Need to Reexamine Key Activity/EF Assumptions Employed in Base Year Inventory  What information is available to suggest alternate values  Does the use of those values lead a fundamental change in the source apportionment?  Need to test impact on inventory/source apportionment so (a) SIP modeling can proceed and (b) guidance can be provided to Assembly on source significance/control measure options

Space Heating – Residential  Square feet of space to be heated – no alternative to tax records  EF’s – OMNI provides alternative values to test (e.g., lower certified/uncertified wood stove values, etc.) relative to AP-42 values  Adjustment for cold vs. hot-to-hot OMNI tests  Fuel use as function of ambient temperature – home measurements versus degree day/unit efficiency  Zip code fuel split – 2008 versus 2010 survey data  Wood moisture – 2010 moisture survey versus 2011 home heating instrumentation  Vacancy rate fuel use – should decision to not use wood be reconsidered?

Space Heating – Commercial  Square feet of space to be heated – no alternative to tax records, but tax exempt structures (e.g., religious, associations, etc.) not represented  EF’s – OMNI can provide alternatives for default AP-42 values  Fuel use as a function of ambient temperature – no alternative to degree day/unit efficiency

On-Road Mobile Sources  Fairbanks testing indicates MOVES overestimates gasoline vehicle emissions under arctic conditions  No representation of block heater benefits  Slope of cold start emissions more than twice measured values  Unlike MOVES, hot start measurements showed no residual temperature influence  MOVES based estimates indicate gasoline vehicles not a significant source  Revisions to address problems need to be made outside of MOVES  How much effort is appropriate to address this issue?

Point Sources  Base year values use fuel use/emissions data supplied by each source for episode days  Three days inadvertently left out of January/February request (Feb 11 – 13)  Placeholder assumption held February 10 values constant for remaining days  Sources are being contacting for missing fuel use/emissions data  Alternate approach to limit time delay would be to construct temperature relationship similar to that use in developing PCA inventories

Aircraft  Base year values based on reported LTO’s and applicable EFs  Emissions represented as point source (similar to inventory practice employed in other communities) up to 3,000 meters (AGL)  Not a significant emissions source, alternate forms of representation not worth investigating

Rail  Base year values based on # of train operations between fixed points and average fuel use per operation  Differences between yard and line-haul operations addressed  Not a significant source of emissions, alternate forms of representation not obvious

Other Non-Road Sources  Based on NONROAD2008 model runs (with seasonal allocations) as developed under EPA/ORD inventory

Next Steps  Turn-around time for data requests is an important consideration in light of SIP schedule  Which sources/revisions should be further examined?