When backflow or backsiphonage prevention devices are required by this subchapter, the prevention devices shall provide a minimum level of protection as provided in the following graph; provided, however, this shall be a minimum standard of protection. When, in the opinion of the village, a different level of protection would be more appropriate, the Superintendent shall prescribe the method of backflow or backsiphonage protection.
Direct or Indirect Waste Connections | Degree of Hazard | Recommended Device | ||||||
Severe | Moderate | Minor | Air Gap | For Backflow | For Backsiphonage | |||
Reduced Pressure Device | Double Check Valve Assembly | Pressure Vacuum Breaker | Atmos- pheric Vacuum Breaker | |||||
I. Subject to back pressure: A. Pumps, tanks and lines handling: 1. Sewage and lethal substances 2. Toxic substances 3. Nontoxic substances B. Water connection to steam and steam boiler: 1. Boiler or steam connection is toxic substances 2. Boiler or steam connection is nontoxic substances (boiler blowoff through approved gap) | X X X | X X | X X X X | X X X X X | X X | |||
II. Not subject to backpressure: A. Sewer connected waste line (not subject to waste stoppages) B. Low inlets to receptacles containing toxic substances C. Low inlets to receptacles containing nontoxic substances D. Low inlets into domestic water tanks E. Coils or jackets used as heat exchanges in compressors, degreasors, etc.: 1. In sewer lines 2. In lines carrying toxic substances 3. In lines carrying nonsubstances F. Flush valve toilets G. Toilet & urinal tanks H. Trough urinals I. Valved outlets or fixtures with hose attachments that may constitute a cross connection to: 1. Toxic substances 2. Nontoxic substances | X X X X X X | X X X X X | X | X X X X X X X X X | X X X Each treated X X Each treated X X X | X case separately case separately X | X X X should X should X X | X X X be X be X X X |
(Ord. D-108, passed 6-7-1993; Am. Ord. D-130, passed 3-11-1996)