The study dealt with the bottom sediments from the Narew River in the section Bondary-Tykocin 18 tributaries in the catchment of the upper Narew. Samples were collected in summer (August) and autumn (October) 2005 from the surface layer of bottom sediments in the shore zone. Determinations of organic carbon were performed on a TOC 1200 analyzer (Thermo Euroglas). The bottom sediments collected from the upper Narew contained less organic carbon, which resulted from intensive mineralization. Sediments from the small rivers were most abundant in organic carbon. These rivers are characterized by a low flow rate and, in most cases, they are overgrown by water plants. The organic carbon contents were highly varied between the sampling points. Positive linear correlation was found between combustion loss and organic carbon content.
The aim of the present study was to evaluate the spatial distribution of concentrations of some elements in shallow ground waters as well as to find the main sources of their origin. The investigations were carried out in 8 villages in Podlasie region. The water sampling sites were in the villages Sobótka, Narew, Ciełuszki, Kaniuki, Zawyki, Uhowo, Topilec, and Złotoria, all on or near the Narew River. Water samples were collected in spring, summer, and autumn of 2006. The samples underwent determinations of calcium, magnesium, sodium, potassium, zinc, and iron concentrations by means of AAS and EAS techniques after previous filtering through micro-pore filters (d=0.45 pm). None of the tested water samples met the standards for potable water specified in the Decree of the Ministry for Health of 2007 as they exceeded permissible concentrations of iron ions. Regarding potassium ions, the well waters were classified to underground waters quality class V. The waters with the highest values of the tested parameters were found in wells in Kaniuki, Złotoria and Zawyki.