Wastewater Treatment Plant Construction History Table
1937 – 5.2 MGD Primary Treatment Process
- Flocculation Tank
- Rectangular Primary Clarifiers
- Sludge Drawoff Building
- Anaerobic Digesters
- Sludge Drying Beds
1962 – 9.0 MGD Primary Treatment Process
- Added comminutor and screen chamber
- Abandoned flocculation tank
- Added preaeration tanks
- Added two additional primary clarifiers
- Added another primary sludge building
- Added two additional anaerobic digesters
- Added digested sludge holding tank
- Added sludge filter building
1976 – 12.5 MGD Secondary Treatment and Thermal Sludge Conditioning Facilities
- Added two mechanical bar screens
- Added two grit removal tanks
- Added one additional preaeration tank
- Added two primary effluent screw pumps
- Added 6 octagonal shaped roughing filters
- Added 3 aeration tanks
- Added two raw wastewater screw pumps
- Added 3 circular secondary clarifiers
- Added 2 chlorine contacts tanks
- Added phosphate removal system
- Converted 1937 digesters to sludge thickeners
- Added sludge heat conditioning equipment
1978 – Thermal sludge conditioning facilities we abandoned and the anaerobic sludge digestion process began along with land application of liquid digested sludge.
1985 – Construction upgrade of the existing anaerobic digesters. Lime stabilization process was used during this upgrade. Belt filter press was installed as a back up to liquid land application process.
1987 – Sludge lime stabilization process was discontinued upon completion of modifications to digesters.
1990 – Added an 800,000 gallon digested liquid sludge storage tank.
1996 – Upgraded existing rectangular primary clarifiers (Nos. 1-6) and Primary Sludge Building No. 1.
1998 – Upgraded existing square primary clarifiers (Nos. 7 & 8) and Primary Sludge Building NO. 2.
2002 – 15.8 MGD Advanced Secondary Treatment Process
- Added influent flow monitor to 66” diameter trunk sewer
- Increased size of influent screw pumps from 90” diam to 96” diam
- Modified automatic barscreens from 1” opening to ½ “opening
- Rehabbed existing grit tanks
- Modified grit removal conveyors to screw type
- Added covers to the influent screw pumps, grit tanks and open channels
- Added odor control equipment to influent screenings building, grit tanks, and grit building
- Added emergency overflowing chamber after grit removal process
- Added 2.6 MG diurnal flow retention basin
- Added 3 MG storm flow retention basin
- Added controlled pumps for flow retention basin effluent
- Added retention basin effluent flow monitoring
- Added odor control to primary sludge building number 1
- Added odor control to primary sludge building number 2
- Replaced first and second stage screw pumps
- Replaced roughing filter distributors
- Replaced roughing filter media and siding
- Replaced horizontal rotors in aeration tanks with fine bubble aeration and slow speed vertical mixers
- Added blower building which uses houses centrifugal blowers for the diurnal flow retention basin and the aeration tanks
- Added dissolved oxygen controls for aeration tanks
- Modified aeration basin effluent flow splitting
- Modified the 3 existing suction lift type clarifiers to spiral scraper type
- Added 2 spiral scraper type clarifiers
- Added RAS metering chamber
- Modified existing RAS pumps and wet well
- Modified existing RAS piping flow splitting control
- Added building to house new rapid sand tertiary filters and ultraviolet disinfection
- Added plant effluent parshall flume
- Changed chlorine contact tank to nonpotable water wet well and high river pump station
- Modified nonpotable water pumps and systems
- Changed gravity thickeners to sludge blending tanks
- Replaced thickened sludge pumps with gravity belt thickener feed pumps
- Added gravity belt thickeners
- Modified sludge holding tank into a thickened sludge holding tank
- Modified existing anaerobic digester covers, mixing system and heating system
- Added belt filter press feed pumps
- Added belt filter presses
- Added polymer system for GBTs and BFPs
- Added addition to solids handling building
- Added odor control for solids handling building, thickened sludge holding tanks and sludge blending tanks
- Added sludge storage pad
- Added filtrate pump station
- Changed sludge storage tank into sidestream storage tank
- Added vactor dump pad
- Added maintenance building
- Refurbished laboratory cabinets
- Added plant monitoring system
2013 – 17.0 MGD & Implement a Biological Nutrient Removal (BNR)
The 2013 project also includes improvements to ancillary WWTP systems, either to support the IFAS system, upgrade existing processes, or replace equipment approaching its service life. Numerous improvements were made to the WWTP headworks.
- Replaced the “Chapman Valve” slide gate at the collection system influent structure
- Replaced both influent screw pumps downstream of the influent structure
- Raised the high-water elevation of both sides of the existing flow retention basin to elevation 85.0 (plant vertical datum) to increase total storage by a half-million gallons to a total of 6.1 million gallons
- Added a meter vault and 42-inch magnetic flow meter to the flow retention basin influent piping
- Replaced the existing influent 24-inch magnetic flow meter with a new 24-inch magnetic flow meter
- Added a slide gate and modified the influent structure of Primary Clarifiers 7-8 to allow these clarifiers to be bypassed
- Added a 3-way valve to the discharge line of Sludge Pumps No. 1&2 with 4-inch piping to allow sludge to be recirculated to Primary Clarifiers 1&2 for primary sludge activation
- Demolished the preaeration tanks and constructed fine screen building
- Added two fine screens and a washing compactor units
- Added a headworks odor control system with gas collection piping, exhaust fans, and biotrickling filter tower
- Demolished the first and second stage screw pumps
- Added the primary effluent pump station (PEPS) to convey effluent from the primary clarifiers to the IFAS bioreactors
- Demolished the roughing filters
- Demolished the aeration blowers feeding the aeration tanks
- Converted the aeration tanks to the IFAS bioreactor tanks
- Demolished the tertiary sand filter
- Added tertiary disc cloth filters
- Converted the sludge pre-thickeners with new clarifier mechanisms, launders, and launder covers
- Added a replacement waste gas burner for the anaerobic digesters
- Replaced digester gas piping and related safety equipment
- Constructed a new digester gas boiler room in the Solids Handling Building with replacement boilers
- Performed heating, ventilation, and air conditioning upgrades in the Administration Building and Secondary Clarifier Gallery