Cumulative dispersion modeling of diesel engine emissions from numerous backup generators in Quincy, WA Gary Palcisko Science & Engineering Section Air Quality Program November 7, 2012 PNWIS 2012
A datacenter is a warehouse full of computer servers and related infrastructure air conditioning equipment Electrical power transformers and transmission lines Standby electrical generators
Eastern Washington is attractive to internet telecommunication companies as a site for large data centers Cheap Hydroelectricity Cold Dry Climate Relatively Inexpensive Land Existing Fiber Optic Infrastructure Temporary Sales Tax Exemption
Data center permitting in Washington Datacenter standby diesel generators emit significant amounts of diesel engine exhaust particulate (DEEP) and nitrogen dioxide (NO 2 )
Concerns in Quincy Rapid development of data center projects Uncertainty about frequency and duration of power outages Need for large amount of power Health risks from air pollutants during outages and regular testing and maintenance Vantage
Large data centers use large amounts of electricity IT equipment Cooling / Air Conditioning UPS Power Distribution Lighting and Office (minor) Note: EPA estimated that 1.5% of U.S. electricity consumption was servers and data centers U.S. EPA. (2007, August 2). Report to Congress on Server and Data Center Energy Efficiency - Public Law 109-431. http://www.energystar.gov/ia/partners/prod_development/downloads/epa_datacenter_report_congress _Final1.pdf
Backup Generators at Quincy Data Centers 180 450 160 400 140 350 120 300 100 250 80 Vantage 200 60 40 20 0 Engines Sabey Dell Intuit Yahoo! Microsoft 150 100 50 0 MW capacity 7
Quincy projects details Five projects since 2010, including the new Dell, Sabey, & Vantage data centers and Microsoft & Yahoo! expansions. Each new data center or expansion has increased cancer risk by less than 10 in one million. Ecology has no specific limit on noncancer health risks. Quincy data center permits have been appealed to the PCHB. o Concerns over cumulative health risks and adequacy of emission controls
Key Issues Data center projects trigger DEEP and often NO 2 risk assessments ocompliance with NO 2 NAAQS also an issue Before 2009, DEEP and NO 2 emissions were not assessed as toxics, and NO 2 did not have a 1-hr NAAQS. otherefore, relatively large amounts of emissions were allowable. Permits allowed each engine to operate for about 400 hours per year What are the health risks of: o long-term routine maintenance and testing of engines? oshort-term exposure to NO 2 during a power outage? Given interest in new data centers and expansion of existing ones, what are the cumulative impacts of their air emissions together?
Community-wide approach to protecting public health in Quincy Coordination between data centers for maintenance and testing of engines Reduction in allowable hours of operation for engines permitted prior to 2009 Communication between data centers and local government, schools and neighbors Cumulative cancer risk maximum of 100 in one million at any residential receptor Expanded public outreach Strategies for dealing with extended outages
Average Diesel Particulate Concentration (allowable emissions)
Maximum NO 2 Concentrations
How Often Years Could Between Levels of Concern Occur? Recurrence intervals (years) High NO2 Occurrences
Up to this point. Data centers have not needed to use backup engines for major outages olocalized upsets have occurred requiring limited use of engines None of the data centers have utilized their full allotment of allowable hours in any given year Ecology has communicated the results of these analyses to local government 14
The future Community wants to know: What will data centers do if there is an extended outage? How does this approach account for future increases in rail traffic, truck traffic? Ecology will update cumulative models if other data centers are proposed in Quincy PNWIS 2012 15
Uncertainty Emissions estimates ohow often emergency backup needed? ohow long will data centers be around? ois simultaneous outage a probable scenario? Exposure estimates odispersion modeling Toxicity oextrapolation to relatively low concentrations omany diesel PM studies based on old diesel technology 16
Ecology Air Permitting Requirements Most new sources require a permit called a Notice of Construction approval order Ecology s review of the permit application makes sure: othe correct equipment is installed Best Available Control Technology (BACT) othe project will meet the minimum air pollution control requirements of state and federal law othe project will meet air quality standards, protecting people and the environment ocomply with state requirements for toxic air pollutants
Review Procedure for Toxic Air Pollutants First-tier Review Second-tier Review Third-tier Review Screening Pollutant 1 Pollutant 2 Pollutant 3 Pollutant 4 Exceeds screening threshold Pollutant 5 Pollutant 6 Pollutant 7 Pollutant 8 Health Impact Assessment Prepared by applicant Reviewed by an Ecology review team that includes a toxicologist, an air engineer & a modeler If risks are sufficiently low, then project can be approved Risk Management Decision Ecology s Director considers: Additional ways to reduce pollution Environmental benefit of the project Public hearing
Diesel Smoke Particles Cancer Risk in Washington U. S. EPA NATA 2005 ~40% of Americans (400,000 people per million) get some type of cancer at some time in their lives 19
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Source contribution to risk (at receptor locations outside data center fence line where DPM concentrations are > 100 x ASIL) 21