Regulators in hot water again over the Oceano Dunes

November 30, 2021


For more than a decade, San Luis Obispo County’s Air Pollution Control District has claimed that 100% of the dust particles blowing on the Nipomo Mesa are the result of off-roading at the Oceano Dunes.

It is 100% sand dune dust (mineral dust) from the Oceano Dunes, the APCD reported.

It causes cancers, and lung and kidney disease, the APCD reported.

It can be stopped by reducing vehicle use on the dunes, the APCD reported.

“The APCD has been investigating the source of the high particulate matter concentrations on the Nipomo Mesa for the past decade,” the APCD says on its website. “Several studies performed by the APCD in the Nipomo Mesa area have shown the source of the elevated particulate matter pollution to be windblown dust from the open sand areas of the Oceano Dunes State Vehicular Recreation Area.”

In response to the APCD’s claim, the state of California has spent more than $22 million to reduce dust from the Oceano Dunes, in an attempt to protect the health of people living on the mesa.

However, the prestigious Scripps Institution of Oceanography analyzed the particulate and determined only 14% of the particles blowing on the mesa consist of mineral dust. In other words, State Parks is not to blame for bad air quality on the mesa.

The study determined particulate concentrations are highest during high wind conditions, even when off-road vehicles were banned from the dunes during the pandemic. Researchers also determined the mineral dust blowing on the mesa is more likely caused by natural forces such as wind, than off-road recreation.

Scripps’ findings also call into question the validity of all data collected from the monitoring instruments used by the APCD and many other air districts nationwide.

After 10 years of warning Nipomo residents of the dangers of silica dust, in 2017 the APCD decided to run tests for silica in the air. The testing refuted the APCD’s earlier claims, concluding the dust blowing from the dunes did not contain dangerous levels of crystalline silica.

Even so, in 2018, State Parks entered into a stipulated order of abatement with the APCD. The order requires the state to reduce wind-blown dust, specifically dust particles that are 10 microns or less in diameter, on the Nipomo Mesa by 50%. Despite agreeing to the various terms in the order, State Parks still denied that off-roading causes the dust on the mesa.

After more than a decade of asserting off-road vehicles at the Oceano Dunes are responsible for 100% percent of the dust blowing on the mesa, the APCD has admitted it never analyzed the particulates for mineral dust content.

Despite Scripps’ findings and the APCD’s admissions, State Parks continues to acquiesce to APCD demands that the park reduce dust blowing on the dunes by 50%. State Parks has covered more than 200 acres of dune sand with hay, vegetation or orange plastic fencing in an effort to reduce wind-blown dust.

During the past 12 months, State Parks has spent almost $3 million attempting to comply with the APCD’s demands.

Read the Scripps’ report here.


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Up the fees for camping and offroad vehicles, use the money to pay for a beach cleaner, limit the camping spaces to reduce density, ENFORCE the rules.


It always is irritating when people invent ( make up stuff, lie ) to make their opinions appear valid . I wish the APCD and the Friends of the Dunes would just say “ we hate cars, OHVs , noisy motors and people clogging up our dunes” . Stop hiding behind false health concerns . They are wasting precious public resources .


You can thank the SLO Board of Supervisors for this issue by allowing all the golf course development on the Mesa. Now the big city Karen’s are complaining and filing law suits trying to shut down the OHV recreation because of dust. Funny, before all the millionaires moved in, the APCD didn’t care about all the low income Hispanics that lived around the junk yards.


The APCD will never stop trying to close the Dunes to vehicles no matter how much taxpayer money it costs them in lost court rulings.


Not surprising to see Progressive government officials creating a problem, and then guiding a narrative through deceitful means to reach a desired and false conclusion. They have continually lied to the county residents along with the willing state agencies involved, in their attempt for a government taking of the freedoms that many enjoyed in this designated recreation area.

So glad they are being exposed once again for their lying and deceitful actions. The APCD needs to be investigated by the BOS, and come before the public in a meeting to answer questions for the false claims that have created, which caused the taxpayer millions of dollars. Complete insanity through corruption. Maybe file charges against them whole overseen this debacle of lies.


So……., the Science isn’t settled!! Scripps has waaayyy more prestige, gravitas, and credibility than little ol’ SLOCO APCD.

Eyes Everywhere

Is there a link to the Scripps analysis?