On December 14, 2007, the Los Angeles Department of Water and Power (LADWP) announced that the Silver Lake and Elysee Reservoirs would be drained due to bromate contamination. At Silver Lake and Elyson Reservoirs, bromide, chlorine gas, and sunlight in well water mix to form bromate. The decontamination process took 4 months and discharged more than 600 million US gallons (2.3 x 106 m3) of sewage. 
On June 9, 2008, LADWP began covering the 10-acre (4-hectare), 58-million-US-gallon (0.22×106 m3) surface of the open Ivanhoe Reservoir with black plastic shade balls to block sunlight, causing the naturally occurring The bromide reacts with the chlorine used in the treatment. Three million 40-cent balls are needed to cover the Ivanhoe and Elysian reservoirs.
Bromate is a colorless to pale solid. Slightly soluble in water, the density is higher than water. Contact may be irritating to skin, eyes and mucous membranes. May be toxic if ingested. Used in the manufacture of other chemicals.
Bromate is an oxybromide anion and a monovalent inorganic anion. It is the conjugate base of bromic acid.
Bromate Anion Reduction: A Novel Autocatalytic (EC″) Mechanism for Electrochemical Processes. Its Implications for High Energy and Power Density Redox Flow Batteries.
Given the very high redox charge and energy density of the process, which makes it an attractive source of electrical energy, theoretical studies of bromate electroreduction in strongly acidic solutions have recently been outlined. Keeping in mind the non-electroreactivity of the bromate ion, the possibility of ensuring its rapid conversion via redox mediator cycling (EC’ mechanism) was analysed. Within the framework of several theoretical approaches based on the traditional Nernst layer model or its recently proposed advanced version (the generalized Nernst layer model), disproportionation reactions via the bromine/bromide redox couple and within the solution phase are considered Alternative routes, in the convective-diffusion transport equation. This analysis revealed that the process corresponds to a novel (EC″) electrochemical mechanism, as the conversion of the primary oxidant (bromate) proceeds via an autocatalytic redox cycle, in which bromate consumption leads to bromine/bromide The gradual accumulation process of redox pair catalysis. Therefore, even a trace amount of bromine in the bulk solution can lead to extremely high current density under certain conditions, which may even overcome the diffusion limit of bromate