Historically, the bleaching process used chemicals such as elemental chlorine and sodium hypochlorite to achieve the softness and brightness associated with quality paper products. As environmental issues become a higher priority, the search for environmentally benign, yet effective, chemical replacements become more important. The Texarkana mill has taken drastic action in the last five years to ensure that the bleaching process is the most environmentally friendly in Texas. Our actions have been drastic in that they have been taken at great expense, yet many were not in response to regulatory requirements.
In 1989, the Texarkana mill proposed a 5-year bleaching improvement program that would lead to our mill becoming the first in Texas to have an elemental chlorine free (ECF) bleaching process by the end of 1994. Projects towards this end included the first oxygen delignification system in Texas in our pine bleach plant; substitution of oxygen and hydrogen peroxide for sodium hypochlorite in the extraction stage of the bleaching process; and modified chlorine dioxide generator to eliminate generation of chlorine gas.
Other changes in this upgrade that resulted in reduced water use and improved effluent are closed screen rooms on our pine and hardwood bleach plants and high efficiency brownstock washers in the hardwood bleach plant.
The bleaching process improvements have costs International Paper in excess of $75 million. This retrofit to an existing 20 year old facility represents a significant commitment to the environmental and economic health of Texas.
Since 1988, these projects have resulted in significant reductions in waste generaton. The Texarkana mill has been able to reduce Biological Oxygen Demand (BOD) levels by 60% and dioxin in our effluent to levels so low that they are non-detectable according to the procedures established by the Environmental Protection Agency (EPA). We have also reduced emissions of chloroform, a compound on the list of EPA's 17 most toxic chemicals, by over 360,000 pounds a year or 88%. The oxygen delignification system reduced the use of elemental chlorine by over 19,000 tons per year. Water use at the facility has been reduced by over 5 million gallons a day. Reductions in BOD has allowed us to discontinue use of ammonia (543 tons/year) and phosphoric acid (26 tons/year) additions to our effluent treatment streams.
Details of Reductions
Additional Information :
These projects have been implimented at the expense of the mill. In fact, more than $75 million has been spent in the last five years on this series of successful environmental projects. Reducing water use and chemicals used to treat wastewater has saved the mill about $1.5 million a year in operating costs.