Latest Wastewater Treatment Upgrade Proposal Expensive

Fairhope, Alabama 

 

Proposed new head works.

 

 

OVER $5 MILLION

A proposal to replace the head works at the city's wastewater treatment plant at the north end of Church Street met with a cool reception from some council members due to it $5 million estimated price tag. 

The head works is the point all the wastewater first enters the plant.

Consultant engineers from Garver Engineering said the project would increase overall peak flow capacity from current 10 million gallons per day to 12 million, provide redundancy, and more effective odor control for adjacent bluff neighborhoods.  (7.5 million gpd was the actual peak recorded recently.)

Councilman Burrell told the Times the cost seemed very high considering a comprehensive upgrade to the entire plant completed in 2015  cost only $12 million.

He wondered why the head works upgrades were not included at that time as well.

The new design would enclose some of the open elements in a new building where air would be filtered/recirculated to reduce odor. 

PREVIOUS PLANS

Other plans for an entirely new treatment plant near the airport  ... or smaller plants located elsewhere around town have also been proposed over the years.

Another proposal by one council member in 2010 to sell the plant to a private sewer company so it could be dismantled and relocated failed to gain support either.

 

Summary of proposal: The City of Fairhope’s wastewater treatment plant (WWTP) is a conventional activated sludge facility with a permitted design capacity of 4 million gallons per day (MGD). The City of Fairhope (City) is preparing to improve the fine screening and grit removal processes of the WWTP and has enlisted Garver to assess the existing facility, analyze design alternatives, and provide recommendations and conceptual design concepts for improvements to the headworks. Staff have voiced various concerns with the current headworks facility, and those concerns have been analyzed and addressed in this evaluation. The goals of the conceptual design evaluation, centered around staff feedback, are to increase redundancy, deliver reliability and resiliency, address odor control, and optimize system hydraulics to accommodate increasing future flows. This evaluation analyzes current plant conditions as well as potential alternatives and future hydraulic loadings.

A hydraulic profile for the existing headworks facility and upstream/downstream yard piping systems at the Fairhope WWTP was developed and analyzed for the historical/current flow conditions, the existing equipment capacity conditions, and the desired headworks capacity. For this conceptual evaluation, this hydraulic profile was developed to identify hydraulic limitations that might exist within the preliminary treatment facilities at the WWTP. Since a current survey was not conducted, information used in the hydraulic analysis was gathered from available record drawings. Flow data was assembled from monthly reports from 2019 to current, and the hydraulics of the existing preliminary treatment facilities were analyzed for the existing peak day flow condition (7.43 MGD), current stated capacity of the current headworks equipment (10 MGD), as well as desired future headworks capacity (12 MGD). While it is recommended that a full survey be conducted to verify the findings, the current system appears to have adequate freeboard in the system and up to the influent junction box at current peak day flow conditions (7.43 MGD) and at equipment peak flow ratings of 10 MGD. When a desired future capacity of 12 MGD is analyzed in the current system (assuming the screening and grit removal equipment are also upgraded to accommodate the future capacity), the water surface elevations in the upstream junction box and manhole 5 do not maintain adequate freeboard of 2-feet. There is also currently no hydraulic break between the headworks and collection system. While additional investigation is required to determine the extent of this impact, the water surface elevation upstream of the mechanical screen may significantly influence the conveyance capacity and hydraulic conditions within the upstream gravity portion of the collection system. In lieu of rehabilitating the existing headworks facilities due to constructability concerns and the limited hydraulics, it was recommended that a new headworks facility be considered.