Vallejo, the Northern California city that sought chapter 9 bankruptcy protection in 2008, is set to sell about $19 million in water-revenue bonds next week in its first municipal-debt sale since the filing, Bloomberg News reported yesterday. Proceeds from the deal, scheduled for Oct. 30, will refinance outstanding debt, offering documents show. The water fund from which debt-service payments are made wasn’t impaired in the bankruptcy proceedings, according to the documents. Standard & Poor’s rates the bonds A+, fifth-highest. They will mature from 2027 to 2031. The offering from Vallejo, a city of about 120,000 in the Bay Area, may serve as an example of how much localities will have to pay for post-bankruptcy access to the $3.7 trillion municipal market. The city officially exited bankruptcy on Nov. 1, 2011.