Final Technical Memorandum Summary Project: –2014 Long Range Water Supply Plan Memo: TM 25- IPL Integration TM Submitted to Dallas: Monday, November 17, 2014 Associated Report Section (s): Section 7.5

TM Summary

Technical Memorandum 25 (TM-25) presents the findings from analysis evaluating various alternatives for delivery of the Lake Palestine supply through the Integrated Pipeline (IPL) with Tarrant Regional Water District (TRWD) to the Bachman WTP. TM-25 includes an evaluation of adding a fourth water treatment plant (Southwest WTP) to the Dallas system and compares the cost with the expansion of Dallas’ Elm Fork WTP and associated facilities.

Related Sections in 2014 Dallas LRWSP

TM 25 was used in the development of Section 7.5 of the 2014 Dallas Long Range Water Supply Plan (LRWSP) describing the IPL connection to the Bachman WTP.

Transition from Final TM to 2014 Dallas LRWSP

No substantial changes occurred between the finalization of TM-25 and the completion of the LRWSP. Minor refinements may have occurred in response to comments received from Dallas and meetings that occurred throughout the LRWSP process. Any edits after the release of TM- 25 are not considered significant and do not change the results or recommendations presented.

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April 2015 | 1 Dallas LRWSP – Memo

To: Dallas Water Utilities

From: Adam Cory Shockley P.E. 94761,

Kenneth Choffel, Texas P.E. 45686,

HDR Engineering, Firm Registration F-754.

Date: November 17, 2014

Subject: IPL Integration – Task 4.15 – Technical Memorandum 25 The purpose of this technical memorandum (TM) is to furnish the results of Task 4.15 of the Dallas Long Range Water Supply Plan (LRWSP). These results present the findings from the analysis evaluating various alternatives for delivery of the Lake Palestine supply through the Integrated Pipeline (IPL) with Tarrant Regional Water District (TRWD). This TM includes an evaluation of adding a fourth water treatment plant (Southwest Water Treatment Plant or Southwest WTP) to the Dallas system and compares the cost with the expansion of Dallas’ Elm Fork WTP and associated facilities. This TM was prepared by CDM-Smith with review performed by HDR Engineering. The Tarrant Regional Water District (TRWD) and City of Dallas have partnered on the planning and development of an integrated raw water transmission system to meet future water needs in North . The purpose of the Integrated Pipeline (IPL) is to bring water from Lake Palestine, Richland-Chambers Reservoir and Cedar Creek Reservoir to Dallas and TRWD in a cost efficient way as water demands grow. The 150-mile long raw water transmission pipeline from Lake Palestine to Lake Benbrook ranges in diameter from 84-inch to 120-inch conveying water with a peak planned capacity of 347 million gallons per day (mgd). Dallas’ portion of the capacity of the shared pipeline is planned to be 150 mgd. This TM presents six alternatives available to Dallas to bring water into their system from the IPL. These six alternatives deliver water through the Joe Pool area to the Bachman WTP using a variety of pipeline and open channel flow options. Table ES-1 presents a comparison of the six alternatives of both quantitative costs and qualitative criteria. The capital cost range from $832M to $1,020M dollars and include transmission costs, water treatment plant expansion / construction costs, and treated water transmission improvements (distribution system) costs. All of these components are required to fully integrate the IPL-Palestine water into the Dallas system. Annual costs range from $63 M to $83 M and include energy costs, staffing and administration costs for the new Southwest WTP and debt service.

HDR Engineering, Inc. Page 1 of 2

Table ES-1. Comparison Matrix Summary Legal/ Transmission Total Total Permitting Water Quality/ Alternatives Political System Capital Cost Annual Cost Feasibility Blending Feasibility Flexibility

Alternative 1 – Delivery of water from the IPL $ 1020 M $73 M MEDIUM LOWER LOWER LOWER directly to the Bachman WTP by pipeline Alternative 2 – Delivery of water from the IPL to Joe Pool for diversion from Joe Pool Lake to $ 951 M $69 M MEDIUM MEDIUM MEDIUM LOWER Bachman WTP by pipeline Alternative 3 - Delivery of water from the IPL to Joe Pool with water released from Joe $ 886 M $64 M MEDIUM MEDIUM HIGHER LOWER Pool for diversion from Mountain Creek to Bachman WTP by pipeline Alternative 4 - Delivery of water from the IPL MUCH directly by pipeline to a new 150 mgd $ 934 M $83 M MEDIUM LOWER MEDIUM HIGHER Southwest WTP near Joe Pool Lake Alternative 5 - Delivery of water from the IPL MUCH to Joe Pool Lake for diversion from Joe Pool $ 832 M $77 M HIGHER MEDIUM MEDIUM HIGHER Lake to a new 150 mgd Southwest WTP Alternative 6- Delivery of water from IPL through Joe Pool, Mountain Creek Lake and $ 874 M $63 M HIGHER MEDIUM HIGHER LOWER Channel to Bachman WTP Note that raw water transmission costs are based on open-cut trenching along the floodway only. Should tunneling be required, it would add an additional estimated $262 M in capital costs and $ 18 M in annual costs. Key findings of the TM include:  A new Southwest WTP would incur higher annual costs than routing IPL water to the Bachman WTP, and would also incur comparatively high implementation risks. This suggests that a preferred alternative includes routing the water to the Bachman WTP, through one of four remaining alternatives.  Of the remaining four alternatives that route IPL water to the Bachman WTP and rely upon expanding the Elm Fork WTP, there appears to be tradeoffs between risk and capital/annual costs. Both capital and probable annual costs decrease with increased utilization of open water bodies for conveyance, but the implementation risks increase.  Based on the information presented in this memorandum: o To minimize near-term costs, Alternative 6 (Trinity River Dam and maximum usage of open water bodies for conveyance) would be preferred. o To minimize risk and invest in a higher likelihood of success, Alternative 1 (pipeline directly from the IPL to the Bachman Plant) would be preferred. o Alternative 2 (routing water only through Joe Pool Lake and piping it the rest of the way to Bachman) represents a reasonable balance between expected costs and risks based on the current qualitative rankings. o A joint study with Dallas and the owners of Joe Pool Lake and Mountain Creek reservoir is advised to determine opportunities to use those bodies for conveyance as opposed to the pipeline conveyance options.

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Dallas LRWSP – Memo

To: Ken Choffel, P.E. HDR

From: Tina Petersen, Ph.D., P.E. 1, Tom Charles, P.E.1, Project: Dallas Long Range Water Supply Plan Susan Crawford, P.E.1, Mike Gilbert

CC: Cory Shockley, P.E.

Date: November 17, 2014 Task/ 10733-94576 Task 4.15 Job No: Technical Memorandum 25 - IPL Integration Options and Southwest WTP Recommendation

1 CDM Smith, Texas Firm No. F-3043

RE: Evaluation of Alternatives for Delivery of Water from the Integrated Pipeline (IPL) and Potential New Southwest WTP

1. Introduction Dallas will require additional water supply within the next 50 years from surface water, groundwater, demand reduction, and/or reuse. As part of the 2014 Dallas Long Range Water Supply Plan (LRWSP), the HDR-CDM Smith Team has evaluated options for integrating water from the IPL into the Dallas system considering both treatment and distribution facilities. The Tarrant Regional Water District (TRWD) and City of Dallas have partnered on the planning and development of an integrated raw water transmission system to meet future water needs in North Central Texas. The purpose of the Integrated Pipeline (IPL) is to bring water from Lake Palestine, Richland-Chambers Reservoir and Cedar Creek Reservoir to Dallas and TRWD in a cost efficient way as water demands grow. The 150-mile long raw water transmission pipeline from Lake Palestine to Lake Benbrook ranges in diameter from 84-inch to 120-inch conveying water with a peak planned capacity of 347 million gallons per day (mgd). Dallas’ portion of the capacity of the shared pipeline is planned to be 150 mgd. The IPL was subdivided into segments to facilitate description of the system, allocate costs between TRWD and Dallas as well as split the design and construction into multiple packages. Figure 1 shows the various pipe segments, lake intake stations, and the three booster pump stations that are part of the IPL transmission system. Segment 12 as currently planned (shown in this figure) will deliver Dallas’ portion of water carried through the IPL (a blend of Lake Palestine water with Richland Chambers and/or Cedar Creek Reservoir under most scenarios) to Dallas at a location southwest of Joe Pool Lake.

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Dallas LRWSP – Evaluation of Alternatives for Delivery of Water from IPL and Potential New Southwest WTP

Figure 1. IPL Pipe Segments (from http://www.iplproject.com/about-the-ipl/map/)

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Dallas LRWSP – Evaluation of Alternatives for Delivery of Water from IPL and Potential New Southwest WTP

In this memorandum, five (5) previously evaluated alternatives are further evaluated and refined while one new alternative (Alternative 6) is also introduced and evaluated. These alternatives include:  Alternative 1 – Delivery of water from the IPL directly to the Bachman Water Treatment Plant (WTP) by pipeline. This alternative considers the possible additional costs - both with and without - the expansion of the Elm Fork WTP by 150 mgd.  Alternative 2 – Delivery of water from the IPL to Joe Pool Lake for diversion from Joe Pool Lake to Bachman WTP by pipeline. This alternative includes evaluating use of the existing Lakeview intake (which was determined to be too small as part of the evaluation conducted in this study) or constructing a new intake, constructing a raw water pump station, and the delivery of raw water from Joe Pool Lake to Bachman WTP. This alternative considers the additional costs, both with and without, the potential expansion of the Elm Fork WTP by 150 mgd.  Alternative 3 – Delivery of water from the IPL to Mountain Creek Lake with water released from Joe Pool Lake for diversion from Mountain Creek to Bachman WTP by pipeline. This alternative includes constructing a new intake on Mountain Creek Lake and new raw water pump station, with the delivery of raw water from Mountain Creek Lake to Bachman WTP. This alternative considers the additional costs (both with and without) the potential expansion of the Elm Fork WTP by 150 mgd.  Alternative 4 – Delivery of water from the IPL by pipeline directly to a new 150 mgd Southwest WTP adjacent to Joe Pool Lake. This alternative includes constructing a new 150 mgd Southwest WTP adjacent to Joe Pool Lake (but not discharging IPL water into Joe Pool Lake) along with new water distribution pipelines to deliver the treated water into the Dallas water distribution system. Because delivery to a new Southwest WTP changes the dynamics of Dallas’ water transmission and distribution system, this option also considers the savings associated with the potential downsizing of the planned Southwest transmission pipeline or alternative transmission options.  Alternative 5 – Delivery of water from the IPL to Joe Pool Lake for diversion from Joe Pool Lake to a new 150 mgd Southwest WTP. This alternative includes evaluating the use of the existing Lakeview intake on Joe Pool Lake (which was found to be too small in the evaluation conducted for this study) or constructing a new intake, constructing a raw water pump station and a new 150 mgd Southwest WTP adjacent to Joe Pool Lake along with new water distribution pipelines to deliver the treated water into the Dallas water distribution system. Because delivery to a new Southwest WTP changes the dynamics of Dallas’ water transmission and distribution system, this option also considers the savings associated with the potential downsizing of the planned Southwest transmission pipeline or alternative transmission options.  Alternative 6 – Delivery of water from the IPL through Joe Pool Lake, Mountain Creek Lake and Trinity River Channel with Delivery to Bachman WTP. This alternative includes elements of Alternative 3 except that flows would be released through the Mountain Creek Reservoir dam into the downstream channel rather than being pumped into a closed pressurized conduit. A low head dam would be constructed below the confluence with the Trinity River channel receiving flows from the Mountain Creek release. Water would be allowed to backwater upstream (north) of the low head dam within the Elm Fork channel to below Frasier dam. A low head pump station would pump from the backwater pool over the Frasier dam into Fishing Hole Lake for deliveries into Bachman WTP.

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Dallas LRWSP – Evaluation of Alternatives for Delivery of Water from IPL and Potential New Southwest WTP

Alternatives 2, 3, 5 and 6 assume that agreements with the water right owners of Joe Pool and Mountain Creek Lakes and the US Army Corps of Engineers (USACE) for temporary storage of water from the IPL in Joe Pool and/or Mountain Creek Lakes could be achieved. This memorandum also includes a discussion and costs associated with three possible options for crossing the Trinity River as required for Alternatives 1, 2, 3 and 6. With respect to invasive species issues, because Alternatives 1 and 4 deliver water directly to WTPs and do not include mixing in streams or lakes, these alternatives will require significantly less effort to permit and will have significantly less coordination with other entities than the other alternatives. This memorandum summarizes the results of evaluations and compares each alternative according to the following criteria:  Transmission System Capital Cost (updated from previous studies),  Treatment and Distribution System Capital Costs,  Probable Annual Costs (updated from previous studies to include IPL and Dallas System Pumping Costs), and  Qualitative Criteria which include: o Permitting Feasibility, o Legal/Political Feasibility, o Water Quality and Blending considerations, and o Transmission System Flexibility. 2. Methodology This section defines the primary assumptions and methodology used as the basis for comparing the alternatives.

2.1 Capital Costs Capital costs included in this study include transmission system costs, water treatment plant costs, and water distribution system costs. Each of these are discussed in more detail in the subsequent section. 2.1.1 Transmission System Capital Cost Estimates Project cost estimates for each transmission system associated with each alternative were developed using TRWD’s IPL Opinion of Probable Construction Costing (OPCC) template as developed by TRWD for use in the IPL design. The project cost estimates developed with the OPCC include capital costs, engineering and construction costs, general conditions, home office O&P, bonds and insurance, contingencies, and land acquisition. Annual costs were developed using the Unified Costing Model (UCM) developed for the Texas Water Development Board’s (TWDB) use in regional water planning. Annual costs include debt service, operation and maintenance, and pumping energy costs. The UCM was also used to derive costs for certain additional elements not readily included in the OPCC template. This includes water treatment facility capital costs and pumping system capital costs. These are summarized in the detailed cost sheets included in Appendix C. Assumptions that apply to all of the strategies are included below and assumptions specific to each alternative are presented in subsequent sections:

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Dallas LRWSP – Evaluation of Alternatives for Delivery of Water from IPL and Potential New Southwest WTP

 Capital costs are based on September 2013 dollars.  Segment 12 costs are part of the IPL design project and are not included in this estimate.  The capital cost generated for each corridor option is based on recent bid tabs from several large diameter pipeline and pump station projects constructed in the Dallas/Fort Worth area and local manufacturers’ pipeline unit cost data. Senior cost estimating personnel with CDM Smith Constructors Division were consulted in finalizing planning level costs for each alternative.  Capital costs were adjusted to include indirect project costs including: general conditions (6%), home office O&P (8%), bonds and insurance (2.5%), and engineering and construction contingencies (30%). Sales taxes related to equipment rental and material, legal and permitting costs are not included in the project costs. Pump station and WTP unit costs derived from the UCM use a 35% contingency as recommended in the UCM to cover engineering, legal, construction contingencies and other items.  The number of utility crossings along each pipeline route were estimated.  All paved road crossings and stream crossings (widths greater than 25 feet) were assumed to be tunneled.  The pipe material could be either pre-stressed concrete cylinder pipe (PCCP) or steel for this type of application but the pipe unit costs in these calculations are based on steel pipe.  150 feet of construction easement width was assumed to allow for adequate construction corridor.  Land acquisition costs refer to the easement costs for pipelines and are based on Dallas Delivery Location Analysis developed previously (in 2009) as part of IPL study. Pump station and water treatment plant land acquisitions are not included in this easement cost component, but they are included in their respective unit costs.  Highway and stream crossings were counted for each pipeline route and included in the OPCC.  For the transmission alternatives delivering water to Bachman WTP (i.e., Alternatives 1, 2, and 3), an additional cost to expand the Elm Fork WTP to 150 mgd is anticipated to be $405M. This assumes the plant expansion cost of the Elm Fork WTP is $2 per gallon of treatment capacity with a 35% contingency. This cost is more than that calculated by the UCM for conventional WTP expansions and was selected based on our team’s understanding of expansion issues for of the Elm Fork WTP and the historical costs for large plant expansions in Texas and the United States.  Annual costs were developed using the following assumptions: o Debt service period of 30 years. (Note: Additionally, for consistency with the TWDB planning process, an additional financing option using a 20 year debt service period for non-reservoir portions of projects is included in Appendix C.) o Annual interest rate for the debt service is 5.5%. o The default values were used for all other pumping energy cost components in the UCM. o The electricity rate used is $0.08/kWh.

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Dallas LRWSP – Evaluation of Alternatives for Delivery of Water from IPL and Potential New Southwest WTP

2.1.2 Southwest WTP Cost Estimate For the Southwest WTP, we have assumed that the plant would be located on the northeast side of Joe Pool Lake. This plant site location was also evaluated previously for Dallas in the 2011 Lake Palestine Water Supply—Water Transmission System Impacts Evaluation (CH2MHill, 2011). The cost estimate for the new Southwest WTP assumes the plant would include conventional treatment with ozone, similar to the existing Dallas water treatment plants. Assumptions that apply to all of the strategies with the Southwest WTP are included below and assumptions specific to each alternative are presented in subsequent sections:  Cost of a new Southwest WTP is based on the UCM unit costing.  Annual costs were developed using the following assumptions: o Labor and administartive services related to labor based on annual costs for Bachman WTP o Debt service period of 30 years. o Annual interest rate for the debt service is 5.5%. 2.1.3 Treated Water Transmission System Capital Cost Estimates Improvements are necessary in the treated water transmission system for implementing the six alternatives. Capital costs associated with transmission system improvements were examined for two primary scenarios: A) an expanded Elm Fork WTP, or B) a new Southwest WTP. The transmission system analysis was completed using an existing hydraulic model of the Dallas transmission and distribution system that had been previously prepared and was provided by Dallas for use in this study. Figure 2, a schematic of the existing system from the Dallas Water Utilities Water Capital Infrastructure Assessment & Hydraulic Modeling Report developed by Black & Veatch (2007), was used to understand the connections of existing facilities to the different pressure zones. Updated 2070 demands from this current study were input into the existing hydraulic model and the model was used to determine how changes in the distribution of projected water demand may alter previously proposed improvements from a study conducted in 2011 (CH2MHill, 2011). The capital costs of the improvements based on the new demands were then calculated and included as part of the cost comparison of the raw water delivery alternatives. Improvements included cover all major treated water transmission system improvements that will be needed by 2070. Most improvements vary or change depending upon the source of the treated water (e.g. from an expanded Elm Fork WTP or a new Southwest WTP). These changes may be directly or indirectly related to the treated water source. A few projects are the same or similar between the two scenarios. To make sure any similar projects were not left out of future studies, all major projects are included in the cost estimates. A summary of the methodology used to develop treated water transmission system capital costs is presented in Appendix D.

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