Standard & Poor's Ratings Services has lowered its rating on the Central Delaware County Authority, which pipes wastewater out of 10 townships and boroughs, two full notches, to A- from A+. Analyst Alexander Vargas cited "inadequate" revenues to cover its debt service, and a practice of using working capital to make bond payments, since the authority borrowed money for sewer upgrades four years ago. Authority officials weren't immediately available for comment.

The authority, which covers Marple, Newtown, Nether Providence, Ridley, Springfield and Edgmont Townships, along with Swarthmore, Morton, Prospect Park, Ridley Park and Rutledge boroughs, also suffers from "high debt levels, with plans to issue additional debt," Vargas warned.

"Recent rate increases to member municipalities will be sufficient to provide at least adequate debt service coverage," the analyst predicted, though "we understand that the authority may decide to draw down cash reserves for capital improvements." If finances don't recover despite the higher rates, "we would likely lower the rating further," and are unlikely to boost the rating at least for the next couple of years even if the increase yields extra cash as expected, "given CDCA's recent history of weak financial performance" along with its high debt and plans to borrow more.

Low bond ratings tend to force towns to pay extra in order to convince investors to lend them money, for example by buying their bonds.