[A/S] Holding Tank Question

["Harvey Barlow" <harveybarlow@xxxxxxxxxxxxx>]

John,

I understand your situation now.  You have the same predicament that all of
us who own vintage Airstreams have, no gray water tank and what to do with
gray water.

It would not normally be a good idea to leave the sewer line cap on while
opening the black waste tank dump valve.  Gray water will indeed run into
the black tank if you do so but black waste will contaminate the piping
downstream of the dump valve and the entire gray water drain system if you
do so.  If you should accidentally fill the black tank with a combination of
black waste and gray water while the dump valve is in the open position,
combined waste will back up into the gray water piping, possibly emerging
through bath tub drain or sink drains.  At the least, you will have sewer
odor vented into the interior of the trailer.  At worst you will have a bath
tub filled with sewage.  Not a pleasant situation to discover early some
cold morning when you awaken.

A better and very common solution is to buy a special cap for the sewer line
that contains a standard male garden hose fitting in the center.  Designate
a short piece of discarded garden hose, preferably other than white in
color, and use it only to drain gray water on the ground whenever it is
permitted (or unnoticed).  Gray water will not harm anything other than the
sensitivities of environmentalists.  It will actually promote growth of
healthy grass.  Draining it on the ground is illegal in some areas however.
Another more environmentally correct solution is a "blue tank."  A blue tank
is a large plastic tank mounted on an axle and pair of small wheels with a
sewer hose receptacle on the top side.  It can be purchased at any RV store
or RV mail order catalog.  The blue boy as they are sometimes referred to
can be parked under the rear of the trailer with your sewer drain hose
attached to catch gray water.  When full it can be rolled to a dump station
or even lifted and the contents poured into a bathhouse toilet.

Harvey