(Washington Post graphic)

But the numbers could be better. The District last month joined at least 47 other jurisdictions in lodging an official challenge to its Census count. Official documents indicate that D.C. is the largest polity to do so, but there are reports today that New York has also filed a challenge.

The city successfully challenged its 2005 estimate upward by more than 31,000. City planning director Harriet Tregoning said not to expect such a big boost this time.

The issue isn’t a massive undercount, Tregoning said, “just that there’s numbers that are nonsensical.”

”There probably is an undercount, but it’s not substantial,” she added.

The city has identified 549 census blocks where counts appear to be in error. For instance, some folks are counted as living on tracts where there simply are no residences — a median on Massachusetts Avenue NW, for instance. In other cases, census data don’t match the District’s housing records.

The errors, Tregoning said, could cause more errors down the road, whether in redrawing lines for voting precincts or drafting federal grant applications.

”Accuracy is important for a lot of things,” she said.

Mayor Vincent C. Gray’s letter to the Census Bureau: