NY -- Standard&Poor's CreditWire 10/26/98 -- Standard&Poor's today assigned it double-'A' rating to Huntsville, Ala.'s $21 million water system revenue warrants series 1998 dated Nov. 1, 1998 due Nov. 1, 2018. The rating reflects: -- An expanding economic base with above-average wealth and income levels, and low unemployment rates, (Huntsville's GO rating is double-'A'); -- Low water rates when compared to those of peers on a regional and national scale, resulting in tremendous rate flexibility; -- Sound financial performance and position, which generated solid debt service coverage levels of 2 times (x ) in 1997; -- A moderate capital improvement program, which is expected to be funded from surplus cash; and -- A strong, proactive management