Stormwater

 

stormwater pipeBoth the US Environmental Protection Agency (EPA) and Massachusetts Department of Environmental Protection (DEP) regulate stormwater in Massachusetts. In addition municipalities may have local drainage, sewer, wetland, or other ordinances that regulate stormwater. 

In 1987, Congress passed the Clean Water Act to help improve the quality of the nation's water supply. Overall conditions improved, however, some water bodies remained polluted. The 1996 National Water Quality Inventory, which examined each state's water quality, concluded that 40 percent of surveyed US water bodies were still polluted and fell short of water quality standards. A major contributor to this contamination is polluted runoff.

At the state level, Massachusetts enacted a Stormwater Management Policy in 1997 to promote nine stormwater management standards. These were the first state-wide requirements for stormwater quality treatment, maintaining groundwater recharge processes, and maintaining stormwater treatment systems. The policy was added as an amendment to the state Wetlands Protection Act and is enforced by local Conservation Commissions.

National Phase I and II Stormwater Regulations

The issue of stormwater runoff was first addressed at the national level in Phase I of the EPA's stormwater program in 1990. Phase I required permit coverage under the National Pollutant Discharge Elimination System (NPDES). Those required to apply for permits included municipal separate sewer systems that serve populations of approximately 100,00 people or more, and construction activity disturbing five or more acres of land.

Storm Water Phase II Final Rule is the EPA's next step in addressing stormwater runoff pollution. Phase II expands upon those required to hold permits under Phase I to include all of the towns on Cape Cod except Provincetown, Wellfleet, and Truro because they are considered to be "operators of MS4s (municipal separate storm sewer systems) in urbanized areas." Phase II also applies to operators of small constructions sites that disturb between one and five acres of land, and 10 categories of industrial activity.

Phase II is anticipated to further reduce adverse impacts to water quality and aquatic habitat by controlling the unregulated sources of stormwater discharges that hold the greatest likelihood of significantly contributing to stormwater pollution. The law states that towns must comply with the six required minimum control measures of Phase II to maximize community awareness of stormwater pollution.

Project STORM

storm drain labelThe Cape Cod Commission water resources staff coordinates Project STORM (Stormwater Outreach for Regional Municipalities), a collaborative effort among towns on Cape Cod to share resources, ideas, and solutions to mitigate the impacts of stormwater and to educate all citizens on effective means to control impacts from stormwater pollution. The project provides assistance to towns that must comply with EPA Phase II stormwater regulations. AmeriCorps Cape Cod members support the effort by assisting towns with stormwater mapping and the identification of catch basin and outfall locations. Commission staff working on Project STORM have also created resources for Cape residents about the importance of stopping stormwater pollution to make our water bodies cleaner and safer to use.

Best Management Practices (BMPs)

  • Structural: Structural BMPs are devices used to control or treat stormwater pollution. They perform differently and require different physical factors and maintenance to achieve top efficiency. Options include:
    • Pretreatment to remove sediments and reduce velocity of water before final stormwater disposal. The most common pretreatment devices for Cape Cod include water quality swales, sediment traps, and water quality inlets.
    • Infiltration devices to drain water directly into the ground. Infiltration trenches and dry wells are located below ground to directly infiltrate stormwater run-off to the soils and groundwater. Infiltration basis are above ground; these storage depressions function by storing water and allowing it to slowly infiltrate into the ground. Vegetation planted in an infiltration basin encourages bioretention; in this passive, inexpensive way, the treatment of stormwater is greatly enhanced.
    • Innovative technologies that work well in the sandy soils of Cape Cod, including permeable paving materials, centrifugal devices, and shut-off valves
  • Non-structural: Nonstructural BMPs are intended to prevent or reduce the contamination of stormwater runoff. They can be used in a variety of different sources or activities. By reducing pollutant generation, adverse water quality impacts are diminished from the start. Examples include:
    • Disposal of household waste and toxic chemicals
    • Use of pesticides, herbicides, and fertilizers
    • Automobile maintenance and vehicle washing
    • Spill prevention and response

Preventing and controlling the sources of these pollutants requires a change in behavior. Many municipalities have already implemented nonstructural BMPs as a means to address other concerns, such as controlling product loss, minimizing waste production, accident and fire prevention, worker health and safety, or site security. Regulating these issues can bring municipalities into compliance with environmental/stormwater regulations even though they were never explicitly addressing stormwater issues. For example, municipalities may stress public safety and educate on spill prevention and response, which addresses stormwater quality at the same time.

  • Low Impact Development (LID) Concept: LID is a cost-effective alternative to stormwater control technology that is being used by developers across the nation. Unlike traditional stormwater control techniques, LID strategies prioritizes resource conservation and increasing green space, while simultaneously controlling runoff discharge, volume, and quality to reach levels of preconstruction stormwater control. One of the primary goals of LID design is to reduce runoff volume by infiltrating rainfall water to groundwater, evaporating rain water back to the atmosphere after a storm, and finding beneficial uses for water rather than exporting it as a waste product down storm sewers. LID is a blend of measures that include conservation, minimization of impacts, maintaining historic, pre-developed runoff rates, integrated management practices, and pollution prevention techniques. Together, these form a holistic approach to site design and stormwater management:
    • Conserve natural areas.
    • Minimize development impacts.
    • Maintain site runoff rate.
    • Use integrated management practices.
    • Implement pollution prevention, proper maintenance, and public education programs.
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