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IBM, Biological Treatment Alternative
Meeting Minutes
April 2, 1996
Ruma Kohli presented information on the processes at IBM which use IPA and the work that has been completed over the past several years to reduce the volume of IPA used and the quantity of waste generated.
Keith Peterson reviewed the work done by IBM to date to fully evaluate the waste stream constitutes for all IPA using tools and identify those tools which do not process chemicals which would add underlying constituents to the IPA stream. This review is important because of the Land Disposal Restrictions.
Several questions were raised as to why the IPA could not be recycled or used in concentrations less than 24%. The following points were discussed:
1. IBM has looked at utilizing recyclers located in North America. There are two identified IPA recyclers, neither of which meet IBM standards for Hazardous Waste management vendors.
2. On-site recycle of IPA is difficult due to the affinity of IPA for water. This results in high energy costs to process the IPA to the quality specifications required in the semiconductor industry. The example of the demise of the in-tool IPA recycle systems on the CFM tools was used. The recyclers had to be turned off due to quality problems with the recycled IPA.
3 IBM is pursing the use of <24% IPA wherever feasible. However, IPA is often used for its "drying" properties; the ability of the solvent to remove water from the wafer. Us of <24% IPA negates this capability.
4. IBM is pursuing two resale options for the IPA for a lower grade use. These opportunities depend on some of the information being gathered as part of the Project XL and resale is not an immediate option.
Larry Rogacki presented information on the wastewater treatment processes at IBM, both the biological plant, where the IPA will be treated, and the chemical precipitation plant through which effluent from the bioplant is treated with other streams from the site prior to discharge to the Winooski River. Larry explained the workings of the SBR system, how it is different from the chemical precipitation plant (IW treatment) in both treatment method and permit requirements, and the discharge requirements which govern treatment of the IPA. A planned tour of the wastewater treatment facility was deferred until the next meeting in the interests of time.
Several questions were raised during the wastewater discussion:
1. What is the composition of the high BOD wastestream and how is it treated?
The IPA adds between 3000-6000 mg/l of biochemical oxygen demand (BOD) to the wastewater influent received by the bioplant. It is amenable to biological treatment, with the bacteria oftentimes preferring the IPA over other organics present in the stream. The IPA is converted to carbon dioxide and water in the process of being converted by the bacteria. One point of discussion was that it was important to assure during the project that the presence of the IPA did not significantly affect the overall TOC removal in the process.
2. Where is the treatment occurring?
During the discussion, some confusion resulted in the relative roles of the biological treatment system and the chemical precipitation treatment system. This was heightened by the fact that Larry pointed out that there is a 50% removal of IPA across the chemical precipitation plant due to chemical oxidation of the IPA. It was explained that the IPA being added for treatment will be added to the biological plant with the intent being to fully remove it across the biological treatment system.
3. What will the impact of the project be on the water quality of the Winooski River?
The requirement of the proposed Project XL are that there will be no average degradation of the quality of the discharge to the Winooski River and that the overall quality should be improved through the improved performance of the nitrification process due to the presence of additional carbon. IBM intends to fully treat the IPA in the biological plant while maintaining TOC removal rates within a specified average.
Jay Dietrich presented an outline of the proposed monitoring plan for the FPA for consideration by the group. Some of the discussion outlined in question 3 above occurred during this presentation. The group was asked to review the monitoring proposal over the next month and come prepared to the next meeting to discuss specifics of that proposal.
TENTATIVE AGENDA FOR THE NEXT STAKEHOLDER MEETING:
1. Tour of the wastewater treatment facility.
2. Discussion of the proposed monitoring plan for the project and the specific conditions required for the implementation of the project and performance specifications to measure the success of the project.
3. Review of the Draft FPA. Jay Dietrich will try to have a draft FPA prepared to be mailed out with the letter documenting the proposed meeting.
4. Other items as proposed by the group.