Acid water leaking from old mines underneath Johannesburg is so polluted it is now impacting on tourist sites, including a hippo dam and a lion enclosure at a popular game reserve. In addition, some farmers along the contaminated Tweelopiespruit downstream from an acid mine water flashpoint say their borehole water is now too polluted to drink.These were some of the startling discoveries when the Sunday Times visited the area this week to gauge the impact of acid water leaking out of a massive mine "void" running around and beneath Johannesburg - estimated to be 1600km².mini_story_image_vleft1Some 30million litres of acid mine water are decanting from an old mine shaft near Randfontein, where it is being "neutralised" and piped into the Tweelopiespruit by the Department of Water and Sanitation.However, the current emergency treatment plan is not nearly enough to stem the toxic flood, according to an inspection report released last week by the Department of Environmental Affairs.Not only is acidic water regularly spilling unchecked into water courses near the old mines, the treatment project does not comply with several legal provisions, the report says.Environmental affairs spokesman Albi Modise said a follow-up inspection would take place next month. If noncompliance was still an issue, the department would institute criminal proceedings or administrative action against the Department of Water and Sanitation .The Sunday Times established that:Untreated acid mine water is trickling into Tweelopiespruit from an old mine shaft near Krugersdorp Game Reserve. This trickle becomes a strong flow in the rainy season;The water in the game reserve is so acidic a member of the local water management steering committee, Mariette Liefferink, says it has eaten away some of the fence surrounding the lion enclosure and retaining wall at the hippo 'dam'. The waterfall is stained a bright sulphate brown;The partially treated water still contains a much higher concentration of sulphate than is considered safe for human consumption;Almost 12000 people living in the area use the groundwater for irrigation and domestic purposes, according to a government report;The mining companies largely responsible for the mess, including JCI and Harmony Gold, no longer exist, leaving newcomer Sibanye Gold with an environmental liability;Polluted water is also leaking out of about 270 tailings dams across the Witwatersrand gold basin. These dams contain radioactive mine sludge produced during the gold extraction process; andContaminated water is flowing into the Limpopo River system, which could impact on key industrial users including Eskom and the coal industry, which need relatively clean water for industrial use.full_story_image_hleft2Landowner Garfield Krige said the water was polluting one of Gauteng's most important aquifers to the extent that he could no longer drink the water. Sulphate levels above 500mg a litre can cause serious diarrhoea.Department of Water and Sanitation spokesman Sputnik Ratau confirmed some acid mine water mitigation projects were under scrutiny for "perceived noncompliance"."In January 2013, the Department of Environmental Affairs issued an authorisation for the Department of Water and Sanitation to undertake the 'Emergency Works' project for acid mine drainage mitigation on the Witwatersrand," Ratau said. "The [departments] are engaging continuously to ensure total compliance."But Phil Hobbs of the Council for Scientific and Industrial Research said groundwater quality downstream of the treatment plant had actually improved over the past 18 months, possibly because of last season's below-average summer rainfall - which resulted in less water becoming contaminated.He warned that high rainfall in the coming season could reverse this trend, and urged the Department of Water and Sanitation to increase capacity at its treatment facility: "If [the rain] is hectic then rather than the one or two steps we've taken forward, we will find ourselves a hundred steps back."Hobbs said it was vital to see acid water pollution in context. When the mines were active, polluted water was often released untreated into river systems.jordanb@sundaytimes.co.za..