Congestible natural assets that are prone to market failure include pastures, fisheries, and aquifers, but also the assimilative capacities of waste sinks such as rivers, oceans, air and atmospheres to absorb and eliminate the residual by-products from consumption and production. Each of these assets corresponds to goods and services that should be priced at marginal cost in a first-best world (for example using Pigouvian taxes where property rights cannot be assigned). In a second-best world where government also uses taxes to raise revenue, each of these separate goods should also be taxed additionally as part of an optimal revenue-raising tax program with "Ramsey" taxes. In each case, the taxes on these exogenously-supplied congestible assets will produce two benefits: it will restore allocative efficiency, and (up to the Pigouvian price) it will appropriate the resource rents as a non-distorting source of revenue. The "total" optimal tax will in general be higher, and the optimal pollution level lower, because Ramsey taxes are added to to Pigouvian pricing of the good. The two welfare benefits from these taxes will derive from improved allocative efficiency and tax efficiency. Based on a general equilibrium model with k commodities and n-k environmental waste sinks, the analysis further shows that even if pollution damages are zero, it will still be optimal to tax waste disposal because it broadens the tax base and pays to concentrate distortionary taxes on exogenously supplied resources. In this case, Pigouvian pricing (equal to zero) combined with indirect labor taxation will not produce efficiency because it would capture no rents from the free waste disposal service. These conclusions support the strong double dividend hypothesis, and are more general than those in recent literature which has called into question the strong "double dividend" hypothesis. This is due primarily to the inclusion of waste disposal services separately in the model, and by allowing non-zero marginal rates of technical substitution between commodities and disposal.