Discharging Waste Into Sanitary Sewers
State and Federal laws and regulations and the Springfield sewer use ordinance restrict the disposal of certain chemicals into the Publicly Owned Treatment Works (POTW). The Springfield City Industrial Pretreatment Program provides guidelines on what can be discharged into the municipal sewerage system and what is prohibited.
Only waste that will have no harmful affects on the sewage collection system or treatment system, and that will not endanger persons exposed to the wastes will be considered for discharge into the sewerage system. All other waste will be shipped off-site for disposal.
Prohibited wastes:
- Waste with a flashpoint of less than 140 degrees Fahrenheit (60 degrees Celsius). However, very small amounts of certain ignitable waste may be disposed of into the sanitary sewers with the approval of the Director of Environmental Management.
- Wastes that have a pH lower than 5.0 or higher than 12.5. In some cases these wastes can be neutralized as long as they do not have elevated levels of the heavy metals or toxics listed on the attached lists. (See waste neutralization guidance)
- Solid or viscous material such as, but not limited to: grease, animal tissues, hair, sand, spent lime, stone or marble dust, rags, plastics, lubricating oil, mud or glass grinding or polishing wastes.
- Petroleum oil or non-biodegradable cutting oil. Products of mineral oil origin are allowed in small amounts – less than 100 ml.
- Radioactive waste or isotopes.
- Chlorinated hydrocarbons.
- Medical wastes.
- Any noxious or malodorous liquids, gases or solids which either singly or by intersection with other wastes are sufficient to create a public nuisance or hazard to life and property or that result in toxic gases, vapors, and fumes in a quantity that may cause acute worker health and safety problems.
Aqueous wastes that do not contain F-listed wastes and which contain less than five (5)% hazardous constituents will be considered for disposal into the POTW. Examples would be mixtures of water and ethanol, isopropyl alcohol, and cyclohexane that, due to being mixed with water during the laboratory activities, no longer exhibit the characteristic of ignitability. Other commonly generated wastes such as aqueous mixtures of potassium permanganate are also candidates for disposal into the sewers. The Director of Environmental Management must be consulted prior to discharging these wastes into the sewers.
Small amounts of ethanol and isopropyl alcohol may be disposed of into the sanitary sewers but must be flushed with water equal to at least ten times the quantity of waste. No more than 50 ml of waste may be flushed at any one time unless it is an aqueous solution of at least 95% water. The amount of "ignitable waste" must be recorded for reporting purposes.
Missouri State University will discharge no more than 15 kg (15 liters or about four gallons) of hazardous waste per month into the municipal sewers. Departments/Principal Investigators will track any and all hazardous waste that is discharged to the sanitary sewers, and forward this information to the Director of Environmental Management annually. This information will be made available to Springfield Sanitary Sewer Operations personnel on request. Neutralized waste does not count in the 15 kg.
In some cases, small amounts of F-listed wastes such as methanol and xylene may be discharged into the municipal sewers. This must be done only with the approval of the Director of Environmental Management and in accordance with procedures for disposal of F-Listed wastes.
The Director of Environmental Management must be consulted before any wastes that could be classified as hazardous wastes are disposed of into the municipal sewerage system. Once hazardous waste streams are approved for disposal into the sewers, the generator of the waste must track the types and amounts of wastes for monthly reporting to the Director of Environmental Management who will compile the information and report to the city.
If there are questions about specific wastes, please contact Environmental Management at 417-836-8334 or EnvironmentalManagement@missouristate.edu.
City of Springfield, MO. Section 120-113: Specific Pollutant Limitations. Local Discharge Limitations
| Parameters mg/l unless noted | Southwest Plant |
|---|---|
| Arsenic (As) | 0.51 |
| Cadmium (Cd) | 0.13 |
| Chromium - total (Cr) | 2.91 |
| Copper (Cu) | 2.44 |
| Cyanide (CN) | 0.33 |
| Lead (Pb) | 0.53 |
| Mercury (Hg) | 0.02 |
| Nickel (Ni) | 5.79 |
| Zinc (Zn) | 6.54 |
| Oil and Grease (Animal and/or vegetable) | 100 |
The above limits apply at the point where wastewater is discharged to the POTW. All concentrations for metallic substances are for "total" metal unless indicated otherwise.