Its that time of the decade again. 

Chances are youve seen one of the commercials on TV perhaps during the Super Bowl. Or maybe youve already gotten a letter in the mail. Or noticed an ad while using public transportation.

With National Census Day looming on April 1, the months of work leading up to this years count culminate in a final full-court press of information prior to the deadline.

However, getting the count right is by no means administrative busywork.

The population data collected determines, among other things, how more than $400 billion in federal funding is allocated to states, counties and cities each year. According to the U.S. Census website, that amount exceeds the yearly economic output of Switzerland.

With so much on the line, an undercount could curb crucial funding of public service projects for the next decade, according to Ralph Rosenbaum of the citys Department of Planning and Zoning.

The undercount may not seem big the last time we had a figure was 1990 and that was about 3,300 people but when you consider theres $400 billion out there in state and federal money thats distributed on a per-capita basis. That can add up to real money, Rosenbaum said.

In 1990, the undercount represented nearly 3 percent of the citys population, according to city statistics.

Alexandrias last official count in 2000 identified about 128,000 people living in the city, according to the U.S. Census Bureau. Estimates done two years ago approximated the citys population at about 144,000.

You think about it, a 3,000 person undercount in a city like Alexandria thats huge dollars over a decade, said Justin Wilson, a former City Council member and head of Alexandrias Complete Count Committee.

Spread over 10 years, the discrepancy created by an undercount could equal the construction cost for two elementary schools, Rosenbaum said.

That fact was not lost on city leaders in need of at least two elementary schools in the years to come. Recognizing the imperative of avoiding an undercount, the City Council set aside $30,000 in this years budget for census outreach efforts.

To get the word out, census committee members have met with neighborhood stakeholders, mailed some 28,000 letters to households in English, Spanish, Arabic and Amharic in areas where there could be an undercount, worked with schools and produced posters for DASH buses and storefronts, Rosenbaum said.

Enlisting the help of Alexandria students to get the word to their parents could also get the students an iTunes gift card or an iPod shuffle, Rosenbaum said. The giveaway, part of $30,000 worth of incentives approved by the Council last year, was met with questions from some officials and residents but passed as an investment in future funding.

In Alexandria, the groups that contribute most to the undercounted population are fittingly diverse. 

Very wealthy people, minorities and immigrants are among the groups most reticent to participate, Rosenbaum said.

We spend a lot of time dealing with rumor control, Wilson said. Theres always a concern in the undocumented immigrant community regarding participating and we have to deal with those issues and try and get the truth out.

Contrary to information that may be circling in some neighborhoods, the decennial survey has no interest in citizenship and is wholly separate from immigration authorities, census officials said.

The census just cares if youre here, Rosenbaum said. Theres no question about citizenship on the census theres nothing about that at all.

Its safe, its confidential.

In Arlandria, an area with a large immigrant population, Tenants and Workers United is launching their own outreach and canvassing program to clear up misconceptions about the census.

Traditionally, low-income communities, communities of color and immigrant communities are undercounted and there are a variety of reasons for that, said Lucero Beebe-Giudice of TWU.

They tend to be a little more transient and the immigrant community is a little weary of the federal government and disclosing information to them, she said. There are a lot of myths that need to be busted.

The official census count also determines representation in Congress and the states legislative bodies and, Wilson said, plays an integral role in future economic development.

Companies rely on good data about their customer base to go out and sell, Wilson said. If they dont know the nature of a community, how can they sell to it?

Despite being ten years in the making, time is still the biggest challenge, Rosenbaum said. Beyond getting out information ahead of time far cheaper than the $20 an hour federal census workers receive to go door to door after April 1 to retrieve missing info the second crunch is getting all the information possible by years end.

It comes up much faster than you ever think it will, Rosenbaum said.

At press time, a countdown clock on the citys website reminds visitors that the official start of the U.S. Census is 21 days away.