In garages for public buildings where a drain receives wastewater from floor areas used by vehicles, how must wastewater from areas where vehicles will be serviced discharge?

• A. Directly to a municipal sewer
• B. Into the ground
• C. Through a garage catch basin or oil interceptor connected to a municipal sewer or holding tank approved to receive industrial wastewater
• D. Through a floor drain to the storm sewer

Answer: (C)

Wastewater from areas where vehicles are serviced contains oils, greases, and other automotive contaminants, so it must be treated before disposal. The proper path is to route that water through a garage catch basin or an oil interceptor that is connected to the municipal sewer or to a holding tank approved to receive industrial wastewater. This setup separates or concentrates the oils and contaminants, preventing them from entering the public sewer system or the environment, while still allowing the treated water to be disposed of legally.

Directly discharging to the municipal sewer would bypass the necessary oil separation. Letting it go into the ground risks soil and groundwater contamination. Sending it through a floor drain to the storm sewer would send industrial pollutants to the stormwater system, which is not allowed.