Dick, I can't locate the implementation date for the RVIA standards
, perhaps you will be successful where I failed.
That website is only an overview of the standards, the actual verbage must be purchased.
This is an excerpt from the website: "Vents to release gases from any waste holding tank must be provided." To me that means the vacuum-breakers under the counter cannot be the only opening, as they are not a vent. I sure would not want one inside my RV releasing any tank gasses purposely.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"