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Memo Landfill IssuesC I T Y O F H O P K I N S M E M O R A N D U M DATE: December 12, 1991 TO: Honorable Mayor and City Council FROM: Jim Gessele, Engineering Superintendent Jili SUBJECT: LANDFILL ISSUES This memo serves as an introduction to a Doherty Rumble Butler report regarding continuing landfill issues faced by the City. The main thrust of DRB's report is to discuss methane remedial action alternatives for the western and northern boundaries of the 7th Street South landfill site. An overview of how the City has arrived at "institutional remediation" as a means of addressing the methane migration at the remaining boundaries is presented. "Institutional controls" go hand -in -hand with "institutional remediation," and that simply means the City must decide to either acquire property adjacent to or on landfill deposits or negotiate restrictive pollution easements. The concept of "institutional remediation" raises several questions that legal counsel enumerates. In brief they are: o Cost /value of fee acquisition of Rutledge and ABJ properties (see attached map) o Easement acquisition costs o Impermanence of easement approach o MPCA /legislative funding for land acquisition o Feasibility of roadway construction across landfill site o Waste on Venturian property adjacent to the west o Cost /value of northern 17 acres of Venturian property to the west (see attached map) DRB recommends to Council that staff be authorized to open negotiations with ABJ and Rutledge for either acquisition of parcels or pollution easements, that staff negotiate with Venturian regarding a limited access road to serve the parcel on the western boundary. The report concludes with updates concerning environmental investigations on the Venturian and Justus properties along County Road 3, negotiation with the Westbrooke Association concerning amendment of the existing agreement and the location of ground water monitoring wells, status of the financial assurance agreement with the MPCA, and financial reimbursement for the current methane remediation project. You will also find attached the latest gas monitoring report from Braun Intertec subsequent to corrective repositioning of the barrier. Representatives from Doherty Rumble & Butler will be present to answer questions. Attachments JG12121B bj M E M O R A N D U M TO: Steve Mielke, City Manager, City of Hopkins FROM: Jim Gessele, City of Hopkins and Jon Scoll and Dick Nowlin, Doherty, Rumble & Butler RE: Remedial Action Alternatives North Boundary 7th Street Landfill DATE: December 12, 1991 The following is written to discuss three issues relating to remedial action with regard to methane migration on the northern and western boundaries of the 7th Street Landfill. These issues are brought to your attention because of potentially significant policy and economic consequences to the City. The memo asks for and recommends a decision with regard to only one of these issues at this time: whether to acquire the ABJ and Rutledge parcels in fee or to simply secure an easement interest allowing these land uses to remain. Pursuant to the Closure Order, the City prepared and submitted a gas control /Recovery Remedial Measures Plan and Alternatives Report dated July 31, 1991, (the Report) discussing the data relating to methane migration on the northern and western boundaries of the Landfill and discussing alternative remediation approaches. The Report was prepared and submitted by Braun Intertec following City staff and consultant review. In brief summary, the report indicates that methane concentrations exist on and beyond the ABJ and Rutledge properties to the north but that migration in this direction does not extend beyond the railroad tracks located north of these properties. The report also indicates that methane is not migrating to any significant degree into lands adjacent to the western boundary of the Landfill owned by Venturian. The high groundwater table /condition on the land adjacent to the boundary apparently stops the lateral migration of measurable quantities of methane. The Report goes on to note the City sold part of the land located on the northern edge of the Landfill to ABJ and Rutledge in the 1980's and that these owners are making use of the property largely for outside storage of equipment, machinery, and materials. Waste exists under some portions of these storage areas; this waste was placed in these locations in the 1960's and early 1970's, making these areas some of the oldest parts of the Landfill. As a result, it is assumed that these areas are generating less methane than in the past. The issue of whether to acquire a fee or easement interest in the ABJ or Rutledge property arises because the Report noted that "institutional controls" could be used to mitigate /prevent problems associated with methane migration to the north and west. This means that instead of constructing an active or passive methane control system, the City would use land use restrictions and /or land ownership with continued methane monitoring for remediation. The Report suggested the use of institutional controls in part because of the high cost of an active methane recovery /removal system and problems noted by Braun, RCM, and Lofy, relating to the ability of such a system to effectively and efficiently prevent methane migration. Institutional controls in this setting could include: (i) the acquisition of the ABJ and Rutledge properties; (ii) the purchase of an easement acknowledging and authorizing the continued presence of subsurface waste, and the generation and /or migration of methane on these properties; or (iii) zoning controls to ensure appropriate building and setback requirements. The approach selected by the City ultimately needs MPCA approval. The MPCA reviewed the Report and requested by letter of October 16, 1991, that the City provide more specification vis -a -vis the use of institutional controls to mitigate /prevent methane migration at these locations. Along the northern boundary there is an opportunity to chose between the acquisition of a fee interest in this property or simply a "pollution easement." On the western boundary, due to the lack of horizontal migration and the City of Minnetonka's setback requirements, it does not appear that the acquisition of an easement or fee title to a portion of this property would be necessary at this time. The decision about whether to acquire the ABJ and Rutledge parcels is complicated by the fact that the Minnetonka City staff indicates that in order to develop the Venturian property west of the Landfill for multi- family residential use, some form of access to this property will be necessary via 7th Street extended. In order to provide this access: (i) the MPCA needs to authorize the construction of a roadway on top of the waste deposit; (ii) the road needs to be able to be constructed from an engineering standpoint to a level satisfactory to serve purposes identified by the City of Minnetonka; and (iii) and funds need to be made available for its cost. The fee or easement acquisition of ABJ and Rutledge is not directly tied to the 7th Street extension decision. If only an easement were acquired, the ABJ and Rutledge properties likely would pay a portion of the costs of this road as they would receive some benefit. Road construction could also affect the easement vs. fee issue in that if the Venturian property to the west were to be acquired by the City and devoted to other than residential use (e.g., for park or recreational purposes), it is unlikely that 7th Street would have to be extended and a road constructed across the waste deposit. Following is a list and responses to various specific questions relating to the decision whether to authorize the acquisition of a fee or easement interest in this property. 1. Cost /Value of the Rutledge Property Assuming Fee Acquisition. The Rutledge parcel purchased for 42 per square foot (gross purchase price $12,500); market value of the property remains at $12,500 today. The ABJ property, slightly less than two acres, was purchased for $42,000, or 52.5 per square foot. The ABJ property is currently shown on the records of the City Assessor at a value of $44,100. 2. Cost of Acquiring an Easement. The cost of an easement would presumably be considerably less than that for a fee, and might also be more easily negotiated since Rutledge and ABJ want to remain on their sites. 3. Impermanence of Easement Approach -Need for Land Subsequently in Connection with Remediation. The easement approach would not give the City the right it would need should it later prove necessary to enter the ABJ or Rutledge properties to perform active remediation (e.g., excavation). Should the properties have to be condemned or otherwise acquired, however, the value of the City's easement would be credited against the landowners' compensation. The need to acquire either property at this time appears remote. It should be noted that the MPCA staff have not acquiesced in the concept of a "pollution easement" for these parcels. Staff (Ken Meyer) has surfaced a concern that allowing such an easement would in effect constitute an acquiescence in the present condition of the properties, including the present venting of methane or other VOCs on these properties. 4. MPCA /Legislative Funding For Acquisition of these Parcels. Based on Petrofund and other precedent, as well as the continuing value of the property acquired by the City, it is not likely that the City would be able to secure state or metro funding for this land acquisition. Not absolutely impossible however. 5. Cost, Feasibility of Road Construction. Three types of roads could be developed across the landfill: (i) a standard city street (bituminous surface, concrete curb and gutter, 44 ft. width); (ii) a rural street (bituminous surface, no curb or gutter, but a ditch section for stormwater runoff to the existing storm sewer, 44 ft. in width) ; or (iii) a fire access road (aggregate surface only, no bituminous, same ditch as (ii), 22 ft. wide). The cost of a standard city street would be approximately $308,000 under the circumstances; the cost of the rural street would be approximately $253,000 and the cost of a fire access road $106,000. The fire access road would not give legal access to Rutledge or ABJ, so that a portion of the road would in all events have to meet the standard for a rural street. Based on preliminary conversations with the MPCA, it is probable that a design could be developed which would meet the MPCA concerns, which are primarily related to property drainage, and the avoidance of accumulations of water in ditches which would increase or exacerbate leachate problems. A preliminary conversation with the city engineer of Minnetonka suggests that Minnetonka would not oppose the concept of a fire access road as such. (Gessele conversation with Mike Johnson, Assistant Engineer of Minnetonka, December 11, 1991). 6. Existence of Waste on Unowned Western Property. As a result of seven borings performed on the west edge of the landfill on December 6, 1991 by Braun, it now appears that at most, only insignificant traces of waste exist on this property. Of seven borings, only one encountered any evidence of waste (a trace amount of plastic) . 7. Cost /Value of Northern 17 Acres of Venturian Property to the West. On September 19, 1991, Mr. Rappaport's attorney indicated that Mr. Rappaport would sell the northerly 17 acres of the site for $1,000,000. Additional acreage to the south could be acquired for $300,000, for a total sale price of $1,300,000. Information from the Minnetonka City Assessor indicates somewhat lower values. The 17.4 acres, adjoining the landfill has been assessed at $150,000 fair market value by Minnetonka City Assessor; the 7.4 acres directly west of the Greenfield Apartments is assessed at $200,000 and the property adjoining Smetana Road, approximately 11.2 acres, is assessed at $325,000, for a total value of all Rappaport property (approximately 36 acres in total) of $675,000, per the assessor's records. An issue exists with respect to a proposed designation by the City of Minnetonka of portions of all three parcels as wetland, but the wetland designation process has not concluded. Recommendation. Based on all of the above factors, it would appear appropriate for the City to authorize the staff to enter into negotiations with ABJ and Rutledge for the acquisition of a fee interest in or a pollution easement covering their properties on the northern boundary. If the cost of acquisition is reasonable, this would be the preferred alternative. On the � other hand, if it would be overly expensive to acquire the fee and ABJ and Rutledge are willing to comply'with strict City (or MPCA) requirements as to control of use, etc., and provide an easement at reasonable cost, this alternative would be preferred. We also recommend that the City Council direct staff to negotiate with G. Rappaport regarding construction of a limited access road serve his parcel to the west. The results of these negotiations, together with the results of discussions with ABJ and Rutledge, as well as the answers to the issues under paragraphs 5, 6, and 7, will serve to guide staff and the City Council in determining which course(s) of action to pursue. Additional Information is submitted for your guidance and that of the City Council: (a) Venturian/Justus Lumber Parcels on Highway 3. Tentative agreement has been reached with Braun, Venturian and the City regarding the sharing of investigative expenses on the Venturian parcel, and the manner in which the services of Braun are to be separately invoiced to the City and to the landowner. A similar arrangement exists with respect to Justus Lumber. A work plan for a remedial investigation on the venturian property is presently being reviewed by the MPCA. Although no similar work plan has been � submitted yet with respect to Justus, Braun will prepare the Phase II audit proposal with the idea that the Phase II investigative work will be performed not later than this spring. (b) Westbrooke Association Status. The contract between the City and Westbrooke Patio Homes Association controls the City's relationship with the homeowners, vis-a-vis the 1988 Closure Qrder. Counsel to the homeowners has requested an amendment which would eliminate the verbiage related to the barrier construction, etc., and deal only with long term-access for monitoring. We have agreed, and are presently commencing discussions regarding completion of the monitoring well location process. (c) Financial Assurance Mechanism. It now appears that preliminary agreement with the MPCA has been reached regarding the restructuring of the financial assurance mechanism. This will entail a two year pay-in into a trust of an amount equal two years post-closure maintenance costs. � FDN 0028116.WP FDN 0028116.WP (d) Funding from MLCAT. The appropriation of $1.3 million from the Metropolitan Landfill Contingency Action Trust requires (i) submission of an "as- built" set of plans to the MPCA; and (ii) submission of invoices for costs incurred to remediate methane at the Landfill. It is anticipated that this information will be submitted in December, with funding anticipated in January or February. BRAUN" INTERTEC Date: December 9, 1991 To: Jim Gessele From: Paula Connell Re: Gas Monitoring and Borings at Hopkins Sanitary Landfill Gas Monitoring Results Memorandum Gas monitoring of probes along the eastern side of the Landfill, i.e. near Westbrooke, was performed on December 9. Results from the last two years, as well as the figure showing the probe locations, are attached. The barrier was installed in April through June 1991 and was modified in November 1991. To date, we only have one set of results since the modification of the barrier. These results are rather inconclusive at this time. However, the readings have decreased in some of the probes since the barrier modification. It may be that the frozen condition of the ground would delay dissipation of gases present in the soil prior to the modification. Readings in probes G -14 and G -18, as well as several of the readings in the nested probes are above the permitted levels of 5% gas (100% LEL). However, readings in G -15, G -16, and G -17 are zero, or close to zero. Readings in these probes had historically been high, up to 65 %. Additional monitoring should be performed to evaluate whether the readings we are getting are due to residual gas in the soil. I suggest that we monitor once every two to four weeks for the next two to three months. Boring Results Seven power auger borings were performed along the west edge of the Landfill on December 6, 1991. The approximate locations are also shown on an attached figure. The borings were located approximately two feet west of the property line and were placed on the slope. The borings were conducted to the water table, up to approximately 10 feet below the surface. A trace amount of plastic was found in the 2'-6' depth range in boring PAB -5. As a consequence, PAB -6 and PAB -7 were placed approximately 50' north and south, respectively of PAB -5. No trash was found in any of the other borings. 7. 1 : I t I 1 ' 4 I t . • • , ;.,.e • .... ,t (7! (1 0 0 00 0 `♦ \ O O 0 0 o I 5 a t7 } N a. 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