Contracts OK'd for Nipomo air pollution study

Contracts for a nearly $206,000 study of air pollution on the Nipomo Mesa have been approved by the San Luis Obispo County Air Pollution Control District.

The study, which is already under way, is aimed at determining how much off-road vehicles in the Oceano Dunes State Vehicular Recreation Area are contributing to high particulate pollution on the Mesa.

Board members present at a Wednesday meeting voted 7-0 to approve a contract with the Delta Group at the University of California, Davis, to conduct specialized air monitoring and data analysis in Phase 2 of the study.

The board also ratified an already signed agreement between the district and the Center for Natural Lands Management for access to the Rancho Guadalupe Dunes Preserve and authorized the air pollution control officer to sign any other agreements needed for the study.

The only concern expressed by board members is the looming $27,000 shortfall in the study budget as the result of the California Department of Parks and Recreation pulling out of the project, said Larry Allen, air pollution control officer.

APCD board members requested the Phase 2 study after Phase 1, conducted in 2004, “was not able to conclude the SVRA played a role in the pollution,” Allen said.

Allen said the district has been working on the study since July 2007, and actual sampling began in February.

The high levels of particulate pollution that have been recorded on the Mesa for years are “a significant health hazard to residents,” he said.

“It's quite heavy. We've seen violations of every state and federal particulate standard for PM-10,” Allen said, referring to airborne particles with a mean diameter of 10 microns or less.

“We also saw violations of the PM-2.5 standards in the last study,” he added. “We need to determine what the cause is so we can work toward a solution.”

In a report to the APCD board, Allen said particulate pollution on the Mesa exceeded the state's 24-hour PM-10 standard on more than a quarter of the days the air was sampled.

Five of the six state and federal particulate health standards also were exceeded during the study period.

An analysis of that data concluded that most of the particles collected from the air were of “earth crustal elements” that originated in the Oceano Dunes upwind of the Mesa.

Allen couldn't say whether a solution might be shutting down the off-road vehicle park if it is determined to be a major source of particulate pollution.

“At this point, we're just interested in trying to find out if (the off-road park) is contributing to the pollution,” he said. “It will be up to our board and State Parks to decide what next step to take.

“We're doing our best to put together the most objective and most comprehensive study that we can.”

The study is sampling the air downwind from the off-road vehicle park and downwind from similar dune areas where off-roading is not allowed and downwind from adjacent agricultural areas.

In addition to analyzing off-road vehicle use and meteorological conditions on sampling days, the study will include soil sampling and analysis to develop a “fingerprint” for each geologic source in the area, including refinery coke piles.

Land-based and possibly aerial photography will be used to track particulate plumes.

Information on the density and use of dirt roads on the Mesa as well as rail traffic in the area, ConocoPhillips refinery operation logs, and such agricultural data as tilling and aerial spraying also will be collected and analyzed.

Allen said he expects the sampling to be completed by March 2009, after which several months will be spent analyzing the tremendous volume of data that will be collected.

He said the staff expects to deliver a report on the study to the Air Pollution Control District board by late summer or early fall 2009.

The total cost of the study is pegged at $205,874. Of that, the district expects to pay $113,100, with ConocoPhillips kicking in $28,300 and the U.S. Environmental Protection Agency contributing $25,000.

About $90,725 will represent indirect and in-kind APCD costs, such as staff installation, set-up, operation and maintenance of monitoring sites, processing of raw data, analysis of processed data and preparation of the report.

The California Department of Parks and Recreation has dropped out of the study, which means it will not provide the $51,000 it previously committed, Allen said.

“State Parks decided not to participate any further because we couldn't come to an agreement with each other on some aspects of the study design,” he said.

The available funding will leave the study budget $27,000 short. Staff hopes to make up most of that by applying for a grant from the California Coastal Conservancy.

May 16, 2008