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creating the Standard Reqasirements for Storm Drainage Design Criteria and <br />Construction Standctrds which require the following: <br />l. For new residential developments, limit the release from on-site detention <br />facilities to the 2-year existing condition peak discharge during the 1Q0 year <br />storm event. <br />2. For new commercial and industrial developments, limit the release from on- <br />site detention facilities to the 10-year existing condition peak discharge <br />during the 100 year storm event. <br />Even �vith the creation of restrictive localized detention requirements for future <br />development, the need still exists to enlarge and expand onto existing infrastructure <br />and create regional infrastructure in order to accommodate storm water runoff from <br />the existing undetained developments within these communities. _ <br />Storm Water Quality Opportunities: <br />Urban storm water runoff contains many types and forms of pollutants. Runoff <br />from undeveloped basins contain sediment particles, oxygen demanding <br />compounds, nutrients, metals, and other constituents. The 1989 Amendments to <br />the Clean Water Act include discussion that non-point source pollution (including <br />storm water runof� will be minimized. The State of Colorado, Department of <br />Public Health and Environment has primacy for regulating non-point pollution. <br />Presently, cities with populations larger than 100,000 persons are required to file <br />a permit with the State of Colorado. Although the communities of Dacono, <br />Frederick, Evanston, and Firestone are very small, it is important that they do their <br />part to reduce pollutants from storm water runoff. To reduce the concentrations <br />and the loads of these constituents that reach waters of the United States, various <br />Best Management Practices (BMP's) are available. Both structural and non- <br />structural BMP's are available. The regional detention facility will be equipped <br />with a water quality extended detention outlet mechanism to allow the first flush <br />of storm water runoff an opportunity to further settle out pollutants before exiting <br />the facility. <br />Social-�conomic Information: <br />The communities of Dacono, Frederick, Evanston, and Firestone were once a coal <br />minina center surrounded by rural farmland. Now the farmland is quickly <br />developing. The residents are a mixture of retired miners, farmers, migrant farm <br />workers and young families �vith single incomes. The Median Household Income <br />for the three communities, according to available 1990 statistics, are: <br />0 <br />