Abstract: A dispersion of 2,2-dibromo-3-nitrilopropionamide (“DBNPA”) particles in a restrictedly viscosified concentrated brine solution effectively negates gelling of the brine solution because the naturally occurring gum used does not exhibits Ellis-Plastic behavior in the concentrated brine at a pH of from about 1 to 4. Because the DBNPA particles are much less soluble in the brine than in water, the particles are held in the stable dispersion. Moreover, a dispersion of DBNPA particles in viscosified brine provides at least the same biocidal effect as a solution of DBNPA, relative to the same concentration of DBNPA in solution in glycol, but also concurrently nullifies the degradation of the DBNPA during storage so that the loss due to hydrolysis of the DBNPA is less than 3% over a period of three months at a temperature in the range from ?5° C. to 25° C. A process is disclosed for making the dispersion which can be stored at a temperature in the range from about ?5° C. to 25° C.