Get Tanked Services Ltd manufacture plastic waste and water holding containment tanks for motorhomes and caravans.I measure up the space available where the tank is wanted and construct it from polypropolene plastic. The tanks meet self containment regulations for the new zealand motor caravan assosiation (N.Z.M.C.A) and I also fit the tanks fully plumbed for usage. the tanks hold human effulent(toilet waste), dirty water (shower, sink), and fresh water for drinking etc.