map of methane gas leaks in Bloomingdale -- near 1st & W St NW, 200 blk of S St NW

See the first paragraph of this Washington Post article

Dangerously high methane levels detected in D.C.

By Ted Mellnik and Gene Thorp, Published: Jan. 16, 2014

This map shows 5,800 places where a scientific survey sniffed out evidence of natural gas leaks. The scientists, who drove methane gas-detection equipment along all 1,500 miles of D.C. streets, also pinpointed a dozen manholes with enough gas to explode.

You can click on the article link and navigate around the supplied map. 

I see yellow dots near 1st and W St NW and on the 200 block of S Street NW.