Table 1. Estimated job-years required for well plugging in different states

Number of wells	Alberta	Colorado	North Dakota	Pennsylvania	Average
10	1.0	2.2	4.3	2.1	2.4
56,000	5,543	12,277	23,908	11,481	13,302

Source: Internal communications with oil and gas regulators in Alberta, Colorado, and Pennsylvania, citing historical data. North Dakota estimate comes from recent reporting (MacPherson 2020), quoting Lynn Helms (Director of the ND Department of Mineral Resources).