*2.7. Soil Water Leachate*

Williams et al. (1996) [59] observed that there are amplified concentrations of both calcium and potassium in groundwaters and soils, with some movement of aluminum and magnesium in it. In a long-term experiment, soil leachate at a 20 cm depth taken from mineral soils displayed elevated levels of calcium, magnesium, and potassium, but no significant impact on nitrate concentration, pH or Cd, Cu, Cr, and Pb levels [51]. The storage of moistened WWA in the air led to an adverse effect: it increased potassium leaching. The leaching of phosphorous, magnesium, and metal species from the ash matrix is generally low with a high pH prevailing in the water phase during short-term leaching [60].
