Modeling to Evaluate Contribution of Oil and Gas Emissions to Air Pollution

Figures & data

Figure 1. The CAMx modeling domain showing the outer 36-km domain covering the entire United States and the nested 12-km domain covering the western U.S. national parks, which are outlined in blue, and non-NPs Class I areas, which are in green. The extent of major U.S. oil and gas basins as of 2011 is shown in pink.

Figure 2. Modeled contribution of emissions associated with oil and gas production activity to the fourth highest daily maximum 8-hr averaged ozone concentration in ppb. National parks and Class I areas are outlined in black.

Figure 3. Modeled contribution of emissions associated with oil and gas production activity to annual average PM_2.5 concentration. National parks and Class I areas are outlined in black.

Figure 4. Modeled contribution of emissions associated with oil and gas production activity to visibility on the 20% haziest days. National parks and Class I areas are outlined in black.

Figure 5. Modeled contribution of emissions associated with oil and gas production activity to visibility on the 20% clearest days. National parks and Class I areas are outlined in black.

Figure 6. Modeled contribution of emissions associated with oil and gas production activity to total nitrogen deposition (kg N/ha/year). National parks and Class I areas are outlined in black.

Figure 7. Modeled contribution of emissions associated with oil and gas production activity to the annual maximum W126 ozone concentration (ppm-hr). National parks and Class I areas are outlined in black.

Table 1. Twenty national parks and Class I areas with the largest contribution of oil and gas emissions to the fourth highest daily maximum 8-hr ozone concentration (ppb).

NPS unit	State	Name	Base case (ppb)	No oil and gas (ppb)	Oil and gas contribution (ppb)	Percent of base case
Yes	OK	Washita Battlefield	76.3	69.3	7.0	9.2%
Yes	UT	Hovenweep	78.0	71.4	6.6	8.5%
Yes	CO	Dinosaur	73.6	67.2	6.4	8.7%
	CO	Weminuche Wilderness	81.3	74.9	6.4	7.9%
Yes	KS	Fort Larned	75.2	68.9	6.3	8.4%
	CO	Flat Tops Wilderness	72.2	66.4	5.7	8.0%
Yes	MO	Harry S. Truman	88.9	83.3	5.6	6.3%
Yes	KS	Fort Scott	78.3	72.8	5.5	7.0%
Yes	NM	Aztec Ruins	82.5	77.2	5.3	6.4%
Yes	NM	Pecos Wilderness	82.8	77.6	5.2	6.3%
Yes	CO	Colorado	73.3	68.2	5.2	7.1%
Yes	CO	Rocky Mountain	73.1	68.2	4.9	6.7%
Yes	MO	George Washington Carver	85.1	80.4	4.7	5.6%
Yes	UT	Arches	75.0	70.2	4.7	6.3%
Yes	AR	Pea Ridge	80.7	76.6	4.2	5.2%
	CO	Maroon Bells–Snowmass Wilderness	74.3	70.3	4.0	5.4%
	AR	Caney Creek Wilderness	74.7	70.8	3.9	5.2%
Yes	AR	President William Jefferson Clinton Birthplace Home	77.4	73.6	3.8	5.0%
Yes	CO	Bent’s Old Fort	74.7	70.9	3.8	5.0%
	CO	Mount Zirkel Wilderness	73.1	69.4	3.7	5.0%

Table 2. Twenty national parks and Class I areas with the largest contribution of oil and gas emissions to the W126 ozone metric (ppm-hr).

NPS unit	State	Park name	Base case W126	No oil and gas W126	Difference W126	Percent of base case
Yes	KS	Fort Larned	30.35	21.97	8.37	28%
Yes	OK	Washita Battlefield	31.86	24.03	7.82	25%
Yes	AR	President William Jefferson Clinton Birthplace Home	32.46	25.25	7.21	22%
Yes	AR	Fort Smith	35.74	28.71	7.02	20%
Yes	OK	Chickasaw	40.84	33.94	6.90	17%
Yes	KS	Tallgrass Prairie	31.62	24.84	6.78	21%
Yes	CO	Dinosaur	24.42	17.89	6.53	27%
Yes	CO	Sand Creek Massacre	29.47	23.06	6.41	22%
Yes	KS	Nicodemus	23.65	17.58	6.07	26%
Yes	TX	Lake Meredith	38.68	32.63	6.05	16%
Yes	KS	Brown v. Board of Education	36.88	30.84	6.04	16%
	CO	Flat Tops Wilderness	24.25	18.39	5.86	24%
Yes	TX	Alibates Flint Quarries	38.55	32.79	5.76	15%
Yes	AR	Buffalo	26.58	20.99	5.60	21%
	AR	Upper Buffalo Wilderness	26.58	20.99	5.60	21%
Yes	CO	Bent’s Old Fort	28.63	23.05	5.58	20%
Yes	KS	Fort Scott	31.71	26.15	5.56	18%
Yes	AR	Pea Ridge	33.52	28.19	5.33	16%
Yes	NM	Carlsbad Caverns NP	29.47	24.22	5.24	18%
	CO	Weminuche Wilderness	27.73	22.62	5.11	18%

Table 3. Twenty national parks and Class I areas with the largest contribution of oil and gas emissions to the average visibility index ranked by the impact on the 20% haziest days (dv), and the number of days the modeled oil and gas impact to visibility is greater than 0.5 dv and 1.0 dv.

NPS unit	Park name	State	Oil and gas Avg Impacts on 20% haziest days (dv)	Oil and gas average impacts on 20% clearest days (dv)	Number of days average impacts >0.5 dv	Number of days average impacts >1.0 dv
Yes	Fort Larned	KS	1.18	0.29	132	78
Yes	Lake Meredith	TX	0.91	0.55	147	65
Yes	Colorado	CO	0.88	0.31	85	24
Yes	Sand Creek Massacre	CO	0.84	0.20	105	39
Yes	Aztec Ruins	NM	0.81	0.84	323	127
Yes	Alibates Flint Quarries	TX	0.81	0.54	136	57
Yes	Homestead	NE	0.79	1.11	279	162
Yes	Tallgrass Prairie	KS	0.70	0.19	84	25
Yes	Nicodemus	KS	0.67	0.16	85	34
Yes	Washita Battlefield	OK	0.65	0.72	187	82
Yes	Dinosaur	CO	0.61	0.28	107	22
Yes	Bent’s Old Fort	CO	0.49	0.09	40	11
Yes	Fort Scott	KS	0.46	0.18	55	17
Yes	Fort Smith	AR	0.45	0.21	61	10
Yes	Fort Laramie	WY	0.43	0.09	28	1
Yes	Bighorn Canyon	MT	0.43	0.13	37	10
Yes	Scotts Bluff	NE	0.41	0.10	41	1
Yes	Brown v. Board of Education	KS	0.39	0.07	30	8
Yes	Pea Ridge	AR	0.39	0.16	50	4
Yes	Devils Tower	WY	0.39	0.07	33	2

Table 4. Twenty national parks and Class I areas with the largest contribution of oil and gas emissions to total nitrogen deposition (Ndep).

NPS unit	State	Park name	Base Ndep (kg N/ha/yr)	No oil and gas Ndep	Maximum difference	Percent of base total	Most conservative critical load value
Yes	NM	Aztec Ruins	5.79	3.88	1.91	32.9%	3
Yes	NE	Homestead	12.30	10.95	1.35	11.0%	5
Yes	OK	Washita Battlefield	5.63	4.75	0.88	15.6%	5
Yes	OK	Chickasaw	10.31	9.45	0.86	8.4%	5
Yes	AR	Fort Smith	24.22	23.36	0.86	3.5%	3
Yes	TX	Big Thicket	7.72	6.95	0.77	9.9%	3
Yes	TX	San Antonio Missions	20.31	19.58	0.74	3.6%	5
Yes	TX	Lake Meredith	7.07	6.44	0.63	8.9%	5
	AR	Caney Creek Wilderness	11.08	10.46	0.62	5.6%	3
Yes	KS	Brown v. Board of Education	15.56	14.94	0.62	4.0%	5
Yes	TX	Alibates Flint Quarries	8.14	7.53	0.61	7.4%	5
Yes	KS	Fort Larned	8.63	8.07	0.56	6.5%	5
Yes	MO	Harry S Truman	17.68	17.13	0.56	3.2%	5
Yes	AR	President William Jefferson Clinton Birthplace Home	13.88	13.35	0.53	3.8%	3
Yes	KS	Tallgrass Prairie	8.38	7.85	0.53	6.3%	5
	CO	Weminuche Wilderness	2.53	2.00	0.53	20.8%	2
Yes	CO	Dinosaur	1.92	1.41	0.51	26.4%	3
	CO	Flat Tops Wilderness	2.86	2.36	0.51	17.7%	2
Yes	AR	Buffalo	10.04	9.54	0.50	5.0%	3
	AR	Upper Buffalo Wilderness	10.04	9.54	0.50	5.0%	3

Figure 8. Colorado national parks and Class I areas showing total modeled nitrogen deposition results both with (lighter red horizontal bar) and without (darker red horizontal bar) oil and gas emissions, plus the lower range critical load values for four endpoints (vertical bars).