Proper Drain Disposal Guidance

What May Be Disposed?

Generally, materials suitable for sewer disposal in limited quantities must meet the following physical and chemical criteria:

  •  They are liquids and readily water soluble (at least 3% soluble)
  •  Easily biodegradable or amenable to treatment by the waste water treatment process
  • Are simple salt solutions of low toxicity inorganic substances
  •  Are dilute organic substances of low aquatic toxicity and low concentration
  •  Have a pH between 3.0 and 10.0

 When discharging waste to the sanitary sewer, you must:

  •  Always discharge to a drain that leads to the sanitary sewer.
  •  Use a sink that does not have a history of clogging or overflowing.
  •  Use a sink in your laboratory.
  •  Flush with at least 10-20 fold excess of water after drain disposal to thoroughly rinse out the sink and sink trap, and to fully neutralize or inactivate the waste for discharge.
  • Limit the quantities being discharged to 100 grams of solute per laboratory per day.
  •  Wear gloves, eye protection and a laboratory coat.
  •  Inactivate biological materials (e.g., autoclave or bleach-treat) before releasing to sewer.

What May NOT Be Disposed?

  •  Ashes, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastics, wood, manure, hair and fleshings, entrails, paint residues, solid or viscous substances capable of causing obstruction to the flow of sewers.
  •  Oil, grease, petroleum, or other water insoluble chemicals
  •  Materials that are not biodegradable or would pass through the sewage treatment plant into the river and be toxic to aquatic organisms or accumulate in sediments.
  •  Materials that could interfere with the biological processes of sewage treatment or would contaminate the sludge-making disposal
  •  All compounds that could result in the presence of toxic gases or
  •  Infectious substances
  •  Hazardous Wastes – either listed or characteristic hazardous wastes, for example:
    •  Halogenated hydrocarbons;
    •  Nitro compounds (organic compounds that contain one or more nitro functional groups (-NO2) and are often explosive);
    •  Mercaptans (thiols);
    •  Flammables (immiscible in water) or at concentrations of concern;
    •  Explosives such as azides and peroxides;
    •  Water soluble polymers that could form gels in the sewer system;
    •  Water reactive materials;
    •  Malodorous chemicals;
    •  Toxic chemicals such as carcinogens, mutagens, teratogens;
    •  Nanomaterials
    •  Substances that boil below 50 °C (122 oF) ;
    •  Solid or viscous substances in amount s that will cause obstruction of the flow in the sewerage system;
    •  Flammable and combustible solvents (flashpoints less than 140oF)
  •  Discharges with a pH below 3.0 or higher than 10.0;
  •  Wastes that could impart color that cannot be removed by treatment process (dye wastes, stains);
  •  Metallic ions and salts