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FREQUENTLY ASKED QUESTIONS ABOUT THE 2004 MWMC WASTEWATER FACILITIES PLAN AND SYSTEM DEVELOPMENT CHARGE METHODOLOGY Table 2 presents the flow projections used in the 2004 Facilities Plan. Also shown in Table 2 are the flow projections based on DEQ guidelines and the 1997 Master Plan. Flow projections based on the DEQ method and the 1997 Master plan are higher than the values used for the basis of planning in the 2004 Facilities Plan. MWMC is still negotiating with DEQ to gain their endorsement of the proposed 2004 Facilities Plan flow projections. However, DEQ may require MWMC to use the higher flow projections resulting from their methodology. The flow projections recommended in the 2004 facilities plan are different than those developed in the 1997 Master Plan because the 1997 Master Plan study used a smaller historical data set (only 5 years of data compared to 12 years of data analyzed for the current effort). The smaller data set included years with higher than average rainfall in the dry season and resulted in flow projections that would be too conservative. TABLE 2 - PROJECTED 2025 FLOWS USED FOR PLANNING PURPOSES 1997 Master Plan DEQ Guidlines 2004 Facility Plan Dry Weather Maximum Month 66 mgd 73 mgd 59 mgd Peak Wet Weather Flow Recommended a 429 mgd 277 mgd sewer system evalutation study as follow-up work. (The MWMC Wet Weather Flow Management Plan provided the follow- up work.) Facilities Plan Question 11. The proposed 20-year project list includes $20 million to develop approximately 10 million gallons per day (mgd) of effluent reuse. This seems like a lot of money. Why is this needed? The MWMC treatment plant discharge permit has a new limit for thermal load discharge into Willamette River. As the wastewater flows increase, the thermal load also increases, making it more difficult to meet the limit. The most cost-effective and environmentally friendly way to meet the thermal load limit is to reduce the discharge of wastewater to the Willamette River. One way to accomplish this is to use the treated wastewater effluent to irrigate crops. This approach is called effluent reuse. The Commission is currently developing facilities to reuse effluent at the Biosolids processing facility, which, in addition to removing the effluent discharge from the river, will save on the cost of a significant amount of fresh water that would otherwise be used. Considering that this new requirement will affect MWMC's approach to effluent discharge, the Commissioners have directed the development of a modest reuse program, including funds to develop 10 mgd of effluent reuse. There is some uncertainty surrounding the total maximum daily load for temperature in the Willamette River, and it is possible that the current thermal load limit could change to become more stringent. For this planning effort it was anticipated that the SHAWNS COMMENTS TO FAQ'S ON 4-16-04_1.DOC PAGE 9 OF 13