives) are designated depending on the intended use of the water resource (e.g. drinking water, fishing water, spawning grounds).

To establish water quality standards, identify and describe how surface waters are used and what water quality parameters should be managed.

The “designated uses” of a water body are grouped into four categories:

• Agricultural and industrial water supply provide water for crop irrigation, livestock drinking, or process water for industrial activities.

• Recreation water is for human activities that involve complete immersion (swimming, diving, and water-skiing) or incomplete immersion (boating, fishing, or wading).

• Public water supply provides water for drinking and domestic use by man.

• Aquatic life includes waters that support the growth and reproduction of wildlife species (USEPA, 1994, 2007).

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Principles for water quality standard

Effluent standards are usually based on either of the following two principles or a combination of both:

1. Fixed Emission Standard Approach

This approach requires some treatment of all wastewater, regardless of its conditions and the use of the receiving water body. Standards or guidelines developed according to this approach must be very restrictive to protect the environment effectively. They must consider the most critical situations and locations.

Advantage:

This approach requires simple administrative implications.

Disadvantages:

• Incurring unnecessary treatment costs.

• Lead to inappropriate treatment and excessive pollution, depending on the emission standards and the absorbing capacity of the receiving water body.

2. Environmental Quality Standard Approach

This approach involves defining the effluent standards to allow compliance with the quality objectives for the receiving water body.

This allows for a more flexible administration of environmental management, and optimization of treatment efforts and costs. The level of treatment can be tuned to the actual assimilation capacity of the receiving waters.

Problems with this approach include;

• Difficulty in practical application.

• Knowledge of the absorptive capacity requires studies of the hydraulic, dispersive, physicochemical and biological conditions of the water body.

• Plans for future development in the area should be considered.

• The costs of applying these principles may be too high in developing countries.

• The administrative capacity to enforce high water quality standards may be lacking. Only regulations that can be enforced should be implemented. Water quality standards in developing countries should be adjusted to reflect the local economic and technological
realities.

3. Economic Instruments

The application of economic instruments in water pollution control offers several advantages e.g. providing incentives for environmentally sound behavior, raising revenue to finance pollution control activities, and allowing the attainment of water quality objectives. The main types of economic instruments applicable in water pollution control include (Warford, 1994):

1. Resource pricing

2. Effluent charges

3. Product charges

4. Subsidies or removal of subsidies and non-compliance fees (fines).

Successful implementation of economic instruments depends on appropriate standards, effective administration, monitoring and enforcement capacities, institutional coordination, and economic stability.

Effluent charges, for example, require a well-established enabling environment and large institutional capacity and coordination while product charges are easier to administer (Warford, 1994).

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Factors Affecting the Successful Implementation of Economic Instruments

1. Appropriate setting of prices and tariffs – very low fines, prices, or tariffs may allow polluters to pollute and pay the fines. Low prices will not generate adequate revenues for system operation and maintenance. Prices should cover direct costs, opportunity costs, and environmental costs (Nordic Freshwater Initiative, 1991).

2. Economic instruments incorporate the polluter-pays-principle to various degrees. Subsidies counter the polluter-pays principle but may be applied for political or social reasons. Effluent charges work with the polluter-pays-principle. Regulatory versus Economic Instruments

Compared with economic instruments, the regulatory approach to water pollution control offers a reasonable degree of predictability about the reduction of pollution, i.e. it offers control to authorities over what environmental goals can be achieved and when they can be achieved (Bartone et al., 1994). A major disadvantage of the regulatory approach is
its economic inefficiency.

Economic instruments provide incentives to modify the behavior of polluters in support of pollution control and revenue to finance pollution control activities. Economic incentives are better suited to deal with non-point sources of pollution.

In developing countries, the most important criteria for balancing economic and regulatory instruments should be cost-effectiveness and administrative feasibility. With highly toxic discharges, or when a drastic reduction or complete halt in the discharge is required,
regulatory instruments (e.g. a ban) rather than economic instruments should be applied.