TUNNELING UNDER AUSTIN PROTECTING THE ENVIRONMENT, AND PRESERVING THE PEACE

Transcription

1 TUNNELING UNDER AUSTIN PROTECTING THE ENVIRONMENT, AND PRESERVING THE PEACE Reynaldo Cantu, Pervez Jameel, Susan Kelly Brown and Caldwell 9011 Mountain Ridge Drive, Suite 100 Austin, TX ABSTRACT For over a decade, an existing 42-inch wastewater interceptor has plagued the Austin Water Utility (Utility) with higher than usual maintenance demands. Located in the Walnut Creek flow line, this interceptor is partially exposed with manholes rising several feet above the creek bed due to years of erosion. The interceptor suffers from external erosion and is victim to debris floating down the creek during rain events. On two separate occasions, the Utility designed a new parallel interceptor to replace the existing one only to have the project halted by the public and local home owners association. The environmental concerns, coupled with stream bank erosion and stabilization issues, made this project a heated debate for City residents. To further aggravate the situation, in 1999 the Utility was put under an Administrative Order by the U.S. Environmental Protection Agency (EPA) to eliminate sanitary sewer overflows in their wastewater conveyance system by December 31, This project utilizes trenchless technology coupled with traditional construction methods to develop a variety of solutions - and ultimately the best solution for the project. It was imperative to keep the public impacts to a minimum and have the project substantially complete by the mandated date of the EPA s Administrative Order. The fast tract schedule mandated work in double shifts for at least a portion of the project and did not leave much time for changed or unforeseen conditions. Because of these specific project conditions, it was important to assure that the element of risk on the project was kept to a minimum and shared by the Utility and the Contractor. In order achieve this several items were incorporated into the project, and are listed below: 1. Differing Site Conditions Clause 2. Geotechnical Baseline Report 3. Disputes Review Board 4. Escrow Bid Documents 5. Pre-Construction Survey 6. Noise Abatement 7. Monitoring Ground Movement A win-win for the Utility and the residents, this project won acceptance from the residents, minimized impacts to the community and the environment, and eliminated land acquisition requirements. The project began construction in June of 2004 and the tunneling operation was 5467

2 complete in November of In January of 2006 the City Manager received a letter from a resident of the Little Walnut Creek Community stating the following: Where s the new sewer line we ve been promised? The City promised us the line down Northeast With the tunnel mining operation complete two months prior to the resident s letter, it was clear that the resident was unaware that the construction for the sewer line down Northeast Drive had already been completed. Clearly a sign that impacts to the community were kept to a minimum. The project reached substantial completion in July of 2006 well within the projects fast track schedule. The project is ultimately a success with neighborhood acceptance and minimal impact to the community and the environment. KEYWORDS Trenchless Technology, Public Acceptance, Dispute Review Board INTRODUCTION Due to the simple laws of physics, wastewater collection systems flow by gravity to sewer basin creeks and rivers. Over time the soils and soft rock formations along the creek beds erode and shift and wastewater collection systems become exposed or misaligned and damaged. The Austin Water Utility (Utility) is no stranger to this phenomenon with what they commonly referred to as the Little Walnut Creek Interceptor. 5468

3 This existing 42-inch wastewater interceptor has plagued the Utility with higher than usual maintenance demands for over a decade. Located in Walnut Creek, this interceptor is partially exposed with manholes rising several feet above the flow line of the creek due to years of stream bed erosion. Several of the interceptor s manholes have been damaged over time due to high velocities carrying debris down the creek during storm events. Put into service in the 1960s the interceptor has also reached capacity and with infiltration and inflow, struggles to keep up during rain events. To remedy the capacity issue the Utility designed a relief sewer in the creek bed on at least two individual occasions in the past. These two designs met significant opposition from the public and the local home owners association and were never constructed. The Little Walnut Creek bed has shown a significant amount of erosion over the past several decades and if left un-stabilized the creek will continue to erode at a rate of two feet per year. Residents and business owners along the creek are concerned Figure 1 Little Walnut Creek Interceptor that further disturbance would only accelerate the erosion of the creek bed and compromise the stability of the river banks. Additionally due to the exposed nature of the existing interceptor, residents have been subject to several sanitary sewer overflows and argue that an additional interceptor in the creek will only amplify the problem. The environmental concerns, coupled with the stream bank erosion and stabilization issues, have made this project a heated debate for City residents. To further aggravate the situation; in 1999 the Utility was put under an Administrative Order by the U.S. Environmental Protection Agency (EPA) to eliminate sanitary sewer overflows in their wastewater conveyance system by December 31, It was now imperative that the Utility find a solution for the Little Walnut Creek Interceptor. The primary goals of the project were to augment the capacity of over 15,000 linear feet of the existing 42-inch interceptor, achieve public acceptance, and meet the terms of the Administrative Order. For this project to be a success an alignment needed to be selected that would protect the environment, minimize public impact and meet the Administrative Order deadline. This project utilizes trenchless technology coupled with traditional construction methods to develop a variety of solutions - and ultimately the best solution for the project. This paper will 5469

4 discuss the challenges of the alignment selection, design and construction phases and how solutions were put in to place to meet these challenges. ALIGNMENT SELECTION With environmental impacts and public acceptance as two of the major drivers on this project, the construction methods considered for this interceptor were primarily trenchless. Using trenchless technology such as tunneling or boring would eliminate community concerns for accelerating stream bed erosion, disturbing environmental wet lands or impacting the neighborhood. With trenchless technology as a viable option, the next hurdle was to select an alignment that was geotechnically favorable to trenchless construction methods, and would satisfy the needs of the Utility and appease the public. Within the first two months of the project, a detailed feasibility study was completed to clearly define the design parameters and determine the best route selection as it relates to: Hydraulic capacity Permitting Sufficient amount of cover Land or easement acquisition Constructability Construction cost Geotechnical characteristics Impacts to the community Environmental issues Scheduling Long term operation and maintenance requirements In the feasibility study six alignments were ultimately identified; however, three of the alignments were dismissed early on due to high risk in constructability, prohibitive costs, environmental constraints, excessive land acquisition, and/or public opposition. The remaining three alignments were investigated in greater detail and are described below: Green This alignment paralleled the existing interceptor in the creek. It required a drop structure at the tie in point to the existing interceptor on the upstream end and required land acquisition of several properties. Purple This alignment meandered within the creek and the road right-ofway (approximately 50/50) and had one aerial creek crossing. This alignment also required a drop structure at the tie in point to the existing interceptor on the upstream end and required the land acquisition of several properties. 5470

5 Figure 2 Proposed Project s 5471

6 Red - This alignment was completely within street right-of-way with the exception of two properties, one of which was owned by the City. This alignment was slightly longer than the others; however, there was no need for a drop structure and land acquisition was very minimal. Once the three alignments were verified to meet the above criteria, the criteria were rated against each other using specified evaluation criteria and a decision matrix. The evaluation criteria were divided into 6 main categories, including: 1. Schedule 2. Public impacts 3. Environmental impacts 4. Land acquisition 5. Constructability 6. Cost A weighting factor was assigned to each category, and the sum of all of the categories weighted factors equaled 100 percent. Categories with greater importance were assigned a higher percentage of the weighting factor. Each of the alignment alternatives were then rated under each category on a scale of 1 to 3 with 1 being the better or preferred choice. These ratings were then incorporated into the comparison matrix for an overall rating of each alternative. Each of the evaluation categories and the alternative ratings are defined below. Schedule - Weighting Factor 20% The milestones of this project which impact the schedule are the design, bid, land acquisition and construction phases. The amount of time required for the design and bid phase is the same for each of the alignment alternatives. However the land acquisition and construction phases are different for each of the alternatives. For example, the Red will take longer to construct due to the fact that it is longer in length, and the Green and Purple s will take longer to reach the construction phase due to the larger number of property owners involved with land acquisitions. Since land acquisitions are rated as a separate category of evaluation criterion in the comparison matrix, it is not necessary to rate the alternatives with respect to land acquisitions under the schedule category. Therefore this category rated each alternative with respect to the construction schedule only. The estimated time for the construction phase for each of the alignment alternatives and their ratings are shown below. 5472

7 Table 1 Construction Duration Construction Duration 1 Rating Green 17 months 1 Purple 19 months 3 Red 18 months 2 1. Rating 1 through 3, 1 being the preferred rating Due to the importance of this project to be complete by the Environmental Protection Agency s Administrative Order deadline, the weighting factor for this evaluation criteria was assigned a higher weight of 20 percent in the comparison matrix. Public Impacts - Weighting Factor 10% The Utility strives to keep impacts to the public a minimum on all of their projects. The Little Walnut Creek residents are a particularly active group and have opposed and overruled two previous plans for wastewater improvements within their creek which runs through the center of their subdivision. The criteria used to rate public impact addresses short term impacts which occur during the construction phase and long term impacts after the project is complete. These criteria and the alternatives ratings are listed below: Short Term Public Impacts (during construction) Easement Acquisition Easements needed to be acquired from residential, commercial and park properties. The Green required easements from 30 properties, the Purple required easements from 7 properties and the Red required easements from 2 properties. Acquiring Residential Properties The Green and Purple s ran between two residential properties. A drop structure was also required at this location which would significantly impact the residential properties and possibly render these properties unacceptable for residential housing. Construction Adjacent to Occupied Properties During construction, residents or businesses adjacent to work shafts or open cuts construction will be inconvenienced by noise, dust, and traffic caused by construction activities. Each alignment has construction adjacent to occupied properties. Truck Hauling Routes Truck hauling routes will be necessary to haul tunnel excavation spoils and bring in pipe and other supplies needed for construction. The Red had the more direct route to U.S., Highway 183 however all alternatives would impact the residents to some degree. 5473

8 Long Term Public Impacts (after construction is completed) Above Ground Improvements Each alignment will require access shafts for maintenance. The Green and Purple s will also need a drop structure in the creek at the upstream end of the project. Visual Aesthetics The local community is very concerned about the conditions and appearance of their creek. The Green and Purple s will require a drop shaft and 500 lf of open cut construction within the limits of the creek which will require streambed stabilization. Additionally, the Purple will have an aerial creek crossing in the northern portion of the alignment. Odor The drop structure required for the Green and Purple s may emit odors and may require an odor control facility. Description of Impact Table 2 Public Impact Ratings Green Purple Red Short Term Public Impacts Easement acquisition (30) (7) (2) Acquiring residential property Construction adjacent to occupied properties Truck Hauling Routes Above Ground Improvements Long Term Public Impacts Visual Aesthetics Odor Control 1 Rating Rating 1 through 3, 1 being the preferred rating It would be impossible to construct any of the alternatives without impacting the public to some extent, therefore, the weighting factor for this evaluation criterion was assigned a lower weight of 10 percent in the comparison matrix. Environmental Impacts - Weighting Factor 10% As noted in the Public Impacts section above, the City of Austin continues to strive to keep impacts to the environment to a minimum on all of their projects. The primary area of environmental concern on this project is construction within the creek bed during which, a proactive erosion, sedimentation and dewatering program must be in place. Additionally streambed stabilization will be required to protect the improvements within the creek bed from future erosion and scouring caused by natural creek flow. The Green and Purple s have approximately 800 lf of open cut construction within the creek bed located at the upstream portion of the project. Therefore they received a lower rating than the Red under this criteria as shown below. 5474

9 Table 3 Environmental Impacts 1 Rating Green 3 Purple 3 Red 1 1. Rating 1 through 3, 1 being the preferred rating Environmental impacts are present in all of the alternatives to some extent, therefore, the weighting factor for this evaluation criterion was assigned a lower weight of 10 percent in the comparison matrix. Land acquisition Weighting Factor 30% Easement acquisition for temporary and permanent easements will be required for all three of the alternatives. Any easement, regardless of its size, requires the same documentation and level of effort from the City s Real-Estate department and the property owners. As previously mentioned in this report, this project must be completed by September 2007 in order to be in compliance with the Environmental Protection Agency s Administrative Order. A concern is the easement acquisition process would hold up the construction phase of the project. The number of properties that require easements for each alignment alternative and their rating under this criteria is shown below. Table 4 Land Acquisition Number of Properties 1 Rating Green 30 3 Purple 7 2 Red Rating 1 through 3, 1 being the preferred rating Due to the importance of this project to be complete by the Environmental Protection Agency s Administrative Order deadline of September 2007, the weighting factor for this evaluation criterion was assigned a higher weight of 30 percent in the comparison matrix. Constructability Weighting Factor 10% Each alignment alternative consists of similar lengths of open cut and tunneling construction and each of the alternatives can be tunneled with the same tunneling methods. The constructability of these alternatives is impacted by several items. These items include tunneling under creek crossings with minimal cover, tunneling through mixed face conditions tunneling under or close 5475

10 to developed property, and construction of a hydraulic drop structure on a creek embankment. The Green and Purple s share many of the items above however the Red does not have to address these issues and is the preferred route under these rating criteria. Table 5 - Constructability Tunneling Under Creek Tunneling Through Mixed Face Soil Conditions Tunneling with minimal cover Tunneling Close to Developed Property 1 Rating Green 3 Purple 2 Red 1 1. Rating 1 through 3, 1 being the preferred rating Constructability issues are present in all of the alternatives to some extent, therefore the weighting factor for this evaluation criterion was assigned a lower weight of 10 percent in the comparison matrix. Cost Weighting Factor 10% The cost estimates for each proposed alignment alternatives were for comparison purposes only because subsurface investigations were not performed for each alignment alternative. Should actual subsurface conditions vary from those assumed in this evaluation, construction costs would also vary. The cost estimates include labor, equipment, equipment operation, materials, supplies, subcontractors, mobilization and demobilization. Table 6 Construction Cost Cost 1 Rating Green $17,050,000 1 Purple $17,107,800 2 Red $18,326, Rating 1 through 3, 1 being the preferred rating Cost varies amongst the alternatives by a minimal 7%, therefore, this evaluation criterion was assigned a lower importance weighting factor of 10 percent. Comparison Matrix The table below compares the three alignment alternatives using the above described evaluation criteria. As noted above, the evaluation criteria were divided into 6 main categories, which are 5476

11 shown in the comparison matrix as items 1 through 6. Each of these categories has been assigned a weighting factor, the sum of which totals 100%. Each alignment alternative was rated under each category from 1 through 3 with 1 being the preferred or best alternative under the evaluation category. The total or overall rating of each alignment is summarized at the bottom of the matrix. Evaluation Criteria Total Weight % Table 7 Comparison Matrix Green Purple Red 1 Rating Total 1 Rating Total 1 Rating Total Schedule Public Impacts Environmental Impacts Land Acquisition Constructability Cost Total Overall Rating Rating 1 through 3 with 1 being the preferred rating The Red was the recommended alignment, and it was ultimately chosen. With the proposed project alignment accepted by the community the next challenge was to design and construct the project successfully and on time. DESIGN CONSIDERATIONS During the design phase several important components of the design required special attention. One of the major characteristics attributing to the project challenges was the limited access along the route. The project had a 10,000 linear foot span within the right-of-way of a residential road (Northeast Drive) that had virtually no points of access. Additionally the right-of-way had several curves requiring negotiation during construction. This limited access meant that the project would have to be constructed in one continuous run with no intermediate shaft. Other key characteristics included the hydraulics of the sewer line with respect to odor, corrosion and erosion, and an extensive geotechnical investigation. Construction Methods A combination of trenchless technology and conventional construction methods were used on this project. Tunneling applications were evaluated for the installation of pipelines, where the alignments are deep or the ground surface cannot be disturbed due to existing improvements or environmental constraints. The tunneling methods evaluated for this project were road header, tunnel boring machine, and microtunnel boring machine. The road header constructs a horseshoe shaped tunnel by means of excavation, while the tunnel boring and microtunnel boring machines construct a circular tunnel by means of boring. Each of these methods has advantages and disadvantages related to tunneling capabilities, procurement and mobilization, and rate of tunneling progress. The table below summarizes the key points for each tunneling method. 5477

12 Tunneling Method Construction Method Procurement Set-Up & Breakdown of Operation Manipulation of Bends on Rate of Tunneling Per Shift Road Header Excavation 1 month 1 week Yes (any) 25 feet Tunnel Boring Machine Microtunnel Boring Machine Boring 3 to 7 months 1 month Boring 1 month 1 week per 1,000 linear feet of construction Yes 350 R max No, must have bore pit to make bend 75 feet 35 feet The chosen alignment consisted of approximately 5,000 linear feet of pipeline in undeveloped property owned by the City, and 10,000 linear feet of pipeline along residential streets within City right-of-way. The alignment located on City property was relatively shallow, and on both constructability and environmental standpoint lent itself to traditional open cut construction methods. The alignment located within the street right-of-way was over 140-feet deep in some locations; had curves that needed to be negotiated; and the need for any intermediate shafts would have required land acquisition with possible condemnation, significant impact to the community, and public opposition. Due to these constraints, the Tunnel Boring Machine (TBM) was the chosen method of construction within the street right-of-way with the use of the road header excavator in the more shallow areas consisting of non-cohesive soils, which typically do not lend themselves to TBM construction methods. Hydraulics, Odor and Corrosion Figure 3 Tunnel Boring Machine During the design phase, special attention was paid to the capacity of the proposed tunnel and the existing upstream and downstream flows. It was observed that the upstream flow was supercritical and the downstream flow was subcritical. In order to eliminate a hydraulic jump, which may cause odor and corrosion problems in the future, the new tunnel diameter and slope were selected to maintain a flow at normal depth at the transition of supercritical to subcritical 5478

13 flow. Additionally, conduits were specified in the junction structures in the event that future odor control would be needed. Once the carrier pipe size was determined, the actual TBM size was selected. In determining the size it was important to take into account that the tunnel would have no intermediate shaft within its 10,000 linear foot alignment; therefore, larger ventilation ducting and power and ventilation booster stations would be required. Geotechnical Investigations Since this project was such a political issue to the residents and under the Administrative Order s fast track schedule, it was important to take special measures during the design to minimize risk and eliminate causes for construction delays. For this reason, an aggressive geotechnical investigation was performed, which included over 30 soil borings ranging in depth from 50 to 150 feet and two inclined borings used to identify possible fault locations. These borings were on display for the contractors to view during the bidding phase. The location of the tunnel starter shaft was dictated by the ground conditions. It was the desire to launch the TBM in solid rock not mixed face soil conditions; therefore, several borings were taken at the starter shaft location to identify where and at what depth the transition from non-cohesive soil to rock took place. As the ultimate location of the starter tunnel did have some mixed face properties in the vicinity of the crown of the tunnel, ground modifications through the use of surface grouting were also specified. CONSTRUCTION AND KEEPING THE PEACE The project was located in a very developed and active residential community with several schools, churches and businesses in the area. It was important for the Utility to keep the public impacts to a minimum and have the project substantially complete by the mandated date of the EPA s Administrative Order. The fast track schedule mandated work in double shifts for at least a portion of the project and did not leave much time for changed or unforeseen conditions. Because of these specific project conditions, it was important to assure the element of risk on the project was kept to a minimum and shared by the Utility and the Contractor. In order to do this, several items were incorporated into the project. These are listed below and are described in more detail on the following pages. 8. Differing Site Conditions Clause 9. Geotechnical Baseline Report 10. Disputes Review Board 11. Escrow Bid Documents 12. Pre-Construction Survey 13. Noise Abatement 14. Monitoring Ground Movement Differing Site Conditions Clause To keep the peace between the residents, the Contractor and the Utility, all parties must accept the basic philosophy of risk sharing. The contract must begin with a complete and accurate set of plans, specifications and contact documents. On this project site conditions were specific to 5479

14 the underground. Even with the new and advanced geotechnical study and exploration methods it remains difficult to foresee all conditions that will be encountered in underground construction projects. It is for this reason that a provision for Differing Site Conditions was included in the contract documents. To back up this provision, the contract provided for an equitable price and time adjustment so if differing site conditions were encountered they could be easily resolved. The standard Federal clause for Differing Site Conditions states: DIFFERING SITE CONDITIONS (a) The Contractor shall promptly, and before the conditions are disturbed, notify the [Contracting Officer, Owner, Engineer] in writing of: (1) subsurface or latent physical conditions at the site differing materially from those indicated in this contract, or (2) unknown physical conditions at the site, of an unusual nature, differing materially from those ordinarily encountered and generally recognized as inherent in work of the character provided for in this contract. The [Contracting Officer, Owner, Engineer] shall promptly investigate the conditions, and if he finds that such conditions do materially so differ and cause an increase or decrease in the Contractor s cost of, or the time required for, performance of any part of the work under this contract, whether or not changed as a result of such conditions, an equitable adjustment shall be made and the contract modified in writing accordingly. (b) No claim of the Contractor under this clause shall be allowed unless the Contractor has given the notice required in (a) above; provided, however, the time prescribed therefore, may be extended by the (Government, Owner). (c) No claim by the Contractor for an equitable adjustment hereunder shall be allowed if asserted after final payment under this contract. Geotechnical Baseline Report The Geotechnical Baseline Report (GBR) sets forth the geotechnical engineers interpretations regarding anticipated conditions for the site and construction. The GBR is typically made part of the contract documents by reference and establishes the baseline for all anticipated conditions on the site. The incorporation of the GBR generally promotes a cooperative climate since the emphasis is on openness and truthfulness and, if conditions differ from the baseline report, the Contractor can typically demonstrate the financial impact. Additionally the GBR when prepared properly enhances the Contractor s opportunity to be innovative. By having information on anticipated ground behavior, the Contractor can better estimate the impacts of using innovative construction methods at his own cost. Dispute Review Board The Dispute Review Board (DRB) provides a forum that fosters cooperation between the owner and the contractor and provides a means of resolving disputes fairly and quickly. The DRB is made up of three board members who are considered experts in the construction methods of the project. The DRB is selected immediately after contract award. A member is selected by the Contractor and by the Utility. These two Board members then select a third member for the 5480

15 Board who is the lead board member. The Board met at the construction site on a quarterly basis throughout the duration of the project. The role of the board was to provide an independent assessment of any disputes and recommendations for solutions. The Board s recommendations are not binding; however, the knowledge of an experienced and impartial party is very respected by both parties. On this project, there were no disputes or need for any Board recommendations. Escrow Bid Documents Escrow Bid Documents included all quantity take-offs, calculations, price quotes and other information that the contractor used to develop his bid. Typically in a bid the three highest bidders are requested to submit their escrow bid document in a sealed envelope. The documents are considered the property of the contractor and are to be stored in the care of a third party and returned to the contractor at project completion. If during construction there is a dispute over cost or pricing, the escrow bid documents can be opened to assist in finalizing the pricing dispute. The documents can be opened only in the presence of the designated representatives from the Utility and the Contractor. In addition to enhance the effectiveness and improve realization of the contract goals, the following three specific concepts were also added to protect the Contractor: Pre-Construction Survey With the tunneling to take place under a developed residential neighborhood, several of the residents were concerned that ground movement may occur and possibly cause damage to their property foundations. To protect the contractor and prevent a wrongful claim, the Contractor was required to produce an audio/video recording of the entire construction route and any other adjacent areas that may be impacted by construction operations. The video was required to digitally show time and date of the recording and was to capture the address of the areas being filmed or other landmarks to provide orientation of video location. Noise Abatement The starter shaft for the tunneling operation was located adjacent to an apartment complex. Concerns about noise and the need for double shift operations called for a plan to monitor and abate the noise. The contract documents included a line item for noise monitoring and abatement which required the contractor to meet City Noise Ordinances during the execution of his work. The work included continual monitoring of noise at the property line and the use of portable sound barriers to mitigate the noise. Monitoring Ground Movement Prior to the commencement of construction, ground monitoring systems were installed by the Contractor at strategic locations along the project. The purpose of the ground monitoring systems was to determine ground behavior for comparison with design assumptions and to provide a timely warning for the implementation of remedial measures in order to prevent possible damage to structures and utilities. Four types of monitoring devices were installed, 5481

16 surface settlement markers, subsurface shallow settlement indicators, multiple position borehole extensometers and inclinometers. The combination of these devices measured any settlement, heave, or lateral movements in the ground and assisted in serving as a baseline of ground conditions prior to the commencement of construction. CONCLUSION The project began construction in June of 2004 and the tunneling operation was complete in November of In January of 2006 the City Manager received a letter from a resident of the Little Walnut Creek Community stating the following: Where s the new sewer line we ve been promised? The City promised us the line down Northeast With the tunnel mining operation complete two months prior to the resident s letter, it was clear the resident was unaware the construction for the sewer line down Northeast Drive had already been completed. Clearly a sign that impacts to the community were kept to a minimum. The project reached substantial completion in July of 2006 well within the projects fast track schedule. The project is ultimately a success with neighborhood acceptance and minimal impact to the community and the environment. The chosen alignment, which pushed the envelope for construction methods with the elimination of an intermediate shaft, prevented the need for extensive land acquisition, and made the project schedule a feasible one to maintain. During the design phase a thorough and comprehensive feasibility study and design approach eliminated risk and any unforeseen conditions which typically haunt fast track or challenging projects. During the construction phase, the proactive use of partnering and a Dispute Review Board kept the project on track and ultimately made it a win-win for the residents, the EPA and the Utility. 5482