Storm Water Quality

Municipal Separate Storm Sewer System

A Municipal Separate Storm Sewer System (MS4) community owns or operates a system for collecting and conveying storm water. It does not include combined sewer overflows and publicly owned treatment works. 

Regulated conveyance systems include:

  • Roads with Drains
  • Municipal Streets
  • Catch Basins
  • Curbs
  • Gutters
  • Storm Drains

  • Piping
  • Channels
  • Ditches
  • Tunnels
  • Conduits

Water Quality

MS4 is an unfunded, federally mandated program that requires municipalities to take measures to reduce pollutants in stormwater runoff to improve water quality. The state requires the Town of Chesterton to comply with this rule (327 IAC 15-13).

Common Ground, Common Water - A Shared Priority
Video from Purdue University

Chesterton's Storm Water Permit

The MS4 is permitted under the National Pollutant Discharge Elimination System (NPDES) program through the Indiana Department of Environmental Management (IDEM). MS4 permits are granted in 5-year cycles at the end of which the permit must be renewed. The Town of Chesterton’s 1st NPDES permit was granted in 2003. The permit was renewed in 2008 and 2013.

Storm Water Quality Management Plan (SWQMP)

The SWQMP is divided into 3 distinct components.

Part A

The first part of the SWQMP is Part A or the initial application. Part A includes a general budget sheet used to indicate to the State that a budget allocation has been made to the MS4 Program.

Part B

Part B is the baseline characterization. The MS4 Operator provides in the Part B information on the characterization of known water quality of all waters that receive storm water outfall discharges within the MS4 area.

Part C

The third component is the Implementation Plan and is designated as Part C. Part C is the working document that outlines the priorities, goals, and implementation strategies that the MS4 will utilize to improve water quality. It is expected that this document will change as issues are solved, best management practices are utilized, and technology improvements are developed.