Environmental Information for Sweeping Professionals
Stormwater Regulations --
Smaller municipalities and other agencies were brought under the stormwater regulations of the Clean Water Act three years ago. The five-year implementation cycle will be complete in 2008.
Road and street construction and maintenance are affected by the program's six goals:
These same agencies, as they work their way into using the regulations, can control costs by using low-impact-development practices for stormwater management.
What is LID?
Low-impact-development strategies let water infiltration occur as closely to the original area of rainfall as possible.
Landscaping, including soil placement and vegetation, can help reduce the need for expensive engineered runoff removal systems.
Designs need to include ways to avoid pollution from stormwater runoff — another reason for absorbing the moisture as quickly as possible.
Most pollutants get carried along in the first half inch of the storm. LID Systems need to include a buffer to filter the pollutants, particularly during this period. Several companies make retrofits for existing stormwater inlets to do this job, including AquaShield, Stormtreat Systems, Stormceptor, and Stormwater Management.
Best LID stormwater practices include:
Use of engineered grass swales and other LID methods may cost only 35 to 50% of more conventional controls.
Even so, large or highly industrialized cities may have pollutant levels that can't be handled by LID filtration. And, local regulations may need to be overhauled to allow use of LID methods.
Minnesota is a good example of a state that has provided municipalities with help in meeting stormwater regulations. Assessment protocol progress is a key part of their program, with a project team working with the University of Minnesota Extension Services offering help to consultants as well as municipal and county engineers. The team drafted an Assessment Protocol Outline last year.
Their program will monitor various stormwater management practices as the protocol continues to be developed. Work will include assessment of three underground proprietary devices for the Local Road Research Board.
Input sessions last year were geared to several objectives:
Revised stormwater rules now require stormwater permits for cities over 10,000, or over 5,000 if the municipalities are located within a half mile of outstanding value resource water or impaired water.
Small municipalities must develop a Stormwater Pollution Prevention Program that covers:
Wading through regs
Stormwater regulations are complicated and likely to become more so.
Dr. Stephen J. Souza at Princeton Hydro in Ringoes, New Jersey has developed an introduction to help municipal officials understand the new regulations.
“Over 60% of existing water quality problems are the result of non-point source pollution linked to stormwater runoff,’ Souza says. Stormwater runoff can degrade the quality of wetlands, surface water, and groundwater. This impacts the ecological, recreations, and aesthetic attributes of these resources. Degraded surface and groundwater can cause or lead to human health impacts.
Use of a control program is especially needed in developed areas where storm runoff is about 55% of the total downfall compared to 10 to 15% runoff on undeveloped land.
“States were required to adopt municipal stormwater management rules by March of 2003,’ Souza says. The rules pertain to MS4s — Municipal Separate Storm Sewer Systems. The intent of the new rules is to improve the quality of surface waters, letting them meet designated uses.
Rules affect both large and small municipalities, but requirements differ. Both Tier A (large) and Tier B (small) cities must develop and adopt stormwater management plans, develop and adopt a stormwater management ordinance, conduct public education, and implement additional measures as needed.
The regulation timetable is full implementation by 2008.
Construction site regulations especially affect agencies and erosion control practices must be enforced at all construction sites, Souza says. Pollution prevention measures must be implemented at construction sites. The practices apply to disturbances of greater than one or more acres of land. The regulations do not do away with the need for county permits for disturbances of 5,000 square feet or more.
After construction, continued stormwater measures include adoption of a stormwater management plan, adoption and implementation of a stormwater management ordinance, ensured maintenance of stormwater best-management practices, implementation of state stormwater management regulations, and meeting design standards for storm drain inlets.
Source control activities required include pollution prevention, salt and sand storage, and road erosion control.
For a copy of Souza's presentation, e-mail him at Ssouza@princetonhydro.com.
Ways to Reduce Road Runoff
According to the National Education for Municipal Officials, some basic steps will help reduce road runoff:
Source: University of Connecticut.
Top 12 Stormwater Practices Needing Further Assessment
Source: Minnesota Pollution Control Agency.
Reprinted from Better Roads Magazine
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