Underground and uncontaminated waters in terms of chemical and microbiological constitution of natural variability of physical and chemical characteristics, which comply with at least one of the conditions:
• the content of dissolved permanent mineral elements is at least equal or exceeds 1,000 mg/dm3;
• the content of iron ions is at least equal or exceeds 10 mg/dm3 (ferruginous waters)
• the content of fluorine ions is at least equal or exceeds 2 mg/dm3 (fluoride waters),
• the content of iodine ions is at least equal or exceeds 1 mg/dm3 (iodine waters),
• the content of bivalent sulphur is at least equal or exceeds 1 mg/dm3 (sulphide waters),
• the content of metasilicic acid is at least equal or exceeds 70 mg/dm3 (silicon waters),
• the content of radon is at least equal or exceeds 74 Bq/dm3 (radon waters),
• the content of unbound carbon dioxide is at least equal or exceeds 250 mg/dm3 (250-1000 mg/dm3 – carbon-dioxide water; above 1,000 mg/dm3 oxalate).