NOVELTY - A bioremediation foam composition (C1) comprising water, at least one microorganism capable of degrading organic material and at least one water dispersible or water soluble polymer (a), is new.    USE - As bioremediation foam composition for treating contaminated subterranean material by in-situ method (claimed); and for delivery of microorganisms e.g. bacteria to contaminated soils for reducing or removing contaminants from the contaminated environments. The microorganisms include bacteria such as Arthrobacter species, Pseudomonas species, Rhodosporium species and Bacillus subtilis.    ADVANTAGE - The composition allows in-situ bioremediation. The adaptor generates the foam at the wellhead; allows easy pumping of foams; enables efficient pumping of the foamable composition to the wellhead and effective formation of foam at the last possible moment before injection into the wellhead.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a foam generating well head adaptor (C2) comprising a foam generating chamber (b), a conduit (c) for injection of foamable composition into the adaptor, a conduit (d) for injection of compressed air into the adaptor, and device (e) for securing attachment of the adaptor to the head of an in-situ bioremediation well;    (2) a bioremediation injection well (C3) comprising (C2);    (3) in-situ bioremediation (P1) of contaminated subterranean material involving: supplying foamable composition and compressed air to an in-situ bioremediation well comprising (C2), to form bioremediation foam composition which under the applied pressure of foamable composition and/or compressed air to the wellhead is forced into the contaminated subterranean material to be bioremediated;    (4) in-situ bioremediation (P2) of contaminated soil involving: treating contaminated soil by injecting (C1) into a subterranean region of contaminated soil via injection well having outlet located at a depth of at least 1 meter below the subterranean surface and proximate to the subterranean contamination; and treating contaminated soil by injecting a composition comprising at least one microorganism capable of degrading organic material and (a) at a concentration of 0.1 - 0.5 wt.% of (a) based on the total weight of the composition, into the subterranean region of contaminated soil via injection lance which is inserted into the surface of the soil such that the composition is injected at a depth of up to 1 meter depth below the soil surface; and    (5) in-situ bioremediation (P3) of contaminated soil involving: treating contaminated soil by injecting (C1) into a subterranean region of contaminated soil via injection well having outlet located at a depth of at least 1 meter below the subterranean surface and proximate to the subterranean contamination; and treating contaminated soil by injecting composition comprising at least one microorganism capable of degrading organic material and (a) at a concentration of 0.25 - 5 wt.% of (a) based on the total weight of the composition.