Agenda - Environmental Policy Board - 01/18/2017

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Item-by-item guidance Chapter Additional Resources: • MPCA web page on Subsurface Sewage Treatment Systems: http://www.pca.state.mn.us/ud x. b�09. 3)This response must include identification of receiving waters for discharges,including tile lines, ditches,streams,lakes,or other surface or ground waters.This includes any downstream waters that may be noticeably influenced by the discharge,especially those more sensitive or more valuable than the waters receiving the direct discharge.An estimate of the impact of the discharge(s)on the quality of the receiving waters should be made. The level of sophistication of this analysis must be guided by the likely magnitude of the impact and the importance of the water body(les)affected. Where it is clear on the basis of the amounts and quality of the discharge compared to the volume,quality and assimilative capacity of the receiving waters that only a minor degradation of water quality will occur, and no noticeable impairment of uses of the water would result,only a qualitative discussion is generally needed. Where noticeable impairment may occur,however,more quantitative assessment methods should be employed, and predictions should be made about whether any water quality standards will be violated. In the event that a wastewater discharge may degrade a lake,a numerical nutrient budget analysis may be required.However,it is unlikely that any new discharges to any lake would be permitted by the MPCA. Any nutrient budget should be based on a generally accepted model of a lake's response to increase in phosphorus loading or other critical nutrients if phosphorus is not limiting. The choice of a model should be based on available data,and its expected accuracy based on the likely magnitude of the impact,in addition to the time and costs of using the model. In other words,the greater the likely impact,the greater the need for a more sophisticated model. If insufficient data is available to allow the use of any numerical model,it is necessary to gather the minimally needed data unless the EAW can establish through other analysis that there is no reason to expect noticeable degradation. If the matter is left in doubt in the EAW, it may result in calls for an EIS and a more in-depth analysis. If receiving water is impaired,identify if the wastewater will contribute to the condition or numeric impairment. If a TMDL has been completed,describe how the discharge relates to the load allocations. If an implementation plan has been developed,describe how the discharge relates to the plan. ii. Stormwater. The intent of this question is to characterize the effect of the project on the amounts and the composition of stormwater runoff from the site and the techniques planned to minimize adverse impacts from stormwater quantity and quality. Specific erosion and sedimentation control measures for both during and after construction should be described. If the proposer has not prepared definite plans for these measures,the requirements of the local governmental unit and the MPCA should be described and how those requirements mitigate the impacts. Projects that disturb more than one acre need to apply for and receive coverage under the MPCA Construction Stormwater General NPDES Permit. Some site features such as highly erodible soils(identified in Item 10), steep slopes, and sensitive receiving waters will require special attention to avoid adverse environmental effects. The MPCA has identified increased Best Management Practices(BMPs)that are required to be used in areas discharging to and within one mile of designated Special or Impaired Waters. If applicable these BMPs should be identified and discussed. These BMPs are included as Appendix A of the Construction Stormwater General Permit. The permit and list of Special Waters and Impaired Waters can be accessed from the MPCA website. Environmental Quality Board EAW Guidelines—October 2013 26