A new report on La Plata County greenhouse-gas emissions pegs them about 50 percent higher than previous estimates.
The two biggest reasons for the jump were an increase in the estimate of emissions produced by natural-gas operations, including compressors and wellheads, and the naturally occurring seepage of methane from the Fruitland outcrop.
The original report produced by The Brendle Group of Fort Collins was released last year and found three-fourths of emissions in the county come from the natural-gas industry.
Industry representatives, however, disputed the findings, citing the reliance on estimates from the New Mexico portion of the San Juan Basin.
In response, the county brought together a working group that included industry representatives, environmentalists and county staff to come up with a better estimate.
The result was worse, not better, for the industry.
Based on the industry's own data, about 1.9 million short tons of carbon dioxide were emitted in the operation of equipment fueled by natural gas in 2005, the report's baseline year. The estimate in the original report was 638,000 tons. The amount of emissions from operations using electricity was unchanged, 555,500 short tons.
The original report did not include an estimate of emissions from the outcrop, which is where the northern edge of the bowl-shaped Fruitland coal formation of the San Juan Basin reaches the surface. The estimate in the new report is 1.2 million short tons.
Studies are being conducted to determine if drilling can help diminish or capture some of the seepage.
Emissions from all other sources, including transportation, commercial and residential, were estimated at 1.3 million short tons.
Pat Cummins, air quality program director for the Western Governors' Association, told La Plata County commissioners during a presentation of the report on Tuesday that the Brendle report's forecast of emissions into the next decade, assuming no major changes, underestimated the future contribution from the gas industry and over estimated the contributed from population growth, which has tempered as a result of the economic slowdown.
Commissioner Kellie Hotter praised the group of sometimes adversaries for collaborating.
"I have had nothing but rave reviews for the cooperation that went into this," she said.
Christi Zeller, executive director of the La Plata County Energy Council, said significant uncertainty remains in the findings. Data have not been collected on the amount of meth-ane that escapes during production, so the estimate of 1 million tons contained in the report is little more than a guess, she said.
But, in the interest of collaboration, the industry accepts the estimate and wants to move forward with improving future estimates, she said.
Proposed rules from the U.S. Environmental Protection Ag-ency would set new requirement for reporting emissions by industry. This could include methods for quantifying the so-called fugitive emissions.
The original emissions inventory was commissioned by the county to provide baseline data for development of a climate action plan.
