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 Mobile ViewPLUMBING SYSTEM INSPECT DIAGNOSE REPAIR AGE of PLUMBING MATERIALS & FIXTURES AIR DISCHARGE at FAUCETS, FIXTURES AIR INLET VALVE, WATER TANK AIR VOLUME CONTROLS, WATER TANK ANTI-SCALD VALVES APPLIANCE EFFICIENCY RATINGS AQUASTAT CONTROL Functions BACKDRAFTING HEATING EQUIPMENT BACKUP PREVENTION, SEWER LINE BATH & KITCHEN DESIGN GUIDE BATHROOM MOLD BATHROOM VENTILATION BIOLOGICAL POLLUTANTS Bisphenol-A, BPA BLEVE EXPLOSIONS BLOCKED DRAIN REPAIR METHODS BOILERS, HEATING BUILDING SAFETY HAZARDS GUIDE CARBON MONOXIDE - CO CHECK VALVES CHEMICAL CONTAMINANTS in WATER CHIMNEY INSPECTION DIAGNOSIS REPAIR CHLORAMINE / CHLORINE Tests CHLORINE IN DRINKING WATER CHLORINE in WATER, HOW TO TEST FOR CHLORINE IN SEPTIC WASTEWATER CISTERNS CLOGGED DRAIN DIAGNOSIS & REPAIR CLOGGED SUPPLY PIPING CROSS CONNECTIONS, PLUMBING DRAIN a WATER HEATER TANK DRINKING WATER - EMERGENCY PURIFICATION DRINKING WATER - EMERGENCY SOURCES Water Heater Anode & Dip Tube Check FLOODED HEATING EQUIPMENT REPAIR FLOODED WATER HEATER REPAIR FLOODED SEPTIC SYSTEMS, REPAIR FLUSHOMETER VALVES for TOILETS URINALS GALVANIC SCALE & METAL CORROSION GAS BURNER Flame & Noise Defects GAS FIRED WATER HEATERS GALVANIC SCALE & METAL CORROSION GAS BURNER Flame & Noise Defects GAS FIRED WATER HEATERS GAS PIPING, VALVES, CONTROLS HARD WATER - SOFTENERS HEAT TAPES, Heat, Insulation prevent Freeze-Up HOT WATER HEATERS KITCHEN & BATH DESIGN GUIDE KITCHEN VENTILATION LEAD POISONING HAZARDS GUIDE LEED GREEN BUILDING CERTIFICATION MANUALS & PARTS GUIDES - HVAC MIXING / ANTI-SCALD VALVES MUNICIPAL WATER PRESSURE IMPROVEMENTS MOLD INFORMATION CENTER MVOCs & MOLDY MUSTY ODORS NOISE / SOUND DIAGNOSIS & CURE NOISE CONTROL for HEATING SYSTEMS NOISE CONTROL for PLUMBING NOISE, PLUMBING DRAIN DIAGNOSIS NOISE, PLUMBING DRAIN REPAIR NOISE, PLUMBING CHECKLIST NOISES, WATER HEATER NOISES, WATER PUMP ODORS & SMELLS DIAGNOSIS & CURE ODORS GASES SMELLS, DIAGNOSIS & CURE ODORS IN WATER ODORS, SEPTIC or SEWER ODORS, SULPHUR SMELL SOURCES ODORS, URINE REMOVAL SEWER GAS ODORS SEWER GAS ODORS in COLD WEATHER OIL FIRED WATER HEATERS OIL-FIRED BOILERS, HEATING OIL & GAS PIPING OIL TANKS OUTHOUSES & LATRINES PIPING IN buildings, Clogs Leaks Types SEWER LINE REPLACEMENT PLUMBING FIXTURES, KITCHEN, BATH Plumbing Materials & Fixtures, Age, Types PUMPS & WELLS RANGE BOILERS RELIEF VALVES - TP Valves on Boilers RELIEF VALVES - Water Heaters RELIEF VALVES - Water Tanks SEPTIC SYSTEM INSPECT DIAGNOSE REPAIR SEPTIC & CESSPOOL SAFETY SEWAGE BACKUP TEST & CLEANUP SEWAGE & SEPTIC CONTAMINANTS SEWAGE CONTAMINATION in buildings SEWAGE CONTAMINANTS in FRUIT / VEGETABLES SEWAGE EJECTOR / GRINDER PUMPS SEWAGE NITROGEN CONTAMINANTS SEWAGE PATHOGENS in SEPTIC SLUDGE SEWAGE PUMPS SEWAGE PUMP CLOG DAMAGE SEWER BACKUP PREVENTION SEWER GAS ODORS SEWER LINE REPLACEMENT SCALE REMOVAL, WATER HEATERS SOLAR ENERGY SYSTEMS SUMP PUMPS GUIDE SWEATING (CONDENSATION) on PIPES, TANKS TANK TYPES: WATER, OIL, EXPANSION, ALL TANKLESS COILS TANKLESS WATER HEATERS Temperature Pressure Relief Valves - Water Heaters TIMERS for ELECTRIC WATER HEATERS TOILETS, INSPECT, INSTALL, REPAIR TOILET ALTERNATIVES TOILET FLUSHOMETER VALVES TOILET INSTALLATION PROCEDURE TOILET OVERFLOW EMERGENCY TOILET PLUGS, SEWER BACKUP TOILET REPAIR GUIDE TOILET TISSUE CHOICES TOILET TISSUE TEST TOILET TYPES Toilet Types, Flush Methods TOILETS, DON'T FLUSH LIST TRAPS on PLUMBING FIXTURES WATER HEATERS AGE of WATER HEATERS ALTERNATIVE HOT WATER SOURCES ANODES & DIP TUBES on WATER HEATERS ANTI SCALD VALVES APPLIANCE EFFICIENCY RATINGS AQUASTAT CONTROL Functions BACKDRAFTING HEATING EQUIPMENT BLEVE EXPLOSIONS DEBRIS in WATER SUPPLY, Water Heater DRAIN a WATER HEATER TANK ELECTRIC WATER HEATERS FLOODED WATER HEATER REPAIR GAS FIRED WATER HEATERS SPILL SWITCHES - Flue Gas Detection HOT WATER IMPROVEMENTS HOT WATER DELIVERY SPEED UP HOT WATER PRESSURE EXPANSION RATE HOT WATER PRESSURE LOSS HOT WATER QUANTITY IMPROVEMENT INDIRECT FIRED WATER HEATERS KITCHEN & BATH DESIGN GUIDE MIXING / ANTI-SCALD VALVES NO HEAT - NO HOT WATER: HEATER DIAGNOSIS NOISES COMING FROM WATER HEATER ODORS GASES SMELLS, DIAGNOSIS & CURE ODORS IN WATER OIL FIRED WATER HEATERS MIXING / ANTI-SCALD VALVES NO HEAT - NO HOT WATER: HEATER DIAGNOSIS NOISE / SOUND DIAGNOSIS & CURE NOISE CONTROL for HEATING SYSTEMS NOISE CONTROL for PLUMBING NOISE, PLUMBING DRAIN DIAGNOSIS NOISE, PLUMBING DRAIN REPAIR NOISE, PLUMBING CHECKLIST NOISES, WATER HEATER NOISES, WATER PUMP ODORS & SMELLS DIAGNOSIS & CURE ODORS GASES SMELLS, DIAGNOSIS & CURE ODORS IN WATER OIL FIRED WATER HEATERS PLASTIC HEATER VENT RANGE BOILERS RELIEF VALVES - TP Valves on Boilers RELIEF VALVES - Water Heaters RELIEF VALVES - Water Tanks SAFETY, HEATING INSPECTION SCALE REMOVAL, WATER HEATERS SEWER BACKUP PREVENTION SEWER GAS ODORS SEWER LINE REPLACEMENT SOLAR ENERGY SYSTEMS SOLAR HOT WATER HEATERS SOOT on OIL FIRED HEATING EQUIPMENT SPILL SWITCHES - Flue Gas Detection TANKLESS COILS TANKLESS WATER HEATERS Temperature Pressure Relief Valves - Water Heaters TIMERS for ELECTRIC WATER HEATERS TRAPS on PLUMBING FIXTURES VALVES, PLUMBING VENT PIPING WATER CONTAMINANT LEVELS WATER FILTERS WATER HAMMER NOISE DIAGNOSE & CURE WATER HEATERS WATER HEATER ALTERNATIVES WATER HEATER ANODES, DIP TUBES WATER HEATER AIR INLET WATER HEATER DEBRIS FLUSH WATER HEATER DRAIN PROCEDURE WATER HEATER FLUSH PROCEDURE WATER HEATER NOISES WATER HEATER PROPERTIES WATER HEATER SCALE - De-Liming Procedure WATER HEATER SCALE PREVENTION WATER FILTERS WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS WATER PUMPS & WELLS WATER PUMP SAFETY WATER PUMP CAPACITIES TYPES RATES GPM WATER PUMP CONTROLS & SWITCHES WATER PUMP PRESSURE CONTROL ADJUSTMENT WATER PUMP PRESSURE CONTROL REPAIR WATER PUMP PROBLEM DIAGNOSTIC TABLE WATER PUMP REPAIR GUIDE WATER PUMP SAFETY WATER PUMP SHORT CYCLING WATER PUMP TYPES & LIFE EXPECTANCY WATER PUMP WONT STOP RUNNING WATER PRESSURE & FLOW MEASUREMENT WATER PRESSURE GAUGE ACCURACY WATER PRESSURE LOSS DIAGNOSIS & REPAIR WATER PRESSURE PROBLEM DIAGNOSIS TABLE WATER PRESSURE REDUCER / REGULATOR WATER PRESSURE REGULATOR ADJUSTMENT WATER PRESSURE REPAIR GUIDE - WELLS WATER PURIFIERS WATER QUALITY TESTS, CONTAMINANTS, TREATMENT WATER QUANTITY IMPROVEMENT WATER QUANTITY USAGE GUIDE WATER SHUTOFF VALVE LOCATION, USE WATER SHUTOFF VALVE, WELL PUMP WATER SOFTENERS & CONDITIONERS WATER SOURCE ALTERNATIVES WATER SUPPLY & DRAIN PIPING WATER TANK AIR, HOW TO ADD WATER TANK: USES, TROUBLESHOOTING WATER TANK TYPES: WATER, OIL, EXPANSION, ALL WATER TANK AIR, HOW TO ADD WATER TANK BLADDERS & CAPTIVE AIR WATER TANK CAPTIVE AIR vs TRADITIONAL WellMate WATER TANK DRAIN VALVE WATER TANK LIFE EXPECTANCY WATER TANK PRESSURE CALCULATIONS WATER TANK PRESSURE GAUGE WATER TANK PRESSURE GAUGE ACCURACY WATER TANK PRESSURE RELIEF VALVE WATER TANK REPAIRS WATER TANK REPLACEMENT WATER TANK SAFETY WATER TANK SIZE & VOLUME WATER TESTS, CONTAMINANTS, TREATMENT WATER TESTING ADVICE CHEATING on WATER TESTS CORRECTING BAD WATER EPA GUIDE to WATER QUALITY SEWAGE CONTAMINATION WATER CONTAMINANT LEVELS WATER ODORS, CAUSE CURE WATER PURIFIERS WATER QUALITY TESTS, CONTAMINANTS, TREATMENT WATER TEST CHOICES & WATER TEST FEES WATER TEST FEES WATER TEST INTERPRETATION WATER TREATMENT EQUIPMENT CHOICES WELL PUMP PRIMING PROCEDURE WELLS CISTERNS & SPRINGS WINTERIZE A BUILDING More Information |
Plumbing cross connections: this article gives a definition of a plumbing system cross connection and explains why plumbing or piping cross connections can be unsanitary or even dangerous. InspectAPedia offers impartial, unbiased advice without conflicts of interest. We will block advertisements which we discover or readers inform us are associated with bad business practices, false-advertising, or junk science. Our contact info is at InspectAPedia.com/Contact.htm.
© Copyright 2012 InspectAPedia.com, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use page top links to major topics or use links at the left of each page to navigate within topics and documents at this website. Green links show where you are in a document series or at this website. Plumbing CROSS CONNECTIONS - Health Risks from Plumbing Cross Connections Any physical connection or arrangement between potable water and any source of contamination. A cross connection risks contamination of building water piping or municipal water supply with bacteria. As Carson Dunlop's Home Reference Book points out, a cross connection is a dangerous situation where waste water may enter and contaminate the supply water. A cross connection can occur in many places. One example is where a laundry tub has a faucet below the top of the laundry tub. If the faucet enters the tub through the wall, it is possible that when the tub is filled, the faucet will be submerged. If this happens, the waste water in the tub may back up into the drinking water through the faucet if the supply piping is being drained. The solution to plumbing cross connections is to raise the faucets above the top of a tub or basin, creating an air gap between the faucet and water in the tub. Cross connections are avoided through the use of an overflow. In bathtubs, for example, where the faucets may enter through the wall of the tub below the top, an overflow provided below the faucets will prevent a cross connection.
Bathroom fixture cross connections
Bidets Cross Connections - Vacuum BreakersSome plumbing fixtures necessarily create a situation which could lead to a cross connection. A bidet is a good example of this.A bidet has a water supply at the bottom of the bowl. This allows water to be directed up in a spray from the bottom center of the bowl.
There is, of course, the potential for waste water in the bowl to get into this supply water. A special device (vacuum breaker) prevents water from flowing back into the supply plumbing. Dishwasher Cross Connections & Air Gap DevicesThe air gap device shown in the sketch (below-left) demonstrates how we avoid a plumbing cross connection at dishwashers. The dishwasher in our photograph (below right) was installed with no air gap device and forms a potential cross-connection in this home.
Garden Hose Cross ConnectionsWhile cross connections are normally avoided during original plumbing work, home handy man changes can create them. Careless use of the house plumbing system can also create a cross connection. Care should be taken, for example, to avoid placing a garden hose in a position to allow waste water to flow back into the supply plumbing system. For example, if the hose is left in a pail of water, it is possible for the contaminated water to flow back through the hose into the drinking water. This may happen if the house water supply is shut off and partially drained for some reason, while the hose is in the pail. Back-flow preventers (like the atmospheric vacuum breaker in the illustration) on the hose bib can prevent this. Cross connections by garden-hose plumbing also occur when someone improperly connects a garden hose directly to a sewage waste pipe for any reason (photo, below right). We have found garden hoses connected in this fashion as building piping drains, water softener drains, boiler drains, etc.
Back-flow preventers (like the atmospheric vacuum breaker in the illustration at above-left) on the hose bib can prevent this. We show another back flow preventer at Plumbing Cross Connections at Heating Boilers - Adapted with permission from Carson Dunlop's Home Reference Book Clothes Washer Plumbing Cross Connection leads to Sewage Backup into Washing Machine
A washing machine drain hose in our photo (left) had been connected directly to the sewer line without an air gap. We pointed out the cross connection and risk of sewage backup into the washing machine, potentially providing a path of bacterial contamination back through the washing machine into the house water supply piping. Our client thought that the risk of sewage backup into the washing machine was not a concern. The new homeowner called us two weeks later with an amazing house noise and sewage backup story. The home occupants woke at 2: AM, hearing a noise in their basement. Walking downstairs into the basement the occupants found that mysteriously the clothes washing machine had begun to agitate. This was an old washing machine that would start agitating when a sensor determined that the liquid level in the washer had reached a sufficient level.
Water Softener Cross Connections Between Drains and Water Supply Piping This may sound like an unlikely event in buildings but in fact it is common in a few instances: installers often make a tight connection between the water softener backwash/discharge drain (usually a small diameter plastic tube) and a building drain. While it is not unique to water softener installations, this plumbing error is often made when these devices are installed. It is unsanitary and is a health risk. What's the problem? In the unlikely event of a sewer line backup, sewage may be forced backwards up the drain and into the supply fixture, in this case the water softener - a very unsanitary event. There is also a possible bacterial growth path up such drains even when a sewer backup is not occurring.
Plumbing Cross Connections at Heating Boilers
Sump Pump Plumbing Cross Connections
Cross connections are defined with further examples at Home Inspection Definitions & Terms. - Adapted with permission from Carson Dunlop's Home Reference Book Questions & Answers regarding this articleQuestions & answers about cross connections in plumbing supply & drain piping, appliances, and plumbing fixtures. Ask a Question or Search InspectAPediaHTML Comment Box is loading comments...
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