Engineering and Policy Decisions at the Energy-Water Nexus

Keynote Lecture
\"Engineering and Policy Decisions at the Energy-Water Nexus\"
Speaker: Jeanne M. VanBriesen

Coal-fired power plants are under increasing pressure to manage air quality emissions while remaining profitable in a competitive electricity market. Engineering and policy choices designed to support these objectives can have unexpected effects on pollutant discharges to surface waters that are used as sources at drinking water treatment facilities.

Of particular concern is the release of bromide from coal-fired power plants operating wet flue gas desulfurization (FGD) units. Bromide, while unreactive in surface waters, interacts with treatment chemicals at the drinking water facility to produce halogenated organic compounds called disinfection by-products (DBPs). DBPs containing bromide are more toxic and carcinogenic than chlorinated DBPs, and the current regulatory structure may not adequately protect drinking water consumers from this changing risk.

Bromine, which is naturally present in coals, is not removed in FGD wastewater prior to discharge. Recently, new technologies based on bromide addition have been deployed at power plants to reduce airborne mercury releases and to qualify for federal tax credits. The addition of bromide can significantly increase bromide loading to surface waters and negatively impact drinking water facilities and
consumer risk.

Watershed-, state-, and national-level analyses will be presented that highlight the critical characteristics of regions where current bromide loads are affecting drinking water consumers as well as regions at risk for impacts under future plans for bromide addition and FGD wastewater discharges. The work is particularly timely as the U.S. EPA is re-considering the Effluent Limitation Guidelines for Steam Electric Power Utilities, which currently do not require control of bromide discharges from FGD systems.