1. Colorado Regional Haze SIP Reasonable Progress Analysis Rocky Mountain National Park Longs Peak – 14,259’ Colorado’s 15 th Tallest Curt Taipale Colorado DPHE - APCD

2. Topics Analysis Context UP vs RP –What is reasonable? Preliminary 2018 Modeling Results for Colorado RP Analysis for Rocky Mountain NP –Sulfate & Nitrate PSAT –Boundary Conditions & International impacts –Organic Carbon –Elemental Carbon –Fine Soil –Coarse Mass Final Thoughts Page 2

3. Analysis Context Time is short – SIPs are due in December –Ideally, today’s Reasonable Progress analysis should be based on final BART modeling for the whole WRAP region –Realistically, it’s too late to implement additional controls beyond BART In lieu of these limitations, Colorado plans “State Share” analysis for determining RP on the dominant man-caused species of visibility impairing pollutants – sulfate & nitrate –Assumes that each state is working on emission reduction strategies that benefit all impacted Class I Areas –Some CIAs w/high out-of-state impacts may not benefit from this approach Can be addressed through interstate collaboration OC addressed with limited PSAT; EC, CM & fine soil can be addressed through a more basic analysis using weighted emission potential (WEP), emission inventory (EI), positive matrix factorization (PMF) and Emissions Trace (ET) Analysis focused on Worst Days –Assume 2018 model projections are adequate for estimating maintenance of Best Days –Future IMPROVE monitoring will validate this assumption Page 3

4. Uniform Progress vs Reasonable Progress For Colorado, we will assume the overall 2018 UP goal in Haze Index metric (deciviews) is 14/60 ths or about 23% –UP is a goal that is defined by the 60-year glide slope UP not necessarily equal to Reasonable Progress RP is unique to each CIA (or IMPROVE monitor), and/or component of visibility extinction. Page 4

5. Species-Specific Approach to RP Page 5

6. URP depends on metric In the Haze Index (deciview) metric, the URP goal is 23.3%, but in the Extinction (1/Mm) metric, the species-specific URP goal is different for each component of extinction due to the non-linear relationship & site- specific Rayleigh HI = 10ln(bext/10) Page 6

7. Measure Progress from Glide Slope In the extinction metric, 23% is not the goal for each species, 2018 modeling progress is measured against the URP point on glide slope. Non-linearity between extinction and HI is addressed by the curve of the extinction glide slope. For ROMO, the corresponding 2018 extinction reduction is about 28% Page 7

8. Preliminary 2018 Modeling Results (three RRFs methods averaged) Page 8

9. Rocky Mountain National Park 265,000 acres on the Continental Divide 2.5 million visitors/year 1 st area in US with critical load – 1.5 kg N/ha/yr (wet nitrogen deposition) Page 9

10. Rocky Mountain National Park – BD/WD Composition Page 10 Highest Sulfate & Nitrate in Colorado

11. ROMO – Best Days 64 FR 35766 requires the RP goal for each CIA: “.. ensure no degradation in visibility for the least impaired days..” Is a glide slope analysis necessary? –Rule requires maintenance not improvement of best days 2018 modeling below 2000-2004 best days baseline of 2.29 dv Thus - maintenance of best days is forecast for 2018 Page 11

12. Preliminary 2018 Modeling – Species-Specific for Worst Days Page 12

13. Preliminary 2018 Modeling – Haze Index for Worst Days Page 13

14. Rocky Mountain NP – Uniform Progress Analysis In HI, the modeled reduction is around 13%, so we’d like an additional 10% reduction to make the 23% UP goal. More sulfate & nitrate reductions expected in next model run –Not all Colorado BART is included Additional reductions in SO 2 and NO x will be in place by 2018 Biggest: Pawnee (505 MW)  13,500 tpy SO 2 –Do we need additional emission reductions beyond BART? Won’t know for sure until all CO BART controls are modeled PSAT provides some clues on progress towards Colorado share Page 14

15. PSAT for Sulfate and Nitrate For sulfate & nitrate in 2018, the overall reductions  50% –Colorado will rely on other contributing states to do their part –Need another  20%-33% to just meet the UP goal Colorado Share:  80% SO4 and  67% NO3 –Does Colorado need to do more? –CO BART modeling will provide more reductions in SO4 & NO3 –Will they be enough? Let’s look at other contributors. Page 15

16. 4-Highest Sulfate & Nitrate Contributors at ROMO We see that Boundary Conditions are the highest contributor for SO 4 and 2 nd for NO 3 at Rocky in 2018. Across Colorado, BCs are the highest sulfate contributor for all our CIAs and in the top 3 for nitrate. Page 16

17. Technique to address BCs Colorado may be unique, high BC impacts at our CIAs may be due to Colorado’s close proximity to the center of the model domain and our relatively clean air compared to the rest of the world. We can’t control the BC emissions entering from the edge of the modeling domain. BC Options –Control them – Can’t –Ignore them – Not, they are too big! –Remove them from the analysis – Yes! How do we do that? Page 17

18. Boundary Conditions/International (BCI) Visibility Impacts The PSAT BC visibility impacts are estimated by looking at the extinction difference (or delta) between 2018 CMAQ modeling and 2018 uniform rate of progress. We see that BCs represent 0.35 [1/Mm] of sulfate & nitrate extinction on the worst days at Rocky Mountain If we add in the international impacts of Canada, Mexico and Pacific Ocean the resultant extinction is 0.49 [1/Mm] This Boundary Condition/International (BCI) extinction is beyond the control of Colorado or any other State. Thus, Colorado will be removing BCI extinction estimates for SO4 & NO3 from the 2018 PSAT modeling. Page 18

19. Sulfate BCI delta extinction Page 19

20. Sulfate BCI extinction held to URP Page 20

21. Nitrate BCI delta extinction Page 21

22. Nitrate BCI extinction held to URP Page 22

23. Removing BCI from the 2018 Modeling Sulfate BCI deduction (0.364 1/Mm) from CMAQ 2018 modeling –Overall progress towards 2018 goal improves from 54% to 72% (+18%) Nitrate BCI deduction (0.123 1/Mm) from CMAQ 2018 modeling –Overall progress towards 2018 goal improves from 49% to 60% (+11%) Is it fair to remove the BCI impacts from the 2018 modeling? –In the context of truly improving visibility at a CIA –probably not. –For CIAs close to UP and on the cusp of triggering additional State controls, this analysis properly accounts for impacts beyond the control of a state. –Further, “Is it fair to require more reductions from other sources to compensate for BCI impacts?” – maybe not in the 1 st planning period Page 23

24. ROMO Sulfate RP Overall, SO 4 is 28% short of 2018 URP –Colorado anticipates that SO2 emission reductions from WY (7.7% Impact) and CEN (7.2% Impact) will provide improved progress in 2018. –It is unreasonable for Colorado to provide additional SO2 reductions beyond CO share. Colorado share of SO 4 reductions fall short of CO UP goal by 20%, thus additional sulfate controls may be warranted. –New 2018 CMAQ modeling (done in May 07?) of CO BART will likely provide additional reductions (moderate) in sulfate impacts at the Park –Existing modeling analysis shows some CO BART SO 2 reductions that occurred early under the Metro VERA, and consent decrees on Craig & Hayden –Until CO BART is modeled, Division staff is hesitant to suggest additional sulfate controls. Will CO BART SO 2 reductions yield a ROMO SO4  >20% ? - maybe –If CO BART modeling falls short, the timing of quantifying the benefits of additional SO 2 controls, would likely occur after the RH SIP submittal date. Intuitively, we suspect coal-fired boilers and IC engines are the major source of most of the SO 2 at ROMO but are there other uncontrolled or under-controlled source categories? –lets looks at the Sulfate ET - Whats that? Page 24

25. ROMO 2018 Sulfate Emissions Trace Page 25

26. ROMO Nitrate RP Overall, NO 3 is 40% short of 2018 URP –Colorado anticipates that NOx emission reductions from WY (11.0%) and UT (5.9%) will provide improved progress in 2018. –It is unreasonable for Colorado to provide additional NOx reductions beyond CO share. Colorado share of NO 3 reductions fall short of CO UP goal by 33%, thus additional nitrate controls are likely warranted –New 2018 CMAQ modeling of CO BART will provide some minor reductions in nitrate impacts at the Park but probably not near enough to make CO NO3 UP –Top 100 under controlled or uncontrolled point sources (largest contributor) nearby the Park will be evaluated for controls –Timing of quantifying the benefits of additional NO x controls, would likely occur after the RH SIP submittal date. Through stakeholder process, Division will develop RH-RP regulation that will establish process for deciding controls/sources Intuitively, we suspect coal-fired boilers, IC engines and mobile sources are the major sources of most of the NOx at ROMO but are there other uncontrolled or under controlled source categories? –lets looks at the Nitrate ET Page 26

27. ROMO 2018 Nitrate Emissions Trace Page 27

28. Top Colorado NOx Point Sources BART controlled sources highlighted in green Closest big non-BART NOx source –Rawhide (285 MW) has LNB w/OFA Page 28

29. ROMO Organic Carbon Wild Basin Area of Rocky Mountain National Park, Thunder Lake (Photo courtesy of NPS) Page 29

30. Organic Carbon RP Analysis PSAT modeling allows for some limited analysis of OC under organic aerosol tracer for three species –AORGA: Secondary Organic Aerosol (SOA) Biogenic –AORGB: SOA Anthropogenic –AORGPA: Primary Organic Aerosol (POA) Anthro & Biogenic –Limitations: Source regions unknown – can’t use “State Share” analysis tool Analysis Approach –Use PSAT to identify amount of extinction attributed to biogenic –Use Positive Matrix Factorization (PMF) to further confirm portion attributable to smoke –Use Weighted Emissions Potential (WEP) tools to identify source regions & type emissions contributing to POA & VOC (forms SOA) –Use POA & VOC emission inventories (plan 02 & base 18) to determine contributing sources & changes in anthropogenic portion –Use OC ET to confirm sources Page 30

31. OC PSAT for Worst Days in 02b, 02c & 18b Modeled 2018 OC shows  27% (we need 100%), far short of OC UP goal (see slide 15) Based on OC PSAT for worst days, OC occurs over three seasons Not much seasonal variation Page 31

32. OC PSAT for 2018 Worst Days How much OC is controllable? Since there isn’t much seasonal variation in worst days, all seasons averaged –71% AORGB (SOA Biogenic – in green) Likely VOCs from vegetation & wildfire smoke –Check PMF to see how much is smoke Wildfire is a necessary part of forest ecology Thus, AORGB is not controllable –5% AORGA (SOA Anthropogenic – in red) Mostly point, area, mobile –Check VOC Emission Inventory for 02c & 18b –AORGA contribution to OC is very small –24% AORGPA (POA Biogenic/Anthro – in blue) Mostly area & mobile, some biogenic –Check POA Emission Inventory for 02c & 18b –Look at OC Emissions Trace Page 32

33. Positive Matrix Factorization (PMF) PMF indicates that smoke is a significant contributor (44%) to OC impairment on the worst days at ROMO during the baseline period Page 33 Smoke Profile

34. Statewide & FR VOC Emission Changes Bar chart indicates sharp contrast between statewide & FR biogenic VOC In Front Range, area, point & mobile sources contribute 53% of the VOC emissions that could form SOA anthropogenic (5% of total OC) By 2018, FR area sources  by 40% but mobile  significantly Lets look at the OC WEP to see the source regions impacting ROMO Page 34

35. OC Weighted Emissions Potential (WEP) Map Realize the WEP tool doesn’t consider complex chemistry or deposition OC WEP map indicates that the Front Range is the dominant source of anthro OC VOC WEP Bar Chart indicates that Colorado biogenics are the biggest source of VOC (source of OC SOA), with anthropogenic sources (point, area & mobile) contributing a very little to OC SOA –Thus, even huge reductions in anthro VOC emissions would have little effect on  OC SOA Page 35

36. POA Weighted Emissions Potential (WEP) Remaining OC contributor is AORGPA- Primary Biogenic & Anthro –Primary Organic Aerosol (POA) emissions are the source of AORGPA We see that Colorado area sources & anthro fire are the largest contributors to POA Page 36

37. Statewide & FR POA Emission Changes 2018 POA emissions from natural/biogenic sources are insignificant <3% 2018 POA emissions from anthro sources (area, mobile & Rx fire) about 96% –We see FR area sources  4% by 2018, but mobile  >26% Let’s look at the OC ET to put all this in perspective Page 37

38. ROMO 2018 OC Emissions Trace POA is not inventoried in Colorado, thus area source POA is likely modeled –How do we evaluate potential emission controls on such a category? Can’t Additional VOC controls on point & area sources would yield little  OC SOA Division recommends that additional VOC or POA emission controls are not reasonable, thus OC RP is satisfied Page 38

39. ROMO Elemental Carbon Page 39

40. ROMO 2018 EC for Worst Days Modeled 2018 EC shows  127% which exceeds UP goal (see slide 15) Is this reduction reasonable progress? –What are the sources of EC? –Lets look to see if much more can be done? We see that 2018 EC (in black) appears to higher during the summer Page 40

41. ROMO PMF for EC PMF indicates all categories (except dust) contribute to EC Page 41 Nitrate Rich-Secondary Profile Mobile Profile Smoke Profile Sulfate Rich-Secondary/Coal Combustion Profile

42. ROMO EC WEP for 2018 Worst Days Remember the WEP analysis doesn’t consider complex chemistry or deposition EC WEP indicates that Area, On & Off-Road Mobile sources are the largest contributors –Highest EC concentrations are from Denver metro area Page 42

43. FR & Statewide PEC Emission Changes Colorado area & mobile sources comprise over 97% of FR PEC emissions WRAP Area source pivot table doesn’t track EC emissions Page 43 Area Source Pivot

44. ROMO 2018 EC Emissions Trace Overall PEC emissions  51% from Plan02c to Base18b On & Off-road mobile sources  75% &  55% respectively and are largely regulated under the federal rules –Other than VMT reductions, State would need to request EPA approval for CA fuel & emission standards for on/off-road mobile sources –a lengthy & costly process Area sources  5%, Colorado doesn’t inventory EC emissions, thus area source EC is likely modeled –Not sure a 4-factor RP analysis can be done on modeled number Based on the analysis, the Division recommends that additional controls for EC are not reasonable, thus EC RP is satisfied Page 44

45. ROMO Soil (PM Fine) Page 45

46. ROMO 2018 Modeled Soil Projections Modeled 2018 Soil  344% (slide 15) –Soil glide slope is pretty flat, thus any small change is exaggerated –Let’s look at the change in PM Fine emissions from plan02c to plan18b Page 46

47. FR & Statewide Soil (PM Fine) Emissions For 2018, statewide soil emissions  9% but FR  32% Based on relative contribution, we see fugitives change the most Let’s look at Fine PM WEP Page 47

48. ROMO 2018 Soil WEP for Worst Days WEP shows soil sources are widely scattered statewide with the highest concentrations in FR corridor Windblown & fugitive dust comprise about 51% of Colorado impact Colorado area & on-road mobile sources about 47% Page 48

49. ROMO 2018 PM Fine Emissions Trace What makes up on-road, area, fugitive and windblown dust? –Windblown –On-road Mobile –Ag tilling –Residential wood burning –Road construction –Industrial/Commercial Construction Page 49

50. ROMO 2018 PM Fine Emission Sources Windblown 0% change – modeled from land use & soil texture –Windblown is largely uncontrollable, thus no controls are considered reasonable On-road Mobile  54% - PM Fine is from vehicle exhaust and re-entrained dust which is a function of silt loading, vehicle speed & VMT –Metro area has a diesel vehicle inspection program for particulates –Metro area encourages vehicle trip reductions through mass transit and silt loading is addressed by municipal street sweeping programs, use of liquid deicers or coarse anti-skid materials and permit controls on construction track-out –Portion attributed to unpaved roads is not known –Additional controls could include expanding the diesel vehicle program area, expanding the use of street sweeping & use of liquid deicers, and paving busy unpaved roads in close proximity to ROMO Ag Tilling - for most agricultural crops, tilling is a necessity and largely uncontrollable –NRCS soil management plans address susceptible soils –State Ag Dept. encourages ag best management practices (no till, soil conservation etc.), –Additional controls not considered reasonable Page 50

51. ROMO 2018 PM Fine Emission Sources -Continued Residential Wood Burning –Wood-fired stoves must meet EPA certifications statewide, woodburning is limited during winter in Denver metro area and since 1990’s, new homes must have NG fueled fireplaces throughout metro area –Additional controls could include expanding the new home woodburning exclusion area Road construction and Industrial/Commercial Construction –Division issues dust mitigation permits on all construction activities disturbing more than 25 acres. –Additional controls could include tightening dust permit control requirements or  permit threshold Page 51

52. ROMO 2018 Soil Reasonable Progress Summary Did we make reasonable Soil progress at ROMO? No, 2018 PM Fine emissions statewide  2,977 tpy (  9%) and in Front Range  2,585 tpy (  32%) –2018 Point, Area, On-Road Mobile & Fugitives all increased –2018 Off-Road Mobile, Anthro Fire & Road Dust all decreased Can we do more? –Division will evaluate additional controls such as: Expanding the Diesel Vehicle Inspection Control Area Expanding the use of liquid MgCl deicers & street sweeping Paving busy unpaved roads in close proximity to ROMO Tightening land development permit control requirements Reducing acreage threshold on land development permits statewide Expanding the new home woodburning exclusion area to northern Colorado Page 52

53. The Wall- ROMO Coarse Mass Page 53

54. Coarse Mass CMAQ modeling For all IMPROVE sites, CMAQ v4.5 under-predicts for all months by 20-150% For ROMO baseline worst days, CM seems highest during spring/summer/fall (Apr- For Oct) which corresponds to a CMAQ monthly error bias > -90%. Even a modeler would say this is not good –We need to use another analysis technique Page 54

55. ROMO 2018 Coarse Mass Projections CMAQ model holds 2018 CM modeling projections at baseline value CM needs about 0.9 [1/Mm] of visibility improvement needed by 2064 –Without CMAQ modeling, we must use emission inventories and WEP tools to see were we are going Page 55

56. FR & Statewide Coarse Mass (CM) Emissions For 2018, statewide fugitive dust emissions  63% but FR  210% –FR fugitives comprise 49% of dust emissions, windblown is 20% Page 56

57. ROMO 2018 CM WEP 2018 CM WEP map shows that in addition to the FR, CM sources on the west slope & eastern plains contribute significantly to ROMO WEP indicates that CO point, fugitives, windblown & road dust are the major contributors to CM with some WB impacts from CENRAP Let’s look at the CM ET Page 57

58. ROMO 2018 CM Emissions Trace What makes up point, fugitives, windblown and road dust? –Point: Mineral Products, Electric Generation, Site Remediation, Primary Metal Production, Solid Waste Disposal, Food & Agriculture –Others: Ag Tilling, Road Construction, Industrial Construction, Residential Wood Burning & Residential Construction Page 58 2018 PM 10 from Area Source Pivot Table doesn’t match up w/Emission Inventory

59. ROMO 2018 CM Emission Sources Point Sources  34% Division issues NSR/PSD permits on all PM10 sources > 2 tpy Major PM10 (>100 tpy) sources subject to BACT controls Minor PM10 (<100 tpy) sources subject to RACT controls –Mineral Products (60%) 47% Sand & Gravel 26% Coal Mining & Handling 7% Stone Quarrying –Electric Generation (11%) - mostly coal-fired boilers Major PM10 sources have baghouse controls –Site Remediation (6%) one source - Rocky Mountain Arsenal –Primary Metal Production (4%) –Solid Waste Disposal (4%) mostly municipal landfills Controlled to BACT/BACM levels ? –Food & Agriculture Production (4%) –Miscellaneous Manufacturing (4%) Appears point sources >2 tpy are reasonably controlled to BACT/RACT levels Page 59

60. ROMO 2018 CM Emission Sources - Continued Windblown 0% change – modeled from land use & soil texture –Windblown is largely uncontrollable, thus no controls are considered reasonable Fugitive Dust  63% & Road Dust  44% –Ag Tilling (?%)- for most crops, tilling is a necessity & largely uncontrollable NRCS soil management plans address susceptible soils State Ag Dept. encourages ag best management practices (no till, soil conservation etc.), Additional controls not considered reasonable –Road Construction (46%)/ Industrial & Commercial Construction (30%) and Residential Construction (6%) Division issues dust mitigation permits on all construction activities disturbing more than 25 acres. Additional controls could include tightening dust permit control requirements or  permit threshold –Residential wood burning (6%) Wood-fired stoves must meet EPA certifications statewide, woodburning is limited during winter in Denver metro area and since 1990’s, new homes must have NG fueled fireplaces throughout Denver metro area Additional controls could include expanding the new home woodburning exclusion area Page 60

61. ROMO 2018 CM Reasonable Progress Summary Did we make reasonable CM progress at ROMO? No, 2018 PM10 emissions statewide  41,125 tpy (  18%) and in Front Range  31,305 tpy (  70%) –2018 Point, On-Road Mobile, Road Dust & Fugitives all increased –2018 Area, Off-Road Mobile and Anthro Fire all decreased Can we do more? –Division will evaluate additional controls such as: Tightening land development permit control requirements Reducing acreage threshold on land development permits statewide Expanding the new home woodburning exclusion area to northern Colorado Page 61

62. Final Thoughts Pivot tables can be tricky –Different SCC levels can tell you different things Page 62

63. A view from space Page 63 Longs Peak Estes Park Allenspark Rocky Mountain National Park NORTH

64. Extra Slides

65. Page 65

66. Sulfate CMAQ modeling CMAQ v4.5 does pretty well in predicting wintertime SO4 but under- predicts in the summer months when concentrations are higher. For ROMO baseline worst days, sulfate seems highest during spring/summer (Apr-Aug) but winter/fall seasons periodically appear as significant contributors ROMO 2018b sulfate RRF is 0.82 Page 66

67. Nitrate CMAQ modeling CMAQ v4.5 tends to over-predict nitrate in the winter months and under-predict in the summer months when concentrations are lower. For ROMO baseline worst days, nitrate seems highest during winter (Nov-Mar) but spring & summer seasons periodically appear as contributors ROMO 2018b nitrate RRF is 0.87 Page 67

68. Organic Carbon CMAQ modeling CMAQ v4.5 does a really good job in predicting summertime OC but spring & fall OC is over-predicted by 10-20% For ROMO baseline worst days, OC seems highest during summer (Jun-Aug) but spring & fall seasons also appear as significant contributors ROMO 2018b OC RRF is 0.95 Page 68

69. Elemental Carbon CMAQ modeling CMAQ v4.5 does a pretty good job in predicting summertime EC but spring & fall EC is under-predicted by 10-20% For ROMO baseline worst days, EC seems highest during summer (Jun-Aug) but spring & fall seasons also appear as significant contributors ROMO 2018b EC RRF is 0.74 Page 69

70. Fine Soil CMAQ modeling CMAQ v4.5 under-predicts during the spring/summer/fall months by 10-80% and over predicts in the winter by 10-40% For ROMO baseline worst days, soil seems highest during spring/summer/fall (Apr-Oct) ROMO 2018b soil RRF is 1.15 Page 70