Xcel Energy Inc. · NASDAQ:XEL
Xcel Energy — Corporate Update (May 2023)
31 slides from Xcel Energy's corporate update, May 23, 2023
Slide 1: Valmont Station Groundwater Program and Remedy Evaluation
VALMONT STATION Groundwater Program and Remedy Evaluation May 23, 2023 Public Meeting/Open House © 2023 Xcel Energy
Slide 2: What is CCR? (or Coal Ash?)
WHAT IS CCR? (OR COAL ASH?) • CCR = Coal Combustion Residuals (or Coal Ash) • Created when coal is burned to produce electricity • Similar to ash from a wood burning fireplace • Comprised of rocks, minerals and other natural materials that cannot be burned • Contains less than 1% of trace elements,
Slide 3: How is Coal Ash Regulated Under Federal Law?
HOW IS COAL ASH REGULATED UNDER FEDERAL LAW? • U.S. Environmental Protection Agency (EPA) CCR (Coal Ash) Rule • Regulated as a non-hazardous solid waste • Waste storage requirements • Groundwater monitoring • To ensure meeting Groundwater Protection Standards (GPS) • GPS set to protect people and th
Slide 4: Valmont Groundwater Monitoring
VALMONT GROUNDWATER MONITORING • We regularly sample and test groundwater in monitoring wells around our coal ash units • Our test results show levels of some substances in groundwater above GPS • In this presentation we will discuss • What these levels mean • What we have done to date • We removed
Slide 5: How Are Chemicals in Groundwater Measured?
HOW ARE CHEMICALS IN GROUNDWATER MEASURED? © 2023 Xcel Energy 5
Slide 6: Groundwater Monitoring 'Basics'
GROUNDWATER MONITORING ‘BASICS’ • Groundwater is sampled from specially designed monitoring wells • Samples are tested by specialized laboratories certified in methods and procedures • Background groundwater quality • ‘Natural’ conditions, no potential to be affected by activity at a site • Groundwa
Slide 7: Site Overview - Regulated Coal Ash Units
SITE OVERVIEW - 3 REGULATED COAL ASH UNITS Units regulated by the CCR Rule: • Landfill: • Ceased receiving waste in 2021 • Interim closure, planned ash removal for beneficial use project • Groundwater monitoring ongoing • Lithium and selenium (on- and off-site) • Former Inactive Impoundment (Settlin
Slide 8: Timeline
TIMELINE INVESTIGATION: 2015 2015-2017 2017 2017-2018 Establish Background Develop Site-Specific Detection Groundwater Groundwater Quality Background Sampling: Screen Monitoring Well Monitoring Groundwater Quality for Indicator Network (8+ Sampling Events) Values Constituents EVALUATION: 2018 – Pres
Slide 9: Timeline
TIMELINE INVESTIGATION: 2015 2015-2017 2017 2017-2018 Establish Groundwater Background Groundwater Develop Site-Specific Detection Sampling: Monitoring Well Quality Monitoring Background Groundwater Screen for Indicator Network (8+ Sampling Events) Quality Values Constituents EVALUATION: 2018-presen
Slide 10: Landfill: Lithium Exceedances
LANDFILL: LITHIUM EXCEEDANCES • GPS = 0.051 mg/L = Cleanup std Private Wells All • Lithium plume onsite Have Lithium < GPS at Treated Tap • Reservoirs < GPS • Lithium plume offsite northeast • No drinking water risk • Private wells < GPS at tap • Lithium plume offsite west Close In-Place with Close
Slide 11: Lithium in the Environment
LITHIUM IN THE ENVIRONMENT • Lithium is present naturally in the environment in rocks, soils, and minerals such as coal. • Like most substances, lithium can be potentially harmful if very large amounts are ingested • Nearly everyone is exposed to low levels of lithium every day through • the food we
Slide 12: Landfill: Selenium Exceedances
LANDFILL: SELENIUM EXCEEDANCES • GPS = 0.05 mg/L = Cleanup std Private Wells • Selenium plume onsite Selenium < GPS • Reservoirs < GPS • Selenium plume offsite northeast • No drinking water risk • Private wells < GPS Close In-Place with Close Engineered by Cover Remov Close Close by al by Close Remo
Slide 13: Selenium in the Environment
SELENIUM IN THE ENVIRONMENT • Selenium is present naturally in the environment in rocks, soils, and minerals such as coal. • Like most substances, lithium can be potentially harmful if very large amounts are ingested • Nearly everyone is exposed to low levels of lithium and selenium every day throug
Slide 14: State Groundwater Regulations
STATE GROUNDWATER REGULATIONS • Dept of Public Health and Environment – Solid Waste Regulations • Similar but separate program – Landfill only - groundwater monitoring, clean-up and closure • Potential constituents above State standards • Boron (agricultural standard) • Fluoride (agricultural standa
Slide 15: Landfill Geology and Groundwater
LANDFILL GEOLOGY AND GROUNDWATER Groundwater N Understanding the geology and groundwater allows us to design a remedy for how to capture and treat impacted groundwater moving offsite in the area between Valmont Road and the ash landfill. © 2023 Xcel Energy S 15
Slide 16: Landfill Remedy Evaluation Criteria
LANDFILL REMEDY EVALUATION CRITERIA Assessment of Corrective Measures - 2 Categories of Remedy Alternatives: 1. Ash focused 2. Groundwater focused Alternatives reviewed for the following Criteria: • Effectiveness • Performance and reliability • Ease or difficulty of implementation • Potential impact
Slide 17: Timeline
TIMELINE EVALUATION: 2018-present 2019-present 2019-present 2019-present Present Assessment Sampling: Evaluation of Groundwater Add Monitoring Wells to Additional Data Public Evaluate Levels of Remedy Options Define the Groundwater Collection for Meeting and Contaminants of Concern (Assessment of Co
Slide 18: Landfill Remedy Alternatives Evaluation
LANDFILL REMEDY ALTERNATIVES EVALUATION 1. Ash-Focused Remedial Action Alternatives Pros Cons X 1a. Landfill Cover Keeps rainwater out of landfill Ash remains in place 1b. Majority Ash Removal Remove ash Long timeframe to complete 2. Groundwater Remedial Action Alternatives Pros Cons Physical barrie
Slide 19: 1. Ash Focused Remedial Alternatives
1. ASH FOCUSED REMEDIAL ALTERNATIVES A. Landfill Cover X B. Majority Ash Removal • Engineered cover will prevent additional • Why recommended: precipitation and runoff infiltration • Removes majority of ash (Cell D to remain in place because not impacting • Shorter implementation time groundwater
Slide 20: 2. Groundwater Remedial Alternatives Considered But Not Recommended
2. GROUNDWATER REMEDIAL ALTERNATIVES X A. Slurry Wall B. Permeable CONSIDERED BUT NOT RECOMMENDED X Reactive Barrier X C. In-Situ Solidification A. Slurry Wall B. Permeable Reactive Barrier X D. MNA/Enhanced MNA • Remedy Mechanism: Solidified wall • Remedy Mechanism: Impacted E. Pump and Treat and/o
Slide 21: 2. Groundwater Remedial Alternatives Considered But Not Recommended
2. GROUNDWATER REMEDIAL ALTERNATIVES X A. Slurry Wall B. Permeable CONSIDERED BUT NOT RECOMMENDED X Reactive Barrier X C. In-Situ Solidification C. In-Situ Solidification (ISS) X D. MNA/Enhanced MNA E. Pump and Treat and/or Evaporation • Remedy Mechanism: Cement injected into ash to create solid blo
Slide 22: 2. Groundwater Remedial Alternatives Considered But Not Recommended
2. GROUNDWATER REMEDIAL ALTERNATIVES X A. Slurry Wall B. Permeable CONSIDERED BUT NOT RECOMMENDED X Reactive Barrier X C. In-Situ Solidification D1. Monitored Natural D2. Enhanced MNA X D. MNA/Enhanced MNA Attenuation (MNA) • Remedy Mechanism: Targeted E. Pump and • Remedy Mechanism: Groundwater tre
Slide 23: 2. Recommended Groundwater Remedial Alternative
2. RECOMMENDED GROUNDWATER X A. Slurry Wall B. Permeable REMEDIAL ALTERNATIVE X Reactive Barrier X C. In-Situ Solidification E. Pump and Treat and/or Evaporate X D. MNA/Enhanced MNA E. Pump and Treat and/or Evaporation • Remedy Mechanism: • Extraction wells or trench placed to strategically target c
Slide 24: Timeline
TIMELINE INVESTIGATION: 2015 2015-2017 2017 2017-2018 Establish Groundwater Background Groundwater Develop Site-Specific Detection Sampling: Monitoring Well Quality Monitoring Background Groundwater Screen for Indicator Network (8+ Sampling Events) Quality Values Constituents EVALUATION: 2018-presen
Slide 25: Former Settling and Bottom Ash Ponds
FORMER SETTLING AND BOTTOM ASH PONDS © 2023 Xcel Energy 25
Slide 26: Ponds Before and After Cleanout
PONDS BEFORE AND AFTER CLEANOUT Settling Pond Bottom Ash before closure Ponds before closure Settling Pond after 2017 closure Bottom Ash Ponds by ash removal after 2018 closure by ash removal Groundwater Standards Met in 2021 = Clean Closure Groundwater Monitoring Ongoing © 2023 Xcel Energy 26
Slide 27: Former Bottom Ash Ponds
FORMER BOTTOM ASH PONDS Remedy - Ash Removal and Groundwater Levels Trending Down • Ash Removed in 2018 = physical closure complete • Cobalt levels > GPS in 3 wells (on-site only) Groundwater levels trending down • Molybdenum levels > GPS in one well (on-site only) © 2023 Xcel Energy 27
Slide 28: Cobalt in the Environment
COBALT IN THE ENVIRONMENT • Cobalt is present naturally in the environment in rocks, soils, and minerals such as coal. • Like most substances, cobalt can be potentially harmful if very large amounts are ingested • Nearly everyone is exposed to low levels of cobalt every day through • the food we eat
Slide 29: Molybdenum in the Environment
MOLYBDENUM IN THE ENVIRONMENT • Molybdenum is present naturally in the environment in rocks, soils, and minerals such as coal. • Like most substances, cobalt can be potentially harmful if very large amounts are ingested • Nearly everyone is exposed to low levels of molybdenum every day • In the food
Slide 30: Next Steps
NEXT STEPS Federal CCR Program: • Public comment on evaluation and proposed alternative • Select Final Remedy Following Public Meeting/Comments • Already Completed Ash Removal from Impoundments • Majority of Ash will be removed from regulated landfill between 2024~2034 • Pump and Treat Groundwater t
Slide 31: Additional Questions and Discussion
ADDITIONAL QUESTIONS AND DISCUSSION © 2023 Xcel Energy