Nevertheless, environmental concerns regarding high
concentration of nitrates in the drainage (Katsoulas et al., 2006), which can contaminate
water reservoirs (in the surface or sub-surface streams) have raised the needs of looking at
alternatives like the closed systems (Massa et al., 2010). In closed systems water quality
is very important (Schwarz et al., 2005), since this makes it easier to manage ion relations
and accumulation of potentially toxic ions like sodium and chlorine is avoided.
Simulation studies have shown that with low quality water the use of closed systems is
not financially viable (Stanghellini et al., 2005).