In 1987, testing of fish samples from Wham Brake, downstream from the paper mill, indicated trace amounts of dioxin (2378 TCDD, measured in parts per trillion). In 1988, IP began a voluntary study together with other pulp & paper manufacturers, EPA, the American Paper Institute, and the National Council for Air & Stream Improvement to study the issue. They concluded that dioxin pollution resulted from using elemental chlorine (CL2) in the paper bleaching process. In 1989 the Departments of Health & Hospitals and Environmental Quality banned fishing from Wham Brake.IP decided to virtually eliminate dioxin and furan by-product formation by substituting chlorine dioxide (ClO2) for elemental chlorine in the Louisiana Mills pulp bleaching process. In phase I, the mill replaced a 10 ton/day for a 30 ton/day ClO2 generator system which included a 1200 ton chiller to cool 500 gpm of water from 95 F to 45 F. In phase II, ClO2 capacity was raised to 50 ton/day by adding a second 900 ton chiller and related equipment. By 1994 the substitution was complete.
International Paper decided to implement this new technology well ahead of proposed new EPA rules controlling dioxin emissions.
The toxicity equivalency (TEQ) of Wham Brake fish tissue dropped from an average of 28.3 ppt in 90 and 91 to 6.ppt in 96, 75% lower than the 25 ppt recommended by the FDA as an advisory level for limited consumption due to dioxin. Furthermore, chloroform air emissions dropped from 410,000 lbs in 1989 to below TRI reporting thresholds in 1995. Chlorine air emissions were virtually eliminated (39,000 lbs in 88 but only 7 lbs in 95). Dioxin is also non-detectable in the bleach process effluent.
Details of Reductions
Additional Information :
All project phases together cost about $30 million, and the fish testing program cost $250,000.