The report states the environmental documents estimate one of the plants will emit 189 tons of nitrogen oxides, or NOx, per year, and the other 2,380 tons. The report also states that under Mexican regulations there are no limits on the amount of NOx that may be released.
Birdsall said NOx is an ozone precursor contributing to ozone pollution.
"Especially vulnerable to ozone pollution are young children, senior citizens and people with existing respiratory and cardiac ailments," the report states. "Since 1983, childhood asthma rates in Imperial County have been two to three times the state average."
Michael Clark, spokesman for Sempra Energy International — which is building the $350 million, 600-Mw, 230-kilovolt plant, said the plant will be built to meet California's emission standards and will use recycled water.
"We are definitely building this to protect California air emission standards," he said Wednesday.
Clark was asked why Sempra would take natural gas into Mexico, use it to generate electricity and then ship the electricity back to this country instead of doing it all here.
He said the permitting process is much shorter in Mexico, that the plant will be close to the needed source of fuel and close to the high-voltage transmission lines with which it will join.
Clark said in Mexico the permitting process is about six months while in California it takes 12 to 24 months.
Clark said the reduced time to permit the plant does not mean the requirements are less stringent, rather, that in Mexico there are less delays allowed for those who would intervene in the project. He said the environmental process is the same.
Nevertheless, Birdsall has urged the county to make its concerns known at the state and federal level to preclude potential damage to public health and the economy; public health due to NOx, the economy because if the county is determined to be a serious nonattainment area for ozone permissible levels of emissions could restrict local growth. The county is considered in moderate nonattainment.
Birdsall said the county's concerns have been made known to the California Environmental Protection Agency, whose director, along with Gov. Gray Davis, met with Mexican President Vicente Fox on Wednesday. Birdsall said the concerns will be discussed.
Birdsall said the county should seek mitigation of the emissions as part of President Bush's approval of the international projects — that is, the movement of natural gas to Mexico and the movement of electricity to this country, or before allowing any connection to the power grid that supplies Western states.
The $230 million, 215-mile, 36-inch natural gas pipeline is owned by PG&E Corp., Sempra Energy International and Próxima Gas S.A. de C.V.
Meanwhile, several county supervisors expressed concern about the two power plants.
"I'm all for economic development, but the emissions which these plants will produce will have a detrimental effect on this county," said Supervisor Wally Leimgruber. "I have been in contact with Sempra Energy and expressed our concerns on how it will affect our air quality."
Supervisor Gary Wyatt said he is concerned with the potential detrimental effects on local air quality from the new power plants.
He said a political border does not stop air pollution from moving at will and the county already has air-quality problems it must address.
"This is just going to exacerbate the problem," he said. "It is something we need to have a dialogue about with our counterparts in Mexico in order to solve the problem before it becomes a problem."
Wyatt would not speculate on why American companies would build the power plants in Mexico only to send the electricity back this way.
Supervisor Hank Kuiper said the county already has problems complying with air-quality standards.
"Those two plants are going to create problems for our air quality and we're the ones who get the blame generally," he said. "I'm not sure what we can do but there's no doubt we need to challenge the presumption that we are the problem. We have to make the regulating authorities realize it's an international problem."
Representatives of the second power plant, Boston-based InterGen Aztec Energy, could not be reached for comment.
Staff Writer Rudy Yniguez can be reached at 337-3440.