Treatment Plant Performance
Statistics
Design Criteria
| Contaminant | Design Average (Daily) | Wet Weather Peak (Daily) |
|---|---|---|
| FLOW | 64 MGD | 100 MGD |
| BOD | 91,300 lbs. | |
| SS | 91,300 lbs. | |
| TKN | 2,510 lbs. |
- MGD - Million Gallons per Day
- BOD - Biochemical Oxygen Demand
- SS - Suspended Solids
- TKN - Total Kjeldahl Nitrogen (Organic Nitrogen + Ammonia)
Effluent Requirements
| Contaminant | Amount |
|---|---|
| BOD | 10 mg/L |
| SS | 10 mg/L |
| NH3 | < 3.1 mg/L |
| pH | 6 - 9 |
| E. Coli | 126 Daily |
| Oil and Grease | Monitoring Only |
Average Effluent Water Quality for 2021
| Contaminant | Testing Result |
|---|---|
| BOD | 6 mg/L |
| SS | 3 mg/L |
| NH3 | .48 mg/L |
| pH (median) | 7.3 |
| E. Coli | 4.9/100 mL |
| Whole Effluent Toxicity Test | Passed |
| Total Phosphorus | 0.38 mg/L |
Charts & Terms
Influent
Industrial and residential wastewater flowing into the SW Wastewater Plant.
Effluent
Fully treated influent flowing from the SW Wastewater Plant to Wilson's Creek.
% Removal of Influent Loading
SW Clean Water Plant is required to have a minimum of 85% removal efficiency on a 30 day average of BOD, TSS, and Ammonia.
Loading
Loading in parts per million (ppm) for influent/effluent:
- Effluent Ammonia Nitrogen (NH3)
- Influent Ammonia Nitrogen (NH3)
- Effluent Biochemical Oxygen Demand (BOD)
- Influent Biochemical Oxygen Demand (BOD)
- Effluent Suspended Solids (SS)
- Influent Suspended Solids (SS)
- Effluent Total Nitrogen(TP)
- Effluent Total Phosphorus (TP)
- Influent Total Phosphorus (TP)
Biochemical Oxygen Demand (BOD)
Measure of the amount of oxygen required to biologically stabilize a waste stream. NPDES Permit limit for Effluent is 10 mg/L.
- Influent Biochemical Oxygen Demand (BOD) (PDF)
- Effluent Biochemical Oxygen Demand (BOD) (PDF)
- % Removal Efficiency Biochemical Oxygen Demand (BOD) (PDF)
Total Suspended Solids (TSS)
The amount of insoluble solids floating and in suspension in the wastewater. NPDES Permit limit for Effluent is 15 mg/L.
- Influent Total Suspended Solids (TSS) (PDF)
- Effluent Total Suspended Solids (TSS) (PDF)
- % Removal Efficiency Effluent Total Suspended Solids (TSS) (PDF)
Ammonia (NH3-N)
A government regulated nutrient which requires removal to prevent degradation of receiving stream. NPDES Permit limit for Effluent 1.3 mg/L seasonally.
- Influent Ammonia (NH3-N) (PDF)
- Effluent Ammonia (NH3-N) (PDF)
- % Removal Efficiency Effluent Ammonia (NH3-N) (PDF)
Total Phosphorus (TP)
Essential chemical element and nutrient for life forms. TP is a Government regulated nutrient which requires removal to prevent degradation of receiving streams. NPDES Permit limit for Effluent is 0.5 mg/L.
Escherichia Coliform (E. Coli)
A genus and species of the fecal coliform bacteria group. E.Coli is present in the intestines of warm-blooded animals and humans. NPDES Permit limit for Effluent is 126 coli/100 mL As of October 2014 the SW Plants NPDES permit changed to monitoring Escherichia Colifom.
Per- and Polyfluoroalkyl Substances
- 2021_01_04 Biosolids results
- 2021_01_05 Water results
- 2021_04_27 Water results
- 2021_04_27 Biosolids results
- 2021_07_19 Water results
- 2021_07_19 Biosolids results
- 2021_10_04 Water & Biosolids results
- 2022_01_03 Water & Biosolids results
- 2022_03_22 Water & Biosolids results
Sludge Volume Index, Food / Microorganism Ratio & Sludge Retention Time
Sludge Volume Index, Food / Microorganism Ratio, and Sludge Retention Time are used in conjunction to assure the proper function of the activated sludge process.
Sludge Volume Index
The Sludge Volume Index (SVI) is the ratio of volume of sludge to settling quality. SVI is an indication of the density the settled sludge attains in a 30 minute settling test. A low number (100 to 200) indicates good settling and shows the process is working properly. A high number (>500) indicates poor settling and shows the process may need adjustment.
Food / Microorganism Ratio
Food / Microorganism Ratio (F/M) is a measure of the amount of food material (organic material in the wastewater) available to the activated sludge microorganisms. The plant processes function best when the amount of food is balanced with the amount of microorganisms. Either too much food or not enough will cause poor plant performance.
A high rate process would require a high food to microorganism ratio (>0.5). This requires a fairly constant food rate and is more prone to upsets. A conventional rate process requires a midrange F/M ratio (0.25 to 0.5). Conventional rate processes take food rate changes better and are easier to control. Extended aeration processes require a F/M in the range of 0.05 to 0.1. They are relatively simple to operate and even less prone to upsets. The NW Treatment Plant is a modified Extended aeration process. The process is regulated to keep the ratio in the range of 0.09 to 0.15.
Sludge Retention Time
Sludge retention time (SRT) is the average number of days microorganisms are kept in the activated sludge process before they are removed for beneficial reuse. The plant processes work best at the proper SRT. The plant is designed to operate in a range of 10 to16 days.
Additional Charts
Southwest Clean Water Plant National Pollution Discharge Elimination System Permit Compliance
Municipal wastewater treatment plants buffer the natural environment from the wastewater generated in urban areas. Uncontrolled the wastewater would degrade the water, land, and air on which we depend. Strict government agencies and regulations, followed by the City of Springfield's Waste Water Treatment Plants, ensure the safe treatment and disposal of wastewater and biosolids. The City of Springfield is committed to protecting the water quality of the Ozarks for many generations to come. The SWCWP is an award winning facility for it high quality of treatment it provides. It has received its Platinum 8 NACWA Award for zero NPDES violations for the 8th consecutive year.
- Governed by Environmental Protection Agency (EPA) and Missouri Department of Natural Resources (MoDNR) through the Clean Water Act
- National Pollutant Discharge Elimination System (NPDES) permit compliance program
- SW Waste Water Treatment Plant NPDES permit
Links
