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HomeMy WebLinkAboutA004 - Memo from City Engineer in response to letters above Memo Public Works Department ♦ Engineering Division Caring Qi�br� EWagpdiaaal Service TO: Mayor and City Council FROM: Tracy L. Warner, P.E. DATE: March 1, 2006 SUBJECT: Response to Letter from Belin Lamson McCormick Zumbach Flynn Attorneys at Law On February 17, 2006, Mayor and City Council received a letter from the above- referenced law firm regarding the Construction Site Erosion and Sediment Control Ordinance. Listed below are additional information in order included with the referenced letter. 1. On February 22, 2005, the City Council approved the adoption of the Statewide Urban Design and Specifications (SUDAS) to establish uniform design practices and construction requirements that would maximize bidding competition and provide the highest quality projects in the most cost effective manner. Throughout the past two years, SUDAS has been working with municipalities and Iowa Department of Natural Resources (IDNR) to incorporate erosion and sediment control measures as part of the manuals. This will provide a common reference manual for any community to use and therefore define common erosion and sediment control measures equally in different communities. The alternative to utilizing SUDAS would be to direct staff to develop and implement an independent set of standards and specifications for use within Ames. 2. This point is already a requirement of IDNR General Permit No. 2, which requires that all disturbed areas area require to be stabilized as soon as practical but in no case where construction activity will not occur for a period of 21 or more calendar days later than the 14th day after no construction activity has occurred on such area. This includes areas for stockpiling of soils. 3. Paragraph 7(b) of the ordinance requires measures and procedures to be identified that will reasonably minimize soil compaction and provide soil quality restoration, in areas to be vegetated. As construction occurs, heavy equipment continually compacts the soil. This results in a reduced capacity for vegetation to get established, therefore reducing the ability to achieve final stabilization on the site. Final stabilization, as defined by IDNR, means that a uniform perennial vegetative cover with a density of 70% for the area has been established. Several methods can be utilized to minimize or restore the soil quality, including deep tillage or increasing organic matter (i.e. compost). 4. This point is already a requirement of General Permit No. 2. If a site has not achieved final stabilization status, a Notice of Discontinuation for permit coverage may not be filed with IDNR. If final stabilization has not been achieved, temporary measures may not be removed since the site is still considered disturbed. 5. Paragraph 7(d) of the ordinance requires that all disturbed areas be permanently stabilized with 70% perennial cover as measured by the USDA line transect method. This further expands the General Permit No. 2 requirements in that specified methods of measuring 70% perennial cover are defined. 6. The general purpose of General Permit No. 2 is to authorize storm water discharge associated with industrial activity from construction sites. This means that nothing other than storm water shall leave the construction site, including sediment. Sediment deposition onto adjacent properties or environmentally sensitive areas would be a violation of the Clean Water Act. 7. Paragraphs 7(f), (g), and (h) are current requirements of General Permit No. 2. The stabilization of steep or long continuous slopes refers to the ability to get vegetation to establish on the slope. If a slope is too steep, sod will be undermined or seed will wash down the slope during a rain event. Stabilization of a waterway and outlet makes reference to the General Permit No. 2 requirement to provide non-erosive velocities at discharge locations. Item h refers to protecting the storm sewer infrastructure from sediment loading, which would ultimately lead to an off-site discharge violation for the permittee. 8. Items 7(i) and Q) are already required as part of General Permit No. 2 since each of these items would lead to an off-site discharge and therefore a violation of the permit. 9. General Permit No. 2 requires that all wastes must be removed from the site for disposal in permitted disposal facilities. In addition, off-site vehicle tracking of sediments shall be minimized. 10. The Land Use Policy Plan refers to certain areas of land as environmentally sensitive land. The requirement to implement buffer zones and enhanced temperature controls were incorporated to protect those areas. 11. Section 5A.3(2) requires that the applicant notify the City when all erosion and sediment control measures are implemented. This will enable staff to begin tracking the two required inspections per calendar year. 12. Section 5A.4(1) is a requirement to "self report" violations to the permit. This is a current approach taken by IDNR to keep record of all active permits throughout the state. Since staff is not able to visit all active construction sites following a storm event, this enables staff to keep our records current when a developer/contractor notifies our office of an off-site violation. 13. As mentioned in the Council Action Form for this ordinance, a performance bond enables the city to stabilize a site if a developer/contractor were to abandon a site. The amount of the bond and the 5 acre minimum was agreed upon through the Storm Water Advisory Committee. 14. Section 5A.7(1)(a) enables the permit applicant to appeal an enforcement action within 5 business days. Any corrective action on the site must be taken within 48 hours.