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Storm Water (MS4)





Storm Water Pollution Prevention

What is Storm Water?

Storm water is water from precipitation that flows across the ground and pavement when it rains or when snow and ice melt.  The water seeps into the ground or drains into what we call storm sewers.  These are the drains you see at street corners or at low points on the sides of your streets.  Collectively, the draining water is called storm water runoff and is a concern to us in commercial and industrial sites as well as your neighborhood because of the pollutants it carries.  If you suspect someone is discharging prohibited material into a storm drain please call the Town Hall immediately at 317-861-4727.  You can report this anonymously.

Where does the storm water go after it drains into a storm drain?

Storm water that does not seep into the ground, drains into systems of underground pipes and may travel into  Ditches.

What are common contributors to storm water pollution?

When it rains, oil, antifreeze, detergents, pesticides and other pollutants get washed from driveways, backyards, parking lots, and streets into storm drains and then directly into ditches untreated! The following items specify everyday pollutants occurring at our homes, businesses, and construction sites.


  • Pet waste left on the ground gets carried away by storm water, contributing harmful bacteria, parasites and viruses to our streams.  Please clean up after your pet.  When your pet goes on the lawn, remember it doesn't just go on the lawn.
  • Vehicle fluids such as oil, gas and antifreeze are the #1 surface water quality problems nationwide.  Recycle used oil in a clean, sealed, plastic container.  Call 317-477-7605 for a list of collection sites that accept used oil or for answers to questions regarding proper disposal of other chemicals.  When your car's leaking oil on the street, remember it's not just leaking oil on the street.
  • SWEEP!  Hosing off pavements washed pollutants into storm drains leading straight to ditches.
  • Deliver old paint, pesticides, solvents and batteries to Tox Away Day drop off sites.  Watch your local paper for dates & times.
  • Street litter such as styrofoam, plastic, and paper can be prevented from blowing into inlets by keeping trash bins covered and by not littering.
  • Yard waste such as grass clippings, tree trimmings, and leaves can be composted and used for fertilizer around the yard .


At industrial sites, chemical spills that contain toxic substances, smoke stacks that spew emissions and uncovered or unprotected outdoor storage or waste areas can contribute pollutants to storm water runoff.  Best management practices include:

  • Washing vehicles or equipment in wash bays hooked up to the sanitary sewer.  Don't wash off detergents, oils, and greases into streets or storm drains.  When you're washing your car in the driveway, remember you're not just washing your car in the driveway.
  • Divert rainfall runoff from fueling islands by building a canopy or cover over them.
  • In compliance with fire code, any barrels containing potentially hazardous liquids should be in a sealed container, stored inside a building or under cover, and propped up on pallets with secondary containment in case of a spill.  Call your local Fire Department for code specifics.
  • Waste and processed water of any type must be discharged to the sanitary sewer.  Discharge of wastewater to the ground or storm drains is prohibited.


  • Waste from chemicals and materials used in construction can wash into drains leading to ditches during rainy weather.  Soil that erodes from construction sites can contribute to environmental degradation.
  • Sediments and other debris clog fish gills, damage fish habitat and block the light needed for the plants to survive.
  • Wash waters from concrete mixers should be disposed of back at the contractors site.  Never rinse out concrete truck chutes with a hose and allow to run down the street into the storm drains.
  • Waste Storage for used oils, solvents and other hazardous fluids must be under cover with secondary containment in case of a spill and to prevent rainfall from contact which would wash hazardous fluids into nearby waterways.
  • Landscaping and earthmoving pollutants include planting, excavation, tilling masonry and concrete, solid wastes such as trees and shrubs, soil additives and revegetation of graded areas, all contribute to soil erosion.  Silt fences to hold back loose soil and sand when it gets windy allows sand and soils to stay out of the street where rainwater can wash it into storm drains.
  • Vehicle and equipment maintenance becomes a significant factor when engine repairs or preventive maintenance such as changing oil and other fluids occurs at the construction site.  Maintain a "dry site" by using off site facilities, performing work in designated areas only, providing cover for materials stored outside, containing and cleaning up spills immediately, and training employees and subcontractors.