The stormwater discharge from ARDOT Municipal Separate Storm Sewer System (MS4) within the Little Rock city limits is covered by a different permit from the remainder of the state.

The city of Little Rock was designated as a medium-size municipality (population size 100,000-250,000) for the purposes of MS4 stormwater permitting. Operators of an MS4 system within this area were required to obtain a permit under the National Pollutant Discharge Elimination System Phase I regulations for MS4s, which resulted in the city of Little Rock and ARDOT becoming co-permittees with a shared SWMP.

Stormwater discharges by the city of Little Rock and ARDOT’s combined MS4 system must meet the conditions of DEQ’s Permit Number ARS000002.

This permit establishes the responsibilities of each co-permittee with regards to compliance, monitoring, record keeping, and reporting permit conditions.