According to Fairfax counties official demographics, Fairfax is about 60% white.
http://www.fairfaxcounty.gov/demogrph/demrpts/report/fullrpt.pdf
Where are whites concentrated? When im out and about, you don't see that many whites and even fewer white kids, unless you are at wegmans/whole foods. Visiting shopping malls you see perhaps 20% whites the rest being a mix of East and South Asians and middle eastern people with a sprinkling of latinos.
Surely Greater Falls Church/McLean can't account for 60% of the population of the county, or is the county included non-europeans as "white" in their demographics.