Effluent Guidelines and Water Quality Management - Program 56

Transcription

1 Effluent Guidelines and Water Quality Management - Program 56 Program Description Program Overview The current Effluent Guidelines for wastewater discharges into surface waters are likely to be significantly revised by the USEPA with a potential focus on additional regulations regarding wet ash handling and wastewater from flue gas desulfurization (FGD) systems. For the electric power industry, available discharge data will be used to broadly characterize the applicability and costs for characterization of trace elements in power plant wastewater steams, and to evaluate the overall performance and costs for wastewater treatment options for trace metals and nutrients, as well as plant wastewater management options such as ash transport. Science-based analyses and extrapolation of the data will be necessary to help inform various stakeholders, including regulatory agencies, industry, and the public. In parallel, some U.S. states and regions are considering low parts-per-trillion limits for mercury and other metals, while some power plants are unable to achieve new selenium permit limits based on traditional removal processes. The Electric Power Research Institute's (EPRI's) Effluent Guidelines and Water Quality Management program delivers scientific data to characterize power plant wastewaters and conducts data analysis to inform potential revisions to effluent guidelines for the electric power industry. The program also develops sound guidelines for effective management of low-volume, non-ash wastewater streams as well as ash pond chemistry and discharges; provides cost-effective and reliable options for wastewater treatment to remove chemicals such as trace metals; and develops practical tools for biofouling control using nontoxic alternatives to oxidizing biocides such as chlorine. Research Value Program research helps facility owners develop effective effluent guideline compliance strategies. As water discharge permit limits for trace metals and nutrients tighten, power companies require accurate analytical methods, reliable data, and independent performance and cost data for plant wastewater management. In addition, as power plants install air pollution control technologies to meet the new hazardous air pollutant standards, these technologies such as bromide addition or trona injection may also impact wastewater and its treatability. Key motivations for this research include the following: The best scientific data available are needed for developing effluent guideline standards. Evaluation of the cross-media impact of air pollution control technologies on wastewater is needed. Inaccurate analytical methods may lead to false permit violations, increased capital and operating/maintenance cost for wastewater treatment, and higher likelihood of permit violations. Additional water treatment may be required for plants to achieve ash pond permit limits. Limited options exist for nonoxidizing alternatives to chlorine. EPRI characterizes power plant waters, evaluates analytical methods, and independently evaluates the overall performance and costs for various water management options. Program results are communicated through briefings for key stakeholders, including regulatory and other government agencies; reports; presentation materials; information summaries for public consumption; and service on various advisory panels. This program delivers Industry-specific data and information that helps determine the need for effluent guideline revisions; Independent evaluation of wastewater treatment systems, including overall treatment performance, capital costs, and operation and maintenance costs; Strategies to ensure compliance with existing or revised discharge permits; p. 1

2 Guidance in managing low-volume wastewaters, including management after conversion to dry fly ash handling; and Optimized ash pond management techniques that can avoid the need for costly chemical/physical wastewater treatment, which may cost tens of millions of dollars at individual power plant sites. Accomplishments The program's research informs industry, regulators, the public, and other stakeholders about potential discharge limits and feasibility of treatment technologies as they relate to effluent guideline revisions. Program information has also been useful to power companies that install new FGD systems, negotiate new wastewater discharge permits, and plan water treatment and management options. Program accomplishments include Laboratory evaluation of selenium chemistry in wet FGD systems; Characterization of mercury in FGD waters and its potential treatment implications; Characterization data and predictive tools for estimating trace metals in ash pond wastewater; Guidelines for plant process wastewater management of total suspended solids, ph, and trace metals; Guidelines for optimizing ash pond management of total suspended solids and ph; and Full-scale evaluation of a nonoxidizing alternative to chlorine for macrofouling control. Current Year Activities Program R&D for 2013 will continue to focus on mercury and selenium water characterization and will also begin to include other constituents of interest (such as arsenic, boron, and nutrients). As power plants install air pollution control technologies such as bromide addition or trona injection, these technologies may impact FGD and ash pond wastewater and its treatability for key trace metals such as mercury and selenium, as well as have possible downstream impacts such as the potential to form trihalomethanes (THMs). Specifically, the research will Continue support of stakeholders in informing the ongoing Effluent Guidelines rulemaking. This work will include analyses of data from EPA's Information Collection Request to support the rulemaking and other available data, as well as conduct of studies to accurately characterize industry water management practices; Evaluate the chemistry of trace metals speciation and its potential impacts on removal rates in wastewater treatment systems; Evaluate the impact of bromide, trona, and carbon injection on FGD and pond wastewater, and its treatment implications; and Provide industrywide analysis of costs and benefits of potential wastewater treatment approaches, including physical/chemical, biological, and zero liquid discharge (ZLD) approaches. Estimated 2013 Program Funding $2.0M Program Manager Paul Chu, , pchu@epri.com Effluent Guidelines and Water Quality Management - Program 56 p. 2

3 Summary of Projects Project Number Project Title Description P Wastewater Toxics Characterization P Effluent Guidelines Support P Cross-Media s to Wastewater Trace metals (including mercury and selenium) and nutrients are characterized to understand how power plant operations impact trace metal fate and distribution in FGDs, ash ponds, and other wastewater streams. Accurate and reliable sampling and analytical methods are developed for these water matrices. Scientifically-sound data and assessment of wastewater management options to help inform the Effluent Guidelines rulemaking, as well as other state and regional permits and limits. Tools and guidance documents for low-volume wastewater characterization and management will be developed to assist power plants in the integrated management, treatment, and recycle/reuse of various wastewaters. P Ash Handling Assessment of bottom ash handling options, and survey of recent applications and evaluations of converting wet fly ash handling systems to provide a summary of industry experience. P Nonoxidizing Biocides for Biofouling Control Pilot- and full-scale evaluations at power plant to evaluate the efficacy of promising biofouling alternatives to chlorine. P Wastewater Toxics Characterization (101139) EPA issued an Information Collection Request (ICR) and conducted sampling and analytical studies at selected power plants to support its effluent guidelines rulemaking for the steam electric industry. Scientifically sound data are needed to support the stakeholder community in providing EPA with the best information available, allowing the Agency to recommend and potentially propose science-based regulatory guidelines. Power plants are installing new air pollution control technologies (wet FGD technologies, selective catalytic reduction [SCR] technologies, mercury controls), as well as changing coal types, which may impact power plant wastewater characteristics. Facilities need accurate data to clarify the impact of plant operational changes on wastewater so that, if necessary, they can implement cost-effective wastewater management options while complying with current permit limits and negotiating future permits. This project will characterize power plant wastewater streams and develop wastewater management options to cost-effectively meet current and future permit limits. Specific project activities will Characterize total, dissolved, and speciated trace metals (such as mercury and selenium) as well as nutrients in FGD waters and ash ponds, and evaluate the partitioning of trace metals in FGD systems; Clarify the chemistry of selenium oxidation in wet FGD systems and optimize selenium wastewater management with sulfur dioxide treatment performance; Characterize the chemistry and various species of mercury in FGD waters, as well as treatment implications; Evaluate the impact of FGD on wastewater discharges and develop water management options; and Evaluate and determine suitable sampling and analytical approaches for trace elements (including speciation for selenium) in power plant matrices, including FGD waters (a joint effort with Program 59, Power Plant Multimedia Toxics Characterization). Effluent Guidelines and Water Quality Management - Program 56 p. 3

4 Assists power plants with managing the impact of future air pollution controls (for example, FGD, SCR, sulfur trioxide mitigation, mercury controls) and coal switching on wastewater Improves risk management and supports development of science-based regulations Provides data for permit negotiations by developing predictive estimates for trace substance concentrations in wastewater, as well as developing toxics management options that could reduce environmental discharges and potentially reduce operating costs Project findings and deliverables will be used by power company staff in environmental affairs/compliance in responding to EPA s effluent guidelines study, so that stakeholders have sufficient high quality, accurate data. The project will also assist facilities in responding to permit negotiations with state and local agencies. The results will assist wastewater engineers and scientists in developing wastewater management options for new FGD systems, as well as in evaluating the potential impact of other power plant operations changes (such as coal changes). In addition, EPRI staff will facilitate broader use and awareness of the results by holding periodic briefings for key stakeholders, including regulatory and other government agencies; developing materials for the trade press/media and the public; and continuing service on various advisory panels. of Limestone on Wet FGD Mercury/Selenium Chemistry : This technical update will summarize laboratory studies to evaluate the impact of limestone on the chemistry for mercury (as well as selenium and other trace metals) in wet FGD systems, and its ultimate impact on wastewater characteristics and treatability. This work may be cosponsored with Program Water Management Technology. P Effluent Guidelines Support (052395) EPA is on schedule to propose revised Effluent Guidelines for the Steam Electric Industry. The Agency is expected to determine best available technology and propose revised effluent guidelines by November EPA issued an ICR and has conducted sampling/analytical studies at selected power plants to support the rulemaking. EPA may also develop guidelines on numerous topics related to power plant wastewaters, and may include coal-fired as well as oil- and gas-fired power plants. Scientifically sound analyses and interpretation of all the data are needed to support stakeholders in providing EPA with the best information available, allowing the Agency to recommend and potentially propose regulatory guidelines that are based on sound science. This project will assess and evaluate the costs, benefits, limitations, and applicability of various water management and treatment approaches for power plant wastewaters, including FGD wastewater, ash transport waters, landfill leachate, metal cleaning wastes, and other plant and process wastewaters. This activity may include Cost/benefit assessment of various FGD wastewater treatment approaches such as physical/chemical, biological, and thermal zero liquid discharge (ZLD), as well as assessment of the applicability and limitations of these approaches; Assessment of wet and dry ash transport approaches, including the applicability and limitations of the various available technologies; Effluent Guidelines and Water Quality Management - Program 56 p. 4

5 Evaluation of management options for landfill leachates, including treatability with other plant wastewaters; and Evaluation of management options for metal cleaning wastes. Provides scientifically sound and reliable performance and cost information to industry and all stakeholders to inform the rulemaking process Evaluates and provides cost-effective, reliable, environmentally protective wastewater treatment approaches and options to achieve increasingly stringent trace metal, inorganic, and organic effluent limits Enhances compliance The results will be employed by corporate environmental staff in responding to EPA s effluent guidelines study. Information from this project will be communicated to regulatory agencies and other stakeholders at the state and federal levels through reports, information summaries, and briefings. FGD Wastewater Treatment Cost/Benefit Assessment: This product will summarize evaluations of the capital and operating costs of various FGD wastewater treatment approaches (physical/chemical, biological, and thermal ZLD) and the associated benefits, such as removal of pollutants from wastewater. Bottom Ash Transport Technology Evaluation: This product will report on the evaluation of key technology options for transport of bottom ash, including their approximate costs, limitations, and applicability. Landfill Leachate Management: This product will evaluate landfill leachate management options, including comanagement and treatment with other plant wastewaters. P Cross-Media s to Wastewater (055830) Power plants are installing new air pollution control technologies (wet FGD technologies, SCR technologies, mercury controls such as bromide addition, trona, and activated carbon injection), as well as changing coal types, which may impact power plant wastewater characteristics. Facilities need accurate data to clarify the impact of plant operational changes on wastewater so that, if necessary, they can implement cost-effective wastewater management options while complying with current permit limits and negotiating future permits. This project will characterize and evaluate the impacts of air pollution control technologies on wastewater and its management and treatment. Specific activities will characterize The impact of bromide addition on FGD wastewater and treatability, as well as the potential formation of trihalomethanes (THMs) in downstream waters; and The impact of trona, calcium, and activated carbon injection on plant wastewaters, including landfill leachate and ash transport waters. Effluent Guidelines and Water Quality Management - Program 56 p. 5

6 Optimizes management and treatment of total suspended solids, ph, nutrients, and trace metals to meet discharge compliance limits at least cost Reduces operations and maintenance costs Enhances compliance to achieve stringent trace metal and organic effluent limits Project findings and deliverables will be employed by wastewater engineers and scientists in developing options for low-volume wastewater management, as well as evaluating the potential impact of plant operations changes (for example, coal changes, SCR and wet FGD additions). Periodic workshops will be used to facilitate broader use and awareness of EPRI results and provide forums for utilities to share experiences and results. Summary information will be provided to external stakeholders, including the public, so they are familiar with the technology and its advantages. Presentations and briefings will be provided as well. Cross-Media of Bromide Addition on Wastewater: This technical update will summarize laboratory studies to evaluate the impact of bromide additions on FGD wastewater, including the impact on chemistry for mercury, selenium, and other trace metals and the ultimate impact on treatability. This work may also include the potential downstream impacts of possible THM formation. Parts of this work may be cosponsored with Program Water Management Technology and P59 - Plant Multiimedia Toxics Characterization. Cross-Media of Dry Sorbent Injection on Plant Wastewaters: This technical update will summarize laboratory and field studies to evaluate the impact of sorbent injection (trona, hydrated lime, activated carbon) on plant wastewaters, including ponds, landfill leachate, and FGD wastewater. This work may be cosponsored with Program Water Management Technology. P Ash Handling (067513) Some power plants may be required to evaluate alternatives to wet bottom ash and fly ash handling as regulatory pressures on ash pond discharges and constraints on water use and consumption become more stringent in the future. This project will evaluate engineering design considerations and implementation issues for the conversion of wet ash handling systems to dry ash handling and semidry high-density slurry systems. The initial effort will consist of a survey of current alternative ash handling systems and issues with operation and maintenance. Reduces capital and operating costs in managing and transporting bottom ash and fly ash Minimizes operating and maintenance issues Project findings and deliverables will be employed by water management staff in evaluating alternatives to dry ash handling. Results may assist in permit negotiations. Effluent Guidelines and Water Quality Management - Program 56 p. 6

7 Dry Bottom Ash Handling Assessment : This technical update will provide an overview of the various options to converting from wet to dry bottom ash handling, and will summarize the applicability, limitations, and possible issues for the most likely approaches. P Nonoxidizing Biocides for Biofouling Control (101136) Biofouling is the undesirable accumulation of microorganisms, plants, and animals on heat transfer surfaces such as condenser tubes. Managing biofouling is critical, as such accumulation reduces the heat transfer rate and can lead to materials corrosion. Biofouling also can lead to significant plant efficiency and availability problems unless it is controlled and managed. Chlorine is commonly used for biofouling control; however, chlorine use will likely become more limited in the future due to regulatory restrictions (for example, revised effluent guidelines). Alternative approaches are needed that will allow plants to maintain or improve efficient operations with lower maintenance costs. This project will provide nontoxic alternatives to oxidizing biocides for biological fouling control (both micro- and macrofouling), aiming to provide environmental benefits while maintaining or improving facility thermal performance. Plant efficiency will become increasingly important in light of possible carbon dioxide emissions constraints. Provides environmentally acceptable alternatives to chlorine for biofouling control Improves or maintains plant heat rates using environmentally acceptable options for controlling biofouling and also possibly reducing corrosion in cooling and service water systems Project findings and deliverables will assist power plant water engineers and scientists in minimizing biofouling where chlorine use is restricted. Operating guidelines will assist water engineers and scientists in managing service and cooling water biofouling while maintaining plant efficiency and reliability. Power plants may participate in pilot- and full-scale evaluations of alternative biocide approaches. Future Year Products Field Evaluations of Non-oxidizing Biocides: This technical update will summarize field evaluations of promising alternative biocides, and would present the field data and key conclusions. 12/31/14 Effluent Guidelines and Water Quality Management - Program 56 p. 7