Accidental spills and releases

4.4.7 Accidental spills and releases

Accidental spills/releases refers to the adverse effects of accidental episodic releases of contaminants and materials to the aquatic environment as a result of human activities. The transboundary status of the issue is shown in Table 4.1. However, based on the prioritisation exercise detailed in Chapter 4, this issue was not considered a priority transboundary issue. Consequently, detailed causal chain analysis beyond the immediate causes of the issue was not carried out.

Environmental impacts

The impacts of this issue are linked closely with those of a number of other issues including other water resource pollution issues in this section such as chemical and microbiological pollution, eutrophication and suspended solids (Section 4.4) are also closely linked.

The increased risk of accidental pollution is inherent to a range of facilities and operations in the Basin including a number of different types of industries (e.g. mining, petrochemical and food), liquid waste storage sites, pipelines and municipal utilities in urbanised areas. Accidental spills can cause the acute deterioration of surface water, ground water and air quality. This can result in the mass kill of living organisms, long-term pollution of the environment and resultant ecological changes.

Mass kills of aquatic organisms due to accidental spills of pollutants have been reported in the Republic of Belarus. These mainly occur during winter periods, when anoxic conditions develop in water bodies covered with ice. Regular fish kills are common for the overwhelming majority of rivers in the Dnipro Basin although there appears to be no arrangement for counting the number of organisms killed.

Accidental spills often result in elevated concentrations of pollutants in the transboundary sections of watercourses and there have been numerous reports of many exceeding maximum admissible levels (Table 4.14).

Table 4.14 Examples of pollutants exceeding maximum admissible levels in the transboundary sections of the Dnipro Basin as a result of accidental spills

Such spills and releases of pollutants are distributed unevenly over the Basin, being mainly concentrated in the larger connurbations and industrial centres. Elevated concentrations of pollutants in the air are often recorded during inclement weather periods. Some examples of recorded exceedences are provided in Table 4.15.

Table 4.15 Examples of recorded exceedences of maximum admissible levels as a result of accidental spills

Immediate causes

The following immediate causes contribute to accidental spills in the Dnipro Basin (also refer Section 4.2):

- Episodic accidental spills of polluted effluents from the liquid waste storage sites;

- Episodic accidental spills of polluted material from industries;

- Spills associated with pipework breakdown etc.

Two opposing trends have dominated the environmental situation in the Dnipro Basin between 1990 and 2000:

1. A gradual (very slow) improvement in the state of environment as a result of the general reduction of pollution load.

2. The increased risk of potential pollution of the environment as a result of accidents and/or emergency situations.

There are a great number of high-pressure pipelines in the Republic of Belarus. Their operation presents a significant risk to the environment. Statistical data indicates that accidents occur once per year per 3,000 km of pipeline. Leaks in oil pipelines are often difficult to detect, as they are mainly placed under the surface. Oil products migrate to the aeration zone, groundwater aquifers, the land surface, and finally reach surface waters with surface runoff and groundwater flow. The high density of pipelines is exacerbated by the intensive development of oil refineries, petrol storage facilities and filling stations etc. Their operation poses a continuous risk of water pollution by oil products and the related cost of environmental damage could amount to many hundreds of billions of Roubles. The most typical accident and emergency scenarios are described below:

1. The risk of accidental pollution from operations related to oil storage, refining and transportation. This risk group includes 2,500 facilities including

oil refineries, filling stations, oil pipelines, oil storage facilities, and exploited oil fields.

2. The large-scale contamination of land as a result of accidents associated with oil pipelines. An example of this was the accident at the Druzhba Oil Pipeline

within the territory of the Korenev Forestry Unit near Gomel.

3. The potential danger of accidental flooding and the resultant washout of pollutants from flooded areas.

In the republic of Belarus, the potential for accidental pollution has increased significantly due to the poor technical state and the significant depreciation of assets and equipment in industry (by up to 70%).

In the Ukrainian part of the Dnipro Basin, 20 accidental spills were reported in 2000, 10 during transportation and 10 during storage of material. In addition, 29 operational failures were reported to have taken place on pipelines. The average depreciation of industrial equipment and assets in Ukraine is 50-70%.

Underlying sectoral causes

The underlying causes of sold waste generation are mainly associated with resource uses and practices dominating the following sectors: industry, urbanisation and energy (Section 4.2).

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