Disposal to Sewage System
Do not use the sanitary sewer for the disposal of hazardous materials, with the exception of trace quantities associated with cleaning and washing operations, e.g., glassware. Under no circumstances should halogenated or non-halogenated solvents be sewered directly or in aqueous solution when the solvent concentrations are more than trace (e.g. >1% by volume).The following discharges to the sanitary sewer are prohibited by the Clean Water Act:
- Wastes that may create a fire or explosion hazard.
- Corrosive wastes with a pH less than 6.0 standard units (s.u.) or greater than 10.0 s.u.
- Solid or viscous waste s in quantities that would obstruct flow or interfere with operations.
- Heated waste discharges which could either inhibit biological activities or increase the wastewater treatment plant influent temperature to 104°F (40°F) and higher.
- Waste discharges of any toxic waste material(s) in volumes or strengths to cause interference with wastewater treatment processes, or possibly contaminate waste sludge or effluent from the wastewater treatment plant so as to violate its NPDES permit.
- Note on Biocides: Do not release concentrated solutions to the sanitary sewer. Limit disposal to one gallon of “working strength” solution per laboratory per day. This also applies to germicides and disinfectants. Pesticides and other chemicals that are persistent in the environment cannot go to the sewer.
Only neutral salts and buffer solutions may be disposed of down the sanitary drain. Do not dispose any of the following down the drain:
- acids with a pH < 6.0 s.u.
- bases with a pH > 10 s.u.
- alcohols, ethers, esters, ketones, aldehydes, amines, amides, nitriles, ethidium bromide, carbon disulfide, phenol or phenolic materials, other halogenated or non-halogenated hydrocarbons, or other chemical agents unless present as trace constituents in aqueous solution
- sodium azide containing wastes
- formaldehyde containing wastes
- solutions with heavy metals
Contact EHS at 919-962-5507 with any questions regarding this policy.