A new concept for monitoring basic water pollution based on a sequential injection analysis system (SIA) provided with two simple spectrophotometric detectors is proposed. The dissolved organic carbonaceous pollution - expressed as TOC (total organic carbon), COD (chemical oxygen demand) or BOD (biological oxygen demand) - and particulate pollution (TSS, total suspended solids) can be estimated using advanced UV spectrophotometry. Moreover, the nitrogenous and phosphorous compounds are determined either directly (nitrate for example) or by addition of a simple reagent, followed by UV-visible detection. (C) 1997 Elsevier Science B.V.