A controlled release biocidal salt of a first component comprises a cation of a N.sup..alpha.--(C.sub.1-C.sub.22)alkanoyl di-basic amino acid alkyl(C.sub.1-C.sub.22)ester cationic biocidal molecule and a second component comprising an anion of a monomeric anionic molecule having insignificant biocidal activity. The salt is characterized such that when the salt is exposed to an aqueous medium, the salt partially dissolves thereby releasing biocidal ions in an amount sufficient to exceed the MIC or MBC of a target bacteria being controlled, and further characterized as leaving a residual reservoir of undissolved salt capable of releasing more biocidal ions as the salt is consumed or otherwise removed from the environment encompassing the target bacteria. The preferred cationic biocidal molecule comprises N.sup..alpha.-lauroyl-L-arginine ethyl ester ("LAE").