Editor's note: Watch Rob's full report on American Morning Monday at 6AM ET.

By Rob Marciano, CNN Meteorologist

It’s been three months since the Macondo well was capped, finally stopping the relentless flow of crude oil into the Gulf of Mexico. Wednesday will mark six months since the Deepwater Horizon rig exploded killing 11 men.

Countless critters in and out of the water have perished and thousands more will be affected down the road. This is easily the worst environmental disaster in American history. Millions of dollars and millions of man hours have been spent trying to clean up the incomparable mess and save the sensitive wildlife. A half year in...it's time for a checkup.

Our first stop is where more people have seen the oil up close: The beach. Northern Gulf beaches were all hit hard with crude and globs of tar. Alabama and Florida’s bright white crushed quartz beaches got it the worst and in the height of the tourist season. Most of the tar on the surface has been cleaned up, but some tar layers remain two feet below the surface, thanks to Hurricane Alex.

Oddly enough, the quickest way to naturally rid the oil is for another hurricane to roll in and scrape the tar back off the beach. Unwilling to wait for mother nature's help, man-made machines are helping dig deep. Cooler temperatures and innovation have brought out the big guns to mechanically clean the sand. But compressing the sand, disrupting a habitat, and burning lots of fuel is not the greenest way to clean an environmental disaster. So does the buried tar really need to be removed?

We took sand core samples with the University of West Florida. Preliminary results show minimal harmful compounds down to two feet. Don't eat it, or roll around in it too long and it’s no worse than changing the oil in your car. Regardless, it's not good for beach business. So cleanup crews are going after it.

Of course, the bigger issue is how the lingering hydrocarbon compounds accumulate in the Gulf's food chain and decrease fish populations. UWF is studying that too but won't have concrete answers for at least 6 months if not several years.

Watch the full story Monday on American Morning. Tuesday's report will feature the continued impact on wildlife. Wednesday we'll show you wetland areas where oil remains and what's being done about it.