Although pleased with ongoing cleanup operations, water officials expressed concern this week that $1.5 million allocated by the state for removal of a toxic underground plume near potable wells in a western Ventura County community may run out before the job is completed.
Officials with the United Water Conservation District toured the pollution site in El Rio on Tuesday to observe the progress of the cleanup.
Workers are focused on removing an underground plume of MTBE, a toxic gasoline additive that leaked from an old Poole Oil Co. fuel storage tank. The plume is 1,300 feet from the district's potable well fields.
The wells provide drinking water for about 200,000 customers in Oxnard and Port Hueneme.
United officials said they are concerned with how extensive the cleanup operation is and the uncertainty over how much longer it will take to complete. The toxic plume measures about 200 feet by 125 feet.
"I feel better having seen it, but I'm still very nervous about the financing," said Sheldon Berger, vice president of the United Water Conservation District. "The $1.5 million we got from the state is almost gone."
The county's Environmental Health Division had placed the MTBE cleanup on a fast-track list and was set to begin work in September 2002. But water district officials sent a letter to state regulators in June urging quicker action.
The state then assumed control of cleanup operations and allocated $1.5 million for the job. But Santa Paula-based PW Environmental didn't begin work until October. The company says the job could take months or even years to finish.
The round-the-clock clean- up operation involves two methods of removing the toxic plume: vapor extraction and air sparging.
The first method employs a series of pipes that target the MTBE located between 30 and 50 feet underground. The pipes are attached to a vacuum that sucks the chemical out of the ground. An oven heats the chemical to 1,450 degrees, turning it into harmless vapor that is released into the air.
The second method involves inserting pipes up to 100 feet into the ground to reach contaminated nonpotable groundwater. Bubbles are blown into the water forcing the MTBE, which attaches itself to the bubbles, to the surface where it is then vacuumed up and vaporized.
PW's senior geologist Eric Kirkegaard said there are 11 air sparging wells and 12 vapor extraction wells.
"We've already seen a decline in the MTBE levels. You get a major part of it done in the first couple of months, but the whole project could take a couple of years as the levels begin to taper off," Kirkegaard said.
He said an additional 10 monitoring wells have been installed at the site to track the pattern of the plume, bringing the total to 28.
Steve Bachman, groundwater manager for United Water Conservation District, said the wells had been checked monthly through December but now are checked on a quarterly basis.
"I initially had some objections to going quarterly, but the plume doesn't appear to be moving any closer to the district wells," Bachman said. "The rains in November and December helped us tremendously.
"If it continues to be a dry winter," Bachman said, "we'll reevaluate because there is always the risk that the contamination could change course and head toward the wells."
He said he remains cautiously optimistic about completion of the cleanup operation. If the state money runs out, Bachman said the district may have to pay for the remaining cleanup operation and then try to recover the money either from the owner of the property or the state.
"Let's just say I'm keeping my fingers crossed," he said.
"We're heading in the right direction. Now we just have to worry about what happens when the money runs out."