Jefferson County, Ala., residents and businesses face a sewer rate increase for the first time in four years as county commissioners seek to raise revenues after massive sewer debt led to the nation’s largest municipal bankruptcy last year.

Commissioners voted 4-0, with one not present, on Nov. 6 to raise rates starting on March 1. The rate hike would generate about $8.3 million in revenue for the debt-plagued sewer system.

The rate increase will add less than $2 per month to most bills, commissioners said. The average monthly sewer bill is about $38.

Septic-tank haulers will see their rates double, to $60 from $30, for dumping 1,000 gallons at county plants.

Commissioners, in a statement issued after the vote, called the rates “fair, reasonable, non-discriminatory and feasible.”

Rates had been unchanged for years but increased more than 300% between 1997 and 2008, after the start of a huge expansion that was the result of a consent agreement with the U.S. Environmental Protection Agency. There were no increases since 2008.

The county claimed $4.23 billion in debt—$3.14 billion from the massive but unplanned sewer expansion and corrupt financing deals—when it sought bankruptcy in November 2011.

Some 26 individuals and companies were fined or jailed as a result of bribery and corruption charges.