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Israel is located in a semi-arid region, thus experiencing an extreme shortage of water supplies. More than 5 x 10(8) m(3) of sewage water are produced annually, about 70% of this quantity is currently reused, following treatment, for agricultural irrigation and aquifer recharge. Since (a) basically, only Secondary (but not tertiary) treatment is applied for sewage water in the country; (b) both the "hard" alkylphenol ethoxylates (APEOs) and the polycyclic aromatic hydrocarbons (PAHs) are barely affected by this treatment; and (c) about 2/3 of the nonionic surfactants used until recently in Israel, were of the 'hard' APEO type, these nonionic surfactants and/or their metabolites and, similarly, the PAHs, originated mainly, in non completed natural and anthropogenic processes reach surface water (rivers, estuaries, reservoirs, e.g., Lake Kinneret) and groundwater and persist there either as such and/or as their metabolites/degradation products.