Stormwater Management

The Clean Water Act Amendments of 1987 established the National Pollutant Discharge Elimination System (NPDES) stormwater program. The Act called for implementation in two phases; Phase I addressed the most significant sources of pollution in stormwater runoff. Phase II addresses other sources to protect water quality. The Phase II regulations were published in the December 8, 1999 Federal Register (PDF).

Phase I of the NPDES Storm Water program began in 1990 and required medium and large municipal separate storm sewer systems (MS4s) to obtain NPDES coverage. The expanded Phase II program began March 2003 and required small MS4s in urbanized areas to obtain NPDES permits and implement six minimum control measures. An urbanized area as delineated by the Bureau of Census is defined as a central place or places and the adjacent densely settled surrounding area that together have a residential population of at least 50,000 people and an overall population density of at least 500 people per square miles.

A few simple ways to help in day-to-day activities include:

• Never dump anything into the street or down a storm drain. They flow directly to creeks, streams and the Mississippi and Rock Rivers.
• Keep leaves and grass clippings out of the streets so that they do not end up washing into the storm drains.
• Properly dispose of paints, solvents, cleaners, weed killers, insecticides, and other chemicals. Utilize the Scott County Household Hazardous Materials facility. ExternalLink.gif
• Collect oil and other automotive products, and recycle or properly dispose of them.
• Wash vehicles at a car wash facility or on your lawn instead of in the driveway. Use biodegradable soap.
• Keep automobiles and your gas-powered lawnmowers or blowers well-tuned so that they are not dripping toxic fluids or emitting toxic fumes.
• If a spill or leak occurs, properly clean up the spill and properly dispose of the cleanup materials.
• Do not use chemicals on your lawn before it is expected to rain, and try using organic or slow-release products, which are better for your lawn and for the environment.
• Be conservative with pesticides and herbicides (weed killers) and try natural alternatives. Call the local Extension Service to find out more about natural pesticides.
• Make sure your air conditioners are in good working order and not leaking harmful chemicals.
• Direct downspouts away from paved areas.
• Clean up pet waste.

Household items with label warnings inform people to be careful of how the items are used. Hazardous items may be labeled "toxic," "acid," "poison," "flammable" or "caustic."

Leftovers of household hazardous materials must be disposed of properly. They should never be poured down the drain, put in the trash or dumped on the ground. When this happens, the materials mix with stormwater runoff and can contaminate our local waterways.

What Is Nonpoint Source Pollution?

Unlike specific points of pollution, such as some factory discharge pipes, nonpoint source pollution comes from many different spots. From farmlands to suburban lawns, people use the land in ways that cause nonpoint source pollution. And it is also more difficult to control nonpoint sources of pollution.

Some examples of nonpoint source pollution include:

• Excess farm and lawn nutrients that move throughout the soil into the groundwater or enter local waters directly through runoff during heavy rains
• Uncontrolled stormwater runoff from construction sites
• Forestry operations
• Animal wastes
• Even pollutants released directly into the atmosphere

Nonpoint source pollution closes beaches, kills wildlife, poisons drinking water resources, destroys fish and shellfish habitat, and causes dangerous algal blooms. In most cases, this pollution comes from various land use practices, air pollutants, and sewer overflows, - and some ordinary activities of everyday life.

What Are the Pollutants?

Nonpoint source pollutants include nutrients, such as nitrogen and phosphorus from fertilizers and septic tank systems, sediments from construction sites, pesticides from agricultural lands, salts from winter road treatment, and trace metals and toxic chemicals from inadequately protected landfills. Individually, these pollutants may not be a major concern, but considered as a whole they can result in widespread water quality problems that must be addressed.

Everyone Is Part of the Solution

Prevention is essential to reducing nonpoint source pollution. Examples of ways to prevent pollution include sedimentation ponds for capturing sediments in stormwater runoff, and buffer strips of vegetation to separate farmed or urban lands from nearby waters. There are also many ways for citizens to help:

• Use pesticides and herbicides sparingly on lawns and gardens, and only after considering more natural methods of control;
• Protect shrubs, vines, and other plants that grow along waterways;
• Seed or mulch areas where soil can wash away;
• Keep toxins such as engine oils, paint thinners, and pesticides out of sewers, septic tanks, and stormwater drains - use carefully and dispose of them safely (at the Scott County household hazardous waste collection site).
• Control fertilizer use on lawns and gardens;
• Take public transportation, ride in a carpool, and limit driving whenever possible to reduce air emissions and oil and gasoline runoff, especially from gas service stations. (proper car maintenance also helps); and
• When changing car oil, make sure used oil is collected and not disposed of on the ground.

Many types of urban activities can directly impact the health of surface water. Local developers, contractors, subcontractors and their crews can adversely impact water quality by not properly planning ahead to keep dirt, debris, and other waste materials away from storm drains and local creeks before, during and after construction activities. Federal, State, and Local law implemented by Rock Island County, mandates that those who undertake construction activities provide pollution protection at their construction sites.

Fill Projects

In some instances, property owners may wish to fill in low-lying areas or ravines on their property with soil or other material. Many times these areas are natural waterways and are therefore considered part of a Municipal Separate Storm Sewer System (MS4). State and federal regulations prohibit contamination of this MS4. Before fill can be allowed on a site the owner must apply for a Grading and Drainage Permit. Approved Fill Material is defined as uncontaminated, nonwater-soluble, nondecomposable inert solid material. Clean fill includes soil, rock, stone, dredged material, used asphalt and brick, block or concrete masonry units (CMUs) that have been broken so as not to become "critter condos", used concrete that has been broken into pieces smaller than 12 inches by 12 inches by 12 inches with no protruding bar from construction and demolition activities that is separate from other waste and recognizable as such. Unused asphalt would not meet the definition of clean fill.

Grading, erosion, and sediment control plans prepared by a licensed professional civil engineer or a certified professional in erosion and sediment control (CPESC), or a person credentialed in a manner acceptable to the County must be submitted and approved before a Stormwater Permit, and consequently a building permit, can be issued. As a minimum, the following information shall be included:

• A location map and pertinent surrounding features
• An overall site plan (minimum scale 1 inch equals 50 feet) clearly indicating the area of the site and the type of land-disturbing activities which will take place.
• Existing and proposed topography shown in one-foot intervals
• The location and description of proposed stormwater management facilities
• The limits of the land-disturbing activities including clearing and grubbing
• Drainage features including open channels, ponds, streams, or rivers
• Existing and proposed structures and utilities which may impact the plan
• Erosion and sediment control methods to be implemented as part of the land-disturbing activities on the site:
  • Location, size, maintenance requirements, and design calculations for best management practices
  • Detail drawings or references to details
  • Type and quantity of seeding, fertilizing, mulching, and other plantings
• The soil types affected by the land-disturbing activities, and location of highly erodible or unstable soils as determined by the most current NRCS soil survey.
• The schedule and staging of grading, erosion, and sediment control practices, and restoration.
• A properly completed Application

Construction can begin once the permit has been issued and the proper installation of required Best Management Practices (BMPs) have been inspected and approved.

Plan review staff will check site plans to ensure they address common, critical elements. The following ten elements of an effective stormwater site plan present a comprehensive approach to addressing construction site runoff. These elements include:

• Minimize Clearing and Grading
  Construction site operators should take all measures possible to avoid clearing/grading stream buffers; forest conservation areas; wetlands, springs and seeps; highly erodible soils; steep slopes; environmental features; and stormwater infiltration areas. In addition, site fingerprinting should be employed and limits of disturbance (LOD) should be mapped, clearly delineated on site with flags and conveyed to personnel.
• Protect Waterways
  Construction site operators should identify waterbodies on site and adjacent to the site. If construction activities occur near a waterbody, clearing/grading activities should be minimal and silt fencing and/or and earthen dikes should be installed.
• Phase Construction to Limit Soil Exposure
  Prior to construction initiation, activities should be broken into phases. Grading activities should be limited to the phase immediately under construction to decrease the time that soil is exposed, which, in turn, decreases the potential for erosion. Additional phases should begin only when the last phase is near completion and preferably exposed soil has been stabilized. Construction scheduling should facilitate installation of erosion and sediment control measures prior to construction start, detail time limits for soil stabilization after grading occurs, and schedule BMP maintenance.
• Immediately Stabilize Exposed Soils
  Exposed soils should be stabilized within two weeks of the onset of exposure. The long-term goal is to establish permanent vegetation after each phase of construction; however, mulch, hydroseeding, or other means of soil coverage may protect exposed soil while facilitating vegetation growth. The stormwater site plan should detail appropriate plant species to be seeded, as well as weather and climactic conditions necessary for germination and successful vegetation establishment.
• Protect Steep Slopes and Cuts
  Cutting and grading of steep slopes (greater than 15%) should be avoided wherever possible. If a steep slope exists, all water flowing onto the slope should be redirected with diversions or a slope drain. Silt fence at top and toe of the slope must be anchored well, although this measure may not provide adequate protection by itself. On steep slopes, jute netting and erosion control blankets (geotextiles) should be used in conjunction with seeding or mulching, as seeding alone may not be effective.
• Install Perimeter Controls to Filter Sediments
  Silt fence should be properly installed around the perimeter of the construction site. A fiber roll on the inside (site-facing) of the silt fence works to provide additional filtration. In areas of heavy flows or breech concern, a properly sized earthen dike with a stabilized outlet should be created. In addition, catch basin inlets receiving stormwater flows from the construction site must be protected with adequate inlet controls.
• Employ Advanced Sediment Settling Controls
  Sediment Basins should be created where space is available; however, discharge from basins must be non-turbid. The use of skimmers and multiple cell construction of basins assist in sediment drop-out.
• Certify and Train Contractors on Stormwater Site Plan Implementation
  Contractors and/or construction staff should be trained in erosion and sediment control practices and procedures to effectively install and manage erosion and sediment control features. Meetings and site inspections by municipal staff provide opportunities for discussion of effective BMPs with site staff. Inspectors should make a strong commitment to contractor education to develop a constructive and responsive relationship.
• Control Waste at the Construction Site
  The site plan should describe the type of construction site waste found at the site (such as discarded building materials, concrete truck washout, chemicals, litter, and sanitary waste) and how that waste will be controlled to minimize adverse impacts to water quality. For example, concrete washout and trash storage areas should be clearly labeled on the plan and should be located away from waterbodies and catch basin inlets.
• Inspect and Maintain BMPs
  Each stormwater site plan should clearly describe the construction site operator's BMP inspection and maintenance, including who will inspect the site and how often. Ideally, an example inspection form should be included with the plan. Inspections should occur at a regular interval and should also occur immediately before and after rain events. The plan should also describe how BMPs will be maintained.