The cause of death was established last week. Bush said water from the Geyer family's well near De Smet in eastern South Dakota contained 152 parts per million of nitrates. Levels exceeding 45 parts per million are considered dangerous for infants. Rising nitrate levels in groundwater are causing increasing concern in the Upper Midwest.
Many authorities blame the heavy nitrogen fertilization of corn.
Common Problem Bush said nitrate contamination of groundwater is a problem in much of eastern South Dakota, sometimes exceeding 1,000 parts per million. But, Bush said, the exact source of the nitrates in the Geyers' well was not known. Bush said that the well water also was contaminated by bacteria, but that if the septic tank were the primary source of the nitrates he would have expected the bacterial count to have been higher than it was. At this stage of the game anything is possible. Bush said he was aware of just one other case of blue baby syndrome in South Dakota in recent years.