Ana Maria Rodriguez, an organizer with Oregon Rural Action, tests water brought from taps in Boardman. (Photo by Julia Shumway/Oregon Capital Chronicle) More than a year after four Oregon agencies released a plan to reduce a decades-long nitrate problem in Eastern Oregon, a lot of work remains, according to the state’s first report on its progress. Overexposure to nitrates is especially harmful to infants, and is linked to cancers and thyroid di…