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6 RCWD RULE C REQUIREMENTS <br />6.1 Rule C Overview <br />The Northeast Lino Lakes CSMP area is located within a single resource of concern drainage area <br />(Figure 3, Appendix A). General drainage patterns as documented in this CSMP will be maintained with <br />any future developments so that stormwater runoff will remain within the Peltier Lake ROC drainage area <br />and be managed to meet RCWD's Rule C requirements. <br />As allowed for under RCWD Rule C.5(f), this CSMP has been prepared as an alternative means to meet <br />the requirements of Rule C.6 Water Quality Treatment and Rule C.7 Peak Stormwater Runoff Control for <br />the development of the area, which is anticipated to be completed in several distinct phases. The peak <br />runoff control and water quality treatment requirements will be met, in aggregate, for the area as a whole. <br />6.2 Water Quality Treatment [RCWD Rule C.6] <br />RCWD's water quality treatment requirements will be met through a variety of measures, including <br />stormwater detention ponds, biofiltration, and infiltration, as is feasible. Figure 14, Appendix A shows the <br />locations and suggested types of regional BMPs. It is anticipated that the study area will include water <br />quality treatment trains with sedimentation BMPs located in upland areas designed to remove solids and <br />particulate matter. These will be combined with surface and media filtration to remove dissolved <br />particulates, nitrogen, and phosphorus prior to entering the new system and discharging into the regional <br />BMPs. <br />Total phosphorus loading under existing and proposed land use conditions was estimated using event <br />mean concentrations from the Minnesota Stormwater Manual (Minnesota Pollution Control Agency 2016). <br />Under existing conditions, the CSMP area contributes approximately 12.6 pounds of total phosphorus <br />annually to Peltier Lake. With the proposed full -build out land uses, in absence of any stormwater <br />treatment, the CSMP area loading would increase to approximately 14.4 pounds per year (Table 6-1 and <br />Appendix E). <br />Table 6-1. Summary of Total Phosphorus (TP) Loading by Region without Stormwater Treatment <br />REGION Area Existing TP Proposed TP Load TP Load Change <br />[ac] Load [Ib] [Ib] [Ib] <br />HUGO <br />215.6 <br />0.72 <br />1.36 <br />+0.64 <br />EAST <br />553.9 <br />4.90 <br />6.43 <br />+1.53 <br />CENTRAL <br />447.3 <br />5.89 <br />6.30 <br />+0.41 <br />WEST <br />152.5 <br />1.06 <br />0.31 <br />-0.75 <br />TOTALS <br />1,349 <br />12.6 <br />14.4 <br />+1.83 <br />The proposed land uses in the West region, including the wetland management corridor and medium <br />density residential have a lower total phosphorus concentration (0.03 and 0.3 mg/L, respectively) than the <br />existing land use of agricultural row crops (0.32 mg/L) and contribute to the reduction in the proposed <br />total phosphorus loading. However, as required by RCWD Rule C.6, water quality treatment is a <br />necessary component of development and we expect the TP loading to be reduced significantly with the <br />required stormwater treatment practices in place. <br />A challenge for the CSMP area will be to infiltrate stormwater to meet the water quality volume reduction <br />in Rule C.6. Review of the CSMP area led to the development of Figure 15, Appendix A (Infiltration <br />Suitability). This map was developed using the following four criteria: <br />Comprehensive Stormwater Management Plan <br />Northeast Lino Lakes Drainage Improvement Project <br />WSB Project No. 2929-79 <br />Page 19 <br />