The Bayaud Street site had a long history of economic production dating back over a hundred years to the time that Denver's economy was dominated by mining and mineral processing. But for the owner, General Chemical, the facilities were old, expensive to maintain, and no longer optimally located.

Joseph Aiken Please provide a brief overview of the project.
Goal of the project: This project achieved multiple goals including

• revitalization of a historical brownfield,
• modernization of facilities for a chemical manufacturer and the City and County of Denver (Denver), and
• realization of the economic and social benefits of a new light rail system.

The Bayaud Street site had a long history of economic production dating back over a hundred years to the time that Denver's economy was dominated by mining and mineral processing. But for the owner, General Chemical, the facilities were old, expensive to maintain, and no longer optimally located. General Chemical was looking to sell the property and build a new facility. For Denver, the site was strategically located adjacent to the iconic Art Deco city waste water building and a perfect site to centrally locate key municipal services. Denver needed such a property because the expansion of the regional light rail system required the acquisition of a Denver property that was being used for maintenance operations. A major sticking point quickly emerged between Denver and General Chemical when Denver could not indemnify General Chemical from environmental liability associated with the site's contamination. International Risk Group, LLC (IRG) was able to provide a solution - they would acquire the site, integrate the cleanup with the site preparation, and sell the property ready for development to Denver and do so within the very tight time schedule. The innovative approach taken on this project enabled Denver to acquire the property despite significant issues due to environmental indemnities. Denver, through their public-private partnership with the IRG, was able to integrate a significant environmental cleanup with the site preparation and construction of their new facilities, was able to use environmental insurance to back the indemnities needed for the transaction, and was able to revitalize a catalytic brownfield property that is yielding benefits to surrounding properties. Denver was able to vacate and transfer properties in a timely fashion to the regional transportation effort. Denver was able to construct their new facilities in a compressed time frame and was able to meet schedule constraints presented by the complexities of this project. General Chemical also achieved their goal of modernization through the construction and opening of a new, more efficient manufacturing facility on another property in an industrial area of the city. Location of the site: The site is located in Denver, Colorado (1271 and 1241 West Bayaud Street), adjacent to the South Platte River and Interstate 25, approximately two miles from downtown Denver. Approximate size of the site (in acres): 37 acres Former use of the site: Starting in the 1880's and continuing through 2008, the property was heavily used for the roasting of mineral ores, the production of acids, and the manufacturing of various chemicals. Much of the property contained fill materials from the beneficiation of mineral ore, and a large area of the site was used for historical disposal of roaster ash, slag, and materials associated with demolition of process plants throughout the history of the facility. Actual end use of the site: The end use includes public works offices, a public works maintenance facility, storage for snow plows and other equipment, a centralized fueling facility for the city maintenance fleet, an animal shelter, and storage facilities for road salt and road de-icing chemicals. These facilities cover the majority of the 37 acres with buildings, roadways, or asphalt parking lots, helping to form a protective cap on the site. The facilities are fully integrated into and part of the environmental remedy. They, along with a 2-foot thick soil cap within the unpaved portions of the site, effectively form a barrier to exposure to subsurface materials, prevent direct human contact with contaminated soil, and prevent infiltration that would come into contact with waste and ultimately impact groundwater at the site. Date the project was complete: Most of the facilities were opened in 2009 and 2010, and the final facility, the Animal shelter, was completed and opened in June 2011

What makes this project unique? How does it stand out among other successful brownfield redevelopment projects?
The four most significant attributes include:

• 1) the public-private partnership that implemented the title transfer and cleanup on the property;
• 2) the build-to-suit aspects of the design that integrated the final facility components into the environmental remediation for the property,
• 3) the accelerated schedule and intricate coordination needed to meet the needs of General Chemical, the light rail expansion and Denver, and
• 4) the efforts to make the development a model of green construction and sustainable practices. Each of these are described below.

Public-private Partnership – Given the environmental conditions and the seller's requirement for environmental indemnification which Denver could not provide, Denver was at an impasse in negotiations to acquire the Bayaud Street property. However, the location and access attributes of the property encouraged Denver to seek an approach providing environmental remediation, indemnification, and security that would facilitate the property transfer. Denver decided to enter into a public-private partnership with IRG to overcome these objections. IRG developed and negotiated a Voluntary Cleanup Plan (VCUP) with the Colorado Department of Public Health and Environment (CDPHE) under the Voluntary Clean Up Program, taking into account the future use and probable development layout, estimated the cost for the remedy, and negotiated costs with the seller and providers of environmental insurance. All parties then executed a three-way program for IRG to take ownership of the property, provide the environmental indemnifications and security needed to complete the deal, and implement environmental cleanup. IRG implemented an accelerated schedule, and achieved a No Further Action (NFA) designation for the soil. Once NFA was received, Denver purchased the property from IRG and began construction of the new facilities. Build-to-suit – In order to build the planned facilities, several key brownfield obstacles needed addressing. The utility installation contractors would not work on the site until assured of worker protection from environmental concerns. Portions of the site were not suitable for building due to historical disposal practices. Rainwater infiltrating into waste roaster ash resulted in a groundwater pH of 4, and concerns over potential discharge of acidic groundwater to the river dictated special attention to this issue. Demolition of rail lines, tankage, and process facilities needed to precede the cleanup and construction. To overcome these types of obstacles, Denver and IRG integrated the remedial planning and the facility design processes to develop a comprehensive plan that would keep cleanup costs to a minimum, integrate clean utility corridors, the buildings and parking lots and roads into the final remedy, and result in the simultaneous implementation of remediation and site preparation for construction. CDPHE approved the integrated concept, which ultimately facilitated the rapid implementation of the program and receipt of the NFA necessary for property transfer. Schedule/coordination – Careful timing in the face of many unknowns was needed to make this project a success and became the greatest implementation challenge. In order to be successful, the project had to almost be envisioned as a three dimensional chessboard with the following pieces:

• General Chemical was constructing a new facility and had to continue manufacturing on the Bayaud site until it opened, and work on that site had its own permitting, construction and implementation complexities;
• Facilities at the Denver Decatur maintenance operations site had to be moved to accommodate the FasTracks schedule;
• Utility work could not be performed until remediation and construction of a clean corridor was complete, which could not be implemented until a majority of the design work for the redevelopment was complete;
• Bevill waste was reused on site to the extent possible and placed under the cap, and repositioning of the waste had to be accomplished prior to capping;
• Work on storm drainage features had to be accelerated to accommodate runoff during construction activities;
• Completion of the remediation and issuance of an NFA from CDPHE was required before Denver could take ownership of the property; and
• Denver's salt dome had to be operating on the Bayaud site in time for the onset of winter, and due to front-end schedules slipping ultimately had to be completed within approximately three months. The project was successful for all parties due to effective communication, flexibility, and aligned interests of the parties. In addition to the contracting mechanisms used, one tool which was critical in this success was the implementation of a Materials Management Plan (MMP). With this plan approved and in place prior to start of the program, unexpected environmental issues could be addressed without a delay necessary for regulatory approval of a response plan. A number of abatements and responses to potentially hazardous materials were performed under the plan smoothly during the course of work at the site. Sustainability – The Central Platte Campus is a model for sustainability in its overall concept, the remediation, as well as the development itself.
• Denver's concept to build an energy efficient, consolidated and centrally located facility provides daily benefits not only to the staff and the City but will reduce energy consumption and operating costs in the long term.
• The decision to integrate the remediation with the development (clean-to-suit) and to reposition Bevill waste to the extent possible underneath the cap reduced the carbon footprint by minimizing emissions from trucking as well as preserving landfill space through waste minimization.
• The development was built using multiple green construction and landscaping strategies for design and operation to achieve LEED-NC gold certification level Additionally, redevelopment of this brownfield improves the livability/recreational opportunities to a key piece of the South Platte River Corridor moving it in the direction of a major urban recreational resource. Integrated sustainable features include extensive photovoltaics, daylighting, solar orientation and water saving strategies. The animal shelter has been designed to a LEED platinum level and, in addition, incorporates recyclable and local materials. Also, General Chemical achieved sustainability improvements by moving to a much more efficient, smaller, state of the art facility in a more suitable industrial area.

What were the primary funding sources (i.e. private or public) for the project and what were the total redevelopment costs?
A variety of funding techniques and sources were used in financing the acquisition, remediation and redevelopment of the property including the voter approved Better Denver Bond issue, a portion of federal ARRA money designed to stimulate the economy in the form of a Colorado Brownfields Revolving Loan Fund grant (a portion of remediation costs), Denver capital improvement funds, and issuance of Certificates of Participation (COPs) to pay the remaining costs. The total redevelopment and remediation costs were $68 million.

What contaminants were present on the site? Please discuss what remediation technologies were used and what the total remediation costs were.
As a former mineral processing facility and chemical manufacturing site, the Bayaud Street site justly deserved the moniker of "brownfield". During the implementation of this program, the contaminants encountered included: metals in soil, such as cadmium, arsenic, and lead that are often associated with Bevill exempt mineral processing wastes; metals in groundwater; petroleum releases; asbestos associated with buried debris; asbestos in the process structures to be demolished; acidic soils and groundwater associated with historical releases; and, other waste chemicals. A large area of the site was an historic landfill for burial of laboratory and process wastes, demolition debris, and other materials. In addition the site was covered in piles of old concrete with rebar, crushed drums, slag and process equipment, and old railroad ties and rails. Given this diverse list of environmental concerns, the plan for the site had many elements. IRG implemented a program that first remediated several corridors to remove contaminated soil to facilitate installation of the new utilities. The primary corridor was 2700 feet long, 12 feet deep and 30 feet wide. This area of the site was "clean-closed" so that utility companies could operate freely without fear of worker exposure. Next, four disposal areas impacting groundwater and not suitable for construction were exhumed, the excavated material was disposed off site, and the remaining soil was blended with lime to neutralize the acid- generating nature of the Bevill wastes. Simultaneous to these first two activities, numerous asbestos areas were abated, several hazardous waste responses were performed for issues such as the discovery of fuming sulfuric acid and unknown laboratory wastes. Structural fill was imported to form a 2 foot cap, bring the site to the construction grade, and raise the site above the South Platte River flood plain where needed. This cap included a blended lime material to provide pH modification for soils and any water that might infiltrate the cap. Additionally, the cap was tested and met permeability requirements of the VCUP. The soil cap helps prevent infiltration of rainwater into the Bevill wastes remaining at the site. However the buildings, roads and parking lots, along with the additional Bevill material that was either excavated and disposed or treated with lime and left in place contributed to the remedy and made the ultimate cap remedy extremely impermeable and constituted a significant part of infiltration prevention. Groundwater pH and metals concentrations are expected to improve once the infiltration was limited. Post construction monitoring shows this to be the case with the overall pH moving from pH4 to about pH6. Metal concentrations have also improved and are approaching the acceptable standards set by CDPHE. To assist in the groundwater cleanup, chemical injection galleries were installed prior to final site paving at several locations. Injection of sodium hydroxide was performed in source areas to mitigate hotspots. The total remediation costs were approximately $5 million.

Before:

After:

Could you describe the use of innovative environmental solutions in the project?
The development of innovative solutions starts with the problems that are encountered for any project. For the Bayaud Street project, a few key problems that were associated with environmental concerns included:

• The need for environmental indemnities to facilitate property transfer;
• The refusal of utility companies to work on the site due to the potential for worker exposure;
• The widespread presence of "fill" material at the site that was the residual of former mineral processing; and
• The need for ongoing environmental cleanup during the construction phase of the project.

One innovative environmental solution used on this project was the approach taken to handle environmental indemnities, which had been the stumbling block in putting together a program to remediate the site and transform it into a key public works facility for the city of Denver. Denver, through a public-private partnership with the International Risk Group (IRG), was able to provide the indemnities required by General Chemical and was able to use environmental insurance to back the indemnities needed for the transaction. A critical component of the deal was that IRG took ownership of the property until the remediation was complete and an NFA. for soil was issued by Colorado Department of Public Health and Environment (CDPHE). In purchasing the property from General Chemical in June 2007, IRG was able to provide Denver and General Chemical with a guaranteed and secured cleanup cost and to solve the problem of indemnification to General Chemical and eliminate Denver's risk associated with buying contaminated property that does not have a regulatory closure. Another innovative environmental approach was the remediation of a "Clean Corridor" to overcome the utility companies concerns regarding worker exposure. The 2700 foot long corridor was essentially clean closed, and approved by CDPHE, to provide assurance that the utility workers would be working in a protected environment. This portion of the remediation and site preparation activity also allowed for the delay-free installation of the main power for the site, for a water main that did not previously exist, and for the sanitary service. One of the primary issues at the site was the presence of Bevill waste, specifically mineral processing waste consisting of acid generating materials (AGM). The typical remedy when dealing with AGM is to cover the material and prevent human contact and contact with water and air. The innovative integration of the cleanup program with the final development plan provided for creative management of Bevill wastes at the site. IRG's "clean-to-suit" approach – the integration of the remediation into the development planning – resulted in achieving the remedial goal of covering the waste and preventing contact with humans, water and air through the use of a low permeability fill to achieve construction grades and Denver's use of buildings, parking lots, and roadways to provide an impermeable cover for the site. During this process, Bevill wastes were repositioned on the site and capped to reduce disposal in landfills and the energy consumption of trucking into and out of the site To achieve the tight schedules dictated by this project, a Materials Management Plan (MMP) was developed to allow quick resolution of unknowns encountered during the remediation and construction. The MMP was approved by CDPHE, gaining pre-approval for the handling of potential environmental discoveries that could occur during construction. This allowed unknown environmental discoveries to become a routine element of the construction project, and avoided the delays that could occur in the absence of a pre-approved program.

How were the environmental results identified and measured?
The approved Voluntary Cleanup Plan (VCUP), developed under the public-private partnership after several earlier unsuccessful submittals, required hot spot removals, capping of the site and groundwater monitoring. In order to achieve regulatory closure, IRG implemented the VCUP and provided the required documentation to the State in the form of a Completion Report, and the State's approval of the soil remediation was determined based on fulfillment of the requirements of the VCUP.

Could you describe the breadth and depth of the remediation required, and was it executed under a consent order or other legal mandate?
The remediation at the Central Platte Campus was implemented under Colorado's Voluntary Cleanup Program. As a former mineral processing facility and chemical manufacturing site nearly all of the 37-acre site contained fill material that was residuals from the processing of minerals, and large areas were historic landfills for burial of laboratory and process wastes, demolition debris, and other materials. In addition the site was covered in piles of old concrete with rebar, crushed drums, slag and process equipment, and old railroad ties and rails. During the implementation of this program, the contaminants encountered included: metals in soil and groundwater, such as cadmium, arsenic, and lead that are often associated with Bevill-exempt mineral processing wastes; petroleum; asbestos associated with buried debris; asbestos in the process structures to be demolished; acidic soils and groundwater associated with historical releases; and, other waste chemicals. Given this diverse list of environmental concerns, the plan for the site had many elements. IRG implemented a program that first remediated several corridors of uncontaminated soil to facilitate installation of the new utilities. The primary corridor was 2700 feet long, 12 feet deep and 30 feet wide. This area of the site was "clean-closed" so that utility companies could operate freely without fear of worker exposure. Next, four disposal areas impacting groundwater and not suitable for construction were exhumed and disposed offsite, the remaining soil was blended with lime to neutralize the acidic nature of the Bevill wastes. Simultaneously, numerous asbestos areas were abated; several hazardous waste responses were performed for issues such as the discovery of fuming sulfuric acid, and unknown laboratory wastes. Structural fill necessary to form a 2 foot cap over the site was delivered to bring the site to the construction grade and raise it above the South Platte River flood plain. This cap included blended lime to provide pH modification for soils and any water that might infiltrate the cap. Additionally, the cap was tested and met permeability requirements of the VCUP. The soil cap helps prevent infiltration of rainwater into the Bevill wastes remaining at the site. However the buildings, roads and parking lots made the cap remedy extremely impermeable and constituted a significant part of infiltration prevention. Groundwater pH and metals concentrations are expected to improve once the infiltration was limited. Post construction monitoring shows this to be the case with the overall pH moving from pH4 to about pH6. Metal concentrations have also improved and are approaching the acceptable standards set by CDPHE. To assist in the groundwater cleanup, chemical injection galleries were installed prior to final site paving at several locations. Injection of sodium hydroxide was performed in source areas to mitigate hotspots.

What was most challenging about the project?
The scheduling and coordination among the parties was the greatest challenge at the Central Platte Campus. There were several hard deadlines on the project, including having facilities in place for the start of the winter maintenance season and having the property ready to receive facilities from Denver property that had to be cleared for the FasTracks program. On the front-end, deadlines for General Chemical to move out slipped due to construction delays at their new site and designs for Denver's final development were still in preparation. Completion of the remediation was a key step in the critical path, and because of the integrated approach chosen for the project, was affected by adjustments in every step of the schedule. When the project began, both General Chemical and Denver had projects on-going that required their access to the subject property. When the property was sold to IRG in 2007, General Chemical needed to continue manufacturing at the subject property (operated under a leaseback arrangement with IRG) until they opened their new facility. General Chemical did not vacate the property until August 2008. IRG had a contractual requirement to complete demolition, remediation, and site preparation, including obtaining an NFA and transferring the property to Denver by June of 2009. This left about 10 months to perform all remediation work and obtain regulatory approvals. Once Denver received the property, they needed to construct several facilities, such as the salt dome to be prepared for the upcoming needs of winter road maintenance. The project was successful for all parties due to effective communication, flexibility, and the aligned interest of the parties.

Did the project receive any loans, grants or financial assistance from any public or private organizations?
A variety of funding techniques and sources were used in financing the acquisition, remediation and redevelopment of the property including the voter approved Better Denver Bond issue, a portion of federal ARRA money designed to stimulate the economy in the form of a Colorado Brownfields Revolving Loan Fund grant (a portion of remediation costs), Denver capital improvement funds, and planned of Certificates of Participation (COPs) to pay the remaining costs.

Could you describe the collaboration that occurred among multiple parties to enable the project to excel?
This project came out of a strategic association between IRG, General Chemical, and Denver with cooperation and coordination with CDPHE and is an example of how a business and local government can enter into Public-Private Partnership and attain a plan that meets the needs of all parties.

• A Public-Private Partnership that allowed a complex property transaction to occur;
• Use of environmental insurance to provide security to a guaranteed fixed-price remediation;
• An innovative plan that provided for the integration of site remediation and site preparation activities to facilitate rapid redevelopment; and,
• A soils management approach that allowed for a smooth transition between remedial and redevelopment activities.

The Public-Private Partnership created an acceptable approach to cleanup funding and the purchase price of the property. Denver wanted to buy the existing General Chemical property, but was restricted by the requirement to indemnify General Chemical regarding environmental concerns about the risk of acquiring contaminated property. The deal was the perfect match of seller and buyer. Denver's proposed light industrial land use, with large areas capped with parking lots, building foundations, and roadways, more closely matched the expected cleanup approach envisioned by the CDPHE for capping and institutional controls. In addition, redevelopment of the property would finally address a property that Denver's Department of Environmental Health had long identified as contributing to degraded water quality in the adjacent South Platte River and also address a generally blighted area within an otherwise vibrant industrial area. Although General Chemical and Denver had agreed to the price, they each had sale terms that were in direct conflict. Denver could not indemnify the seller for future liability, a stated demand, due to State Constitution and City Charter prohibitions and also had concerns about long-term remedy effectiveness. The seller, after making a third attempt, could not get CDPHE approval for a proposed remedy and was unable to provide Denver or any third party with certainty as to the environmental remediation costs. Not wanting to concede the opportunity, Denver engaged IRG to expand their role beyond environmental insurer to act as intermediary, providing indemnification, technical assistance in obtaining a viable cleanup plan, and ultimately taking on remedy implementation responsibility. IRG entered into this partnership with Denver and took ownership of the property from General Chemical. As part of the overall transaction, IRG agreed to sell the property to Denver when environmental closure was achieved and provided General Chemical with a guaranteed fixed price for the closure activities. Denver funded the purchase price of the property, and the cleanup costs were escrowed against the future performance of the work. To assure that the escrowed cleanup costs would be sufficient to achieve regulatory closure, IRG obtained environmental insurance to guarantee the cleanup costs and protect against unknowns that may be encountered during cleanup and development. This surety allowed General Chemical and Denver to arrive at a reasonable purchase price for the site and to complete the transaction. In addition, the insurance provided coverage for Denver during redevelopment activities and ensured the remedial efforts were done properly. IRG also assumed the responsibility for implementing the VCUP, obtaining regulatory closure, and development of a plan that would integrate significant site preparation activities for the redevelopment into the remediation and environmental closure activities. For example, during capping of the site certain storm water control features associated with the final site development were also integrated. IRG developed a plan that integrated the needs for storm water management for both the cap and the redeveloped properties, thereby accomplishing a critical redevelopment need while closing out the environmental issues. IRG entered into the VCUP with CDPHE as the responsible party to clean the site up and initially helped finalized the preparation of the VCUP. IRG then performed the cleanup activities, integrated site preparation activities for planned future use into the cleanup, and received an NFA for soil from CDPHE. Following receipt of the NFA for soil, IRG transferred the property to Denver for final construction of the planned redevelopment. Along with the property transfer, IRG transferred the MMP that allowed Denver to perform redevelopment activities in an uninterrupted manner. It was assumed that activities such as installation of building foundations would result in the discovery of waste materials that were under the cap, but needed to be removed for construction purposes. The materials management plan allowed for these materials to be handled in a routine way without the need for additional CDPHE involvement. Additional collaboration was required to provide the required landscaping to satisfy the Denver Planning Department while using very limited irrigation, as provided in the modified environmental covenant recorded with CDPHE. Development and implementation of the VCUP by IRG required collaboration with Denver and CDPHE due to modifications that were necessary during the program. This VCUP was the fifth iteration, whose scope changed from construction of underground barriers and injection wells to the implemented scope of select hot spot excavation, capping, and groundwater monitoring. The selected scope reduces risk by addressing potential pathways of exposure by a) providing a barrier between the Bevill waste and human contact, b) limiting infiltration of rain and melted snow through the Bevill waste, and c) allowing appropriate use for this site, which is light industrial. As the site was remediated, the scopes of some remediation activities were modified, and the modifications were accommodated by IRG and CDPHE. Examples include the clean utility corridor, the detention pond, and the environmental covenant requirement of no irrigation:

• The primary utility corridor is located under the on site access roadway. This major utility corridor was originally planned to be installed during redevelopment. However, given the schedule and utility worker access requirements, the corridor was excavated by IRG and remediated to allow for unrestricted access by workers. As a result of this level of remediation, an NFA was granted by CDPHE for this corridor.
• The detention pond in the northeast corner of the site is required by Denver's Development and Engineering Code Requirements. Denver had IRG accelerate the construction of the pond to accommodate runoff during construction activities, to remove Bevill waste that could be encountered during pond construction, and to reposition excess Bevill waste on site before capping. IRG met this accelerated schedule.
• The Denver Municipal Animal Shelter is located within the southeastern portion of the former General Chemical site and falls within the environmental covenant that prohibited any on site irrigation. Denver requested a modification to the covenant and was supported by IRG on the basis of a) the planned use as an animal shelter, b) a desire for the animal shelter to be welcoming to the public, c) the site specific geology and occurrence of Bevill waste, and d) a site specific study of potential impacts of limited irrigation in the southeastern portion of the site. The CDPHE granted the covenant modification.

What type of innovative designs and energy-efficient technologies were implemented?
Sustainable Development elements were implemented under the structure of the Leadership in Energy and Design (LEED) certification system. On this Brownfields redevelopment project, Denver and its contractors were able to receive LEED Gold certification. The Fleet Maintenance and Office/Warehouse building design was specifically crafted to accommodate day lighting and photovoltaics (PV). The City established a Purchase Power Agreement (PPA) for this project and other City owned facilities. The saw tooth roof shape allows for a PV surface with a south orientation along with a glazed surface on the north face for day lighting. Each of the saw tooth peaks includes a translucent glazing and greatly enhances the day lighting in both the Fleet Maintenance (38,000 SF) and Office/Warehouse buildings (29,000 SF). In addition, water use inside the building is reduced by more than 40%. The City anticipates 34.5% energy savings on the Fleet Maintenance building and 30.4% energy savings on the Office Warehouse building. 8.What recyclable materials were used to classify this as a 'green' development? Central Platte Campus incorporated the numerous waste reduction strategies in the redevelopment and qualified for the LEED credits for diverting 75% of construction waste from disposal, 10% recycled content, and 20% of materials were extracted, processed and manufactured locally. The Animal Shelter construction project separately implemented similar waste reduction strategies, receiving the same LEED credits, plus a credit for utilizing twice the level (20%) recycled materials.