Sulfur plays an important role in the biogeochemical cycle of trace elements and in the diagenetic reactions in sediments/soils. Due to very low solubility of sulfide compounds, metal sulfides are a big concern in the coastal and marine environment. In this study, we investigated sulfur compounds and speciation in contaminated sediments from the waterways of New York and New Jersey in the region of New York City, USA. Measurements were made on particles from the National Institute of Standards and Technology Standard Reference Material (SRM) 1944 (a composite from 6 locations) and from a mud flat on the Passaic River in New Jersey, USA. The experimental measurements were made at the ID21 X-ray Microscopy beamline at the European Synchrotron Radiation Facility (ESRF), France. Maps of the Si, P, and S distributions were made with a sub-μm beam on individual sediment particles. In order to chemically specify sulfur, X-ray absorption near-edge spectroscopy (XANES) measurements were taken from selected areas (regions-of-interest) within these maps.