Irrigation With Mine Affected Waters: A Demonstration With Untreated Colliery Water In South Africa
Annandale, John George (1); Tanner, Phillip Dale (1); du Plessis, H Meiring (1); Burgess, Jo (2); Ronquest, Zimone D (1); Heuer, Sarah (1)
1: University of Pretoria, South Africa; 2: Isle Utilities Ltd, UK/South Africa
There is renewed interest in the use of mine water for irrigation as a means to reduce mine impacted water treatment costs and to create sustainable livelihoods as mines reach closure and communities need to diversify away from mining. Large volumes of mine waters are impacted, and many mine waters are suitable for irrigation.
A 19 ha demonstration centre pivot has been erected on previously un-mined land in Middelburg District, Mpumalanga, South Africa. Maize (summer) and stooling rye (winter) have been irrigated with an untreated, circum-neutral, calcium and magnesium sulphate dominated mine water since September 2017. Crops grew exceptionally well under irrigation with this particular mine water, far out producing rain fed crop production, and proving more profitable.
Currently, no off-site impacts of irrigation have been detected, and grain produced is safe to consume. A newly developed irrigation water quality assessment tool indicates that Mn and B may be of some concern over time. We advocate regular testing for food or fodder safety, specifically for elements of potential concern, in order to assess if published soil thresholds are robust indicators of the suitability of poor quality waters for irrigation.