Item 5 - Ratify MWMC Budget - Laserfiche WebLink

Home Browse Search

WET WEATHER FLOW MANAC-;-;-;-~ MENT PLAN · Constructed wetlands as a means to treat wet weather flows or as a location where controlled overflows could be directed prior to discharging to the Willamette River or other receiving waters · Modifications to existing building codes to maximize system'perf0rmance through possible changes to the quality of pipeline materials, pipeline construction techniques, and inspection requirements Land use planning to reduce the nu~. ber of private service laterals or to create a process to address private service lateral replacement as a part of new development planning After considering the potential for these measures to address the projected system deficiencies, the CAC determined that these methods were potentially valuable elements of the flow management plan. However, due to the sources and magnitude of the wet weather .... flow, these solutions alone could not address the identified deficiencies and should be considered in addition to the traditional fl0w-control measures of storage, treatment, conveyance, and flow reduction through rehabilitatior~ The CAC concluded that it should review and evaluate various combinations of the traditional solution elements developed by City staff and CH2M HILL. General direction was provided to develop alternatives with the following characteristics: · Maximum use of effective storage inboth cities · Rehabilitation of only the publicly owned portion of the system (no private laterals) · Rehabilitation of both the private and public systems · No storage in the system · · A least-cost combination of all of the available solution elements So as not to lose potentially valuable supplemental elements of the plan, it was decided to incorporate the consideration of other technologies and flow management methods into the CAC's key decisions, listed in Section 3.4, and subsequently as part of the Policy Issues provided in Section 7. $.$ Evaluation 0fA[tematives For the purposes of evaluating project alternatives, evaluation criteria and a scoring system he ere. developed. Although the final selection of the preferred alternative did not result from rigorous application of the scoring system, the criteria were used to guide and assist in the selection of the preferred alte.rna, tive. The selection process was conducted by polling .each. of..the C~.,F members and asking for a ranking of the four alternatives developed. From that trutial polling, Alternatives. S-2 and S-6 were ranked the highest. Through ad~tional .d~. sions ..among CAC members and preliminary definition and recommendations for the ttnplementation of a voluntary private lateral rehabilitation program, Alternative S-6 was recommended as described in Section 6.7.