DESERT HOT SPRINGS, Calif. -

"That's why we have this monitor, to find out if this plant is going to cause damage to residents of the Coachella Valley," said Bob Terry of People Over Pollution, a local environmental group.

The first readings from an air quality monitor indicate the Sentinel peaker power plant in Desert Hot Springs meets federal standards for particle pollution.
    
South Coast Air Quality Management District installed the monitor in May, after valley residents petitioned for it, worried the 800-megawatt natural gas plant would contaminate the air.
    
The monitor produces hourly readings of microscopic particles known as PM2.5.  Anything below 35 ug/m3 (micrograms per cubic meter of air) is considered an acceptable measurement.
 
Readings since May show the plant averaged less than 10 ug/m3. But on June 25, the readings spiked, at one point reaching 170 ug/m3 with no explanation.

"there were some exceedingly high readings and we're trying to determine, was that caused somewhere else or did they fire up more turbines?" Terry said.

Despite the positive data release, local environmentalists want more air quality monitors to be installed throughout the Coachella Valley.

"We can use four here in the valley, but we are demanding three," Terry said.

There's now a petition to install two additional monitors, one at the College of the Desert campus in Palm Desert, the other at the Salton Sea.

Terry says all the monitors should have been installed a year before the plant went online last year.

"So that we have a baseline to see what we already have in the air before the plant goes online. But at least we now have one."

For the complete readings, visit the SCAQMD website at http://www.aqmd.gov/