Title
An Ordinance authorizing the execution of addendum number 5 to an agreement by and between the City of Lee's Summit, Missouri and Olsson Associates Engineering, Inc. for the services related to Tudor Road Pump Station Odor Control in the amount of $107,500 and authorizing the City Manager to enter into same. (PWC 10/23/18)
Body
Issue/Request:
In the early 1990’s studies where performed to address odor and corrosion concerns in the May Brook Drainage Basin in and near the developments around Lakewood. These studies included monitoring of sulfide formation and the release of hydrogen sulfide gas, the comparison of control strategies and recommendation to use ferric chloride to prevent the formation and release of the sulfides. At the time this recommendation was the most effective and best value solution. This strategy worked fairly well until recent years when the reduced flow fixtures and increased service areas begancausing increased residence times in the system. These increased residence times allow the sewage to become septic sooner in the system and create conditions for additional sulfide formation which the ferric chloride has had trouble meeting.
This past year we hired Olsson Associates through our on call contract to revisit the study and determine if the ferric chloride feed can be revamped or if a different technology should be used. To do this we resampled the chemistry of the wastewater and monitored the formation of the hydrogen sulfide at varying flows and varying ferric chloride feed rates. This information proved that it would take a large increase in our ferric feed rates to continue this model. While we were reviewing the current system we also review existing and emerging technologies to determine if there was a more efficient better value model for us to use. The study looked at oxygenation, the addition of other types of chemicals, and adding a Vortex system to the outfall of the force main. The final recommendation ...
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