Dumping RV tanks into home syptic system
For the five or 6 years that I have been RV'ing, for convenience, I would sometimes dump my tanks into my home septic system upon returning home. While I have felt pretty comfortable doing this, I h...
Forum Discussion
Hello, folks. Civil engineer here. I design wastewater systems.
Conventional septic tanks are an anaerobic environment (i.e. "septic") in which breakdown of solids into soluble substances happens on a glacial speed (SLOW). Solids build up on the bottom and grease scum builds up in a layer on the surface. If you are a low loading user, it may take a LONG time for the solids and grease buildup to get to the point where the tank no longer effectively clarifies the septage before it exits the tank and heads for the leach field. In a properly functioning system, the clearest water is in the middle elevation of the tank where the outlet pipe is. But if that outlet starts receiving greases or solids, the leach field will be destroyed (clogged tight).
NOT pumping your tank periodically until/unless there is a problem is similar in strategy to never topping off the oil on an old engine until the low pressure red light comes on on the dash. The damage is irreversible at that point.
The guy who has never pumped his tank and grinds up everything leftover on his plates either has an unsafe leach field built in soils innately made of gravel or his field is totally locked up and the flows are getting out on the surface or in a cross connected drain tile (which you'd never see).
My advice: Find out the dimensions of your tank and inspect it annually to make sure that the scum layer bottom and sediment layer top are at least a foot away from the opening to the outlet pipe (usually an elbow). Yuck. Or pay to pump it every couple of years and ask the honey wagon guy to measure for you before pumping. Increase pumping interval if its not building up much between pumpouts.
Conventional septic tanks are an anaerobic environment (i.e. "septic") in which breakdown of solids into soluble substances happens on a glacial speed (SLOW). Solids build up on the bottom and grease scum builds up in a layer on the surface. If you are a low loading user, it may take a LONG time for the solids and grease buildup to get to the point where the tank no longer effectively clarifies the septage before it exits the tank and heads for the leach field. In a properly functioning system, the clearest water is in the middle elevation of the tank where the outlet pipe is. But if that outlet starts receiving greases or solids, the leach field will be destroyed (clogged tight).
NOT pumping your tank periodically until/unless there is a problem is similar in strategy to never topping off the oil on an old engine until the low pressure red light comes on on the dash. The damage is irreversible at that point.
The guy who has never pumped his tank and grinds up everything leftover on his plates either has an unsafe leach field built in soils innately made of gravel or his field is totally locked up and the flows are getting out on the surface or in a cross connected drain tile (which you'd never see).
My advice: Find out the dimensions of your tank and inspect it annually to make sure that the scum layer bottom and sediment layer top are at least a foot away from the opening to the outlet pipe (usually an elbow). Yuck. Or pay to pump it every couple of years and ask the honey wagon guy to measure for you before pumping. Increase pumping interval if its not building up much between pumpouts.
