A Midwest power plant that was constructed as a zero discharge facility in 2012 was experiencing water management issues due to excessive absorber recycle water with concentrated chlorides and leachate generation from the CCR landfill at the facility. The facility started exploring wastewater management options in 2013 that consisted of evaluating the feasibility of a deep injection well as a fluid disposal option and the results indicated that this option was a technically feasible alternative.
From 2014-2015 the plant continued to experience water balance and chlorides management challenges and conducted a plant review and water balance study to see if the chloride concentration and leachate generation issue could be resolved through process changes within the plant. The resulting water balance study concluded that while minor changes and optimizations could occur, it would not resolve the underlying water quality or water balance challenges at the facility. Other water disposal and management options were also explored by the plant in that included RO, evaporators and the deep well as retained alternatives.
In 2016, the deep injection well was selected as the preferred water management alternative and permitting was initiated. The goal was to get the deep well permitting started while the plant refined plant process modifications and additional water quality data on the feed water(s) is collected.
Water quality data from the site has indicated that iron, carbonate and sulfate are the dominant water quality parameters that drive scaling within the current system and will need to be addressed prior to injection so the well does no scale and clog.
The deep well was completed in 2018 and the final surface treatment system is currently under design. The facility anticipates full-scale operation of the system in early 2020.