Audit no. P/24/058/LKA
In 2020-2023, the coal mines from Śląskie Province discharged into local rivers:
- over 733 million m3 of saline waters – 36% in the Odra River Basin, 64% in the Vistula River Basin,
- nearly 6 million tonnes of salts (chlorides and sulphates) along with mining waters, which makes approx. 1.5 million tonnes per year,
- the average salination of all waters discharged by Silesian coal mines was 8 g/l and it exceeded the average salination of the Baltic Sea waters (7 g/l),
- only in eight water law permits the acceptable concentration of chlorides and sulphates in the wastewater discharged by coal mines complied with the ordinance on substances particularly hazardous for water environment,
- initiatives mitigating negative effects of mining water discharges into rivers were imprecise in 64% of water law permits audited by NIK and in 36% they were not specified at all,
- only about 18% of mining waters were utilised in a different way than by their discharge into rivers.
The majority of coal mines could not effectively retain waters or desalinate them, but also were not obliged to invest in solutions enabling that. They also lacked financial motivation- the desalination of mining waters is expensive and wastewater discharge fees are very low:
- the flat fee is PLN 250 per day per 1 m3/s of wastewater discharged into rivers and has not been changed since 2018,
- the flexible fee for 1 kg of chlorides and sulphates discharged into rivers is 5 gr and has not been changed since 2016. The fee is to be increased but only starting from 2030 and only by 5 gr.
The lack of constraints in saline discharge or non-compliance with those constraints, especially in the periods of low water level in rivers, may lead to subsequent environmental disasters. It is essential to constantly monitor the quantity and quality of these waters, as well as the condition of rivers below and above the places of discharge. The obligation to measure wastewater quality set out in the majority of valid water law permits is far from enough.
