Waste Management Woes
by Preston Hall | Feb 7, 2018 | Case Studies

“What is the best method for thorough cleaning out of the sewer holding tank? Maybe like a pump or a back-wash system or an inside flush system?”
– Darryl, Albuquerque, NM

“Darryl, if I had to pick just one area where I feel RV manufacturers have let us down, I would have to pick the waste management system.We can all agree that waste management is probably the least appealing aspect of the RVing lifestyle. But to enjoy the total freedom RVs give us, it is something we must endure.”

“Thankfully, many RV coach builders have just about mastered the waste containment part by going to full-flow 3-inch outlets on all tanks, including the gray tank, improving the venting, adding better, non-invasive, monitoring systems and installing electric termination valves at the container outlet instead of a manual valve at the end of a long drain pipe. These additions to waste systems have generally made containment and evacuation easier and much safer. And safety is the key when it comes to the health and well-being of RVers! Just ponder the many bacteria, viruses and other disease-carrying critters that must thrive within the holding tanks and termination assemblies of our coaches. But, a serious problem lies between the termination assembly on your rig and the inlet to the dump station or sewer connection at the campground. That gray area (no pun intended), is not governed by any standard! Both entities, the RV manufacturer and the campground, leave that totally up to the discretion of the RV owner. Think about it, that portion of waste transfer, the most vulnerable to spillage, leakage, contamination, and disease, is left to the end user; in many cases, a novice RVer with little or no experience in the correct methods of evacuation and transfer.”

“I’m also a firm believer in allowing both holding tanks to be filled to above 3/4 full before emptying; the fuller, the better. The more force you have behind the evacuation, the less chance you’ll have of leaving contents behind. Any residual build-up in the bottom of any holding tank will eventually grow to become a blockage. You’ll notice I said “both” holding tanks above. Many RVers are instructed to leave open the termination valve for the gray tank and simply let it drain continually while connected to the campsite sewer inlet. This practice will leave behind a residue that will dry out and lead to odors and possible blockages. That’s right; holding tank odors can emanate from the gray tank as well as the solid waste tank. Fill them both and then evacuate when near full. Additionally, leaving the gray tank valve open all the time disrupts the sewer venting balance within the campground sewer system itself.”

“Ever notice a waste odor while strolling through the campground? With open gray valves, the campground now has multiple vents (individual motorhomes) spewing odors closer to the ground via the gray vents on the RV. It’s common practice to dump the black tank first, then the gray tank in order to help rinse the solids out of the termination piping and sewer hose. Continue to do this. I also recommend, where practical, to flush each tank with lots of clean fresh water to help rinse away any particles left over after evacuating. You cannot use too much fresh water in this step.”

“My final recommendation is one you’ll have to sub out. Locate a dealer offering the cleaning services of All Pro Water Flow. This company employs high-pressure hydronics (500 – 3,000 PSI) for cleaning the entire interior of each holding tank. Macerators and pumps may allow holding tanks to be evacuated faster while RVing, but the results will not likely be cleaner or more thorough than liberal amounts of high-pressure water spraying the entire interior surface of each tank once or twice a year (depending on use). For those holding tanks with internal monitor probes, this process will eliminate those erratic tank readings also! Randall, this service will eliminate your current condition.
– Gary Bunzer, The RV Doctor (RVDoctor.com)