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<br />Appendix - Arden Hills Water Quality Task Force - June 2000
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<br />spread use of "French drains," small infiltration trenches placed at the bottom of the discharge pipe from roof gutters that
<br />allow water to infiltrate on site rather than passing into the storm sewer system.
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<br />Filtration Practices
<br />Filtration practices address water quality problems rather than water quantity. Some consist of a chamber containing a filter
<br />medium buried at ground level through which stormwater flows, while some are filter inserts for catchbasins in the storm
<br />sewer system, As stormwater flows pass through the filter medium, it removes particulates and other contaminants, The
<br />filtering materials most frequently used are sand, peat, or compost, although municipalities now use BMPs with synthetic
<br />filter media.4 7
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<br />Endnotes (Cont.)
<br />19 Municipal Operations. (Excerpted from NRDC's nationwide stormwater managment survey.)
<br />A wide range of municipal operations can affect stormwater quantity and quality, NRDC's case studies reveal that some
<br />local govenunents have been able to manage their municipal operations to make a significant positive contribution to
<br />reducing stormwater pollution. Successful municipal operations stormwater strategies address areas of ffiWlicipal activity
<br />(in addition to planning and regulatory/enforcement efforts discussed above) in a variety of ways.
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<br />First, a number of municipal services that primarily provided for other purposes could curb stormwater pollution, Street
<br />sweeping, collection of leaves and other yard waste, collection and recycling of used oil or other substances, and general
<br />trash control all keep contaminants out of urban runoff. Improvement or expansion of such programs significantly
<br />assists stormwater pollution prevention, and because people want these programs, builds support for the broader issue of
<br />stormwater management.
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<br />Second, municipalities engage in a number of activities that directly cause stonnwater pollution. They operate and maintain
<br />vehicle fleets of municipal buses, police cars, and garbage trucks. These vehicles emit into the atmosphere nitrogen and
<br />particulates which eventually end up on the ground and then in the stormwater. These vehicles also deposit oil, grease, and
<br />metals onto roads and parking lots, Municipalities apply pesticides and fertilizers to municipal parks, cemeteries, highway
<br />rights-of-way, and golf courses, Local governments in colder parts of the country salt or sand roads to control ice and snow.
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<br />Municipalities can include stormwater control requirements in all contracts for construction work and other contracts where
<br />such provisions are relevant. Most simply (and a very common action), timely maintenance of vehicles reduces the amount
<br />of oil, grease and metals left on roads and parking lots, More dramatically, municipal fleets can be converted to low-
<br />emission or zero-emission vehicles powered by natural gas, electricity, or other energy sources to reduce emissions and thus
<br />deposition of nitrogen and particulates, A number of municipalities reduce or even eliminate the use of artificial pesticides
<br />and fertilizers by employing sound landscaping practices such as planting native species and using integrated pest
<br />management. Municipalities and transportation departments have found it is relatively easy to monitor road salt and sand
<br />needs to avoid applying more than necessary, which saves money as welL
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<br />Third, municipalities often manage some type of storm sewer or storm drain system; how they do so can make the
<br />difference between simply moving the water to another place and successfully addressing stormwater pollution, For
<br />example, if catchbasins are not properly cleaned, the materials that collect in them -- sediment, trash and other stormwater
<br />contaminants __ can be resuspended in stormwater during a storm and eventually flow into a stream or waterbody. Local
<br />governments have found effective designing devices to reduce velocity using vegetated swales to facilitate infiltration and
<br />purify stormwater runoff, or using preserved natural areas to store or convey stonnwater.
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<br />Fourth, training and education efforts that target municipal officials and agency personnel have also proven to be important,
<br />Park and utility workers educated in integrated pest management, fertilizer use, and composting; fleet workers educated in
<br />fluid disposal; construction workers educated in erosion controls -- all these have made noticeable differences in the
<br />stormwater impacts of mooicipal operations. In mooicipalities constrained by human resources, programs that provide
<br />training or certification for non-government persOIUlel, such as citizen construction site or stormdrain and outfall inspections
<br />have proven effective, Furthermore, the case studies demonstrate that a well-trained and informed staff improves
<br />interactions with the community, raising community awareness, improving credibility, and setting positive examples for the
<br />community.
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<br />Finally, although no local government surveyed had a full program in this area, several local government officials strongly
<br />recommend that periodic environmental audits would make any program far more successful. A broad-based audit would be
<br />particularly useful regarding problems such as stormwater that reflects a cumulation of numerous minor problems. With
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