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HomeMy WebLinkAboutSALUD FAMILY HEALTH CENTER LOT 4 - FDP200011 - SUBMITTAL DOCUMENTS - ROUND 5 - Supporting Documentation (6) Memorandum July 26, 2024 To: Thomas Beck From: Joe Aiken, JA Environmental Consulting, LLC Subject: Salud Family Health Center Lot 4, FDP200011, Round Number 4 Draft Comments from the City of Fort Collins Dear Thomas, Attached please find my responses to the draft comments for the above subject project. I have addressed the environmental comments in a comment/response format below. I have also added these to your live document, but I thought it would be easier or you and John to review in the format below. Please note that there are two of the City staff who used Comments No. 29 and 30 so there are two sets of responses for those comment numbers. A. Comments from Katelyn Puga associated with environmental conditions: Planning Comment Number: 13 - Planning recognizes the executed Environmental Use Restrictions imposed by the Colorado Department of Public Health and Environment (CDPHE) that outlines the requirement that the site needs to be approved by CDPHE prior to the recordation of the FDP. Please continue to work with Environmental Planning and Environmental Regulatory Affairs. Response: The Site does not require prior approval from CDPHE to record the FDP , only that the Site development comply with the Environmental Use Restrictions (EURs)(Record No. 20210035465, 4/7/2021, Larimer County). Salud has worked closely with the Colorado Department of Public Health and the Environment (CDPHE) to address the historical environmental conditions and to place the EURs on the Property as part of a completed Voluntary Cleanup Program (VCP) cleanup that was implemented from about 2015 through 2020 . (The VCP Completion Report for the former Forney Site , 1830 Laporte Ave. has been previously provided to the City with our original submittals) CDPHE approved the completion of the cleanup and the closure of the environmental conditions in 2021 with the issuance of a No Action Determination (NAD letter). The NAD stipulates that the CDPHE approves the land for commercial use and the planned development fits this land use. There are currently no known environmental conditions on the property that require investigation or remediation. The EURs were placed on the property to : 1) address any residual environmental contamination ; 2) provide environmental oversite of intrusive activities in the event that an unknown environmental condition is encountered ; , and 3) to assure full protection of human health and the environment during the redevelopment process and future use of the Property. On January 23, 2024, Salud and the City held a meeting to discuss the City’s environmental comments and questions. Mr. Fonda Apostolopoulos, P.E., Environmental Engineer at the State of Colorado Division of Hazardous Materials, CDPHE joined the meeting by phone and confirmed that the development of the Property could proceed as a long as the EURS were followed. Mr. Apostolopoulos leads the Colorado VCP program at CDPHE . He is knowledgeable of the conditions and issues at this Site as he was involved with the former Forney Industries VCP Site completion. He provided the EC and EURs for the Site and is responsible for hundreds of VCP projects statewide. The meeting with Mr. Apostolopoulos and the City environmental staff was arranged to address concerns outlined in the City comments and was followed up by an additional meeting in March 13,2024 (Zoom meeting). Planning Comment Number: 14 - To acknowledge the Environmental Use Restrictions that applies to the property add the following notes to the site plan cover sheet: • No structures intended for human occupancy (including residences, offices, or other workplaces, etc.) may be built on the Property without a properly designed and constructed vapor mitigation system approved by the City of Fort Collins and by CDPHE as requ ired in the Environmental Use Restrictions. • All land use approvals and associated permits are subject to the approval of CDPHE, prior to recordation. Response: Bullet 1: The EURs placed by Salud Family Health Centers(Salud), the property owner, and CDPHE on the property as part of the completion of the VCP cleanup activities requires vapor mitigation systems (VMS) in all new construction. The VMS will be included in the design plans and drawings as an element of the building construction. The VMS system design will be provided to CDPHE for approval as part of the design process to assure that the VMS meets CDPHE requirements for this site. The VMS will also meet the City of Fort Collins requirements for radon resistant construction. Proposed language for the site plan cover sheet taken directly from the NAD: “As per the Notice of Environmental Use Restrictions placed on the property, any new building will have to have an approved vapor mitigation system installed and certified. As part of the certification process, the owners will have to apply to the Voluntary Cleanup Program and have the state approve a No Action Determination for the installed system. “ Bullet No. 2: No land use approvals and associated permits are subject to the approval of CDPHE at this time All CDPHE approvals regarding the environmental conditions at the Property have been completed with the NAD and the EURs as long as the land use is for Commercial purposes. If residential was being proposed, CDPHE would need to approve that change in land use . The EURs do require future CDPHE approval of the VMS as discussed above. In addition, if any CDPHE stormwater or other permitting is needed, that permitting will be part of the construction requirements of the project and will be addressed with CDPHE when conditions require such permits. Appropriate comments have been added to the Site Plan cover sheet to address this comment. B. Comments from John Gerwel concerning environmental conditions: Engineering Comment Number: 2…. - The environmental status and previous contamination of the property was not something I was aware of having inherited the project, and I'm looking for more information on from the perspective that the City would become the owner of land (right -of-way) for public street purposes. Additional information is needed for review with the information provided in the November 2020 report that City staff was recently m ade are of and still processing and should be identified in the most recent Site Characterization Report: 1) Identify with the proposed development what are the areas of City owned right -of-way and also City maintained infrastructure (utilities, trees, public street) that coincide with areas of contamination identified in the environmental compliance completion reports (such as an overlay of the proposed site development with areas identified in Page 28 of the November 2020 completion report). We don't believe we have all the known information at this time to make this determination. 2) How will the proposed development potentially impact any ongoing compliance efforts (such as Page 28 of the 11/2020 report delineates a "phytoremediation" zone, which appears to potentially be in proximity to the new City right-of-way/street. Is this a "phytoremediation zone", and if so, what is it still ongoing and what is the implication on the loss of vegetation with the development?) 3) A soils report wasn't found in the electronic documents, it should be provided for review to understand the recommendations for the construction of the public street system and whether the report considered the environmental condition. Response: The property has been the subject of extensive environmental investigations and remediation activities under a CDPHE-approved VCP, including soil and groundwater assessment and cleanup. There are currently no known environmental conditions on the property that require further investigation or remediation. The Property is cleared and approved by CDPHE for commercial redevelopment as long as the EURs are implemented as part of the redevelopment program. The closure was done with the placement of EURs due to low concentrations of residual chlorinated solvents in groundwater. CDPHE determined that the concentrations of chlorinated solvent remaining at the Site were not migrating and do not represent a risk to human health and the environment as long as any redevelopment of the Property follows the EURs. Salud met with the City of Fort Collins staff on January 23, 2024 to review the historical soil and groundwater investigation and remediation information and to provide assurance that the EURs will be followed during redevelopment . Mr. Fonda Apostolopoulos of the CDPHE VCP Program participated in that meeting confirming: 1) the site conditions are acceptable to the State of Colorado; 2) that migration of the residual contaminants is not an issue of concern to the CDPHE based on the remediation and monitoring previously performed; 3) there was no need or requirement for additional investigation or remediation activities; and ) 4 the proposed development plans are consistent with the EC as long as the project follows the EURS. In addition, Salud held a subsequent follow up meeting with the City to further discuss the environmental conditions and to provide additional information requested during the January meeting. A Power Point presentation referenced during the March 13, 2024 follow up meeting outlines the meeting topics and is attached as Attachment 1 (March 13, 2024 Meeting Outline). As part of that meeting, Northern Engineering prepared a figure that overlays key environmental sampling locations and data with the planned street and utilities and shows the depth to groundwate r with respect to utilities in the work areas. This figure should help with understanding the Site conditions and shows a compilation of post remediation monitoring data and some data from the initial 2014 and 2015 groundwater investigations at the Site.. The figure shows that only limited sections of the planned street are in areas of possible environmental concern . However, consistent with the MMP, environmental oversight is needed during installation of utilities and road construction for the entire street in accordance with the MMP. The new figure is included as Attachment 2. Engineering Comment Number: 29 - The City does not wish to assume responsibility for land that is subject to an environmental use restriction. Maple Street should be private. If the EUR is successfully removed, then the City would consider accepting the street as a public ROW. The street would also need to be designed to LCUASS standards if the City is to accept the ROW in the future. This can be further solidified in the development agreement. Response: Salud recognizes the City’s concerns regarding the City’s acceptance of the street as a public ROW based on potential environmental considerations. The meetings that were held on January 23, 2024 and March 13, 2024 resulted in significant progress in addressing the City’s issues to accept the street as a public ROW. To be clear, Salud is in the business of providing medical care to underprivileged and underserved people. Salud is not however structured to maintain and manage roadways, and certainly not capable of maintaining a through street with significant public use like the planned Maple extension. The City is concerned with possible environmental liability stemming from accepting the roadway. The conversations on this subject include the facts that: 1) based on the new figure that was provided at the March meeting (Attachment 2), the portion of the street that is in an area where there was environmental contamination is very small. While the entire planned street is in the area that is subject to environmental covenant, the area where there is the potential for an environmental discovery is minimal; 2) Salud is required by the MMP to provide environmental oversite and possible testing during the installation of all utilities for the entire street (not just the area of potential environmental concern). All excavation activities associated with the co nstruction of the roadway are subject to the MMP. If any potential environmental concerns are encountered, Salud is responsible under the MMP and covenant to address the concerns, collect confirmation samples indicating that the concern has been addressed, and documenting the activity in a completion report that will be provided to CDPHE ; 3) The concentrations of residual chlorinated solvent in the groundwater are extremely low, are well below the planned excavation depth, and do not represent an issue for future maintenance workers (see response to Comment 10); and 4) Mr. Fonda Apostolopoulos of the CDPHE indicated in the January meeting that once oversight of the utility installation and the roadway installation has been completed that there is no reason for additional oversight associated with utility or street maintenance; CDPHE has since agreed to provide a letter indicating to the City that once the City accepts the street as a public ROW (following Salud’s oversight of environmental conditions and re porting the oversight efforts to the CDPHE), that implementation of the MMP as part of the environmental use restrictions no longer applies to the ROW. Salud is working with CDPHE to provide written assurance of this MMP modification for the ROW to the City. Engineering Comment Number: 30 - We will want some approval by CDPHE documented in the final submittal documents. That may be through a memo documented in the development agreement. This will depend on what CDPHE is willing to provide. Updates will come when we hear from CDPHE. Ultimately, we feel that having something like that documented in association with this project will be beneficial for all parties. Response: Since this comment was provided, Salud has facilitated a meeting between the City and the CDPHE on January 23, 2024 and we have communicated with CDPHE based on discussions that were held during our March 13, 2024 meeting (see Response to Comment 29). C. Comments from Jesse Schlam regarding environmental conditions: Environmental Regulatory Compliance Comment Number: 29 - All underground utilities (water, wastewater, stormwater, electric, etc.), Foundations, sump pits, and their bedding material should be located outside of the groundwater plume (estimated at 7 feet down). This project will need to prevent contaminates from infiltrating utility pipes (causing groundwater pollutants to be directed off site into the drainage system or sanitary treatment system) or use the bedding to redirect flow an d "shortcut" the groundwater off site. Response: Planned underground utilities will be mostly located outside areas of known and suspected groundwater contamination based on the VCP sampling and investigations. Groundwater at the site was remediated and monitored for about five years during the groundwater cleanup portion of the VCP at the Site. The groundwater level at the site is generally at or around 12 feet below ground surface (bgs) near the irrigation ditch and runs about 20 feet bgs in the area where most of the utilities will be installed. See the Figure presented in Attachment 2 for depths to groundwater. The groundwater plume was remediated using a reductive dehalogenation technology approach and only limited areas of low levels of chlorinated solvent remained on the Site when the NAD was issued. It is unlikely that any residual solvent will be encounte red or caused to move off-site due to construction activities. Where there is the potential for installation of utilities in areas of potential enviro nmental impacts, environmental oversight performed in accordance with the CDPHE approved MMP for the Site will provide for protection of human health and the environment. The above discussion of the groundwater conditions was confirmed by Mr. Fonda Apostolopoulos of CDPHE during our January 2, 2024 meeting on environmental conditions. Additional information on the environmental conditions is presented in Attachment 1 (outline from Salud’s March 13, 2024 meeting with the City ). Environmental Regulatory Compliance Comment Number: 30 - All LID treatment should either be relocated outside of the plume footprint or prevent the addition of water into the groundwater, promoting higher groundwater levels and furthering the spread of contaminants. Response: This comment suggests a misunderstanding of current Site conditions including the contaminant levels and aerial extent. The groundwater plume has been remediated at the Property. Most of the former plume was reduced to concentrations that are below the Colorado Basic Groundwater Standards. There were residual concentration of chlorinated solvents in some areas of the former groundwater plume that remained when the NAD was issued, but these contaminants were at low concentrations, the areas do not have enough contaminant mass to cause significant migration, and the residual concentrations were acceptable to CDPHE with the placement of the EURs for the Site. It is highly unlikely that any LID treatment will cause migration of the residuals , in fact it is likely that any input to groundwater will serve to dilute concentrations of any residuals that may be present. Environmental Regulatory Compliance Comment Number: 31 - Per the Materials Management Plan/Notice of Environmental Use Restrictions and the Fort Collins Drainage Criteria Manual, any Erosion Control Report needs to be updated to provide description of the known contaminants on this project and develop a list of Control Measure or Best Management Practices to address encountering contamination in soil and how those materials will be handled during demo, site grading, and construction. Any soil disturbance will require trained oversight and monitoring. Response: The Material Management Plan (MMP) that was approved by CDPHE will be followed, including oversight of intrusive activities by a trained Environmental Professional (EP). The MMP describes site conditions. All known contaminated soils at the project Site have been remediated as part of the VCP cleanup, however, any impacted soils that are discovered will be handled in a manner that is compliant with State and local requirements. The MMP provides procedures that should be followed for addressing contamination in the soil and groundwater during demolition, site grading, and construction. The MMP will be referenced in the erosion control report. Environmental Regulatory Compliance Comment Number: 32 - Per the Materials Management Plan/Notice of Environmental Use Restrictions and the Fort Collins Drainage Criteria Manual the erosion control report must include Construction Dewatering and the anticipated controls to hand le pollutants in the groundwater. Response: Salud does not anticipate that dewatering activities will be associated with the planned slab-on-grade building or the utilities that will be installed. Since the groundwater table is generally 12 to 20 feet deep, the only area where we may encounter groundwater is potentially during installation of the foundation of the bridge over the irrigation ditch. This construction activity will take place in an area that is not near the footprint of the historic groundwater plume. Any water that is re moved during construction will be assessed by the EP for the site and will be managed appropriately in accordance with the CDPHE approved MMP and applicable regulations. Environmental Regulatory Compliance Comment Number: 33 - The groundwater on this site would not meet the State's low risk discharge and could not be land applied on site. That said, a construction dewatering permit will likely result in a remediation permit which will require collecting samples getting tests and possible institute treatment before any discharges off site. This site may require any groundwater to be collected and properly disposed of rather than dewatering. Any of these dewatering options will result in higher than typical costs related to cons truction. Any sump pumps or foundations would also likely result in a long-term remediation permit which would require ongoing permitting with CDPHE. Response: Remediation of groundwater at the site resulted in most of the monitoring wells being at or below the Colorado Basic Groundwater Standards. A few of the wells had levels of chlorinated solvents that were slightly above the Standards but were at concentrations that CDPHE determined were protective of human health and the environment with the placement of EURs. Attachment 2 provides a new map of the locations where concentrations of solvents were above the standards whe n the NAD was issued is being prepared. Construction dewatering, sump pumps, or foundation dewatering is not anticipated for the slab-on-grade building that is planned, but any dewatering that is necessary in these areas will be done in a manner that is compli ant with state and local requirements as dictated in the CDPHE approved MMP. The EP for the site will be responsible for identifying and properly handling of any environmental conditions including extracted groundwater. Environmental Regulatory Compliance Comment Number: 34 - Based upon the complication to this unique site and the amount of permits and environmental remediation the City recommends that a dedicated and knowledgeable environmental compliance staff member be employed for this sites' design, development, and construction. Response: Historically, there were environmental conditions of concern on this Property ; however, the VCP cleanup has addressed all known environmental conditions as discussed in other comment responses. Salud will follow the EURs for the Site including the implementation of the CDPHE approved MMP. Salud is prepared to work with the City to address any concerns regarding past or existing environmental conditions. During our January 23, 2024 and March 13, 2024 meetings, JAEC contrasted the conditions at the former Forney Industries Si te with the environmental contamination that is present in the downtown Fort Collins area of the Willow Street and the Northside Aztlan Community Center to set perspective on the magnitude of environmental conditions at the two properties. In the Willow Street area, the City is a party to an environmental covenant that is the result of historical landfilling and the presence of a historical manufactured gas plant (MGP) in the area. The residuals present as a result of the MGP operations and landfilling are relatively high, with the presence of highly contaminated groundwater and free product residuals that required a remediation barrier to prevent discharge of the free product coal tar into the Poudre River. The extremely low concentrations of residual chlorinated solvents at the former Forney site are significantly lower than the concentration of compounds such as benzene and naphthalene that are beneath the highly developed Willow Street area. The City also operates a VMS in the Azlan Center to control vapor intrusion from the contamination into the building. The vapors include benzene, naphthalene, and other compounds. Despite the presence of the serious contamination in the area, the environmental conditions and the environmental covenant did not prevent redevelopment in this area; for example, the construction of a major apartment project was done under a Colorado VCP without major issues due to environmental concerns. Mr. Joseph Aiken of JAEC managed the environmental oversight during construction, and the installation of the VMS system for this project. The removal of impacted soils and a sump associated with the former MGP operations, the extraction and proper disposal of groundwater countered during the installation of caissons, and the installation and testing (with CDPHE approval) of a VMS in the buildings all occurred in accordance with the CDPHE approved MMP for that site. In addition, the installation of major new utilities in Willow Street required environmental oversight and Mr. Aiken managed that oversight for the City during the project. No contaminated groundwater or soils were encountered during that utility installation project and conditions that may have caused a health and safety concern were not found during the project. While the very low concentrations of residual chlorinated solvents at the former Forney Industries Property represent a much lower risk than a construction project in the Willow Street area, the planned project at the Site has the same restrictions as the Willow Street projects and will have the same level of oversight as the work that was done in the Willow Street area. Salud plans to provide the necessary oversight by an EP as required by the MMP and we are committed to working with the City and CDPHE on addressing any environmental conditions that are encountered. D. Comments from Kirk Longstein regarding environmental conditions: Environmental Planning Comment Number: 5 - A development agreement will be required prior to issuance of a DCP. The DA will likely include language regarding the environmental contamination issues, which will be determined when all the requested information is available. Response: The EC and EUR language address environmental concerns associated with the site and property development. The EURs generally prohibit the use of groundwater, dictates the implementation of a CDPHE -approved VMS in all new construction, and requires the use of the CDPHE-approved MMP for all construction activities. Since the time this comment was provided Salud has met with the City Staff to review the EC’s and the MMP providing additional background and supporting information. Salud appreciates the opportunity to participate in additional discussions if Staff has further questions. Environmental Planning Comment Number: 6 - The current plans do not show the contaminated groundwater plume as it relates to the designed structure. Please add a sheet to the plans delineating the extent of the plume and the proposed improvements. Response: A map showing the groundwater contamination and proposed project is included as Attachment 2. The groundwater at the Site was historically contaminated with chlorinated solvents but has been remediated to concentrations that are considered by CDPHE to be protective of human health and the environment as long as the EURs are adhered to. The groundwater plume was remediated and closed with a VCP NAD in 2020. The closure allowed for some residual solvent at concentrations that were low enough to not be migrating and are contained in limited areas of the Property. A new map was prepared and discussed at the March meeting. The groundwater map shows the site areas where residual solvents exceeded the Colorado Basic Groundwater Standards as known when the NAD was issued. Environmental Planning Comment Number: 7 - Written approval from CDPHE that the Notice of Environmental Use Restrictions and the accompanying Material Maintenance Plan for this property have been reviewed and meet the State's Criteria for all work in and around the contaminated groundwater plume along with the vapor mitigation system. Response: CDPHE has approved the notice of EURs and the MMP . The approved documents are posted on the CDPHE website under the “Sites with Environmental Covenants and Use Restriction” section. During our January 23, 2024 meeting on the environmental concerns presented in the City’s comments, Mr. Fonda Apostolopoulos of CDPHE confirmed that no additional approvals are required to proceed with the development as long as the EURs are followed and the MMP is implemented. The MMP does require Salud to obtain CDPHE approval of our VMS design when that design is available. CDPHE will approve confirmation sampling that shows that the VMS is working properly . Environmental Planning Comment Number: 8 - Please provide a Remediation and monitoring Plan including specific actions to treat groundwater contaminates: TCE, cis -DCE, and Vinyl Chloride to meet Colorado groundwater standards. Planning staff would like the most recent data from the remediation monitoring wells to see how the site has been progressing over the last 3 years. In addition, we would like an environmental remediation professional to provide a written estimate of how long following natural attenuation verses active remediation would take for all the contaminates to meet the groundwater standards. Response: There are no known environmental conditions that require investigation or remediation at the Site. CDPHE has issued a NAD and EURs for the Site. The site was assessed, remediated, and closed through the Colorado VCP. The latest data was collected as part of the VCP closure in 2020 and is included in the Completion Report for the VCP project. As stated in the above comments, Salud and JAEC met with the City regarding the environmental conditions on January 23, 2024 and March 13, 2024. The Salud project team is available to meet with City staff again if requested to discuss the closure documentation including discussion of the Colorado’s Conditional Closure Policy and Guidance for Low Threat Sites. This guidance document was used to address and close the groundwater issue providing assurance to the CDPHE that the source materials were removed and that the residual chlorinated solvents do not represent a threat to human health and the environment. Environmental Planning Comment Number: 9 - Provide progressive monitoring reports that show groundwater contamination of TCE, cis-DCE, and Vinyl Chloride levels meet CDPHE groundwater standards for four (4) consecutive quarters. Response: All monitoring data is presented in the VCP Completion report for the Property. The site was closed with an EC and EURs to address any chlorinated solvents that were above the Standards at the time of closure. See response to Comment 8. Environmental Planning Comment Number: 10 - The City recommends that the property owner work with the State to lift the Environmental Use Restrictions once groundwater contamination of TCE, cis-DCE, and Vinyl Chloride levels meet CDPHE groundwater standards for four (4) consecutive quarters. Response: In compliance with the NAD there are no plans to sample groundwater at this time. The NAD indicates that the groundwater was remediated to the satisfaction of CDPHE, and no additional monitoring or remediation is necessary. Based on our conversations with CDPHE, once the street has been installed and any observed environmental conditions are addressed, the CDPHE will issue a written statement that future implementation of the MMP is not required in areas of the roadway right- of-way where utilities have been installed as deemed cleared by the Environmental Professional (EP (See response to Comment 29) Groundwater use restrictions and the requirement for vapor mitigation in on-site structures will remain. These restrictions will not apply to the roadway. JAEC has also communicated with CDPHE regarding the potential for worker exposure in utility trenches in the roadway. This concern was raised during Salud’s conversations with the City. While the part of the street that may be in an area of residual groundwater impact is very small, JAEC modelled hypothetical worker exposure to contaminated air in excavated area with the US EPA Vapor Intrusion Screening Level (VISL). The calculation was based on groundwater concentrations found at the site and assumed that the worker was in a basement or closed vault with an annual exposure of 8 -hours per day. We believe this approach is a conservative representation of the potential exposure. The VISL results indicated a very low risk of exposure (1 x 10 -9 range of risk). US EPA considers the 1 x 10 -6 range to be protective of human health and the environment so our calculation indicated a risk that was three orders of magnitude below the protective range. Keep in mind that the actual exposure scenario where a worker is in an open trench is more protective than the indoor air exposure that we calculated because the trench is open to the atmosphere and not a confined space such as a basement. The result of this analysis is that virtually no exposure risk to a worker in a trench at the Site exist. CDPHE stated in our January 2024 meeting that there was a very low probability of a worker issue based on the site data and was satisfied with this assessment. Environmental Conditions Discussion –March 13, 2024 Salud Family Health Center, Laporte Avenue, Fort Collins ATTACHMENT 1 Colorado Voluntary Cleanup Process – Former Forney Industries Site •Property has achieved a “No Action Determination” (NAD) through the Colorado Voluntary Cleanup Program (VCP) following remediation of historical soil and groundwater issues. •VCP cleanups are often associated with a property transaction and includes: •Investigation – Phase I and Phase II ESAs; Supplemental and Additional Investigations •Over 40 Groundwater Sampling Locations and over 30 Soil Sampling Locations •Application for VCP – Qualifications, Site Characterization, Risk Characterization, and Corrective Action Plan (Approved by CDPHE in 2015) •Implementation and Completion – Soil Removal (350 CY), 2 rounds of groundwater (GW) remedial injections (60 points 12/2015; 30 Points 12/2017), GW monitoring for about 4 years, preparation of a Completion Report that Documents conditions, and Application for NAD •Colorado Department of Public Health and The Environment (CDPHE) reviews the Application, Completion Report, and Application for NAD and provides approvals on all work •Mr. Fonda Apostolopoulos – CDPHE Voluntary Cleanup Program Lead GW Remedial Activity •GW injections at about 90 locations •Emulsified Vegetable Oil (EVO) and microorganisms •Microbes eat the EVO and create enzymes that dechlorinate trichloroethylene (TCE) and other chlorinated solvents, including the daughter products dichloroethylene (DCE) and vinyl chloride (VC). •Process has been successful nationwide and for the Former Forney Site is was used as an enhancement to the natural attenuation that was occurring at the Site. •EVO is a long -lasting substrate that is active for 5 to 10 years. •Residual solvents present in the subsurface following the end of monitoring in 2020 are expected to continue to decline with time due to the residual EVO and the natural attenuation. •Natural attenuation includes biodegradation, diffusion and dispersion, volatilization, and abiotic de-chlorination of the target compounds. NAD Approval for Property •CDPHE Approved the Cleanup with a NAD that included an Environmental Covenant (EC) and several Environmental Use Restrictions (EURs) •Followed CDPHE Policy for Closure of Low Threat Sites •Source removal, GW treatment to concentrations that are acceptable to CDPHE, and placement of an EC with EURs •EURs include a prohibition on drinking the groundwater, requirements for a vapor mitigation systems (VMS) in all new construction, and a requirement for the use of a Materials Management Plan (MMP) during redevelopment activities. •MMP requires that Salud provide an Environmental Professional (EP) for oversight, monitoring, sampling (if needed), and proper management of any environmental discoveries found during construction activities •The EC and EURs include the entire property…the EP has authority to determine when the oversight and monitoring are required Conditions that Supported Approval of the NAD – Current Conditions •Known soil issues were removed in the source area of the Site and sitewide soils do not contain chlorinated solvents or other contaminants at levels that would represent a risk to human health and the environment . •GW has been remediated to concentrations where CDPHE does not require any additional action, including monitoring. In addition, CDPHE has confidence that continued decline in concentrations will occur through natural attenuation. •GW has been remediated to concentrations that CDPHE determined is protective of human health and the environment as long as the EURs are followed. •Fonda Apostolopoulos indicated that CDPHE considered the risk as very low and that the concentrations are not at concentrations that would cause migration of contaminants or CDPHE to be involved with the Site •The approved MMP and EC/EURs are considered to be protective by CDPHE; the MMP is in place to discover and address any environmental concerns that may arise during construction activities. Current Conditions Map •The area of the planned Maple Street right of way where residual chlorinated solvent is preset in groundwater or where historical groundwater impacts were located is small (approximately 1 to 2% of the pla n ned Maple Street extension). •The depth to groundwater in the area of impact for construction activities historically has been found at 12 feet (or greater) below ground surface (bgs) near the planned building and at 19 feet or (greater) bgs in the area of the planned Maple Street right of way. Groundwater is not likely to be encountered during utility construction. Planned filling activities will likely increase this depth. •The presence of the historical septic system and septic tank is highlighted because it is likely to be encountered during construction. The MMP oversight and monitoring are in place to identify and properly address any environmental conditions that are encountered. Once oversight has been implemented and any issues removed, environmental conditions are not expected to be an issue for future maintenance. •The areas of probable groundwater impacts are presented based on the 2020 data; it is expected that natural attenuation has and will continue to reduce these concentrations over time. CDPHE Assurances •Fonda Apostolopoulos indicated that he would write a letter to the City to provide assurances that the Site is not an environmental concern that requires any action except for the implementation of the MMP. •We can provide CDPHE with suggestions: •i.e. Once the utilities are installed and the area has been observed and managed in accordance with the MMP, the EP can determine that additional observation is not necessary E E E E E E E E E G G G G G G G G G TF E E E E G G G G FDC E E EM T S S W S W GMT FWE E E E E VAU L T EL E C RMW-2 9.9 10.4 RMW-8 89.7 19.2 7 2 ' R O W STORM DRAIN 2 SEE SHEET ST1 STORM DRAIN 4 SEE SHEET G1 STORM DRAIN 2D-1 SEE SHEET ST2 STORM DRAIN 3 SEE SHEET ST3 SANITARY SEWER A SEE SHEET SS1 SANITARY SEWER A SEE SHEET SS1 72' ROW WATERLINE B SEE SHEET WT2 WATERLINE A SEE SHEET WT2 STORM DRAIN 2C-1 SEE SHEET ST2 STORM DRAIN 5 SEE SHEET G1 RMW-3 17.2 12.5 RMW-5 34.3 14.7 RMW-6 6.2 17.5 MA P L E S T R E E T ND ND ND ND ND TCE 1.5 (2014) TCE 20 (2014) ND ND HISTORICALLY ELEVATED BUT REMEDIATED TO LEVELS SHOWN SEPTIC TANK (SEE NOTE 2) NORTH ( IN FEET ) 0 1 INCH = 80 FEET 80 80 160 240 MAP LEGEND: REMEDIATION MONITORING WELL SEPTIC TANK 1.BASED ON HISTORICAL SITE INVESTIGATIONS THERE IS NO INDICTAION OF SOIL CONTAMINATION EXCEPT IN THE CONSTRUCTION AREAS WITH THE EXCEPTION OF THE SOURCE AREA (WHICH WAS EXCAVATED AND REMEDIATED. 2.ABANDONED SEPTIC TANK IN LEACH FIELD MAY BE ENCOUNTERED DURING CONSTRUCTION; REFER TO PROCEDURES IN SALUD/FORNEY MATERIALS MANAGEMENT PLAN. 3.DATA SHOWN REFLECTS POST REMEDIATION FINAL 2020 MONITORING PRIOR TO OBTAINING A NO ACTION DETERMINATION FROM CDPHE. CONDITIONS WERE CONSIDERED IN PLACEMENT OF THE ENVIRONMENTAL CONVENT AND MATERIALS MANAGEMENT PLAN. 4.ND = NON DETECT NOTES: RMW-# XX ZZ RMW-# YY ZZ REMEDIATION MONITORING WELL - # TCE CONCENTRATION (µ/L) DEPTH TO GROUNDWATER (ft) - 2020 DCE CONCENTRATION (µ/L) REMEDIATION MONITORING WELL - 8 DEPTH TO GROUNDWATER (ft) - 2020 AREA OF CURRENT POSSIBLE GROUNDWATER CONCERN TCE LIMIT = 5 µ/L DCE LIMIT = 14 TO 70 µ/L COLORADO GROUNDWATER STANDARDS APPROXIMATE LOCATION OF HISTORICAL GROUNDWATER SAMPLES (PRE-REMEDIATION APPROXIMATELY 2014) ATTACHMENT 2