Detailed Assessment

6.2. Detailed Assessment

6.2.1. Introduction

The water quality scoring focuses primarily on the beneficial uses of the river which have a significant impact on human health.  The preliminary ranking of communal and industrial sources of pollution (see Section 4) enabled identification of the most significant Hot Spots in terms of contaminant discharge and as a result the most important with respect to the potential adverse impact on the environment.

6.2.2. Drinking Water Supply

6.2.2.1. Location of the Nearest Municipal Drinking Water Withdrawal

This criterion establishes the proximity to the nearest drinking water withdrawal downgradient of the Hot Spot.  Municipal systems have been specified to distinguish from individual water takings.  The criterion is based on the assumption that pollutant assimilation and drinking water supply are incompatible uses in close proximity. 

According to the results of the studies, there are no municipal surface water withdrawals for drinking water supply that are located downstream of the wastewater treatment facility discharges of the 15 subject enterprises. Hence, the value of index 1.1 was scored as 1 point for all enterprises (Attachment C, Table C.1).

6.2.2.2. Municipal Drinking Water Withdrawals under the Direct Influence of River Quality

This criteria examines the situation where the nearest downgradient drinking water withdrawal is influenced by river quality recognizing that in numerous instances well water supplies (and not direct river withdrawals) are used as the source of municipal water supplies.  The criterion is based on an evaluation factor, α, which establishes for a given well supply its connectivity to the river.  The evaluation system takes into account the physical relationship and distance between the well and the river, or the time for contaminant migration between the river and the well.  For scoring purposes it has been assumed that water supplies under the direct influence of the river waters would obtain the highest scores. 

The exploitation of underground water withdrawals causes the formation of cones of depression.  These reach the river flow and as a result the polluted river waters can get into the wells, which has a direct impact on human health. At a qualitative level, the possibility of drawing of polluted river water to the wells is assessed by the level of connectivity rather than quality.  This is assessed with the help of an evaluation factor of the connectivity of the river flow and underground waters (α), which determines the component of river water (Q_river) in the yield of water withdrawal (Q_{water withdrawal}) (α=Q_river/ Q _{water withdrawal}).

The degree and the coefficient of connectivity of the river flow and underground waters is characterised by the physical relationship of the exploitable water-bearing horizon and the river flow, by the distance between the well and the river and the time for contaminant migration between the river and the well.  The degree and the value of the factor of connectivity of the river and underground waters can be determined using the following table, and the assessment can be done separately for each characteristic (Columns 1, 2 and 3).

Table 6.1 : Determination of Coefficients of Connectivity between the River and Underground Water

Underground well supplies are located downstream of the effluent discharge from wastewater treatment facilities of the Minsk effluent treatment plant by means of two large-scale ground water supply systems, the Svisloch River is in the zone of influence of these large-scale ground water supply systems.

The exploitable water-bearing horizon is closely connected to underground waters and the latter in turn are closely connected with the river.  At the same time the wells for water withdrawal are located at some distance away from the river.  There are also some underground water withdrawals downstream, which provide water for the settlements of Svisloch and Pukhovichi. Therefore the degree of connectivity is qualified as medium and the assigned score is 3.

Downstream of the wastewater treatment facilities of “Retchitsa vodokanal” underground wells provide the water supply for the town of Retchitsa, pioneer camp “Ion”, sanatorium “Dneprovsky” and the population of neighbouring inhabited localities.  The degree of connectivity between the quality of water in the river and the quality of drinking water is qualified as 50% (medium), therefore the assigned score is 3.

Downstream of the “Gomel vodokanal” wastewater treatment facility discharge ground water wells are used for water supply for pioneer camps, sanatoria and country houses. Ground water is also used for water supply for rural localities downstream of the “Borisov vodokanal” effluent discharges.  The degree of impact of the quality of surface water on the quality of underground water in these two cases is qualified as possible, but minor.  Therefore the assigned score is 2.

Downstream of the other subject enterprises, ground water is used for water supply, however connectivity between the ground water and surface water has not been observed and the assigned score is 0.  Consequently, the values for index 1.2 have been scored as follows: cities of Minsk and Retchitsa – 3 points; Gomel and Borisov – 2 points; all the rest – 0 points (Table C2).

6.2.2.3. Population being Supplied by River Water within 25 km Downstream of Hot Spot

A pollutant discharge can pose a threat to drinking water supply.  The specified 25 km limit was arbitrarily selected for comparison purposes and does not represent a real measure of the potential impact zone.

Groundwater supply systems located within the limits of 25 km downstream of the Minsk effluent treatment plant discharge provide drinking water supply to 200 thousand people.  The population served by groundwater supplies within 25 km downstream of the other enterprise discharges do not exceed 10 thousand people.  As a result the value of index 1.3 for Minsk vodokanal was scored as 4 points, and for the remaining enterprises, 1 point was assigned (Table C2).

6.2.3. Recreation

Recreation scoring criteria should be assigned a lower weight than Drinking Water Supply scoring criteria.  Poor quality drinking water is a greater threat to human health than aquatic recreation.  For contact recreation (e.g. swimming), the level of bacteriological contamination is of primary importance, however the aesthetic aspect also should not be underestimated.

6.2.3.1. Recreational Bathing Areas Located near the Hot Spot

The presence of recreational bathing (swimming) areas in close proximity to a Hot Spot discharge is a potential source of concern.  A greater distance downstream assumes greater pollutant assimilative potential and hence a reduced concern (and reduced score for the Hot Spot).

There are formally established and spontaneous bathing areas within 1 km downstream or in the immediate proximity upstream of the discharges from wastewater treatment facilities of Retchitsa vodokanal, Gomel vodokanal, Svetlogorsk “Khimvolokno” and Svetlogorsk heat station.  There are bathing areas within 3 km downstream of the effluent discharge from the town of Orsha.  In the towns of Mogilev and Zhlobin, there are bathing areas within 5 km downstream of the discharges. Formally established bathing areas exist in inhabited localities situated at a distance of more than 10 km downstream of the discharges from the Minsk effluent treatment plant and Mozyrsky petroleum refinery, as well as vodokanals of the cities of Borisov, Bereza, Pinsk, Soligorsk and Slutsk.  The scores are given in Table C-4 (Annex C).

6.2.3.2. Other Aquatic Recreational Activities Located near the Hot Spot

Direct contact with water can take place during rowing, sailing and other aquatic recreational activities.  Poor aesthetics (e.g., eutrophication, colour, odour) can diminish enjoyment of these activities.

According to the available information, aquatic recreational areas are located within 3 km downstream of the wastewater treatment facilities of Retchitsa vodokanal.  The location of aquatic recreational areas are typically at a distance of more than 10 km downstream from the effluent discharges for all of the other enterprises.  Hence the value of this index for the town of Retchitsa is scored as 4 points, and 1 point has been assigned for all of the remaining enterprises (Table C-5).

6.2.3.3. Any Illnesses Attributed to the Recreational Areas

This criterion provides higher scores to Hot Spots which have the potential to be directly implicated with causing illness in people engaged in recreational activities regardless of whether the Hot Spot is the confirmed cause of the reported illness.

There is no documented evidence of any illnesses which are associated with swimming or other water contact recreational activities downstream of the effluent discharges from the subject enterprises.  Hence, the assigned score for this index for all of the enterprises is 0 (Table C6).

6.2.3.4. Hot Spot identified as Source of Illnesses

This criterion provides higher scores to Hot Spots, which have been directly implicated with causing illnesses in people engaged in aquatic recreational activities.  The criterion provides a zero score where the Hot Spot is not characterized by bacteriological releases and hence cannot be identified as a source of illness.

There is no confirmatory evidence that the effluent discharges of the fifteen subject enterprises are associated with any illnesses listed in paragraph 2 of the scoring sheet for water quality issues.  Hence, the value of this index is scored as 0 for all of the subject enterprises (Table C7).

6.2.4. Recreational Fishing

For recreational fishing (Criterion 1) the potential impact on fishing opportunities is determined by using proximity of established licensed fishing areas to the Hot Spot discharge location. Commercial fishing is addressed in Criterion 4.1.  The overall health of the fisheries is considered under Environmental, Biodiversity & Natural Areas Issues.

6.2.4.1. Proximity of Recreational Fishing Areas and Sustainability

This scoring criterion addresses the potential impact on recreational fishing opportunities by using proximity of fishing areas to the Hot Spot discharge as a measure of potential impact. While it is recognized that recreational fishing is conducted throughout the watershed, the scoring system has been based on the proximity of the Hot Spot to designated, licensed recreational fishing areas to help differentiate Hot Spots.  The highest score is assigned to Hot Spots which have already been identified as having adversely impacted these recreational fishing areas.  So as not to bias the scoring, the scoring criteria take into account the possibility that no recreational fishing is carried out anymore at some locations because river conditions are so degraded.  In these cases it is assumed that further degradation is unacceptable and a high score is warranted.

There are no established recreational fishing zones downstream of the discharges from the wastewater treatment facilities of Minsk, Retchitsa, Mogilev, Bobruisk, Zlobin and Soligorsk vodokanals. Established recreational fishing zones are located within 5 km downstream or 5 km upstream of the Gomel vodokanal and Berezonsk vodokanal effluent discharges.  Established recreational fishing zones are located at a distance of more than 25 km downstream of the Borisov, Orsha, Pinsk, Soligorsk vodokanals, as well as, Svetlogorsk “Khimvolokno” and Svetlogorsk heat station discharges. Recreational fishing is prohibited downstream of the effluent discharge from the “Mozyrsky petroleum refinery” wastewater treatment facilities as there is a Pripyat radiation reserve.  Scores assigned to the index 3.1 are given in (Table C 8).

6.2.5. Commercial Fishing

For commercial fishing (Criterion 4.1) the original intent was to base the scoring on human exposure (health risks) to trace organics and heavy metals, which may bioaccumulate in fish flesh. While testing of commercial fish for potential contamination prior to their reaching the market is routinely carried out, no overall database of contaminant levels in fish are maintained in the three countries.  Several scientific studies on bioaccumulation are available or underway, however these are very site-specific, research-oriented studies (often focused on specific fish organs) which cannot be applied basin-wide.  For this reason the commercial fishing criterion was modeled after that developed for recreational fishing.

The overall health of the fisheries is considered under Environmental, Biodiversity & Natural Areas Issues.

6.2.5.1. Proximity of Commercial Fishing Areas and Sustainability

This criterion focuses on the potential impact on commercial fishing opportunities by using the proximity of designated, licensed commercial fishing areas to the Hot Spot discharge.  The closer the licensed commercial fishing areas are to the Hot Spot, the greater the overall risk to human consumers.  The highest score is assigned to Hot Spots which have already been identified as having adversely impacted these commercial fishing areas.  So as not to bias the scoring, the scoring criteria take into account the possibility that no commercial fishing is carried out anymore at some designated locations because river conditions are so degraded.  In these cases it is assumed that further degradation is unacceptable and a high score is warranted.

The absence of established commercial fishing zones downstream of the Minsk wastewater treatment plant is an  immediate result of effluent discharge; this applies only downstream of the Minsk effluent treatment plant.  There are no established zones of commercial fishing in Slutsk rayon.  Established commercial fishing zones are located within 5 km downstream or 5 km upstream of the effluent discharges from the towns of Retchitsa, Gomel and Zhlobin.  Established commercial fishing zones are located at a distance of more than 25 km downstream of the wastewater treatment facilities of the towns of Mogilev, Borisov, Bereza, Orsha, Pinsk and Soligorsk, as well as, Svetlogorsk “Khimvolokno” and the Svetlogorsk heat station.  Within the territory of Belarus commercial fishing does not take place downstream of the wastewater treatment facilities of “Mozyrsky petroleum refinery”.  Based on the above-mentioned information, the scores assigned to index 4.1 are as given in Table C9.

6.2.6. Agricultural Water Taking

6.2.6.1. Agricultural Water Utilization in Proximity to Hot Spot

Agricultural water taking for crop irrigation and livestock watering are important uses of the river particularly in the lower reaches of the river.  Proximity to a Hot Spot is used as a potential indicator of increased risk to livestock and crops.  Scoring assigns a higher risk to areas where this beneficial use is carried out more extensively.  The degree of use is a relative scale which takes into consideration the following factors: presence of large pumping stations (investment); crop water consumption normals in conjunction with areas (hectares) under cultivation for specific crops, and; calculated water deficits by basin area and licensed water taking volumes.

A high level of water utilization for agricultural purposes exists within 10 km downstream of the Retchitsa vodokanal discharge.  A low level of water utilization is observed within 10 km downstream of the wastewater treatment facilities of Svetlogorsk “Khimvolokno” and the Svetlogorsk heat station.  Utilization of considerable volumes of water for agricultural purposes within 10 km downstream of the other enterprises is not typical.  As a result of the above information, the value of index 5.1 for Retchitsa vodokanal was scored as 4 points, 2 points were assigned for Svetlogorsk “Khimvolokno” and the Svetlogorsk heat station and a score of 0 was assigned for all remaining enterprises (Table C10).

6.2.7. Sediment Quality

6.2.7.1. Sediment Contamination

For the purpose of this criterion, an area of sediment contamination is defined as an area where the sediment quality concentration for at least one parameter is over five times the respective sediment background concentration for that parameter.  The scoring methodology assumes that there will likely not be enough data available to attribute sediment contamination to a specific Hot Spot discharge.  However, where the Hot Spot is the confirmed source of the contamination, the highest score is assigned.  A score of zero is assigned if the Hot Spot discharge does not contain significant quantities of the subject contaminant parameter on which the contamination was defined.

Earlier studies conducted by some research institutions have shown that contamination of the bottom sediments of the Svisloch River by heavy metals greatly exceeds maximum allowable concentrations along its entire length from the Minsk effluent treatment plant discharge to the Osipovichsky storage pond (Minsk Oblast).  No studies of sediment quality are available downstream of the discharges for the remaining subject enterprises.  Therefore, the value of index 6.1 for Minsk effluent treatment plant was assigned a score of 5 points and a score of 0 was assigned for the remaining enterprises (Table C 11).

6.2.8. Transboundary Pollution

6.2.8.1. Proximity to National Boundaries

This criterion reflects one of the stated objectives of this UNIDO project to reduce transboundary transport of pollutants and loadings to the Black Sea.  Hot Spots located in close proximity to national boundaries (or the Black Sea) warrant higher scores than those more distant as they will have a greater impact on their downstream “neighbours”.

Taking into considerations that all of the Hot Spot discharges are located at distances which exceed 30 km from the national boundary, the limits were modified to reflect the situation in Belarus.  As a result, 5 points were assigned for Hot Spot discharges in the event that the national boundary is within 100 km downstream; 4 points if within 150 km; 3 points if within 200 km; 2 points if within 300 km and 1 point if the distance exceeds 300 km.  Table 6.2 contains information on the distance of the national boundary from the Hot Spot discharges.  The respective scores for the subject enterprises are provided in (Table C12).

Table 6.2 : Proximity of Effluent discharges to National Boundary

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