Nitrate is a very toxic compound that can get into the water supply from runoff from fertilizer use, leaking from septic tanks and sewage, and from erosion of natural deposits. Infants below the age of six months who ingest water containing nitrate excess of 10 mg per liter can become seriously ill and, if untreated, run the risk of death. High doses of nitrate can cause “baby-blue syndrome”, which happens to infants whose stomach acid is not as strong as an adults’. Symptoms include a bluish color of the skin, particularly around the eyes and mouth, headache, dizziness, and weakness or difficulty breathing.