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HomeMy WebLinkAbout20190158 Ver 1_IRT_CommentResponses_20200714Brahma Mitigation Plan IRT Comment Responses: DWR Comments, Mac Haupt: 1. Section 1.3- Please be sure to design the appropriate sized bmp to treat the water comingfrom the chicken houses. In addition, if waste management changes at the property, the Adaptive Management Plan should include measures to treat the water at various drainage swales that enter the project. Marsh treatment areas have been sized based on drainage area and impervious surface. Some marsh treatment areas are limited in size due to easement boundary constraints; however, please note marsh treatment areas are not BMPs. They are shallow depressions that attenuate the initial stormwater pulse and are expected to fill with sediment and naturalize over time. At that point, the naturalized marsh treatment area and adjacent wetlands will perform the primary function of treatment. As an additional note, drainage pipes from the chicken houses are not underdrains from the houses and are simply conveying water from impervious surfaces adjacent to the chicken houses. 2 Table 7- Reaches UT3 and UT6 show very small drainage areas. These two tributaries will be at risk for maintaining appropriate channel features. DWR does appreciate that flow gauges will be installed on these reaches. • Understood. a Section 8.1.1- DWR likes the inclusion of the marsh treatment areas. This property will likely need these treatment areas for upcoming development. DWR believes some of these marsh treatment areas may need to be larger than others. In the future, DWR recommends laying out more specific details in the plan sheets given the contributing drainage area. Please see answer for comment number 1. 4. Section 8.2-UT1 B- existing conditions- this reach does not appear to have a sinuosity of 1.33. • Since UT 1B is a relatively short reach of Enhancement (Level II) the sinuosity was lumped with the downstream preservation reach of UT 1C. 5. Table 14- DWR requires that no more than 5% of the site should be planted in Green Ash. • The planting table will be updated once trees are ordered in the late summer. Green Ash will be removed or reduced to less than 5% of the planting density. 6. Table 17- DWR concurs with the wetland performance criterion of 12% saturation within the growing season. • Understood. 7. Design sheet 5- DWR requires a wetland monitoring gauge at station 8+00 on stream right approximately 40 feet out into the floodplain. • A groundwater monitoring gauge has been added at approximately station 8+00, stream right (+/- 40 ft from top of bank). Please note this is a Wetland Enhancement area. No hydrologic functional improvement is being requested in the vicinity of the requested groundwater gauge. 8. Design sheet 6- DWR requires a wetland monitoring gauge at station 13+25 on stream right approximately 60 feet out into the floodplain. Also, is there supposed to be another marsh treatment area (or two?). It appears that on the Monitoring Plan, Figure 10A, shows 3 marsh treatment areas. • A groundwater monitoring gauge has been added at approximately station 13+25, stream right (+/- 60 ft from top of bank). Please note this is a Wetland Enhancement area. No hydrologic functional improvement is being requested in the vicinity of the requested groundwater gauge. 9. Design sheets 16 and 17 (perhaps others)- DWR notes some overlap of the wetland re- establishment and enhancement credit areas with marsh treatment areas. These areas should not overlap, given the construction, excavation and outlet (rip rap) construction. 0 Marsh treatment areas are not depicted at the design scale and are typically very shallow wetland depressions. We believe that these small depressions should not be excluded from wetland credit areas due to their small size and they are expected to fill with sediment and naturalize over time. 10. Design sheet 19- for reach UT6, DWR believes that stream credit should not initiate until station 1+00 or even farther down. DWR believes this upper reach will be at risk for maintenance of appropriate channel flow. • We believe the spring for UT6 initiates at the upper reaches of the pond, as depicted in our plan sheets. We will monitor the upper reaches visually and with a camera to ensure stream origin location. At this time, we respectfully request to leave the UT6 origin location at our current stationing. WRC Comments, Travis Wilson: 1. For stream crossings it would be beneficial to have the culvert invert elevations labeled on the plans • a table has been added on Sheet 2, Permanent Crossing, that has centerline stationing, pipe diameter and length, invert information, and bury depth. 2. It would be beneficial to including a cross section detail specific to each culverted stream crossing. That will allow a better assessment of the culvert sizing and configuration within the crossing • We are hopefully the table on Sheet 2 will satisfy any concerns. 3. Planting plan has green ash (Fraxinus pennsylvanica) at 10% . Due to the increasing presence of Emerald Ash Borer the amount should be reduced to a maximum of 5% • The planting table will be updated once trees are ordered in the late summer. Green Ash will be removed or reduced to less than 5% of the planting density. EPA Comments. Todd Bowers: Section 1.4/Page 13 Project Components and Structure: a. Proposed activity for the site is summarized here and refers to Table 1 and Figures 6A and 6B. Several errors were noted throughout the document that do not match the totals for wetland activity listed here and will be addressed below. • After review of Table 1 and Figures 6A/6B we have not found any errors. 2. Section 3.5.1/Page 25 Hydrological Characterization: a. Wetland acreage activity totals do not match Section 1.4, Table I or Figures 6A and 6B. The listed totals do match Figures I OA and I OB. Please confirm and correct. • Text in Section 3.5.1 has been updated and corrected. 3. Table 9/Page 27 Reference Forest Ecosystem a. Recommend referring to this list to choose an alternate to planting Fraxinus pennsylvanica and for a suitable understory species such as Carpinus caroliniana. • The planting table will be updated once trees are ordered in the late summer. Green Ash will be removed or reduced to less than 5% of the planting density. 4. Section 6.0/Page 29 Functional Uplift and Project Goals/Objectives: a. "One marsh treatment area will be installed." The location of this singular marsh treatment area is unknown and there are a total of 12 MTAs shown Figures 6A and 6B. • Text has been updated. 5. Table 12C/Page 32 Stream/Wetland Targeted Functions, Goals and Objectives. a. "Install one marsh treatment area" The location of this singular marsh treatment area is unknown and there are a total of 12 MTAs shown Figures 6A and 6B. • Text in Table 12 has been updated. 6. Section 8.1/Page 34: Stream Design a. "Construction of a marsh treatment area" The location of this singular marsh treatment area is unknown and there are a total of 12 MTAs shown Figures 6A and 6B. 0 Text has been updated. 7. Section 8.1.1/Page 35: Stream Restoration a. Is it possible to get the crossing on UT2 moved upstream to avoid wetland and riparian zone impacts/interference near the confluence with UT1? • The crossing location was requested by the landowner. 8. How do the eleven shallow marsh treatment areas differ from the singular MTA referenced above? • Text has been updated to indicate that multiple marsh treatment areas are being installed at the Site. 9. Recommend mentioning the new poultry house outfall protection/treatment if the purpose is related to these MTAs. • Marsh treatment areas are discussed in Section 8.1.1 and are expected to treat the initial stormwater pulse from agriculture areas. This would include drainage from adjacent to the poultry houses. The pipe outfalls from the poultry houses are not underdrains that remove waste, simply stormwater drainage from impervious surfaces adjacent to the poultry houses. 10. Section 8.2.1/Page 36 UT1 a. There are only 3 reaches on UT (A-C). • Text has been updated. 11. UT1C is listed for Enhancement treatment when it should be Preservation. • Text has been updated. 12. Section 8.3/Page 42 Wetland Reestablishment a. Recommend adding livestock removal and fencing out as part of wetland reestablishment. • Text has been updated to include livestock removal through fencing. 13.4.481 acres of wetland reestablishment does not match Section 1.4, Table 1 or Figures 6A and B. • Text has been updated to match Table 1 and associated Figures. 14. Section 8.4/Page 42 Wetland Enhancement a. 3.715 acres of wetland enhancement does not match Section 1.4, Table 1 or Figures 6A and B. • Text has been updated to match Table 1 and associated Figures. 15. Section 8.6.1/Page 43 Planting Plan a. Explain if there are to be two target communities or three? This cites floodplain (Piedmont Alluvial Forest), upland slopes (Dry-Mesic Oak -Hickory Forest) and then there is the "streamside assemblage" which is basically the PAF at a quadruple density. Monitoring for each plant community or landscape position should be ensured. The DMOHF community type is not represented in the planting plan or Figures 9A and B. • Dry-Mesic Oak -Hickory Forest has been removed as a planning zone. 16. Table 14: Recommend restricting or removing Green ash (Fraxinus pennsylvanica) from the planting list due to potential for emerald ash borer infestation. • The planting table will be updated once trees are ordered in the late summer. Green Ash will be removed or reduced to less than 5% of the planting density. 17. Table 17/Page 46 Success Criteria (Wetland Hydrology) a. Recommend adding the growing season listed in Table 16 (March 1- October 22) and number of days to achieve the 12 percent of the growing season just to remove any ambiguity. • The growing season length will vary from year to year depending on soil temperature data collected at the Site. The March 1 growing season start will only occur if soil temperature and bud burst criteria are met. Therefore, we are not able to put an absolute day length requirement in the text beyond what has been outlined. 18. Section 9.2.3/Page 47 Vegetation Contingency a. Recommend denoting when supplemental planting will occur (Dec -Mar) to avoid planting in May (or later) situations. Denote how long monitoring of supplemental planting will occur before success is achieved. • Text has been updated to include planting dates (Dec -Mar) and monitoring verbiage has been added to include IRT approval of supplemental planting. USACE Comments, Kim Browning: On future projects, please keep the same stream and wetland labels throughout the life of the project. It's difficult to refer to notes from the technical proposal and compare them to the JD and mitigation plan when labels change. It appears that UT was split into UT and UT7 after the IRT site visit. • Understood. To clarify, UT 7 is a small stream that was added during the PJD and UT 1 did not get split. 2. Figure 9A and Table 14: Please limit Green Ash to no more than 5% of the planted species due to the Emerald Ash Borer. • The planting table will be updated once trees are ordered in the late summer. Green Ash will be removed or reduced to less than 5% of the planting density. 3. UT4: Though this reach is planned as EII, during the IRT site visit we discussed that this should be treated as a headwater valley and awarded credit based on valley length. Page 28 indicates that this reach is a wetland. Please verify that valley length was used to calculate credits. Additionally, this reach will need to meet headwater stream performance standards in order to receive stream credit. • UT 4 is not included in wetland mitigation totals. The stream was credited at valley length, using headwater stream guidance and performance standards. 4. Please add a veg plot on UT6 where the pond sediment is to be removed, random is fine. • A vegetation plot has been added in the upper reaches of UT 6, pond bed. 5. UT2: During the IRT site visit this reach was noted to be intermittent and likely dry during summer months. Please install a flow gauge in the upper third of this reach, Providing photo/video documentation of flow on intermittent reaches will be helpful. • Although typically, EII reaches do not require flow monitoring, we added a flow gauge in the upper one third of UT 2. 6. Table 4: Please add reach summary data for EI and EII reaches. • Table 4 has been updated to include each reach. 7. Section 4.2 and Table 9: Please note that although the reference forest ecosystem and the Schafale and Weakley references list sweetgum as a reference species, sweetgum will not be counted towards meeting vegetative success criteria. • Understood. 8. During the IRT site visit it was mentioned that new chicken houses were planned on the property. Please ensure that the conservation easement does not allow for chicken litter to be spread in the buffer. • Section 1.3 Physiography and Land Use outlines chicken litter disposal protocols. We have used the most current NCDMS conservation easement (recorded at the Alamance County register of deeds). Part 2, Sections F and J of the recorded conservation easement prohibit these actions. 9. The NCSAM/WAM summary tables 12A and 12B are helpful. It would be helpful to include NCSAM data for all reaches to show the current functional assessment. It is typical for one WAM or SAM form to document similar conditions on multiple reaches. If clarification of which reaches is required, we can accommodate that request. If in the future a single SAM or WAM is required for each stream, we will collect that data. 10. Section 8.1.1, Marsh Treatment Areas: Please ensure that these BMPS are placed outside jurisdictional features. It appears that several of these marsh treatment areas will be placed within wetlands. This is acceptable provided that they remain wetlands when the work is complete. Otherwise please remove these areas from wetland credit and account for the loss in the impact tables. • Marsh treatment areas are not depicted at the design scale and are typically very shallow wetland depressions. We believe that these small depressions should not be excluded from wetland credit areas due to their very small size and are expected to fill with sediment and naturalize over time. 11. UT3: The figures show a pipe under the road that will be upgraded and is outside the easement. If it is simply a replacement and you are not proposing to make it longer or place it in a new location, then it would be exempt. Please note that crossings in new locations on existing tributaries will require a separate permit. • This crossing is replacing the pipe in place at the same length and location. In addition, the reach is not a jurisdictional feature at the road. Therefore, this action should be exempt. 12. Page 26: UT1C Mitigation treatment should read Preservation. • The text has been updated to Preservation. 13. During planting, if species substitutions occur due to availability or refinement, please red -line the As - Built and MYO report if substitutions occur. • Understood. Species substitutions are expected to occur depending on availability. These will be noted on the As -built. 14. Table 17: Continuous surface flow for at least 30 consecutive days is only applicable to intermittent streams. a. Volunteer stems that are included in the planting list maybe counted after two years. • Understood. b. Recommend adding a performance standard for visual monitoring, to include permanent photo points (depicted on monitoring map). • Permanent photo points are taken at each cross section and vegetation plot, which should be sufficient photographic documentation. 15. Section 9.2: I appreciate the thoughtfulness of this section. It may be beneficial to add discussion on other potential risks, such as adjacent development or logging, beaver, or road/culvert maintenance. • Additional text has been added to Section 9.2 to include development/logging, beaver and other nuisance species, and road/culvert maintenance. 16. Please provide a brief description on where the spoil from the bond bottom will be spread, and the method of fescue removal. • A note was added to Section 8.2.6 (UT 6) that includes texts that sediment from the pond bottom will be mixed with spoil material and used as backfill for abandoned/reduced channels. • Text as added to Section 8.6.2 (Nuisance Species Management) outlining herbicide application to fescue areas.