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HomeMy WebLinkAbout6.g. SKB Interim Use Permit Amendment for the End Cap DesignCITY OF ROSEMOUNT EXECUTIVE SUMMARY FOR ACTION City Council Meeting Date: November 3, 2004. AGENDA ITEM: SKB Interim Use Permit Minor AGENDA SECTION: Amendment. Consent. PREPARED BY: Rick Pearson, City Planner. AGE% . #6 G ATTACHMENTS: Proposed Exhibit E (drawing and design info) , March 6, 2003 City Council APPROVED BY: minutes RECOMMENDED ACTION: Motion to amend the SKB Interim Use Permit Section 98 to approve a revised Exhibit E depicting a closure plan that has a sloped gradient and planted with grasses. ACTION: ISSUE The application before the Council is to modify the design of the end -cap at the SKB land -fill The change is to provide a gradual slope with grasses versus a previous plan that had ridges with landscaping to recreate an oak savannah. The previous idea depended on a significant amount of soil being added to the site to provide a sufficient depth for tree roots that would not puncture the end cap liner. The simplified strategy of a uniform 2.5 ft. thick soil layer with 6 inches of top soil, seed and liner will be much easier to maintain, and greatly simplifies repairs to the end cap if necessary. BACKGROUND On March 6, 2003, the Council approved a major amendment to the SKB Interim Use Permit with conditions. The effect of the major amendment was to increase storage capacity by utilizing "saddle" area between cells. The major amendment also approved a new construction demolition cell along the southeast elevation of the land -fill. One of the issues discussed by the Council, and noted for further discussion and refinement, was the end use plan for the site. The, plan at that time included groupings of trees on ridges that advanced up the slope, allowing for sufficient depth to protect the liners of the end cap from roots. The exact details of the landscape project were not worked out when the IUP was approved. After further examination it became clear that the project entailed more resources than initially expected. For this reason, the city and SKB have been looking at other options that would address previous city concerns. The present concept will allow a more sloped mound that will be easier to maintain. Further, the introduction of trees on the site required a significant amount of fill and dramatically increased the cost. The reason is that a lot of soil was needed to ensure that the end cap was punctured by the tree roots. Applicant & Property Owner(s): Location: Area in Acres: Comp. Guide Plan Desig: Current Zoning: City Council Action: John Domke for SKB Environmental TH 55 Industrial Waste Containment Facility Approx. 235 acres Waste Management Waste Management Approved with conditions 3 -6 -2003. SUMMARY There is the potential for the City to have to become involved with repairs after the cells have been closed. While the tree planting plan can certainly be engineered properly, the cost of maintenance and repairs could be unusually high, particularly on the 4:1 side slopes. Staff is comfortable with the various aspects of the revised proposal; uniform gradients, depth of cover, and turf management. Reasonable visual screening can be accommodated with tree plantings near the highway right -of -way. The changes in the IUP will also be reflected in the SKB Community Trust Management Plan. 2 i J r I �'`✓/ , is ��( �' �/ y Il I � `a �` IMMIMEM 4("A Iv Ml ';. ` B r 1 �a 7 �- i [,_F .� fart � . � ��t'r '• � a , / 7 � f� 1 A� 4� . � �EhEAEE E AEE � g F� X O N TD Q D � e Z JOR DRAWINGS FOR THE KIAJOR MOOIFICATICN 4T THE SKB• ROSESROIJNi INDUSTRIAL WASTE FACILITY ROSEA1pJN T, SMNNESOTA CA00 aaN COBE� OK019 .'�,iwrr „a ..,mxnxen REVISIONS / RENARRS E .���� DaANx an .wB3 OArz� al ®ER. 3001 �VBn R'° 7'� suavErEO ary OATG BY � .�A c �l DATE Br OArE REV 0 o r TOP OF FINAL COVER GRACES REVBE O WcU4xiq 0 RECORD OR&— 6 COM tl. 1OxSTR -1. CW R TO CONTRACT AW/M OWWAS RECOROR. Br DATE 1 3.6.4 Storage Tanks Three leachate storage tanks are located near the access road to the west of Cell 1. The tank design includes a secondary containment structure which is a concrete, bermed pad capable of containing the capacity of one of the tanks plus the 25 -year, 24 -hour storm event and freeboard. See Drawing No. 30. Each tank has a capacity of approximately 250,000 gallons and has a leak detection system. The design will provide flexibility to accommodate the total leachate generated under extreme precipitation conditions and the discharge volumes allowed by the city of Rosemount and the MCES. The tank surfaces are and will be coated or painted to prevent corrosion. Currently one of the tanks is insulated to prevent freezing. The remaining tanks will be insulated as needed. --�- 3.7 Final Cover 3.7.1 Design Closure of each subcell will be initiated when that subcell reaches final capacity. It is anticipated that this will occur about once every three to five years over the estimated 25 -year life of the Facility. The Cell Closure Plan, as identified in Section 8, will be applied to each subcell. As the closure and post closure care operating experience dictates, adjustment and amendments may be made to future subcell closure designs and activities. The entire Facility, Cells 1 through 5, will have the same final cover constructed. See Drawing No. 25 for the final cover typical details. A typical cross section of the completed final cover consists of the following: A prepared waste mound, • A layer of unclassified compacted soil (free of sharp rocks or debris that could potentially damage the liner) 1 -foot thick, • 40 -mil Linear -Low Density Polyethylene (LLDPE) liner, A geocomposite drainage net, • A soil layer 2.5 feet thick, and A 6 -inch layer of topsoil and vegetative cover. The sequence to close a cell /subcell will begin with preparing a waste mound beginning at the perimeter of the cell - subcell and working inward. The mounding of the waste will reduce the subsequent need for additional earth fill material, facilitate grading of the soil cap and reduce the possible formation of depressions that could pond water. The 1 -foot soil layer will be placed and compacted over the waste surface of the final cover sub grade, progressively, so that run off is contained within the cell /subcell confines. KLL1 \KAo1 Sol 9 \Report\R -Vol 1 PermitApplication \10000 Major Modification Foth & Van Dyke • 13 October 2001 Following a settlement and observation period, additional subgrade soil; if needed, will be placed and compacted to correct the surface from the effects of any settlement or subsidence. The 40- mil LLDPE liner will then be installed. A geocomposite drainage net (i.e. drainage net with geotextile filter fabric on one or both sides) will be placed atop the LLDPE liner. A layer of soil 2.5 feet thick will be placed over the drainage layer and will be contoured to avoid forming any depressions that might pond water. A 6 -inch layer of topsoil will be placed over the 2.5 feet of soil cover and seeded, mulched and fertilized to promote the vegetative cover. 3.7.2 Seed Mix The seed mix will be based on approved mixes at the time of closure. Intermediate soil layers will be seeded with typical shallow- rooted, drought - resistant, grasses. The Overall Site Contour Plan may use a native seed mix along with trees and shrubs. Foth & Van Dyke • 14 KLL1 \KA01S019 \Report \R -Vo11 PermitApplication \10000 Major Modification October 2001 Excerpt from the Regular City Council Meeting of March 6, 2003 SKB Interim Use Permit Modification Community Development Director Parsons reviewed discussion for the Interim Use Permit (LU.P.) that would call for renewal every five years. The Permit is tied to state and county approval. The Rosemount Community Trust Fund will be required to be updated within a year from approval of the I.U.P. The end use of the property will affect each cell as it is filled and closed. Hazardous waste will not be accepted at any time as waste material. The MPCA will maintain records of waste material. Council requested that they receive all reports issued from and to SKB Environmental, Inc. The MPCA did decide to have an Environmental Assessment Worksheet done for this expansion. SKB had prepared this worksheet prior to the MPCA's request so time was saved. MPCA noted that on the first review of that document there were no "red flags" or concerns. A public notice will go out for 30 days before a public hearing to allow residents to respond. Beth Lockwood, Supervisor for EPA, noted that notice will be mailed as well to interested parties. A response will be made to each person who contacts the MPCA, which will take a few weeks. So it will likely be two months before approval is complete. Rick O'Gara, President of SKB Environmental, Inc. said they would like to begin construction in the spring. The City's intent for approval of the Interim Use Permit needs to be sent along to the MPCA and Dakota County for them to begin their process of approval. O'Gara noted that traffic has been improved by routing trucks to County Road 38 during peak traffic times on Highway 52. Staff was directed to tighten language in a few places of the permit. Council noted that the end use could possibly change in the future and that. the closure cost should be adjusted to current values by adding "in 2003 dollars ". O'Gara noted that any change in the end use plan would have to have the approval of the MPCA and Dakota County. MOTION by Riley to authorize execution of an amendment to the I.U.P. to SKB Environmental, Inc. conditional on City receipt and approval of EAW and SKB would be responsible to copy any reports to the City. City Attorney LeFevere noted he had composed a motion more inclusive. Council Member Riley withdrew her motion and moved LeFevere's motion. MOTION by Riley to approve the Interim Use Permit and approve the execution of the proposed Interim Use Permit and Development Commitment with the following changes to the Interim Use Permit Agreement: 1) add that all inspection reports received by SKB from the MPCA, Dakota County, OSHA and other governmental regulatory agencies shall be forwarded by SKB to the City within five working days of receipt, 2) add that reports submitted by SKB to the MPCA, Dakota County, or other governmental regulatory agencies shall be submitted to the City simultaneously, and 3) add that references to the cost of the approved post closure plan be changed to reflect that they are stated in 2003 dollars; provided, however, that such approvals are effective on May 16, 2003. The City Council may delay such effective day and approval may be reinstated following completion of the environmental review process conducted pursuant to Minnesota Statutes, Chapter 176D. Second by Shoe - Corrigan. Ayes: Strayton, DeBettignies, Shoe - Corrigan, Droste, Riley. Nays: None. Motion carried.