INCREASES OF LEAD AND CHROMIUM IN DRINKING-WATER FROM USING CEMENT-MORTAR-LINED PIPES - INITIAL MODELING AND ASSESSMENT

A mathematical leaching model was developed for assessing potential in creases of lead and chromium in drinking water from using cement-morta r-lined pipes. The initial wetting process, dissolution, diffusion, an d advection of metals in the lining, accumulation of metals in the sta tic pipe water, and dilution of metals by the flowing water were consi dered. Values for physical and chemical parameters in the model were o btained from literature or were estimated. Based on the modeled result s, the drinking water standards are likely to be exceeded by using cem ent with lead solubility larger than 70 ppb or chromium solubility lar ger than 540 ppb. For one cement kiln studied, it is recommended that cement kiln dust not be fully recirculated when hazardous waste fuel ( HWF) has the maximum allowable amount of lead. It is also recommended that the maximum allowable amount of chromium in HWF be lowered. (C) 1 997 Elsevier Science B.V.