Wastewater Treatment Plant

Design Parameters

Average Daily Flow	5MGD
Daily Flow	8.9 MGD
Wet Weather Peak	11.6 MGD
Design Population	25,000

Current Flow:

Average Flow for City	2.3 MGD
National Beef Packing Plant Flow	3.0 MGD
Combined Average Flow	5.3 MGD

The following description of Liberal's activated sludge wastewater treatment facility will include the basic process description:

The wastewater plant has been in operation since 1983. Nine (9) full-time employees operate the plant. The City's raw influent is first introduced to the treatment process at any one of three enclosed screw pumps. These are 48' diameter and have the capacity of pumping 3750 gallons per minute each. The flow passes into an aerated grit chamber with one mechanical bar screen, then continues through a Parkson automatic fine bar screen, a Parshall flume and flow measuring devices.

After the influent flow is measured and recorded, it is directly introduced into two (2) primary clarifiers. These units are operated in parallel fashion, each having a 10' sidewall depth and a diameter of 55'. A scraping mechanism collects and deposits raw sludge into a hopper on the bottom of each tank while a skimming device removes floatable matter atop each unit.

After the primary phase of the treatment is complete, all flow enters the three (3) aeration basins. The system is designed to complete mix and has three (3) separate parallel enclosures (basins). Each basin has two speed surface mechanical aerators for mixing an oxygen feed process.

The next portion of the treatment process is secondary clarification. Each of the two final clarifiers has a 12' sidewall depth and diameter of 95'. Both are operated in parallel, are centered fed units and use uplift draft tubes for sludge draw-off. All return sludge flows to a common wet well and is subsequently mixed with the primary influent.

We utilize a DAF unit, which is a defused air floatation system. We use this process to waste a portion of our activated sludge (micro-organisms). They are mixed with air pressure, which thickens the waste sludge, then pumped directly to the primary digester.

The next phase of the process is anaerobic digestion. Using two digesters - one is a primary digester which breaks down the organic matter and produces methane gas which is stored in the floatable dome of the secondary digester and then the methane gas is burned in the boiler to heat the primary digester. The primary digester is kept at a constant 98 degrees. The extra methane gas is flared off at the waste gas burner. The secondary digester processes bio solids, which are pumped to a Roediger tower belt press. The bio solids are applied to the belt press, de-watered, and hauled to the landfill for disposal.

In the last phase of the process description, the secondary effluent enters a two sided chlorine contact basin for disinfection process. The effluent then flows through a 20" pipe and is gravity fed approximately 9 miles east of Liberal to the Arkalon Recreational Park where wetlands and several ponds have been created for fishing, recreation and wild life preservation. The excess flow from the ponds exits to the Cimarron River basin.

In an age of dwindling natural resources, it is becoming more important and increasingly more common to require reuse of treated wastewater. To that end the Liberal Wastewater Facility plays a great role.