Good morning from Drain Master, the RV Waste Management Specialists. Our goal is to make your dumping experience more sanitary, environmentally friendly and uneventful.7EssentialHoldingTankTips.pdf The attachment if followed by all RVers will clean up the ground water contamination at RV parks with full hook ups over time. If you have questions or would like to comment on RV Waste management or have an issue with your RV we would be happy to talk to you about it, simply call 877 787 883 X12 Toll free.