Stormwater Pollution Prevention & MS4

According to the Environmental Protection Agency (EPA), stormwater pollution is the number one cause of water pollution in the country. Stormwater pollution occurs when rain or snowmelt flows over a surface, such as a street or a driveway, and picks up pollutants — oils, chemicals, trash, and other materials not found naturally in our waterways. These pollutants then flow into the storm sewer system, which drains untreated to our local lakes, streams, and the Cache la Poudre River. Polluted stormwater may result in significant impacts on the downstream waterways that detrimentally affect both the aquatic ecosystem and quality of life in our community.

In effect, everyone in Windsor plays a role in managing stormwater pollution because we make daily choices that can impact it. Everything from littering, failing to pick up pet excrement, mismanaging dirt on construction sites, not cleaning hazardous material spills on pavement, and more, has an impact on keeping stormwater clean.

Oil in snowmelt
Unknown material in ditch
Sediment in street

The Municipal Storm Sewer System (MS4) Permit

There are two types of sewer systems in Windsor: sanitary sewer and storm sewer, also known as the Municipal Separate Storm Sewer System, or MS4. It is the collection of pipes, ditches, detention ponds and other conveyances that carry stormwater runoff. Both sewer systems are maintained by Town of Windsor Public Works. The difference, however, is big: while water from the sanitary sewer is sent to a treatment plan for removal of pollutants, water from the MS4 ends up in the Cache la Poudre River untreated, along with any pollutants it picks up along the way.

In 2017, the Town of Windsor received its stormwater discharge permit from the Colorado Department of Public Health and Environment. The permit allows the Windsor to discharge the cleanest stormwater possible from its MS4 to the Cache la Poudre River. The MS4 permit program is developed and monitored by the Stormwater Program Coordinator.

Windsor MS4 Brochure (PDF)

Construction Sites

Windsor’s Construction Sites Program Document (PDF) contains the information needed to stay in compliance with the MS4 when proposing and carrying out a construction project in Windsor. Standards and requirements, permit applications, plan requirements and inspection procedures are described in this document.  The Managing Construction Sites Brochure (PDF) contains basic guidance for stormwater pollution prevention on a construction site.

Specifications and Criteria
Windsor’s Storm Drainage Criteria (PDF) and  Notes for Construction Specification (PDF).

Quick Links
GESCP Permit Application (PDF)   GESCP Checklist (PDF)   GESCP Security Cost Worksheet

MS4 Permit Compliance

In compliance with the stormwater discharge permit requirements, Windsor will implement programs to reduce stormwater pollutants. The plan for doing this is outlined in MS4 Program Description Document which can be requested by contacting Stormwater Program Coordinator

As a condition of the permit, the following five measures must be met:

  1. Public Education and Outreach: Educate the community to reduce water quality impacts associated with pollutants in stormwater runoff.
  2. Illicit Detection and Elimination: Develop, implement, and enforce a program to detect and eliminate spills, illegal dumping and other non-stormwater discharges into the town mapped storm sewer system.
  3. Construction Site Stormwater Runoff Control: Develop, implement and enforce a program to reduce discharge of pollutants in stormwater runoff from construction activities.
  4. Post-Construction Stormwater Management: Prevent or minimize impacts to stormwater from new development or redevelopment by ensuring that stormwater conveyance structures are maintained and operate as designed.
  5. Pollution Prevention/Good Housekeeping for Municipal Operations: Develop, implement and enforce a maintenance program to prevent or reduce pollutants in runoff from municipal operations.

The Effects of Stormwater Pollution

Managing stormwater pollution is important because polluted stormwater runoff can have adverse effects on plants, fish, animals and people: 

  • Sediment clouds the water and makes it difficult or impossible for aquatic plants to grow. Sediment can also destroy aquatic habitats.
  • Excess nutrients (like nitrogen, potassium and phosphorus found in fertilizers and pet waste), can cause algae blooms. When algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can’t exist in water with low dissolved oxygen levels.
  • Bacteria and other pathogens can wash into swimming areas and create health hazards, sometimes necessitating swim-beach closures.
  • Trash and plastic bags, six-pack rings, bottles, and cigarette butts washed into waterbodies can choke, suffocate or disable aquatic life such as ducks, fish, turtles and birds.
  • Household hazardous wastes such as insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids can poison aquatic life. Predatory and scavenging animals, as well as people, can become sick or die from eating diseased fish and shellfish or ingesting polluted water.
  • Pollutants can clog pipes and drains, increasing the potential for flooding. Polluted stormwater can also find its way into sources of drinking water. This, in turn, can increase water treatment costs and adversely affect human health.

Source: EPA

Keep Stormwater Drains Free from Pollutants

Windsor needs your help! Motor oil, antifreeze, dirt/sediment, grass clippings, leaves, and paint are common pollutants that can damage our environment. Please make sure that these items are not left in the street, on the sidewalk, or elsewhere. Ideally, only runoff water would enter a storm drain.

Taking a few simple steps will go a long way to reducing pollutants in stormwater runoff.

  • Direct downspouts and gutters onto your lawn and plant beds (or into rain barrels), so runoff seeps into the soil instead of picking up pollutants.
  • Sweep fertilizer and soils onto the lawn so they are not easily washed into storm drains.
  • Collect leaves and grass clippings instead of blowing them into the street, thus reducing nutrient pollution.
  • Promptly clean up oil, gas, or other spills and leaks on your driveway. Use cat litter to absorb oil.
  • Pick up pet waste to help reduce bacterial and nutrient pollution.
  • Remove trash from street gutters to prevent it from falling into storm drains.
  • Motor oil, antifreeze, dirt/sediment, grass clippings, leaves and paint are common pollutants that can be carried away by stormwater. Do not leave these items on the street or sidewalk, and do not put them down the storm drain.
  • See something, say something. If you see a spill or illegal dumping in gutters, storm drains, in or near our lakes, rivers and ditches, report it.

Lawn and Garden Brochure (PDF)

Hazardous Household Waste

Many of the products we use everyday are considered hazardous. They can be readily identified by certain signals words such as Danger, Warning or Poisonous on their labels. These products can be harmful to humans, animals, and the environment if not disposed of properly.

Your home may contain household hazardous waste or HHW: cleaners, paints, sprays, fertilizers, pesticides, motor oil, batteries and more. If these products are dumped in household or storm drains, on the ground or in the trash, toxins are picked up by runoff and may end up in the Cache la Poudre River.

  • Identify and properly dispose of toxic products; always read the label.
  • Purchase the needed amount only to eliminate storage or disposal issues.
  • Share leftover usable products with friends or neighbors who may need it.
  • Buy phosphate-free, biodegradable, water-based products when possible.
  • Switch out chemical cleaners for lemon juice, hot H2O, vinegar, borax, and baking soda.
  • Take toxic products to your county HHW disposal site.

Residents who live in Weld County, can visit the Weld County Household Hazardous Waste Disposal site. Residents who live in Larimer County, can visit the Larimer County Household Hazardous Waste Disposal site. 

HHW Brochure (PDF)

Windsor Businesses Can Help Prevent Stormwater Pollution

Many businesses  have an impact on stormwater. Landscaping companies, auto repair shops, restaurants, manufacturing and building and remodeling contractors can all make small changes to the way they are doing business with little effort that, collectively, will make a difference. Please see the Stormwater Quality fact sheet to see what you can do to make a difference.

Poudre River