Drainage and noise

Drainage water is cleaned using septic tanks and oil traps before being released into the sea. Recognized monitoring agencies monitor the septic tanks and oil traps and empty them at regular intervals. The limit of oil in drainage water is 15 mg/l. All outlets are monitored and sampled yearly. The oil concentration during the year 2000 was always below these levels, ranging from 3 to 9 ppm.

Noise levels are measured at 14 locations within the ISAL premises so they can be kept within acceptable limits. The largest sources of noise are the unloading equipment and dry adsorption plants, where noise levels are measured during the unloading process. Maximum acceptable noise levels within the ISAL premises are set at 70 dB, and in the year 2000 all measurements showed noise levels between 52 and 66dB - well below that level.

Rio Tinto Iceland Ltd. Straumsvik - P.O. BOX 244 - 222 Hafnarfjordur - T: +354 560 7000 - F: +354 560 7070 - isal@riotinto.com