Waste water treatment and industrial water use has become increasingly efficient over time, increasing salt loading in waste streams.  This has increased the prevalence of Total Dissolved Solids (TDS) related Whole Effluent Toxicity (WET) issues in areas of the country where water conservation has not been a critical issue in the past.  With increasing frequency of drought from global warming effects, receiving streams are under greater challenges to adapt to increases in TDS loadings.  In areas of reduced rainfall TDS concentrations of shallow groundwater basins increase and stream base flows are reduced.  The purpose of this presentation is to demonstrate an array of solutions to TDS-related WET by reviews of available technologies and case histories.  

Results/Conclusions Solutions to TDS-related WET are multidisciplinary. Tools for dealing with TDS came from engineering, the biological/toxicological arena, and regulatory disciplines.  The functionality of these tools fall under basic headings of: 1) Dilution – which are primarily regulatory in nature. 2) Transformation – primarily from biological / toxicological disciplines. 3) Sequestration – primarily by engineering based controls.
Cost effective solutions generally required modeling of multidisciplinary options to properly inform decision makers, and within each discipline advantages and disadvantages are apparent.  The present array of cost effective tools for solving TDS-related WET problems is limited, particularly in the area of engineering controls.