Northwest Wastewater Treatment Plant

The area served by the Northwest Wastewater Treatment Plant is shown on the map for Springfield's northern basins. On the east the Northwest Wastewater Treatment Plant serves the Interstate 44, U.S. 65 area, City of Strafford and to the west the Springfield - Branson Regional Airport area and the City of Willard. The drainage basins served are Rainer Branch, Spring Branch, Pea Ridge and South Dry Sac.

Safety

In 1994 the Northwest Wastewater Treatment Plant was honored by being awarded the Missouri Environment Association's Small Facility Safety Award at its annual meeting.
The Plant has operated for more than 7,300 days, January 1, 1992 - January 1, 2012, without a lost time accident.

Plant Awards

The Northwest Wastewater Treatment Plant has been awarded the following NACWA Peak Performance Awards:

2007-Silver
2008-Gold
2009-Silver
2010-Gold

Improvements

Automation/Monitoring

Phase One

Phase One has been completed. The installation of this equipment has resulted in reduction in both staffing and overtime.

Automatic valve controller and backup power supply have been installed at the influent gate valve in the influent structure at the plant.
Automatic valve controller and a backup power supply have been installed on the gate valve at the diversion box at the Holding Pond used during high flows.
Auto dialer has been added to the existing plant electronic monitoring system to increase reliability of monitoring.
The security fence height has been increased.

Phase Two

Completed: A dedicated phone line for monitoring of the Plant treatment process controls, alarm conditions and effluent quality during hours the Northwest Plant is not staffed.
Completed: The addition of computerized process controlled equipment which will allow for closer control of plant processes and optimization of resources.
In progress: Continue efforts to find reliable methods for biosolids disposal. Lime stabilization of dewatered biosolids was studied. Thickening the Northwest Plant solids to 4% - 6% and hauling the solids to the Southwest Plant for further processing is the more economical solution. At this time a gravity thickener designed to produce 2% solids is being used. A more reliable way of increasing waste solids is being studied to reduce hauling and treatment cost.
Completed: Odor Control System improvements have been made on the headworks, thickener, and biosolids storage basin. Activated carbon filters have been added to the headworks and biosolids thickening process. A Bio-Filter system with secondary activated carbon stage has been installed for the biosolids storage basin. Neither system requires the continuous chemical feed that has been used in the past and the Bio-Filter ahead of the activated carbon extends the life of the carbon.

Phase Three, Completed 2009

Carollo Engineers were hired to design the expansion of the Northwest Treatment Plant to meet expected growth of Springfield's north side. Completion of the plant expansion provides the following:

The plant capacity has increase to a maximum monthly daily peak average of 9.5 million gallons per day basis which is about a 50 percent increase.
Much of the plant including blowers, pumps and valves will be automated to provide better process control, while saving energy.
New Influent pumping and grit removal to allow for future expansion and more reliable treatment
Provision for phosphorus and nitrogen removal through the Installation of equipment and tanks. The design of the tanks will allow for future expansion.
Replacement of aeration blowers, modification of aeration tanks and installation of monitoring and control equipment will provide the ability to optimize treatment and reduce energy costs. Aeration tank dissolved oxygen level set points will be maintained automatically by in-tank dissolved oxygen probes that control air flow.
Addition of secondary settling clarifier will provide better wet weather flow treatment and backup for increased reliability.
Hazardous chlorine and sulfur dioxide gases have been replaced with ultraviolet lights for disinfection of flow before discharge.
All of these improvements were made to provide the best water quality in the State of Missouri for now and in the future. The expansion was designed to provide a safe and environmentally friendly environment while keeping operating cost at a minimum.

Operation

Goals

Plant personnel, in conjunction with personnel from other sections of the Clean Water Services Division, have adopted and are applying a total team approach toward improving the operation and maintenance of the Northwest Wastewater Treatment Plant.
The goal of the team is to continuously identify areas in which safety, quality and cost savings can be improved within the plant and the Division. Once identified, personnel explore these areas to determine the feasibility of making the changes that provide the most positive impact to the plant.