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MWMC WASTEWATER FACILITIES PLAN AND SYSTEM DEVELOPMENT CHARGE UPDATE - RESPONSE TO APRIL 2, 2004, QUESTIONS FROM EUGENE CHAMBER OF COMME.RCE 5. Why is newly developed land that installed new infrastructure (wastewater pipes) required to pay SDC fees relating to wet weather treatment plant improvements? Developers believe that the inflow/infiltration (I/I) Problem in the collection system is an existing deficiency/problem, and that the newly installed sanitary pipes should be tight. This assumption or belief is not correct. The existing system does allow a much greater percentage of the total wet weather flow to enter the system; however, some I/I unavoidably enters the collection system in newly developing areas. That amount of I/! increases over time, even though the cities implement aggressive collection system maintenance and rehabilitation programs. This must be addressed and accounted for by planning and constructing adequate peak flow capacity at the treatment plant. New developments connecting to the facilities are responsible only for a share of the peak flow capacity that is attributable to the I/I contribution of their development over time. It is a much smaller share than that borne by existing system users. While the I/! generated may be a small amount immediately after construction, the design life of a pipeline can be 50 years or greater, and the wet weather flows must be estimated to meet the demands of future conditions. Nationwide experience over the last 25 years has shown that I/! cannot be considered simply a collection system deficiency resolved thrOugh ongoing collection system repair and rehabilitation. That is why wastewater treatment plants must be designed with capacities to handle a certain peak flow that will occur regardless of aggressive ongoing collection system work. The MWMC Wet Weather Flow Management Plan, completed in 2001, determined the most cost-effective combination of I/I work in the collection system and treatment capacity at the regional wastewater facilities. To estimate the a, mount of I/I from future systems, MWMC analyzed the I/I contribution from selected, existing developments that were constructed within the last 20 years using construction techniques and materials similar to those used today. That analysis and the experience of other agencies resulted in the establishment of the I/I contribution amount from future developed areas. 6. What would a common sense standard be for the overflow standard (i.e., the 5-year storm event), and what effect would this have on the Facilities Plan capital project list? Understanding existing standards and their origin has assisted in developing an appropriate overflow standard for MWMC. EPA continues to develop a Sanitary Sewer Overflow (SSO) policy that in part has been delayed by a controversial prohibition clause that prohibits municipal sanitary sewer system discharges that occur prior to a publicly-owned treatment works (POTW). The only exemption would be for severe natural conditions "exceptional, unintentional, temporary and caused by factors beyond the reasonable control of the permittee." These pending regulations are significantly more restrictive than the DEQ standards, and many have interpreted this to mean that a 5- or 10-year storm event would not be considered to be an exceptional event. CHAMBER OF COMMERCE RESPONSES FINAL. DOC PAGE 7 OF 8