Document Moscow_doc_78516839a4

MOSCOW CITY COUNCIL WORKSHOP AGENDA Monday, December 2, 2013 3:00 p.m. – 5:00 p.m. Moscow City Hall Council Chambers 206 East 3rd Street 1. Welcome and Introduction – Walter Steed, Council President 2. Surface Water Reservoir Phase II Report Presentation – Les MacDonald and Christian Petrich (SPF Water Engineering) 3. Question / Answer 4. Adjournment NOTICE: Individuals attending the meeting who require special assistance to accommodate physical, hearing, or other impairments, please contact the City Clerk, at (208) 883-7015 or TDD 883-7019, as soon as possible so that arrangements may be made. ---PAGE BREAK--- City of Moscow Surface Water Feasibility Study – Phase 2 Prepared for City of Moscow 206 East Third Street Moscow, Idaho 83843 Prepared by SPF Water Engineering, LLC 300 East Mallard Drive, Suite 350 Boise, Idaho 83706 (208) 383-4140 TerraGraphics Environmental Engineering, Inc. 121 S. Jackson Street Moscow, Idaho 83843 (208) 882-7858 November 19, 2013 ---PAGE BREAK--- SPF/TerraGraphics Page ii Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Executive Summary The City of Moscow is exploring potential surface-water sources in response to regional groundwater-level declines. The first phase of this investigation focused on potential reservoir sites on Moscow Mountain. This second phase of the investigation explores future regional water demand and non-Moscow Mountain surface-water sources, including diversions from the North Fork Palouse River, Clearwater Basin, Snake River, Paradise Creek, and South Fork Palouse River. Absent conservation, annual water demand by the City of Moscow, City of Pullman, University of Idaho, and Washington State University could grow from approximately 2.4 billion gallons of water in 2012 to approximately 4.3 billion gallons of water by the year 2060. This represents an increase of about 80% over current rates. With an assumed 20% domestic water-demand reduction and a 10% irrigation reduction, the aggregate water demand in the year 2060 might be approximately 3.6 billion gallons, an increase of approximately 49% over current rates. However, climate change is expected to result in increasing evapotranspiration. If this occurs, regional demand could increase to approximately 3.7 billion gallons by the year 2060 (even with conservation) representing an increase of approximately 55% over 2012 water use. The surface-water supply alternatives explored in this report are not cost-effective if compared with the cost of drilling new wells. However, continued groundwater-level declines (or corresponding constraints in obtaining new water rights) may eventually drive Moscow to the use of surface water for a portion of its water supply. Several surface-water alternatives would provide more water than the City of Moscow will need and could therefore be considered as regional water-supply options. The least expensive of the large-scale options may be diversion from the North Fork Palouse River. However, if even larger volumes or year-round diversions are needed, diversions from the Snake River may be the least expensive per-volume alternative. Of the options yielding smaller volumes, diversions from a reservoir in the South Fork Palouse River drainage on Moscow Mountain for non-potable (i.e. irrigation) purposes would be among the least expensive alternatives. Aquifer Storage and Recovery (ASR) using water from Paradise Creek or the South Fork Palouse River with a passive recharge strategy could be even less expensive, but the capacity to recharge sufficiently large volumes of water is very uncertain. ASR using water from Paradise Creek or the South Fork Palouse River with an active recharge strategy may be one of the least expensive local surface-water alternatives (on a per-volume basis) for potable use. Recommendations for next steps include the following: 1. Explore opportunities for more aggressive local and regional water conservation. Conservation will reduce future water demand; ---PAGE BREAK--- SPF/TerraGraphics Page iii Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 2. Explore interest in regional water-supply alternatives with other Palouse communities and universities. 3. Develop a regional water-supply plan should groundwater levels continue to decline; 4. If there is regional interest, prepare conceptual design studies of the Snake River or North Fork Palouse River alternatives. 5. To augment groundwater pumping for irrigation on a local basis, prepare conceptual designs, land-ownership reviews, and initial environmental assessments for impounding, diverting, and conveying water from the South Fork Palouse River drainage on Moscow Mountain to the City of Moscow. 6. To augment groundwater supplies for potable use, explore the direct injection of surface water (using either in-town or Moscow Mountain surface-water sources) into the Wanapum aquifer; 7. Conduct investigations to better define site conditions (including infiltration rates) at possible passive-recharge sites; Specific conclusions and recommendations are provided beginning on page 63. ---PAGE BREAK--- SPF/TerraGraphics Page iv Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Table of Contents 1. Introduction 1 1.1. Background 1 1.2. Purpose and Objectives 1 1.3. Report Organization 2 1.4. Acknowledgments 2 1.5. Abbreviations 2 2. Future Water Demand 3 2.1. Introduction 3 2.2. Current Water Demand 3 2.3. Water-Demand Projections 3 2.3.1. City of Moscow 4 2.3.2. City of Pullman 4 2.3.3. Washington State University 5 2.3.4. University of Idaho 5 2.4. Aggregate Baseline Projections 5 2.5. Projections with Water Conservation 5 2.5.1. Domestic (Non-Irrigation) Conservation 9 2.5.2. Irrigation Conservation 11 2.5.3. Water Conservation within the Universities 11 2.5.4. Conservation Scenario 11 2.6. Climate change Change 11 2.6.1. Overview 11 2.6.2. Potential Climate-Variability Impact on Palouse Water Demand 14 2.7. Spreadsheet Tool 15 2.8. Water Demand Summary 16 3. Additional Water Supply Alternatives 19 3.1. Introduction 19 3.2. Previously Identified Surface-Water Supply Alternatives 22 3.2.1. North Fork Palouse River (Alternative A5) 24 3.2.1.1. Description 24 3.2.1.2. Preliminary Cost Opinion 25 3.2.2. Dworshak Reservoir (Alternative A6) 27 3.2.2.1. Description 27 3.2.2.2. Previously-Calculated Cost in Present-Day Dollars 28 3.2.3. Snake River Pipeline (Alternatives A7a and A7b) 28 3.2.3.1. Description 28 3.2.3.2. Previously-Calculated Cost in Present-Day Dollars (Alternative A7a) 29 3.2.3.3. Refinement of the Snake River Pipeline Alternative 29 3.2.3.4. Cost Estimate Using Same Approach as Other Water Supply Alternatives (Alternative A7b) 30 ---PAGE BREAK--- SPF/TerraGraphics Page v Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 3.3. Increased Use of Reclaimed Wastewater 31 4. Aquifer Storage and Recovery Strategies 34 4.1. Introduction 34 4.2. ASR Overview 34 4.2.1. Passive or Active Recharge 34 4.2.2. Typical Applications 34 4.2.3. Efficient Recovery 35 4.2.4. Water Quality Considerations 35 4.2.5. Geochemical Processes 36 4.2.6. Regulatory Considerations 36 4.3. Existing Regional ASR Investigations and Applications 37 4.4. Potential City of Moscow ASR Stategies Identified in Phase I 40 4.4.1. Previously-Identified Moscow Options 40 4.4.2. Surface Water Availability 40 4.4.3. Hydrogeologic Considerations 42 4.4.4. Recovery Efficiency for a Moscow ASR Application 47 4.5. Water Quality 47 4.5.1. Summary of Existing Information 47 4.5.2. Water Quality Sampling 49 4.6. Workshop 51 4.7. Cost Estimate 54 4.7.1. ASR with Direct Injection (Alternative D3a) 55 4.7.2. ASR with Passive Injection (Alternative D3b) 55 4.7.3. Preliminary Cost Opinion 57 4.8. Aquifer Storage and Recovery – Discussion 58 5. Summary of Preliminary Cost Opinions for Water-Supply Alternatives 60 6. Conclusions and Recommendations 63 6.1. General Conclusions 63 6.2. Specific Conclusions 64 Water Demand Projections 64 Additional Water-Supply Alternatives 64 Aquifer Storage and Recovery 65 Wastewater Reuse 66 Cost Comparisons of Surface-Water Supply Alternatives 66 6.3. Recommendations 68 Recommendations for a Regional Supply 68 Water-Demand Forecasting 68 Aquifer Storage and Recovery 69 South Fork Palouse River 69 Water Conservation 69 Wastewater Reuse 70 7. References 71 ---PAGE BREAK--- SPF/TerraGraphics Page vi Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 List of Figures Figure 1. Projected combined annual domestic and irrigation demand for the cities of Moscow and Pullman, UI, and WSU (no conservation). 6 Figure 2. Projected total demand for the cities of Moscow and Pullman, UI, and WSU (no conservation). 8 Figure 3. Water demand with conservation. 12 Figure 4. Water demand with no conservation and increasing ET. 15 Figure 5. Water demand with conservation and increasing ET. 18 Figure 6. Moscow water supply alternatives 21 Figure 7. Non-Moscow Mountain surface-water supply sources. 22 Figure 8. Mean daily flow, 25th percentile exceedance flow, and 90th percentile exceedance flow, North Fork Palouse River near Potlatch, water years 1978-2012 (USGS Gaging Station 13345000). 26 Figure 9. Average WWTP discharge to Paradise Creek, 2006-2010. 32 Figure 10. Mean daily flow, 75th percentile exceedance flow, and 90th percentile exceedance flow, Paradise Creek at the UI, water years 1978-2012 (USGS Gaging Station 13346800). 41 Figure 11. Estimated mean daily flow, 75th percentile exceedance flow, and 90th percentile exceedance flow, South Fork Palouse River less Paradise Creek, water years 1978-2012 (based on flows measured at USGS Gaging Station 13346800 less flows measured at USGS Gaging Station 13346800). 43 Figure 12. Soil types in potential passive recharge areas. 45 Figure 13. Water quality sampling locations. 49 Figure 14. Hypothetical location of passive infiltration facility. 56 List of Tables Table 1. 2012 water use. 4 Table 2. Summary of water-demand projections. 7 Table 3. Percentages of current and projected withdrawals for Moscow, Pullman, UI, and WSU. 8 Table 4. Potential per-unit residential domestic (indoor) water conservation. 10 ---PAGE BREAK--- SPF/TerraGraphics Page vii Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Table 5. Predictions of average temperature increase. 14 Table 6. Assumptions for water-demand projections. 17 Table 7. Water-supply alternatives from Phases 1 and 2 of this investigation. 20 Table 8. Summary of projections for average annual water demand for domestic purposes. 24 Table 9. Examples of low-permeability soil layers in the vicinity of potential passive recharge sites. 46 Table 10. Area needed for infiltration at various potential infiltration rates. 46 Table 11. Field parameter data. 50 Table 12. Laboratory results. 52 Table 13. Infiltration rate needed for the recharge of 1,100 af within a specific infiltration area. 57 Table 14. Summary of water-supply alternatives (ranked by total cost). 61 Table 15. Summary of water-supply alternatives (ranked by cost per unit annual yield). 62 Appendices Appendix A: Hydraulic profile, North Fork Palouse River Appendix B: Supporting information for conveyance and treatment costs – North Fork Palouse River Appendix C: Hydraulic profile, Snake River to Moscow Appendix D: Supporting information for conveyance and treatment costs – Snake River Appendix E: Water quality reports Appendix F: Surface Water Sampling Plan Appendix G: Preliminary cost opinion for ASR with passive recharge ---PAGE BREAK--- SPF/TerraGraphics Page 1 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 1. INTRODUCTION 1.1. Background The City of Moscow (Moscow), the City of Pullman (Pullman), University of Idaho (UI), Washington State University (WSU), and outlying areas rely on the Wanapum and Grande Ronde aquifers for municipal water supplies. Water levels in the Grande Ronde Aquifer have declined steadily since the 1930s (TerraGraphics/Ralston, 2011) at rates ranging from 0.7 feet per year (1935 to 1963) to 1.77 feet per year (1965 to 1981). Between 1995 and 2007 water levels in the Grande Ronde Aquifer have declined at a rate of 0.86 feet per year. Water levels in the Wanapum Aquifer are also vulnerable to overpumping, as evidenced by declines of more than 140 feet by the 1960s (although water levels subsequently recovered to about 50 feet below land surface by the 1980s). Moscow began exploring potential Moscow Mountain surface-water sources in 2010 in response to regional groundwater-level declines. A report summarizing results of the first phase of this investigation identified four potential reservoir sites to collect and store water for city use (SPF/TerraGraphics, 2011)1. These potential reservoir sites are located in the Flannigan Creek, Hatter Creek, South Fork Palouse River, and Felton Creek watersheds. Water from these drainages could be conveyed to the City by pipeline and, in the case of the South Fork Palouse River, via a natural stream channel. Surface water from these Moscow Mountain sites could be treated and used directly in the Moscow municipal water system, used for non-potable irrigation in a separate water system, or treated and used for aquifer storage and recovery (ASR). 1.2. Purpose and Objectives The first phase of the Surface Water Reservoir Feasibility Study (TerraGraphics/SPF, 2011) explored the feasibility of using Moscow Mountain surface water as an alternative or supplemental supply for the City of Moscow or the Palouse region. The general objectives of this second phase were to explore the feasibility of several non- Moscow Mountain surface-water supply alternatives for comparison with alternatives identified in Phase 1 and evaluate possible uses of Moscow Mountain surface water for Aquifer Storage and Recovery (ASR). Specific objectives/tasks included the following: 1 Also referred to herein as the "Phase 1 Report." ---PAGE BREAK--- SPF/TerraGraphics Page 2 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 1. Compile and review water-demand projections for the cities of Moscow and Pullman for comparison with regional surface-water supply alternatives; 2. Identify and evaluate potential ASR strategies using water from Moscow Mountain, Paradise Creek, and/or the South Fork of the Palouse River; 3. Compare Moscow Mountain reservoir options to other possible water- supply alternatives such as pumping water from the Snake River or the North Fork Palouse River; and/or reuse of treated municipal wastewater. 4. Brief Moscow City Council members on the results of these tasks. 1.3. Report Organization This report summarizes results from Tasks 1, 2, and 3. The report begins with a compilation and review of existing water-demand projections for Moscow, Pullman, UI, and WSU (Section This section also describes two water-demand scenarios: one with increased conservation levels and another with increased irrigation demand as a result of increasing climate variability. Three non-Moscow Mountain surface-water supply alternatives are explored in Section 3. Section 4 explores the use of ASR to augment existing groundwater supplies. Finally, conclusions and recommendations regarding various surface-water supply alternatives to help meet increasing demand are outlined and discussed in Section 5. 1.4. Acknowledgments This evaluation was conducted for the City of Moscow by TerraGraphics Environmental Engineering, Inc. (TerraGraphics) and SPF Water Engineering, LLC (SPF). TerraGraphics was the project lead, with primary responsibility for background ASR research, ASR workshop organization, water quality sampling and analysis, and reviewing previously-proposed water-supply alternatives. SPF prepared water- demand projections, identified and evaluated potential ASR strategies, developed preliminary cost opinions for non-Moscow Mountain water supply alternatives, and compared these alternatives with Moscow Mountain alternatives explored in the Phase 1 investigation. Les MacDonald (Public Works Manager, City of Moscow) reviewed this report and provided helpful comments. 1.5. Abbreviations The following flow and volume abbreviations are used in this report:  af – acre-feet or acre foot  afa – acre-feet per year  cfs – cubic feet per second  gpm – gallons per minute  MG – million gallons  MGY – million gallons per year  MGD – million gallons per day ---PAGE BREAK--- SPF/TerraGraphics Page 3 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 2. FUTURE WATER DEMAND 2.1. Introduction This section presents a compilation of future water-demand projections for Moscow, Pullman, UI, and WSU. These projections, if realized, frame the need for additional local or regional surface water and/or groundwater development. Aggregate future water-demand projections were compiled for the cities of Moscow and Pullman, UI, and WSU because the potential size – and potential cost – of some of the water-supply alternatives identified in Phase 1 of this project make them more suitable for regional consideration than for the Moscow alone. For example, one of the watersheds identified in the first phase of this surface-water supply assessment – the Flannigan Creek watershed – is capable of yielding more water than Moscow currently uses. Other surface-water alternatives, if constructed in aggregate, could supply more than current City of Moscow needs. The following section (Section 2.2) summarizes existing individual water-demand projections for Moscow, Pullman, UI, and WSU. Section 2.4 describes an aggregate baseline projection no conservation). Section 2.5 illustrates potential water savings through conservation, and Section 2.6 illustrates potential effects of regional climate change on future water demand. Section 2.7 summarizes water-demand projections, followed by a brief description of the spreadsheet tool used to make the projections. 2.2. Current Water Demand The Palouse Basin Aquifer Committee (PBAC) compiles and reviews annual groundwater withdrawals by Moscow, Pullman, UI, and WSU. In 2012 (Table these entities pumped approximately 2.41 billion gallons of groundwater, or approximately 7,400 acre-feet (af). The cities of Moscow and Pullman pumped approximately 73% of this amount. 2.3. Water-Demand Projections The aggregate water-demand projections presented in the following sections are based on existing projections for individual water systems. These are described below. ---PAGE BREAK--- SPF/TerraGraphics Page 4 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Millions of gallons acre feet Percent of Total Moscow 861 2,643 36% Pullman 901 2,765 38% UI 158 485 7% WSU 469 1,441 20% 2,389 7,333 100% 2012 Water Usage Source: PBAC data courtesy of Steve Robischon. Table 1. 2012 water use. 2.3.1. City of Moscow Moscow water-demand projections were made as part of Moscow Comprehensive Water System Plan (HDR, 2011). This water-system plan presented combined average-day demand for single family, duplex, multi-family, mobile homes, and non- residential users for the years 2005-2030, 2040, 2050, and 2060. The 2060 projected demand is 1,610 million gallons per year (MGY). The HDR data do not include potential reductions from conservation. However, Moscow is preparing a water-conservation plan (Baker, 2013), which largely targets reductions in domestic demand (through, for example, installation of low-flush toilets). The City anticipates an approximate 5% reduction in water use over current levels as a result of these conservation measures.2 2.3.2. City of Pullman Pullman water-demand projections were made as part of a water-system update in 2007 (HDR, 2007).3 HDR projected that water demand would increase to approximately 1,750 MGY by the year 2057 (and which was projected as part of this project to increase to approximately 1,800 MGY by 2060). HDR estimated that the net demand for the years 2014-2017 would be reduced by approximately 1.4% as a result of conservation efforts, resulting in a projected 1,730 MGY demand by the year 2057. 2 Nicole Baker, personal communication, 6/26/2013. 3 These estimates are currently being updated (Kevin Gardes, personal communication, June 26, 2013). ---PAGE BREAK--- SPF/TerraGraphics Page 5 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 2.3.3. Washington State University Water-demand projections were made for WSU as part of a 2008 water-system plan update (Taylor Engineering, 2008). Water-demand was projected to increase to approximately 590 MGY by the year 2027 with an average increase of 0.5% per year in the years 2023 through 2027. SPF used this same rate of increase to project water demand from 2027 through the year 2060, resulting in a projected 2060 water demand of approximately 700 MGY. 2.3.4. University of Idaho The UI does not have a future water-demand forecast.4 Water demand was projected from 2012 levels to the year 2060 based on an assumed annual growth rate similar to that of WSU 0.5% per year). This resulted in a projected demand of 201 MGY by the year 2060. 2.4. Aggregate Baseline Projections Without water conservation and neglecting potential effects of climate change, the aggregate water demand for the cities of Moscow and Pullman, UI, and WSU could rise from approximately 2.4 billion gallons (7,400 acre feet) in 2012 (Table 1) to 4.3 billion gallons (13,200 af) per year by the year 2060 (Figure 1 and Table Pullman currently pumps approximately 39% of the total aggregate amount (Table 3, page followed by Moscow WSU and UI Under the baseline projection, the relative percentage of the two cities increases compared to the universities because of higher assumed growth rates for the cities (Figure 2 on page 2.5. Projections with Water Conservation The baseline projections summarized in the previous section are likely high because they do not reflect any benefits of water conservation. However, some per-capita water-demand reductions will almost certainly occur as a result of future efficiency improvements, if for no other reason than replacement plumbing fixtures and water- using appliances that are more efficient than many of those installed in previous decades. 4 Mike Holthaus, University of Idaho, personal communication, June 27, 2013 ---PAGE BREAK--- SPF/TerraGraphics Page 6 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Figure 1. Projected combined annual domestic and irrigation demand for the cities of Moscow and Pullman, UI, and WSU (no conservation). Federal mandates (such as requirements for low-flow fixtures and appliances5) and water-provider measures to reduce leakage will further reduce future per-capita water use. It will take some time for these improvements to work their way through existing housing stock, but they will almost certainly result in lower per-unit water-use rates over the next several decades. 5 The Federal Energy Policy Act (FEPA) of 1992 established national maximum allowable water-flow rates for toilets, urinals, showerheads and faucets. Although there are no current applicable federal water-flow rates for washing machines and dishwashers, these appliances have also recently become more water efficient. 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 2010 2020 2030 2040 2050 2060 Projected Annual Water Demand (MGY) Combined annual demand, no conservation Combined indoor use, no conservation Domestic Demand Irrigation Demand ---PAGE BREAK--- SPF/TerraGraphics Page 7 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 City of Moscow City of Pullman UI WSU Total Total afa(2) 2012 861 901 158 469 2,389 7,333 Water demand(4,5,6) 1,610 1,803 201 696 4,309 13,224 % increase over 2013 87% 100% 27% 48% 80% Water demand 1,331 1,496 157 580 3,564 10,939 % increase over 2013 55% 66% 24% 49% % decrease over 2060 baseline ‐17% ‐17% ‐22% ‐17% ‐17% Water demand 1,662 1,867 206 724 4,460 13,686 % increase over 2013 93% 107% 30% 54% 87% % increase over 2060 baseline 3.2% 3.6% 2.6% 4.1% 3.5% Water demand 1,378 1,554 165 606 3,704 11,366 % increase over 2013 60% 73% 4.4% 29% 55% % change over 2060 baseline ‐14% ‐14% ‐18% ‐13% ‐14% MGY(1) Notes: Million gallons per year Acre feet per annum PBAC data. Based on previously‐prepared projections (see text). UI water demand projected at same annual growth rate as City of Moscow WSU water demand projected to grow at 0.5%, based on HDR projections between 2023 and 2027. 2060 Baseline future demand (no conservation, no change in ET) 2060 Water Demand Scenario With Conservation (see text for assumed conservation rates) Increased ET With conservation and increased ET 2012 water‐use demand(3) See Table 6 for list of conservation assumptions. Table 2. Summary of water-demand projections. ---PAGE BREAK--- SPF/TerraGraphics Page 8 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Table 3. Percentages of current and projected withdrawals for Moscow, Pullman, UI, and WSU. Figure 2. Projected total demand for the cities of Moscow and Pullman, UI, and WSU (no conservation). Entity Current Percentage Future Percentage, no conservation Pullman 39% 42% Moscow 33% 37% Washington State University(1) 22% 16% University of Idaho 6% 5% Total 100% 100% Percentage of total water demand by entity, 2013 and 2060 ---PAGE BREAK--- SPF/TerraGraphics Page 9 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 The following subsections describe a reduced water-demand scenario based on more aggressive water conservation assumptions. The purpose of the conservation water- demand scenario is not to predict a particular conservation outcome, but to provide a reduced-demand scenario for the evaluation of surface-water supply alternatives. In other words, greater water-use efficiency reduces the amount of water needed to supply a growing population, regardless of whether the water comes from groundwater or surface-water sources. Although conservation measures to produce these outcomes are plausible, this scenario is not based on the use of particular technologies, fixtures, incentive programs, or pricing structures. 2.5.1. Domestic (Non-Irrigation) Conservation A water-demand scenario was developed to project future water use with more aggressive water conservation. Currently, Moscow uses approximately 170 gallons per day (gpd) per housing unit.6 More efficient toilets, showerheads, faucets, washing machines, and dishwashers could lower this amount to approximately 113 gpd/unit (Table This rate would be approximately 33% less than the current 170 gpd Moscow usage. Thus, it is conceivable that water use could be 20% or more efficient by the year 2060 (compared to current water-use rates). Water savings of up to approximately 20% may be possible through further implementation of voluntary water-conservation measures and programs, continuation of current plumbing codes, incentive/rebate programs, and rate incentives. The water-conservation scenario developed for this analysis was thus based on an assumed 20% reduction in future domestic water-use rates compared to current domestic water-use rates. This amount may appear aggressive, but increasing water rates to cover the construction of surface-water supply options considered later in this report may in and of itself lead to substantial conservation. 6 Based on 9,723 single-family, duplex, multi-family, and mobile-home dwelling units in 2009 (City of Moscow data) and an average 2006-2012 average winter use of 50.2 million gallons, which equates to approximately 170 gpd. The actual residential amount is likely less than 170 gpd, because the water use 50.2 million gallons also includes commercial use. ---PAGE BREAK--- SPF/TerraGraphics Page 10 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Adapted from SPF et al. (2010). Table 4. Potential per-unit residential domestic (indoor) water conservation. Level of Conservation → Toilets 4.00 gpf1 47.3 1.60 gpf1 18.9 1.28 gpf2 15.1 Showerheads 3.25 gpm1 26.6 2.50 gpm1 20.9 2.00 gpm3 16.4 Faucets 2.88 gpm1 35.7 2.00 gpm1 31.9 1.50 gpm1 18.8 Washing Machines 51 gpl1 43.7 27 gpl1 23.1 23 gpl4 19.3 Dishwashers 12 gpl1 2.7 7.0 gpl1 1.6 4.5 gpl1 1 Baths N/A 3.3 N/A 3.3 N/A 3.3 Leaks N/A 26.3 N/A 9.3 N/A 3.3 Other Domestic N/A 4.4 N/A 4.4 N/A 4.4 190 113 82 Total (Daily Average) gpf = gallons per flush gpm = gallons per minute gpl = gallons per load References: 1 Vickers (2001) 2 EPA WaterSense tank-type high efficiency toilet specification (January 24, 2007) 3 New specifications for EPA WaterSense labeled show erheads (available beginning early 2010). 4 Horizontal axis/front loading residential w ashing machine (http://w w w .allianceforw aterefficiency.org) Assumptions: 1. Data corresponding to the number of toilet flushes/person/day, minutes/person/day, faucet use, etc., used in calculating w ater use (gpd/household) are based on Vickers, 2001. 2. The number of baths, show ers, and other domestic uses remain the same for each scenario. 3. Leaks w ill alw ays be present in potable w ater systems, although technology w ill assist to decrease leakage (decrease leakage is assumed for the intermediate and aggressive conservation scenarios). None Intermediate Aggressive Component Flow rate Water use (gpd/unit) Flow rate Water use (gpd/unit) Flow rate Water use (gpd/unit) Conservation Rate, Indoor Domestic Use ---PAGE BREAK--- SPF/TerraGraphics Page 11 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 2.5.2. Irrigation Conservation It was assumed that irrigation water-usage rates for newly irrigated land would be 10% less than existing rates and that the U of I would increase area irrigated by reclaimed wastewater from 80%7 to 90% by the year 2060. Outdoor conservation measures to achieve the 10% savings could include landscape renovation, improved irrigation management, xeric or drought-tolerant landscaping, use of reclaimed wastewater, and/or reductions in irrigated land in new subdivisions. Again, the purpose of this scenario isn’t to predict a particular outcome, but to illustrate the potential impact of water conservation on regional future demand. 2.5.3. Water Conservation within the Universities The assumed growth rates for the universities have a major influence on future water-demand projections. With conservation, the two universities could use less water in 2060 than in 2013. This is because the assumed conservation rate (10%) is greater than the university’s assumed growth rate The amount of future water reuse could have a major influence on future university pumping requirements. Currently the U of I uses wastewater to irrigate approximately 80% of irrigated area (see above). Our understanding is that WSU uses no wastewater for irrigation. Opportunities for using wastewater for WSU irrigation would represent a much greater reduction in overall groundwater pumping than the 10% conservation rate assumed above. 2.5.4. Conservation Scenario With conservation assumptions as outlined above, water use by Moscow, Pullman, UI, and WSU would be approximately 3.6 billion gallons per year (approximately 10,900 acre feet – see Figure 3 and Table 2) by the year 2060. This amount is approximately 17% less than the aggregate baseline projection without conservation of 4.31 billion gallons per year (Section 2.4). 2.6. Climate change Change 2.6.1. Overview The baseline projections presented in Section 2.4 also do not include effects of climate variability. The prospects for future climate variability and changes in future irrigation demand by Moscow, Pullman, UI, and WSU were evaluated based on a literature review conducted as part of a 50-year water-demand projection for the 7 Mike Holthouse, University of Idaho, personal communication, June 27, 2013. ---PAGE BREAK--- SPF/TerraGraphics Page 12 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Rathdrum Prairie Aquifer (SPF et al., 2010).8 The Rathdrum Prairie climate-variability review was based on work prepared or compiled by the Climate Impacts Group (CIG) at the University of Washington. Figure 3. Water demand with conservation. A 2009 CIG study (Climate Impacts Group, 2009) used 20 different climate models to evaluate two greenhouse gas emissions scenarios. The results of the CIG study are generally presented as averages for the Pacific Northwest region and are stated relative to observed 1970-1999 weather averages. The principal conclusions drawn from the CIG study (see SPF et al., 2010) are as follows: 8 An updated climate-variability analysis was outside the scope of this City of Moscow surface-water feasibility analysis. 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 2013 2023 2033 2043 2053 Projected Annual Water Demand (MGY) Combined annual demand, no conservation Combined indoor use, no conservation Combined Annual Demand, with conservation Combined Indoor use, with conservation Irrigation Demand Domestic Demand ---PAGE BREAK--- SPF/TerraGraphics Page 13 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 1. Expect changes in temperature and precipitation to accelerate from 20th century trends, though natural variation will somewhat mask these changes. 2. Expect annual average warming of about 3.2 degrees Fahrenheit by 2040 and about 5.3°F by 2080 (some models showed nearly 10°F warming by 2080 – see Table 3. Expect potential evapotranspiration (PET) to increase up to 6% per degree Celsius increase in temperature. The total PET increases corresponding to the projected 2040 and 2080 temperature increases are about 12% and 19%, respectively. 4. The expected change in precipitation is less clear, but an overall annual increase of 2.3% by 2040, and of 3.8% by 2080, is possible. 5. Expect interior parts of the region the Rathdrum Prairie area or the Palouse region) to become wetter in fall and winter, but drier in spring and summer. 6. If warming is coupled with irrigation-season drying (as the climate modeling suggests for most of the American West), then PET and irrigation requirements (PET minus effect of precipitation) could increase further. 7. Expect runoff to occur earlier, with more winter precipitation falling as rain. 8. Expect heating degree days9 to decline in the fall, winter, and spring, and expect cooling degree days to increase in the summer. 9. Expect extreme temperature and precipitation events to increase in frequency. These findings are generally consistent with other national assessments Brown, 1999; NCADAC, in preparation). More detailed discussion of the assumptions and findings from the CIG study, and presentation of methods for calculating changes in evapotranspiration and heating and cooling degree-days, are presented in Appendix F of the Rathdrum Prairie water demand projections (SPF et al., 2010). 9 Heating and cooling degree days are measures of how cold or warm a location is over a period of time relative to a base temperature (usually 65°F). A decrease in heating degree days indicates a general rise in temperature. Similarly, an increase in cooling degree days also indicates a general rise in temperature. ---PAGE BREAK--- SPF/TerraGraphics Page 14 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Period Temperature Change Precipitation Change 2020s +2.0 (+1.1 to +3.3) +1.3 to +12) 2040s +3.2 (+1.5 to +5.2) +2.3 (-11 to +12) 2080s +5.3 (+2.8 to +9.7) +3.8 (-10 to +20) Source: Climate Impacts Group, 2009. Reported averages are changes relative to 1970-1999, for both medium (A1B) and low (B1) scenarios and all models (39 combinations averaged for each cell in the table). The ranges for the low est to highest projected change are in parentheses. Predictions of Average Temperature Increase Table 5. Predictions of average temperature increase. 2.6.2. Potential Climate-Variability Impact on Palouse Water Demand Water demand for irrigation by the cities of Moscow and Pullman, UI, and WSU could increase in the coming decades if the climate-variability predictions outlined above are realized. This section projects the magnitude of such an increased water demand. The average precipitation deficit (equivalent to an irrigation demand) in northern Idaho could increase between 12% and 19% in the next several decades as a result of increasing evapotranspiration. For the purpose of this analysis, the precipitation deficit (and therefore water demand) was assumed to increase by 12% over the next 50 years. While some increase in average annual precipitation may occur in the coming years, it was assumed that this increase will not occur during the peak-summer irrigation months, but will instead occur during the fall, winter, and/or spring. Thick Palouse soils may be able to retain some of the increased winter or spring precipitation, but this may be offset by increased PET. Nonetheless, the assumed future irrigation requirements in this analysis were not reduced to reflect potential increased precipitation during non-irrigation season months. A 12% increase in irrigation demand from increased evapotranspiration would result in the use of approximately 154 million gallons more water in 2060 (Figure 4 and Table 2) than in the base projection (representing approximately 3.5% greater overall water demand). This relatively small increase reflects the modest portion of overall groundwater withdrawals used for irrigation. A greater precipitation deficit 19%) would result in even greater water demand for irrigation. ---PAGE BREAK--- SPF/TerraGraphics Page 15 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 2013 2023 2033 2043 2053 Projected Annual Water Demand (MGY) Combined annual demand, no conservation Combined indoor use, no conservation Combined Annual Demand, no conservation, with climate change Combined Indoor Use Figure 4. Water demand with no conservation and increasing ET. 2.7. Spreadsheet Tool A spreadsheet tool was constructed to compile existing water-demand projections, extend existing projections to a common year (2060), and evaluate potential effects of water conservation and/or climate variability. The spreadsheet (Moscow Forecast Tool.xlsx) includes the following: 1. A compilation of existing water-demand projections for individual entities (Moscow, Pullman, UI, and WSU), and an aggregate water-demand forecast based on existing data (or projections) for individual entities. 2. Aggregate water-demand forecasts with conservation and/or climate- variability assumptions. 3. Graphs and tables presented in this report, and other supporting data. The forecast tool can be used to evaluate the effects of changing water-demand and climate-variability assumptions. An “Overview” tab lists individual spreadsheets used for projecting water demand. Assumptions used for the water-demand projections listed in this report are summarized in Table 6 and in the “Assumptions” tab of the Irrigation Demand Domestic Demand ---PAGE BREAK--- SPF/TerraGraphics Page 16 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 forecast tool; these assumptions can be modified in the spreadsheet to explore additional “what-if” scenarios. 2.8. Water Demand Summary Existing water-demand projections for Moscow, Pullman, UI, and WSU were compiled and (in the case of the latter three entities) extended to the year 2060. Absent conservation, water demand by the year 2060 could reach approximately 4.3 billion gallons per year (13,200 afa), or 4.5 billion gallons per year if the region experiences increased evapotranspiration as a result of climate variability. Regional water demand with a 20% reduction in domestic water-use rates and a 10% reduction in irrigation rates (without increased evapotranspiration) would result in a regional annual demand of 3.6 billion gallons (about 10,900 af) by the year 2060. It is predicted that climate variability could result in a 5% to 19% increase in potential evapotranspiration in the coming decades. Annual precipitation may also rise, but probably not in the summer. An assumed 12% rise in irrigation demand would result in an overall water-demand increase of approximately 3.5% over the base projection. This is a relatively low amount because irrigation represents modest percentage (approximately 30%) of the current total water demand. Also, climate models predict increased variability, which could result in substantial year-to-year variability in water demand for irrigation. With conservation and increasing evapotranspiration (Figure 5 and Table the total demand would rise to approximately 3.7 billion gallons by the year 2060. This represents an increase of approximately 55% over current production but 14% less than the base (no conservation, no changes in ET) projection. ---PAGE BREAK--- SPF/TerraGraphics Page 17 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Table 6. Assumptions for water-demand projections. Value Baseline Water Demand Projections Percentage indoor use (Moscow) 73% Percentage irrigation use (Moscow) 27% Percentage indoor use (Pullman) 70% Percentage irrigation use (Pullman) 30% Percentage indoor use (UI) 66% Percentage irrigation use (UI) 34% Percentage indoor use (WSU) 78% Percentage irrigation use (WSU) 22% Water Conservation Domestic reduction by 2060 20% Irrigation reduction by 2060 10% Domestic reduction by 2060 20% Irrigation reduction by 2060 10% Domestic reduction by 2060 20% Irrigation reduction by 2060 10% Assumed area currently irrigated with reclaimed wastewater 80% Assumed area irrigated with reclaimed wastewater by 2060 90% Percent reduction in direct groundwater use for irrigation (as a result of increased use of reclaimed wastewater for irrigation) 50% Domestic reduction by 2060 20% Irrigation reduction by 2060 10% Year in which conservation begins 2013 Year in which full conservation is achieved 2060 Increased Evapotranspiration Increase in precipitation deficit (and water demand) over the next 50 years 12% Assumed year in which ET begins increasing 2013 Projection year 2060 Moscow Pullman UI WSU Conservation Implementation Period Water Demand Projections ‐ Assumptions Moscow Pullman UI WSU ---PAGE BREAK--- SPF/TerraGraphics Page 18 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Figure 5. Water demand with conservation and increasing ET. 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 2013 2023 2033 2043 2053 Projected Annual Water Demand (MGY) Combined annual demand, no conservation Combined indoor use, no conservation Combined Annual Demand, with conservation and increased ET Combined indoor use, with conservation Irrigation Demand Domestic Demand ---PAGE BREAK--- SPF/TerraGraphics Page 19 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 3. ADDITIONAL WATER SUPPLY ALTERNATIVES 3.1. Introduction Several alternatives for using surface water from four Moscow Mountain drainages (Flannigan Creek, Hatter Creek, South Fork Palouse River, and Felton Creek watersheds – see Table 7) were examined in the first phase of this feasibility analysis. In these alternatives, water would be conveyed from these watersheds (Figure 6) to Moscow for direct use, non-potable irrigation use, irrigation offset, or aquifer storage and recovery (ASR). This second phase of the feasibility analysis includes examination of four non-Moscow Mountain surface-water supply alternatives: 1. Direct diversion from the North Fork Palouse River of Potlatch, Idaho (Alternative A5, Table 2. Pipeline from Dworshak Reservoir to Moscow (Alternative A6); 3. Direct diversion from the Snake River to Pullman and Moscow (Alternative A7); and 4. Additional use of treated wastewater for irrigation. The first alternative – direct diversion from the North Fork Palouse River (Figure 7, page 22) – was identified following a Moscow City Council workshop on surface-water supply alternatives. The second two alternatives – diversions from the Clearwater drainage or the Snake River (see Figure 7) – were two of numerous alternatives identified in previous water-supply investigations (see Section 3.2 below). The fourth alternative (reclamation and reuse of treated wastewater) was previously explored for the City of Moscow by Kimball Engineering (2001), JUB Engineers (2010), and Keller Associates (2011). The cost of diverting and conveying water from the North Fork Palouse River (Section 3.2.1) was estimated using the same method that was used for estimating costs associated with the Moscow Mountain alternatives (SPF/TerraGraphics, 2011). The costs of diverting and conveying water from Dworshak Reservoir (Section 3.2.2) and the Snake River (Section 3.2.3) were estimated by converting 1989 cost estimates prepared by the US Army Corps of Engineers (USACE) to present-day dollars. The Snake River alternative was then refined by SPF/TerraGraphics to create an alternative more consistent with the long-term Moscow/Pullman regional water demand. The refinement included a more precise pipeline alignment and a cost- estimating approach the same as that used for Phase 1 Moscow Mountain water- supply alternatives. Another water-supply alternative may include increased use of reclaimed wastewater for irrigation of City common areas. The Moscow Comprehensive Sewer System Plan ---PAGE BREAK--- SPF/TerraGraphics Page 20 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 (Keller, 2011) included preliminary cost opinions for various reuse options. These cost opinions are used in this analysis for comparison with other water-supply alternatives. Other options, such as constructing a reservoir at the old Robinson Lake dam site or along the South Fork Palouse River south of Moscow, were also identified in previous studies as water-supply alternatives. However, these options were not considered in this analysis because of likely excess sedimentation. Table 7. Water-supply alternatives from Phases 1 and 2 of this investigation. Alternative number → 1 2 3 4 5 6 7a 7b 8 Alternatives Flannigan Creek Hatter Creek South Fork Palouse River Felton Creek North Fork Palouse River Dworshak Reservoir Snake River (USACE cost estimate) Snake River (SPF cost estimate) Wastewater Reuse A Direct use (pipeline conveyance with treatment) A1 A2 A3 A4 A5 A6 A7a A7b B Non‐potable irrigation (pipeline conveyance) B3 B4 B8 C ASR (Water diverted from a 40‐foot high South Fork Palouse River dam with treatment & injection) C3 D ASR (direct recharge) D3a(2) D ASR (passive recharge) D3b(2) Notes: Also includes Phase I alternatives, see text for explanations. South Fork Palouse River and/or Paradise Creek, diverted from existing channels within the City of Moscow no dam or reservoir). ←Alternative letter Alternatives Matrix(1) Phase 1 Phase 2 ---PAGE BREAK--- SPF/TerraGraphics Page 21 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Figure 6. Moscow water supply alternatives ---PAGE BREAK--- SPF/TerraGraphics Page 22 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Figure 7. Non-Moscow Mountain surface-water supply sources. 3.2. Previously Identified Surface-Water Supply Alternatives Previously-identified water-supply alternatives fall into two categories: development of surface-water supply and increased use of reclaimed municipal wastewater. Previously-identified surface-water supply alternatives are explored in Section 3.2; increased use of reclaimed municipal wastewater is addressed in Section 3.3. EBASCO Services (1958), Stevens et al. (1970), and the U.S. Army Corps of Engineers (USACE, 1989) evaluated a number of water-supply alternatives for Moscow. EBASCO evaluated possible reservoirs at the Robinson Lake site (approximately 5 miles northeast of the center of Moscow); Paradise Creek (approximately 2.5 miles northeast of the center of Moscow); South Fork Palouse River (at a location approximately 3 miles southwest of the center of Moscow near the state line); the Potlatch River at a point of Juliaeta, Idaho; the Clearwater ---PAGE BREAK--- SPF/TerraGraphics Page 23 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 River upstream of Lewiston, Idaho, and the North Fork Palouse River of Potlatch, Idaho). EBASCO (1958) recommended that use of surface water be included as part of Moscow’s long-term water management strategy based upon future water needs and uncertainty regarding sufficient groundwater availability. However, EBASCO concluded that all options except the South Fork Palouse River appeared unnecessary and not economically feasible. The authors felt that an impoundment of the South Fork Palouse River could provide a substantial amount of water to meet the city’s growing needs, and would have fewer pumping requirements than more distant locations. The EBASCO water-supply review was undertaken before Lower Granite and Dworshak dams were constructed. The resources that these dams could provide electricity and pooled diversion area) would therefore not have been considered in EBASCO’s analysis. Stevens et al. (1970) evaluated developing a water supply from the Snake River at Wawawai; North Fork Palouse River at Elberton, Palouse, Princeton, Harvard, and/or Laird; Moscow Mountain watershed near Troy; east fork of the Potlatch River; North Fork of the Clearwater River above Dworshak Reservoir; and the Paradise Creek at the Moscow Wastewater Treatment Plant. Of these options, the authors concluded that the two best alternatives would be pumping water from the Snake River or the North Fork Palouse River. The USACE (1989) evaluated water-supply options based on various physical, economic, and environmental criteria minimize flooding, enhance municipal and industrial water supply, improve surface water quality, and potential hydropower and recreation opportunities). The USACE considered dam sites on the North Fork Palouse River, pumping water from Dworshak reservoir, and pumping water from the Snake River near Wawawai. The Laird Dam and Dworshak Reservoir sites had similar expected costs (capital costs of $79.9 million and $77.4 million, respectively, in 1989 dollars) that far exceeded the Snake River site (capital cost of $47.6 million in 1989 dollars). The USACE concluded the Snake River site was the least costly water supply alternative of the three, but the Laird site should also be given consideration given the multipurpose development possibilities. The USACE went on to state that water conservation and additional groundwater sources may contribute to meeting future demand. ---PAGE BREAK--- SPF/TerraGraphics Page 24 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 3.2.1. North Fork Palouse River (Alternative A5) 3.2.1.1. Description A direct diversion (no reservoir) from the North Fork Palouse River was considered for this analysis. The diversion would only occur during the months that water in the North Fork would be available. Direct diversion from the North Fork Palouse River (Alternative A5) would consist of a river intake structure, pipeline, and treatment facility. Although direct diversion would yield less water than a surface impoundment, a surface impoundment would entail substantially greater cost. It was assumed that the intake structure could be located on the south side of the North Fork Palouse River in the vicinity of the Highway 95 Bridge. The intake would be a concrete structure from which water would be routed to a nearby pump station. The pipeline would be aligned within the public right-of-way of Highway 95 extending from the river to Moscow (Figure The hydraulic profile for conveying water to Moscow is provided in Appendix A. Three pump stations would be required to lift water over two hills along the pipe line alignment. The maximum elevation gain for the pipeline conveying water from the North Fork Palouse River to Moscow is 597 feet. Opportunities for generating electricity via turbine on downhill sections would help recoup some lifting costs and would reduce pressure requirements in some pipeline sections. The proposed design capacity is 6.5 million gallons per day (MGD), equivalent to 10 cubic feet per second (cfs) or 4,500 gallons per minute (gpm), when water is available in the North Fork Palouse River. This amount represents more than the 7.9 cfs currently used on a year-round basis for domestic purposes by the two cities and two universities (Table However, the 10-cfs design capacity would provide less than the 12.9-cfs average demand for domestic purposes projected by the year 2060 without conservation efforts, but more than the 2060 projected demand with conservation (10.4 cfs). City of Moscow City of Pullman UI WSU Total 2013 2.7 3.1 0.5 1.6 7.9 5.0 5.3 0.7 1.9 12.9 4.0 4.3 0.5 1.6 10.4 2060 Baseline With conservation Current projected usage Domestic Water Demand Table 8. Summary of projections for average annual water demand for domestic purposes. ---PAGE BREAK--- SPF/TerraGraphics Page 25 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Hydrographs show that a 10-cfs diversion rate represents 25% or less of the average North Fork Palouse River flow from November through June (Figure This diversion rate would supply approximately 1.56 billion gallons of water per year (4,760 afa), or approximately 59% of the projected 2.64 billion gallon regional demand in 2013 (Table In dry years (approximated by the 90th percentile exceedance flow in Figure a 10- cfs diversion would represent approximately 25% or less of the flow from approximately mid-February through mid-June. A 10-cfs diversion for about 4 months would yield approximately 780 million gallons (2,380 afa), or approximately 30% of the projected 2.64 billion gallon aggregate demand in 2013 (Table Although this is the approximate volume of water that Moscow uses in an entire year, the diversion rate represents more than the city currently uses in the winter and spring months when the water is available in the North Fork Palouse River. 3.2.1.2. Preliminary Cost Opinion The North Fork Palouse River direct-diversion alternative (Alternative A5 in Table 7) includes a river intake, three pump stations, two small hydropower facilities, approximately 14 miles of pipeline along Highway 95, and a treatment facility. The alternative would require 3 pump stations: the first to convey flow from the point of diversion to mile 3.3, the second and third to convey water across the high points located at approximately mile 4.4 and 9.5 (based on distance from source). The conceptual design for this alternative includes 2 hydropower facilities. The first hydropower facility would be located at approximately 6.3 miles from the point of diversion. The hydropower facility would reduce pressure in the pipeline by approximately 129 psi, and would generate approximately 227 kilowatts (kW) of power. The second hydropower facility would be located approximately 11.5 miles from the point of diversion, would reduce pressure in the pipeline by approximately 162 psi, and would generate approximately 286 kW of power. The maximum anticipated pressure in the pipeline is approximately 199 psi, allowing the use of HDPE piping for the full extent of the pipeline. The hydraulic profile is included in Appendix A. ---PAGE BREAK--- SPF/TerraGraphics Page 26 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Note: same graph with different y-axis scales. Figure 8. Mean daily flow, 25th percentile exceedance flow, and 90th percentile exceedance flow, North Fork Palouse River near Potlatch, water years 1978-2012 (USGS Gaging Station 13345000). 0 200 400 600 800 1,000 1,200 9/30 10/30 11/29 12/30 1/29 2/29 3/30 4/30 5/30 6/29 7/30 8/29 9/29 Flow (cfs) Mean Daily Flow 75th Percentile Exceedance 90th Percentile Exceedance 0 10 20 30 40 50 60 70 80 90 100 9/30 10/30 11/29 12/30 1/29 2/29 3/30 4/30 5/30 6/29 7/30 8/29 9/29 Flow (cfs) Mean Daily Flow 75th Percentile Exceedance 90th Percentile Exceedance ---PAGE BREAK--- SPF/TerraGraphics Page 27 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 The estimated costs for Alternative A5 include $22.5 million for conveyance and $18.2 million for treatment,10 for a total estimated project cost of $40.7 million (SPF/TerraGraphics, 2011). Assuming an average annual yield of 4,760 acre feet 10 cfs for 4 months), the cost for this alternative would be approximately $8,550 per acre foot of average yield. Costs for conveyance and treatment are provided in Appendix B. The hydropower facilities (with engineering and contingency) are estimated to cost approximately $640,000. Hydropower generation reduces pipe pressure, reducing the need for high-pressure pipe. Alternatives to the hydropower facilities include installing approximately 4.5 miles of high-pressure pipe instead of low-pressure pipe and one pressure-reducing valve station at the water treatment facility or installing two pressure-reducing valve stations in place of the two hydropower stations. The first of these options would result in an overall project cost increase of approximately $2.2 million (from $41.7 million to $43.9 million, primarily for the high-pressure pipe). The second of these options results in an overall project cost decrease of approximately $200,000. However, the hydropower facilities are estimated to produce approximately $274,000 of power every year (at full operation), so the payback period for the hydropower facilities would be approximately one year. Our experience has been that there has not been a substantial increase in construction costs between 2010-2011 (when construction costs were estimated for the Moscow Mountain surface-water supply alternatives) and 2013. The North Fork Palouse River cost estimate provided above is therefore roughly comparable to the Phase 1 Moscow Mountain water-supply alternatives.11 3.2.2. Dworshak Reservoir (Alternative A6) 3.2.2.1. Description Diversions from Dworshak Reservoir could conceivably be used for municipal supply in the Moscow-Pullman area. The USACE (1989) calculated that a 55-mile long pipeline would be required to deliver water to Moscow. The pipeline would require 2 pumping stations (one at the reservoir and one near Kendrick, Idaho) for conveying 10 Two main categories of treatment technology were considered in this analysis: conventional treatment and membrane filtration. Membrane treatment cost between 20% and 40% more than conventional treatment, but was selected because it has a smaller footprint and can be more automated as compared to conventional treatment (SPF/TG, 2011). 11 Updating costs of the Moscow Mountain water-supply alternatives was outside of the scope of this Phase 2 investigation. ---PAGE BREAK--- SPF/TerraGraphics Page 28 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 water. As a surface-water supply, water from Dworshak reservoir would require treatment for direct municipal use. The USACE contemplated a diversion of 22,265 acre-feet per year (afa), or about 7,255 MGY. This translates to an average diversion rate of approximately 19.9 MGD or 31 cfs. This amount is far in excess of the current year-round domestic requirements for the cities of Moscow and Pullman and the two universities (7.9 cfs – see Table 8) and projected baseline no conservation) year-round requirements in the year 2060 (12.9 cfs). 3.2.2.2. Previously-Calculated Cost in Present-Day Dollars The USACE (1989) estimated that the cost for land and easements, pipeline, Dworshak pumping plant, Kendrick pumping plant, approximately 10 miles of power transmission lines, power facilities, a water treatment plant, terminal storage (with engineering and design) would cost approximately $77.4 million in 1989 dollars. Based on a multiplier of 1.93 (ENR Construction Cost Index), this cost in 2013 dollars would be approximately $149 million. The $149 million cost is approximately equivalent to $6,700 per acre foot of pipeline capacity. Alternatively, the cost is approximately equivalent to $18,400 per acre foot of current annual aggregate demand, or $15,300 per acre foot of aggregate 2060 demand (with conservation and climate change). 3.2.3. Snake River Pipeline (Alternatives A7a and A7b) 3.2.3.1. Description The USACE 1989 study identified the Snake River near Wawawai as a potential surface-water supply for Moscow. The USACE contemplated a diversion of 22,265 afa, or about 7,255 MGY. This translates to an average diversion rate of approximately 19.9 MGD or 31 cfs. Again, this amount is far in excess of the current year-round domestic requirements for the cities of Moscow and Pullman and the two universities (7.9 cfs – see Table 8) and projected baseline no conservation) year- round requirements in the year 2060 (12.9 cfs). The USACE contemplated a pumping plant located approximately 3 miles upstream of Lower Granite Dam and a treatment plant located approximately 2 miles up Wawawai Canyon. A second pumping plant would then pump water to Pullman and Moscow via pipelines totaling 21.6 miles. The USACE study noted that withdrawals from the Snake River could potentially impact anadromous fish in the Snake River system, even though the withdrawal rate would be relatively small. Impacts on anadromous migrants are still a regional concern. There are likely approaches for mitigating this impact and/or limiting diversions during certain migrating periods. ---PAGE BREAK--- SPF/TerraGraphics Page 29 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 3.2.3.2. Previously-Calculated Cost in Present-Day Dollars (Alternative A7a) The USACE developed cost estimates for lands and easements, the Wawawai pumping plant, a pipeline to the treatment plant, a water treatment plant, a main and booster pumping plant, pipeline and terminal storage, a Moscow pumping plant, and Moscow pipeline and terminal storage. The USACE estimated that the total cost of this project (with engineering and design) would be approximately $47 million in 1989 dollars. Based on a multiplier of 1.93 (ENR Construction Cost Index), this cost in 2013 dollars would be approximately $92 million. The $92 million cost is approximately equivalent to $4,100 per acre foot of capacity. The cost is approximately equivalent to $12,500 per acre foot of current annual aggregate demand (7,300 af), or $8,100 per acre foot of 2060 demand (with conservation and climate change). The amount of water that could be conveyed with this pipeline (7.25 billion gallons annually, or 22,265 afa) far exceeds the 4.3 billion gallon annual projected baseline demand (13,200 afa) for Moscow, Pullman, UI, and WSU by the year 2060. The cost to divert and convey a smaller amount would be less than $92 million, but not proportionately less. 3.2.3.3. Refinement of the Snake River Pipeline Alternative The USACE 1989 cost estimates for pipelines from Dworshak Reservoir and the Snake River were sized for an amount of water in excess of current and projected 2060 needs. While having the greatest overall construction cost, the construction cost per acre foot of yield is relatively low compared to some of the other Moscow Mountain surface-water supply alternatives. Based on the USACE cost estimates, the Snake River option was substantially less costly than the Dworshak Reservoir option (based on a per acre foot of yield basis). However, the USACE Snake River cost estimate is not directly comparable with other Moscow Mountain water-supply alternatives because the USACE assumed a much larger pumping rate than would be needed for the projected Palouse needs (Section Also, the USACE used different cost-estimating approach from that used by SPF/TerraGraphics for Moscow Mountain surface-water alternatives. A refined cost estimate for this option was prepared that would reflect a smaller annual pumping volume a volume more consistent with current and future regional water demand). The refined cost estimate was made using the same cost-estimating approach as was used for the Moscow Mountain alternatives. This allows for a more direct comparison with previously-described surface-water supply alternatives. The refined cost estimate is based on a diversion rate of 10 cfs (instead of the 31 cfs contemplated by the USACE) and a pipeline route (Figure 7) following existing public roadway rights-of-way (instead of the more cross-country route priced by the USACE). ---PAGE BREAK--- SPF/TerraGraphics Page 30 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 The pipeline route for this refined cost estimate follows the Wawawai-Pullman Road to Old Country Club Road, then skirts south of Pullman to connect to the Old Moscow Road and deliver water to south Moscow. This results in a longer pipeline route than was contemplated by the USACE. It was assumed that it is also possible to connect this pipeline to Pullman’s water system. Direct diversion from the Snake River under this refined alternative (Alternative A7b) would consist of a river intake structure on the east bank of the Snake River near Wawawai Canyon. The intake would be a concrete structure from which water would be routed to a nearby pump station. The pipeline would be aligned within the public right-of-way of the roadways as described above. The hydraulic profile for this option is provided in Appendix C. This option would require five pumping plants – three to lift water from the Snake River up through the Wawawai Canyon, and two to lift water over hills near Pullman and from Pullman to Moscow. The total pipeline length would be approximately 25 miles. The maximum elevation gain for the pipeline conveying water from the Snake River to Moscow is approximately 1,950 feet. Direct use of Snake River water would require a water treatment plant. The treatment plant could be located near the intake or near the points of delivery the cities of Pullman and/or Moscow). 3.2.3.4. Cost Estimate Using Same Approach as Other Water Supply Alternatives (Alternative A7b) The Snake River direct-diversion alternative includes costs for lands and easements, a river intake, 5 pump stations, approximately 25 miles of pipeline along road rights-of- way, and treatment. The alternative would require 5 pump stations: the first, second and third to convey flow from the point of diversion to the Wawawai Canyon at miles 1, 2.7, and 4.8, and the fourth and fifth to convey water across the two hills located at approximately miles 11.9 and 17.1 (based on distance from source). The maximum anticipated pressure in the pipeline is approximately 355 psi, which is too high to allow the use of HDPE piping. Therefore C200 spirally welded steel pipe was assumed for the entire length of this pipe alignment. The hydraulic profile is included in Appendix C. The estimated cost for Alternative A7b is approximately $56 million. Assuming an average annual yield of 7,240 af (10 cfs 24 hours/day and 365 days/year), the cost for ---PAGE BREAK--- SPF/TerraGraphics Page 31 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 this alternative would be approximately $7,800 per acre-foot of average yield (costs for conveyance and treatment are provided in Appendix An alternative would be to supply this water only (or at least initially only) to Pullman and WSU (Alternative A7c). The construction cost for a system capable of pumping 10 cfs only as far as Pullman would be approximately $46.4 million12, or approximately $6,400 per acre-foot of yield (7,240 af). An additional pipeline to Moscow could be added later, if necessary. Replacing Pullman and WSU groundwater withdrawals with Snake River water would benefit Moscow and UI because withdrawals from the Grande Ronde Aquifer would be substantially diminished. As such, this could be considered a regional approach warranting cost sharing. 3.3. Increased Use of Reclaimed Wastewater Reclamation and reuse of treated City wastewater was previously explored for Moscow by Kimball Engineering (2001), JUB Engineers (2010), and Keller Associates (2011). The following paragraphs are based on information provided in these reports. Between 2006 and 2010 the City produced between 143 and 206 af of wastewater between May and October (or between 47 to 67 MG per month). The University of Idaho uses approximately 50% of this wastewater during peak irrigation months to irrigate about 80% of its campus (Table The amount of wastewater discharged to Paradise Creek between 2006 and 2010 ranged from 67 to 194 af per month (22 to 63 MG per month) during the summer irrigation period (Figure A study by Kimball Engineering in 2001 identified a list of areas within Moscow that could be irrigated with recycled water. The report concluded that the land available within the City for irrigation with recycled water was insufficient to use all of the City's effluent and thus eliminate discharge between May 15 and October 15 (page 5-3). However, JUB estimated that additional water could be available if the City reconfigured its chlorination system. JUB conducted a planning analysis in 2010 for using reclaimed water to irrigate a proposed 27-acre City ball field complex in the southwest corner of Moscow on Palouse River Drive. According to JUB, the infrastructure needed to supply this water would cost between approximately $1.3 million and $2.1 million for an average 12 A 10-cfs pipeline would likely not be warranted for Pullman and Washington State University alone; the 10 cfs reflects capacity for the entire Palouse. The average annual demand by Pullman and Washington State University by the year 2060 would be approximately 3.5 cfs (no conservation, no climate change) and 2.5 cfs (with conservation and increased evapotranspiration). ---PAGE BREAK--- SPF/TerraGraphics Page 32 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 irrigation flow of 0.78 MG per week or 19.94 MG for the May to October irrigation season. This volume is equivalent to 61.2 acre-feet. Thus, JUB's cost estimate is equivalent to $21,200 to $34,300 per acre foot. This cost per acre foot could potentially be reduced if effluent was piped to more than the 27-acre City ball field. Data source: Table 5.1, Keller Associates (2011). Figure 9. Average WWTP discharge to Paradise Creek, 2006- 2010. The City/UI currently irrigates approximately 88 acres (based on data in Table 5.3 in Keller, 2011). Keller identified approximately 35 acres for future irrigation (for a total of 123 irrigated common-space acres). Keller estimates that the existing common-space irrigation requires approximately 40 MG, or would require 58 MG/season with future irrigated areas. The current effluent discharge to Paradise Creek ranges from approximately 21 MG to 63 MG; thus, the effluent could be used to provide the majority (if not all) of the irrigation water to these common spaces (Keller, 2011, page 5-7). Keller explored the use of scalping plants for treating portions of Moscow’s total wastewater stream near potential places of irrigation use. Keller concluded that it is more cost-effective to bring treated effluent from the existing wastewater treatment plant than to construct scalping plants which would provide the same amount of recycled water. Keller estimated that the cost for doing so, based on costs updated from the Kimball (2001) study, would be approximately $7.9 million, and would yield 0 10 20 30 40 50 60 70 80 0 50 100 150 200 250 May June July Aug. Sep. Oct. WWTP Discharge (mg) WWTP Discharge (af) ---PAGE BREAK--- SPF/TerraGraphics Page 33 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 an average annual recycled amount of 44.36 MG (136 acre feet), or approximately $58,000 per acre foot of “annual yield.” While expensive compared to other water-supply options, reuse would have other benefits (such as reducing wastewater discharge). Also, unit cost cost of water per acre-foot of annual yield) would be less if more reclaimed wastewater could be used for irrigation (up to approximately 976 acre-feet may be available on average basis between May and October – see Table 5.1 in Comprehensive Sewer System Plan). Finally, pumping reclaimed wastewater to just a few high-use areas may be more efficient than serving all of the City’s common-space areas with reclaimed wastewater. ---PAGE BREAK--- SPF/TerraGraphics Page 34 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 4. AQUIFER STORAGE AND RECOVERY STRATEGIES 4.1. Introduction Aquifer Storage and Recovery (ASR) is the process of actively storing water in an aquifer for subsequent recovery and use. ASR was identified in the first phase of this project as a way of augmenting local groundwater supplies with surface water from Moscow Mountain or other sources. Actively storing water in an aquifer is conceptually equivalent to storing water in a surface reservoir. This section provides additional exploration and discussion of potential ASR options for Moscow. The section begins with a general overview of ASR strategies (Section 4.2). Section 4.3 then outlines previous regional ASR applications considered and/or constructed, followed by a review of potential ASR strategies identified in Phase 1 (Section 4.4). Section 4.5 provides a review of relevant water quality characteristics in Paradise Creek and the South Fork Palouse River. Section 4.6 summarizes a March 2013 Moscow ASR workshop, followed by a review of preliminary ASR cost estimates (Section 4.7) and a discussion of ASR as a water-supply strategy for Moscow (Section 4.8). 4.2. ASR Overview 4.2.1. Passive or Active Recharge ASR typically begins with the augmentation of natural recharge to an aquifer. This is accomplished through passive recharge through enhanced surface infiltration spreading basins or other infiltration facilities) or active recharge through direct injection of treated water through recharge wells. Water is recovered by pumping from one or more wells. The following subsections provide an overview of typical ASR applications, water recovery, water quality considerations, geochemical processes, and regulatory considerations. 4.2.2. Typical Applications Typical ASR applications include the following: 1. Seasonal storage. Seasonally available water is injected into an aquifer, stored, and subsequently recovered during times of peak demand. 2. Longer-term storage. Water available during years of high surface runoff can be used to recharge for subsequent recovery during years of low runoff. Proportional recovery may decrease with multiple years of storage, but this disadvantage may be outweighed by the ability to divert water in high-runoff years for use in low-water years. 3. Storage of reclaimed water. ASR has been used in some instances to store high-quality reclaimed wastewater. Further review of IDEQ ---PAGE BREAK--- SPF/TerraGraphics Page 35 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 regulations would be required to determine if this is a feasible option in Idaho. IDAPA 58.01.17.08.d (Reclamation and Reuse rules) currently requires that Class A effluent used for groundwater recharge must have a minimum 6-month time of travel in the aquifer prior to withdrawal. We are not aware of any examples in Idaho where Class A effluent is currently being injected directly into an aquifer. 4. Water quality improvement. There are numerous Idaho examples of seasonally injecting high-quality water from one aquifer (or location) into another aquifer (or location) with poor water quality. The recovered water from the poor-quality aquifer remains equivalent to the high-quality injected water (see Section 4.3). 4.2.3. Efficient Recovery Recovery efficiency is the percentage of stored water that is subsequently recovered in the same ASR cycle (Pyne, 2005). Short-term recovery efficiency for direct injection in the Moscow area should be relatively high, especially if treated surface water is being directly injected into a cone of depression in the target aquifer. Recovery efficiency of passively-recharged water depends on recharge flowpaths and the time required for passively-recharged water to reach the target aquifer. Mounding of passively-recharged water at various depths prior to reaching the target aquifer could result in spreading and lower recovery efficiency. 4.2.4. Water Quality Considerations Surface water being used for ASR may contain parasitic protozoans giardia and pathogenic microbial constituents, or other potential contaminants and will therefore require filtration and/or other treatment (National Research Council, 2008). Suspended solids that may clog aquifer pores, down-hole bacterial activity, and ion exchange and adsorption processes (Pyne, 2005) may also influence the success of an ASR program. Minimizing the physical clogging of formation porosity with suspended solids may be one of the biggest challenges in successful ASR programs (Pyne, 2005). Even water with total suspended solids (TSS) less than drinking water standards may clog aquifers with low hydraulic conductivity. Chemical coagulation, clarification, and filtration may be required if clogging is an issue. Bacteria affecting groundwater chemistry have been found at depths of over 1,500 feet (Pyne, 2005). Bacteria may be attached to aquifer particle surfaces and therefore difficult to detect in groundwater samples. Growth of microorganisms in the wellbore, or in the formation near the wellbore, can reduce recharge efficiency. Factors affecting the growth of microorganisms include organic carbon content (particulate and dissolved), concentration of dissolved oxygen, biological load, temperature, pH, and concentrations of iron, phosphorus, nitrate, and total nitrogen. Again, strategies for ---PAGE BREAK--- SPF/TerraGraphics Page 36 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 minimizing bacterial growth can be developed based on specific water characteristics and site conditions. A disinfectant residual is often maintained in recharge water to minimize downhole bacterial growth. 4.2.5. Geochemical Processes In addition to clogging by suspended solids or bacterial growth, there are several geochemical reactions that can occur as a result of injecting water with chemistry different than the existing aquifer. Many of these processes may also result in plugging of the formation and reduction in recharge efficiency. Potential adverse geochemical processes include adsorption of precipitated flocs, ion exchange reactions that result in suspended clay particles, oxidation of iron carbonate or iron sulfides, or dissolution of metals (Pyne, 2005). Geochemical processes can also result in improved water quality, such as the removal of trihalomethanes and haloacetic acids, or adsorption of arsenic or other undesirable ions. Several geochemical models have been developed to assist in predicting potential problems based on the chemistry of the injected water and the aquifer matrix (Pyne, 2005). Monitoring of recharge and recovery water during initial operation of the ASR system will be necessary to verify actual geochemical reactions. Surface reactions such as ion exchange and adsorption may be evident during initial ASR testing cycles. Longer-term testing over a period of several months may be necessary to observe the effects of dissolution processes. 4.2.6. Regulatory Considerations Regulatory considerations for ASR consist of meeting Idaho Department of Water Resources (IDWR) requirements for water injection, Idaho Department of Environmental Quality (IDEQ) public drinking water regulations, and water right requirements. First, the construction of injection and recovery wells is regulated by IDWR under IDAPA 37.03.03 (Rules for the Construction and Use of Injection Wells). Injected water must meet groundwater quality standards listed in IDAPA 58.01.11 (Ground Water Quality Rule), which are similar to the maximum contaminant levels outlined in IDAPA 58.01.050 for public drinking water systems. Second, a Moscow ASR application would be part of a public water system. As such, IDEQ will review ASR plans to ensure that public water system standards are met. This will likely include a review of the quality of water being used for recharge, water quality of the pumped water, well siting, well construction, and system facilities. Third, withdrawals of ASR water will require a water right permit similar to any other groundwater withdrawal in Idaho. Depletions to local aquifers resulting from withdrawals under new water right permit(s) would be mitigated by the aquifer recharge. Because there would not be a net depletion to aquifers used for ASR, there would be no injury to other water users. ---PAGE BREAK--- SPF/TerraGraphics Page 37 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 From a physical standpoint, it is likely that 100 percent of water injected into the subsurface can be withdrawn in the same calendar year. However, the State may limit the amount of water that can “banked” in the subsurface over a multi-year period. It is likely that new permits would be conditioned similar to Permit 63-31183 (used by Micron Technology at its Boise facilities): “The entire volume of water injected (100%) can be re-diverted from the aquifer under this permit during the calendar year it is injected. Water not diverted during the year it is injected can be carried over as recharge credits for future withdrawal and beneficial use. The volume authorized for withdrawal by the recharge credits will be reduced by 10% each calendar year following the first calendar year the water is injected.” 4.3. Existing Regional ASR Investigations and Applications Nationally, ASR has been used in a variety of applications, including seasonal storage, long-term storage, emergency storage, restoration of declining groundwater levels, and water quality improvements (Pyne, 2005). Numerous ASR project have been considered and/or constructed in Idaho and Washington, including the following:  The City of Kennewick, Washington considered plans to divert water from the Columbia River during high-flow winter months and store the water in the local basalt aquifer to help meet summertime peak demand. The City of Kennewick is currently taking bids for construction of the injection facility. Completion is projected for early 2014.  Since 2002, the City of Walla Walla, Washington has two operational ASR wells. The City submitted an ASR application to the Washington Department of Ecology in 2009 to construct eight additional wells in the Columbia River Basalt. The application proposed diverting water from Mill Creek (a tributary to the Walla Walla River, which in turn flows into the Columbia River). The diverted water would be ozonated and chlorinated prior to injection in 10 wells (includes the two pre-existing wells). As of spring 2013, the application is still undergoing review.  The Boise White Paper, LLC plant located in Wallula, Washington investigated the feasibility of using ASR to divert cold surface water from the Columbia River into a basalt aquifer to store for summer recovery. A pilot-scale test indicated that temperature differences affected the density and viscosity of groundwater, lowering the transmissivity of the aquifer. However, upon recovery, the injected water quickly resembled native groundwater (GSI, 2012).  Golder and HDR (2008) investigated the feasibility of recharging the Grande Ronde Aquifer on behalf of Pullman, Washington. The recharge target would be the contact between the basalt and underlying ---PAGE BREAK--- SPF/TerraGraphics Page 38 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 basement rock where the rock is exposed at the surface near the south side of Kamiak Butte. This is the location of the smallest sedimentary overburden löess) allowing for the easiest infiltration access. The study found that the North Fork Palouse River has a sufficient volume of water to supply an artificial recharge project. Diversion of water was determined to be most feasible with an in-stream diversion structure such as a gravel berm, as there are no listed or endangered fish in the study area. Surface water quality results show that the water would have to be treated prior to recharge. Golder and HDR (2008) found several potential challenges with a project of this type in this area. The contact between the quartzite and basalt occurs at a range of elevations and depths, which limited the size of the infiltration area. The presence of weathered clays along the contact could limit recharge rates. Site-specific geology and hydrology would need to be better understood before such a project could be considered feasible.  Jones et al. (1968) evaluated the use of seasonal runoff from intermittent streams through ASR to offset declining groundwater levels. The authors proposed the following strategy in three stages over 30 years (with costs given in 1968 dollars): 1. Divert water from the South Fork Palouse River to inject 480 million gallons annually until 1980 million). 2. Divert water from Little Bear Creek to inject another 480 million gallons, predicted to meet needs past the year 2000 million). 3. After the year 2000, use effluent from the Moscow Wastewater Treatment Plant to inject an additional 1 billion gallons annually. Recharge was contemplated through either existing or new municipal supply wells. Recharge was also considered through spreading, flooding pits, or infiltration galleries, although these options were discounted because of issues associated with water quality, unfavorable geology, and land costs.  United Water Idaho is the primary municipal water supplier in Boise, Idaho. United Water obtains most of its supply from a network of deep wells throughout the City. Several of these wells have experienced water quality issues that have been solved through a seasonal ASR program. Examples include the following: 1. Swift #1 Well – ASR is conducted for manganese control; injection consists of groundwater and treated surface water; 2. ASR in the Maple Hills Well displaces native water that has elevated uranium concentrations; ---PAGE BREAK--- SPF/TerraGraphics Page 39 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 3. ASR is used in the Settlers Well to displace native water that has elevated uranium concentrations; 4. ASR is used in the Cole Well to displace native hard water that has elevated CO2 and manganese; 5. ASR is used in the Frontier Well to displace native water that has elevated ammonia concentrations; and 6. ASR is used in the Market Well to reduce arsenic concentrations – injections included some treated surface water.  Capitol Water Corporation serves municipal groundwater to approximately 4,000 Boise-area customers. The majority of Capitol Water Corporation’s customers use municipal water for both domestic and landscape irrigation purposes, resulting in much higher water demand in the summer than in winter. Capitol Water Well No. 6 was constructed in 1992 to help meet peak demand, but upon testing, was found to have high concentrations of dissolved iron. Low-iron groundwater is now injected into this well during the fall, winter, and spring at rates of 300 to 500 gpm and recovered during summer at rates of 300 to 1,200 gpm. The ASR project has allowed Capitol Water Corporation to utilize this high-capacity well to improve the overall quality of water supplied to customers, and eliminated the need to drill a replacement supply well.  Centennial Park in southeast Boise required a reliable irrigation water source to supplement a ditch water source. Because the park is located within a groundwater management area, the City of Boise was unable to obtain a water right for a well without mitigation. A mitigation plan was developed whereby surface water is pumped into a passive infiltration system for recharge, and groundwater is recovered from a nearby irrigation well. The project was successful at taking an intermittent surface water supply, utilizing a portion of it for direct irrigation use and the remainder for groundwater recharge, and allowing use of groundwater for irrigation when surface water was unavailable.  Micron Technology, Inc. (Micron) has operated a groundwater recharge project at its Boise campus since 2001. Micron is located within the Southeast Boise Ground Water Management Area, where water level declines in the 1990s resulted in a threatened curtailment of Micron’s existing groundwater rights and prevented appropriation of additional groundwater supply needed for company growth. The Micron ASR project was developed to 1) stabilize local water level declines, 2) provide additional water supply for future growth, and 3) maintain aquifer water quality to support existing beneficial uses. The Micron ASR project consisted of: 1. A surface pump station that diverts water from the Boise River; ---PAGE BREAK--- SPF/TerraGraphics Page 40 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 2. Approximately 4 miles of buried pipeline from the Boise River to the Micron campus; 3. A nominal 2.5 million MGD ultrafiltration membrane treatment plant (expandable to 4 MGD) to remove microorganisms; 4. One 1,200-foot deep injection well; and 5. Three nominal 1,100-foot deep production wells The Micron ASR project, in conjunction with other conservation activities, has been successful at stabilizing groundwater levels in the Southeast Boise Ground Water Management Area, where declines threatened curtailment of Micron’s existing groundwater rights and prevented appropriation of additional supply. 4.4. Potential City of Moscow ASR Stategies Identified in Phase I 4.4.1. Previously-Identified Moscow Options Two ASR strategies were identified in Phase 1 of this effort (SPF/TerraGraphics, 2011): 1. The first alternative consisted of storing water in the upper South Fork Palouse River drainage behind a 40-foot high dam (Alternative C3 – see Table 7) and conveying this water to Moscow for direct use and/or direct injection (after treatment) for ASR. 2. The second option consisted of diverting water solely from in-town, surface-water sources Paradise Creek and the South Fork Palouse River) for use in an ASR strategy. This option would not require the costs of reservoir and conveyance construction, but would require costs associated with passive or active recharge and re-diversion pumping). 4.4.2. Surface Water Availability The amount of water available for ASR based on direct diversions from Paradise Creek and/or the South Fork Palouse River depends on diversion location and seasonal conditions. Streamflow in Paradise Creek is measured at USGS Gaging Station 13346800 (located on the left Bank of Paradise Creek approximately 0.6 miles upstream from the Idaho-Washington state line). On average, 1,100 af might be available from Paradise Creek between January and April (based on an assumed 5- cfs diversion for 4 months – see Figure 10). However, substantially less (or possibly no) water would be available from Paradise Creek in dry years, such as in years with flows represented by 75th or 90th percentile flows (Figure 10). ---PAGE BREAK--- SPF/TerraGraphics Page 41 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 I Note: same graph with different y-axis scales. Figure 10. Mean daily flow, 75th percentile exceedance flow, and 90th percentile exceedance flow, Paradise Creek at the UI, water years 1978-2012 (USGS Gaging Station 13346800). 0 5 10 15 20 25 30 35 40 45 9/30 10/30 11/29 12/30 1/29 2/29 3/30 4/30 5/30 6/29 7/30 8/29 9/29 Flow (cfs) Mean Daily Flow 75th Percentile Exceedance 90th Percentile Exceedance 0 1 2 3 4 5 6 7 8 9/30 10/30 11/29 12/30 1/29 2/29 3/30 4/30 5/30 6/29 7/30 8/29 9/29 Flow (cfs) Mean Daily Flow 75th Percentile Exceedance 90th Percentile Exceedance ---PAGE BREAK--- SPF/TerraGraphics Page 42 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 More water would be available from the South Fork Palouse River than from Paradise Creek. The South Fork Palouse River is ungaged in Idaho. An estimate of flow in the South Fork Palouse River south of Moscow was made by using flow records from a Pullman, Washington gage (USGS Gaging Station 13348000).13 The gage is located of the mouth of Paradise Creek. The streamflow in the South Fork Palouse River south of Moscow (Figure 11) was approximated by subtracting measured Paradise Creek flows from the South Fork Palouse River flows in Pullman. (This approximation neglects any gains to Paradise Creek from the Moscow Wastewater Treatment Plant or other gains or losses from locations between the Paradise Creek gage and the mouth of Paradise Creek, or gains or losses to the South Fork Palouse River between Moscow and Pullman.) Based on the streamflow estimate depicted in Figure 11, at least 5 cfs would be available from January through May in an average year (representing a volume of approximately 1,500 af). Ten cfs might be available for four months in an average year (almost 2,400 af). Even in low-water years, 5 cfs might be available for approximately 3 months, representing a volume of about 900 af. Water that has been piped from a Moscow Mountain Reservoir (Alternative C3) would likely be less than that available as direct diversions from the Paradise Creek and/or the South Fork Palouse River. By example, the average annual watershed yield to a reservoir on the South Fork Palouse River on Moscow Mountain would yield approximately 700 afa (although more may be available from adjacent watersheds). 4.4.3. Hydrogeologic Considerations In general, successful ASR requires saturated or unsaturated subsurface zones capable of transmitting and storing sufficient amounts of water (National Research Council, 2008). Success of a Moscow ASR program – especially one based on passive recharge – would very much depend on local site conditions. Site characteristics influencing potential ASR include the following: 1. Availability and cost of land; 2. Compatibility with surrounding land uses; 3. Lithology, thickness, and depth of aquifer and aquitard zones; 4. Hydraulic characteristics of aquifer and overlying unsaturated and saturated zones; 5. Anticipated infiltration basin/gallery infiltration rates; 13 This gage is located on the right bank at the State Street crossing and Pullman, 600 feet upstream from Missouri Flat Creek. ---PAGE BREAK--- SPF/TerraGraphics Page 43 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Note: same graph with different y-axis scales. Figure 11. Estimated mean daily flow, 75th percentile exceedance flow, and 90th percentile exceedance flow, South Fork Palouse River less Paradise Creek, water years 1978-2012 (based on flows measured at USGS Gaging Station 13346800 less flows measured at USGS Gaging Station 13346800). 0 20 40 60 80 100 120 140 160 180 200 9/30 10/30 11/29 12/30 1/29 2/29 3/30 4/30 5/30 6/29 7/30 8/29 9/29 Flow (cfs) Mean Daily Flow 75th Percentile Exceedance 90th Percentile Exceedance 0 5 10 15 20 25 30 35 40 9/30 10/30 11/29 12/30 1/29 2/29 3/30 4/30 5/30 6/29 7/30 8/29 9/29 Flow (cfs) Mean Daily Flow 75th Percentile Exceedance 90th Percentile Exceedance ---PAGE BREAK--- SPF/TerraGraphics Page 44 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 6. Mineralogy of clays, sands, and other subsurface materials; 7. Local geologic structural features; 8. Water levels, vertical and horizontal hydraulic gradients; 9. Presence of nearby wells, including depth, construction, use, and ownership; 10. Groundwater withdrawal patterns in the vicinity of proposed recharge sites; 11. Proximity to potential sources of contamination; and 12. Proximity to features or facilities that could be adversely affected by groundwater mounding from recharge. In the Palouse, passive recharge is limited by hydraulic characteristics of fine-grained sediments overlying the Wanapum Basalt. Veseth (1985) lists the infiltration rate of clayey paleosols Naff-Thatuna or similar soils) as only 1.5 to 15 inches per day (0.06 to 0.63) inches per hour). The USDA Soil Survey Geographic (SSURGO) database characterizes soils in possible recharge areas along Paradise Creek and the South Fork Palouse River (Figure 12) as having permeability rates ranging from 0 to 2 inches/hour; permeability values for limiting soil horizons are shown in Table 9. A seepage test in an unlined sewage lagoon (SPF/TerraGraphics, 2011) located just west of Moscow (Stadium Way Mobile Home Park) resulted in a measured seepage rate of 0.09 in/day (0.004 in/hr).14 Without maintenance, subsurface infiltration properties could become even less over time as surface-water sediment is filtered in a recharge area. Managed recharge through low-permeability sediments could require substantial land area. Infiltration of 1,100 af over a 4-month period (equivalent to a uniform flow rate of approximately 4.6 cfs, or 2,070 gpm) could require approximately 70 acres at an infiltration rate of 0.06 in/hr and over 1,200 acres at an infiltration rate of approximately 0.004 in/hr (Table 10). Infiltration at a rate of 0.56 in/hr (infiltration rate for Palouse silt loam – see Table 9) would require only approximately 8 acres, but this infiltration rate for the entire sediment profile is likely too optimistic. Fine-grained sediments silt or clay, which are prevalent in the Moscow area) between the upper soil horizons and deeper basalt will also influence infiltration pathways and likely limit infiltration rates. The depth to basalt in the Paradise Creek area upstream of the Moscow Wastewater Treatment Plant extends from 14 The sewage lagoon is thought to have been constructed by essentially removing topsoil to a natural silt/clay layer. ---PAGE BREAK--- SPF/TerraGraphics Page 45 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 approximately 12 to 30 feet; the depth to basalt near the proposed City’s ball field area along the South Fork Palouse River extends from about 38 to 60 feet. Source: soil data from USGS Soil Survey Geographic Database.15 Figure 12. Soil types in potential passive recharge areas. Upper basalt layers may or may not be conducive to vertical infiltration. Basalt fractures typically have greater permeability than unfractured basalt, but sediments within fractures zones may limit permeability. Getting recharge water to target 15 file:///T:/Spatial%20Data/Spatial/Soils/SSURGOOnePlan/SoilSurveyGeographicDatabaseSSURGO.htm Possible passive recharge areas ---PAGE BREAK--- SPF/TerraGraphics Page 46 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 pumping depths through surface infiltration is probably more difficult than simply getting water to the top of the uppermost basalt zones. Table 9. Examples of low-permeability soil layers in the vicinity of potential passive recharge sites. Table 10. Area needed for infiltration at various potential infiltration rates. SOIL TYPE SOIL LAYER NUM TEXTURE UPPER LAYER DEPTH (ft) LOWER LAYER DEPTH (ft) PERM‐ LOW (in/hr) PERM‐ HIGH (in/hr) LATAH SILT LOAM, 0 TO 3 PERCENT SLOPES 2 2 32 60 0 0.05 LATAHCO SILT LOAM, 0 TO 3 PERCENT SLOPES 4 4 28 60 0.19 0.59 NAFF‐THATUNA SILT LOAMS, 7 TO 25 PERCENT SLOPES 2 2 44 60 0.05 0.19 PALOUSE SILT LOAM, 3 TO 7 PERCENT SLOPES 2 2 15 60 0.56 1.99 PALOUSE‐LATAHCO SILT LOAMS, 0 TO 3 PERCENT SLOPES 2 2 28 62 0.19 0.59 THATUNA SILT LOAM, 3 TO 7 PERCENT SLOPES 2 2 44 60 0.05 0.19 THATUNA‐NAFF SILT LOAMS, 25 TO 40 PERCENT SLOPES 2 2 44 60 0.05 0.19 THATUNA‐NAFF SILT LOAMS, 25 TO 40 PERCENT SLOPES 2 2 7 60 0.19 0.59 WESTLAKE‐LATAHCO SILT LOAMS, 0 TO 3 PERCENT SLOPES 2 2 33 60 0.19 0.59 WESTLAKE‐LATAHCO SILT LOAMS, 0 TO 3 PERCENT SLOPES 4 4 28 60 0.19 0.59 Source: USDA Soil Survey Geographic (SSURGO) database. Area Needed for Infiltration (acres) Comment (gpm) (cfs) (in/hr) (in/d) (acres) 2,070 4.61 2.00 48 2.3 Highest infiltration rate listed in SSURGO for soils in vicinity of potential recharge sites (highly unlikely?) 2,070 4.61 0.63 15 7.3 2,070 4.61 0.06 1.5 73 2,070 4.61 0.004 0.09 1,220 Measured infiltration at Stadium Way Mobile Home Park Infiltration Area Infiltration Rate Desired Flow Rate (yields ~1,100 af over a 4‐month period) Infiltration rates listed in Veseth, 1985 ---PAGE BREAK--- SPF/TerraGraphics Page 47 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Alternatively, injection of treated surface water via a well would not depend on overburden characteristics, and could directly target the Wanapum Aquifer. However, water would need to be treated to drinking water standards (which would include removal of microorganisms). 4.4.4. Recovery Efficiency for a Moscow ASR Application The Wanapum Aquifer is the likely target aquifer for a Moscow ASR strategy, because it is closer to ground surface than the regional Grande Ronde Aquifer (closer to surface recharge sources and requiring less pumping lift for recovery) and water levels in the Moscow area can be manipulated by varying diversion rates. An ASR strategy could be designed to raise groundwater levels over a general portion of the Wanapum Aquifer underlying Moscow, thereby increasing the amount of water available for extraction via existing wells. Alternatively, existing or new wells could be used to create a cone of depression through pumping; treated surface water could then be injected into – and pumped from – this cone of depression. In this approach, most 90% or more) of the same water that is injected would be recovered for subsequent use. 4.5. Water Quality Quality of recharge water is a key factor in considering ASR with water from Paradise Creek and/or the South Fork Palouse River. This project therefore included a review of existing water quality data from these streams and reconnaissance-level sample collection and analysis during the spring of 2013. 4.5.1. Summary of Existing Information The following documents review historical water-quality data describing water quality in Paradise Creek and the South Fork Palouse River. In general, elevated concentrations of nitrate and phosphorus were observed at Moscow-area sampling locations. Also, surface-water samples contained fecal coliform and/or E. coli, which is typical for surface water. 1. Paradise Creek Use Attainability Assessment (IDEQ, 1994) IDEQ collected water-quality samples during winter (November 1992 through April 1993) and summer (May 1993 through October 1993) at 4 locations: Mountain View Park, intersection of White Avenue and Troy Highway, intersection of Sixth Street and Deakin Street, and near Moscow Waste Water Treatment Plant by the Idaho/Washington border (see Appendix Nitrate (N03), an indicator of agricultural or septic influence, exceeded typical background concentrations (approximately 2 milligrams per liter, or mg/L) at all locations during at least some winter and summer sampling events. Winter nitrate concentrations were relatively consistent ---PAGE BREAK--- SPF/TerraGraphics Page 48 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 among stations, but summer nitrate concentrations appeared to increase between Mountain View Park and the state line. Similarly, elevated phosphorus concentrations were observed near the state line. Higher values of nutrient concentrations total phosphorus and nitrate) were substantially higher at the state line, presumably reflecting discharge. DEQ noted substantial concentrations of fecal coliform bacteria within Moscow City limits. The was replaced in 2002 with a Biological Nutrient Removal process. In 2010 effluents filters were added to remove phosphorus. 2. Paradise Creek Water Body Assessment and Total Maximum Daily Load (IDEQ, 1997) This report describes the allocation of pollutant loading of Paradise Creek from 3 sources nonpoint sources from above the outfall, and discharge from the UI Aquaculture Research Facility. IDEQ hypothesized nutrients are not a year-round problem in Paradise Creek given the fine-grained nature of the sediment and flushing that occurs during high flow. Nitrate and total phosphorus were highest at the outfall. Again, the was replaced in 2002 with a Biological Nutrient Removal process. In 2010 effluents filters were added to remove phosphorus. 3. UI Paradise Creek Monitoring Report 2001-2011 (Brooks and Boll, 2011) This report summarizes 2001 to 2011 water quality data from Paradise Creek monitoring stations located on Moscow Mountain (Forest Station), upstream of Moscow (Rural Station), and of Moscow near the Idaho/Washington state line (Urban Station). High phosphorus concentrations were found at all 3 sites, mostly as particulate phosphorus. Nitrate concentrations exceeded the National Primary Drinking Water Regulation infrequently (in less than 1.2% of the annual samples) and only at the Rural Station. The authors noted a significant decline in sediment loads in the Paradise Creek watershed between 2001 and 2008. 4. South Fork Palouse River Watershed Assessment and Total Maximum Daily Load (IDEQ, 2007) This report summarized data collected between November 2001 and November 2002 from 4 monitoring points along the South Fork Palouse River (SF-1 was located on a forested portion of Moscow Mountain; SF-2 was located between Moscow Mountain and Moscow; SF-3 was located southeast of Moscow; and SF-4 was located south west of Moscow near ---PAGE BREAK--- SPF/TerraGraphics Page 49 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 the Idaho/Washington state line). Nitrite and nitrate (NO2+NO3) concentrations increased with distance from Moscow Mountain. Typical background concentrations (approximately 2 mg/L) were often exceeded during winter sampling events at stations. 4.5.2. Water Quality Sampling As part of this project, water-quality and field-parameter data were collected in 2013 for reconnaissance purposes at three sites: 1) Paradise Creek by Perimeter Drive, 2) Paradise Creek by the Latah County fairgrounds, and 3) along the South Fork Palouse River west of the Highway 95 Bridge (Figure 13). Samples were collected on February 11, March 19, and April 9, 2013. A sampling plan is included as Appendix F. Figure 13. Water quality sampling locations. Samples were taken at flows ranging from 6.1 cfs to 10 cfs from Paradise Creek (Table 11, page 50). Flow data for the South Fork Palouse River. However, average ---PAGE BREAK--- SPF/TerraGraphics Page 50 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 daily flows at the USGS Gaging Station 13348000 in Pullman ranged from 51 to 55 cfs (this gaging station measures flow of the mouth of Paradise Creek). Table 11. Field parameter data. Field parameters included temperature, pH, dissolved oxygen (DO), oxidation- reduction potential (ORP), and a specific conductance. Laboratory analyses were conducted for the following analytes: E. coli, caffeine, nitrate (N03), total dissolved solids (TDS), total suspended solids (TSS), total organic carbon (TOC), total petroleum hydrocarbons (TPH) differentiated by diesel, gasoline, and lubrication oil constituents. Sample Location Date pH Temp. Specific Conductance (mS/cm) Dissolved Oxygen (mg/L) ORP (mV) Discharge (cfs) 2/11/2013 7.36 1.71 183 12.63 144 10 3/19/2013 7.23 3.74 160 12.40 188 7 4/9/2013 R 10.45 252 13.10 173 6 2/11/2013 7.39 1.45 239 12.45 150 10 3/19/2013 7.48 3.22 135 12.40 140 7 4/9/2013 R 10.8 212 13.02 67.1 6 2/11/2013 7.09 1.89 267 13.47 217 ~45 3/19/2013 7.67 3.54 80 12.78 110 ~45 4/9/2013 R 9.62 98 12.60 67 ~45 Paradise Creek ‐ Perimeter Drive Paradise Creek ‐ Fair Grounds South Fork of the Palouse River Notes: °C = degree centigrade mS/cm = millisiemen per centimeter mg/L = milligram per liter mV = millivolt R = value rejected due to calibration issues Discharge data taken from USGS website. Palouse River is a daily average taken USGS Gaging Station 13346800 (Pullman, WA) less Paradise Creek (USGS Station 13346800) Field Parameter Data ---PAGE BREAK--- SPF/TerraGraphics Page 51 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 E. coli concentrations exceeded the standards16 at each site for each event. The highest concentrations of E. coli were observed in Paradise Creek near the Latah County Fairgrounds (Table 12, page 52). E. coli concentrations in three samples (Paradise Creek near Perimeter Drive on 4/9/2013 and Paradise Creek near the Fairground on 2/11/2013 and 3/19/2013) exceeded the 126-MPN/100 ml threshold used for water with recreational-use designations.17 Observed E. coli concentrations confirm that surface water would require either passive or active treatment as part of an ASR strategy. Nitrate and TDS were below the regulatory threshold of 10 mg/L and 500 mg/L (National Secondary Drinking Water Regulation respectively. However, nitrate concentrations in samples collected on February 11, 2013 at all three sampling sites exceeded typical background concentrations of approximately 2 mg/L. The reduction in nitrate concentrations observed in subsequent sampling events probably reflects flushing associated with spring runoff. Petroleum hydrocarbons were not detected in any of the samples. Caffeine was selected as an indicator of “Contaminants of Emerging Concern” (CECs) that can enter shallow aquifers as a result of leaking sewer pipes and/or septic systems. A caffeine concentration of 0.0278 micrograms per liter (µg/L) was found in the April 9, 2013 sample from the Paradise Creek-Perimeter Drive site, but was otherwise not detected in other samples collected as part of this effort. 4.6. Workshop A workshop focusing on potential use of ASR was held on March 8, 2013 in Moscow. Attending the workshop were Les MacDonald (Moscow), Tom Scallorn (Moscow), Mark Workman (Pullman), Dale Ralston (Ralston Hydrologic Services), Kent Keller (WSU), Mark Solomon (UI), Jerry Fairley (UI), Robin Nimmer (TerraGraphics), Bratz (SPF), and Christian Petrich (SPF). 16 Zero most probable number (MPN)/100 milliliters (mL). 17 IDAPA 58.01.02.251 establishes a 126-MPN/100 ml standard for surface water with recreational use designations. The standard is based on a geometric mean concentration from 5 samples taken every 3 to 7 days over a 30-day period. ---PAGE BREAK--- SPF/TerraGraphics Page 52 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Table 12. Laboratory results. Workshop discussion focused on two seasonal, in-town sources of recharge water: Paradise Creek and the South Fork Palouse River. Possible passive recharge sites using water from Paradise Creek might include areas near the state line between Sample Location Date E. coli a Caffiene Nitrate a TDS b TSS TOC TPH‐ Diesel TPH‐ Gasoline TPH‐ Lube Oil MPN/ 100 mL ug/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L 2/11/2013 55.6 ND 6.89 213 9.76 4.47 <0.63 <0.25 <0.63 3/19/2013 39.9 ND 2.19 182 6.56 5.07 <0.63 <0.25 <0.63 4/9/2013 165.8 0.0278 1.00 131 8.26 6.28 <0.63 <0.25 <0.63 2/11/2013 547.5 ND 8.70 189 10.0 5.74 <0.63 <0.25 <0.63 3/19/2013 1413.6 ND 2.43 168 8.60 5.02 <0.63 <0.25 <0.63 4/9/2013 28.2 ND 1.03 136 8.40 6.78 <0.63 <0.25 <0.63 2/11/2013 62.0 ND 7.18 162 56.1 4.11 <0.63 <0.25 <0.63 3/19/2013 19.9 ND 1.77 128 19.5 3.96 <0.63 <0.25 <0.63 4/9/2013 20.3 ND 1.07 71.7 15.3 3.70 <0.63 <0.25 <0.63 0 NA 10 500 NA NA NA NA NA MPN = most probable number mL = milliliters ug/L = micrograms per liter mg/L = milligrams per liter TDS = total dissolved solids TSS = total suspended solids TOC = total organic carbon TPH = total petroleum hydrocarbons NA = not applicable a Regulatory threshold is National Primary Drinking Water Regulation (maximum contaminant level) b Regulatory threshold is National Secondary Drinking Water Regulation Highest concentration between original and duplicate sample reported. Bold values exceed regulatory threshold Paradise Creek ‐ Perimeter Drive Paradise Creek ‐ Fair Grounds South Fork of the Palouse River Notes Laboratory Results Regulatory Thresholds ---PAGE BREAK--- SPF/TerraGraphics Page 53 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Idaho and Washington, the Sweet Avenue area18 near Highways 95 and 8, and portions of the UI near Paradise Creek. Active recharge sites using water from Paradise Creek might include Mountain View Park, the general vicinity of proposed Moscow Well No. 10, Joseph Street ball fields, and various UI locations. Active recharge sites using water from the South Fork Palouse River might include the cemetery, proposed City ball fields on South Palouse River Drive, Elks Golf Course, and Parker Farm. Discussion of these sites was of a general nature; the feasibility of these sites for active or passive recharge has not been investigated.19 Workshop participants agreed that Wanapum Basalt is a logical ASR target aquifer in the Moscow area. It is shallower than the regional Grande Ronde Aquifer, and in some places is relatively close to ground surface. Pumping of Moscow wells has shown that water levels in the Wanapum Basalt can be drawn down to create a cone of depression into which recharged water could be injected for subsequent withdrawal. However, a successful ASR strategy with passive recharge targeting the Wanapum Basalt would depend on the hydraulic characteristics of overburden between ground surface and the top of the aquifer and aquifer characteristics in the area being recharged. Monitoring shallow groundwater levels at potential passive ASR sites could help describe the degree of hydraulic connection between surface water and potential ASR recharge target zones. For example, it was noted that shallow groundwater levels in shallow basalt aquifers underlying UI property in the vicinity of Perimeter Drive near Paradise Creek show a response to changes in Paradise Creek water levels. However, wells completed deeper in the Wanapum Basalt do not show a response to changes in Paradise Creek water levels. Some intermediate-depth wells in this area show a response, and some do not. Understanding the movement of potential managed recharge to the target aquifer would be critical to the success of an ASR program based on passive recharge. A portion of the workshop discussion focused on CECs, which include pharmaceuticals, personal care products, and other contaminants deriving from municipal, industrial, or agricultural sources. Sources of CECs in shallow groundwater include leaking sewer lines, septic discharge, or municipal wastewater discharge. A 18 This area is a Brownfield site and could require additional measures to ensure water-quality protection. 19 The feasibility of managed recharge at any of these sites would require characterization of depth to basalt, infiltration characteristics of sediments between ground surface and the overlying the basalt, the degree of hydraulic connection between the top basalt and Moscow-area aquifers, etc. ---PAGE BREAK--- SPF/TerraGraphics Page 54 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 recommendation was made to sample shallow alluvium in the Perimeter Drive area for the possible presence of CECs and pesticides/herbicides as an indication of water quality in Paradise Creek and shallow groundwater chemistry that would be encountered with a passive recharge strategy. One workshop member raised the concern about inadvertently drawing (directly or indirectly) treated wastewater from the Moscow Wastewater Treatment Plant discharge containing CECs by pumping shallow Wanapum wells in the western Paradise Creek area. Other factors being equal, passive aquifer recharge was considered preferable to active recharge as part of an ASR strategy. Workshop members commented that passive ASR carries a perception of increased safety, easier operation, and could possibly be more easily permitted by regulatory agencies. However, passive recharge of sufficient magnitude will be difficult or impractical to achieve in places of substantial overburden. In these cases, active recharge of treated surface water may be more achievable. The general conclusion of this workshop is that there are no absolute “showstoppers” to the development of an ASR strategy for Moscow at this time. However, development and implementation of an ASR strategy – whether passive or active – will require substantial additional site-specific investigation. Successful implementation of an ASR program would require a detailed understanding of the following: 1. Hydrogeologic characteristics of the receiving aquifer in vicinity of recharge site; 1. Recharge mechanisms and pathways for a passive ASR strategy to ensure that recharge water reaches target aquifer; 2. Existing groundwater-surface water interconnection at potential recharge sites; 3. Groundwater chemistry, recharge-water chemistry, and the chemistry of groundwater and recharge-water interaction at recharge sites; and 4. Potential surface-water contaminants CECs) and resulting water treatment requirements. 4.7. Cost Estimate Order-of-magnitude cost estimates were prepared for two ASR scenarios using water from Paradise Creek and/or the South Fork Palouse River (Alternative D3a). The first cost estimate was for a direct discharge strategy using water from Paradise Creek or ---PAGE BREAK--- SPF/TerraGraphics Page 55 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 the South Fork Palouse River.20 The second cost estimate is for a passive-recharge ASR approach (Alternative D3b). 4.7.1. ASR with Direct Injection (Alternative D3a) ASR with direct injection requires a river intake pump station to convey water from the river to a water treatment plant that would treat the water to drinking-water standards. The treated water would be injected into the aquifer at an ASR well facility. The water could then be pumped from the aquifer at any time other than the injection period. The assumed design capacity for this alternative was 3.0 MGD or 2,070 gpm, which is based on diverting, treating, and injecting a volume of 1,100 af over a 4-month period. The estimated costs for Alternative D3a include $0.8 million for intake and $12.2 million for treatment and injection, for a total project cost of $12.9 million. Cost estimates for intake, pumping, and distribution facilities are provided in Appendix D of the Phase 1 report (SPF/TerraGraphics, 2011). The expensive cost component for this alternative is clearly the water treatment. This cost would be proportionately less if the treatment facility were to be used with other surface-water supply alternatives. For example, a treatment facility could be used to treat direct diversions from Paradise Creek or South Fork Palouse River during spring runoff and stored surface water from Moscow Mountain during the summer/fall. 4.7.2. ASR with Passive Injection (Alternative D3b) Conceptually, passive treatment (through infiltration) would be much less expensive than above-ground surface-water treatment. Possible methods of infiltration include use of an open, bermed infiltration basin or a subsurface infiltration gallery. An infiltration basin would allow easier access for inspection and maintenance (maintenance might include removal of deposited sediments and/or scarification), but could preclude other land uses (e.g. irrigated ball field). A subsurface infiltration gallery would be more amenable to other coincident land uses, but would be more difficult to maintain, and would probably not be feasible. Design of a passive infiltration system is very dependent on site-specific characteristics that were not investigated as part of this report. However, for illustrative purposes, an order-of-magnitude cost estimate was prepared for a passive infiltration system using a bermed infiltration basin located in a 12-acre hypothetical site on UI property along Paradise Creek east of Perimeter Drive in Moscow and a 32- 20 This approach was first proposed in Phase 1 as Alternative D3; it is now referred to as Alternative D3a. ---PAGE BREAK--- SPF/TerraGraphics Page 56 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 acre site on the South Fork Palouse River (Figure 14). Both of these locations were discussed (along with others) in the March 8, 2013 ASR workshop. Figure 14. Hypothetical location of passive infiltration facility. These sites were used for illustrative costing purposes only. No site characterization was done to suggest that these sites are better or worse than others shown in Figure 12. Furthermore, existing land uses (or introduced fill materials) may preclude use of these sites for managed infiltration as part of an ASR strategy. Surface soils in the vicinity of the hypothetical Perimeter Drive infiltration site have rated permeabilities ranging from 0.19 inches per hour (in/hr) to approximately 2 in/hr (Figure 12 and Table Aggregate infiltration rates for the ground-surface-to-basalt ---PAGE BREAK--- SPF/TerraGraphics Page 57 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 thickness will be less than this amount, especially if clay is encountered. The aggregate infiltration rate for a 12-acre site (Table 13) would need to be at least 9.1 inches per day (and at least 3.5 inches per day for a 32-acre site. Experience suggests that these infiltration rates are likely optimistic for these sites. Table 13. Infiltration rate needed for the recharge of 1,100 af within a specific infiltration area. 4.7.3. Preliminary Cost Opinion ASR using passive recharge (Alternative D3b in Table 7) would require a river intake, pump station, pipeline, and infiltration basin. This alternative also included a clarifier to remove suspended sediment prior to discharging water into the infiltration basin, thereby extending the life (and/or reducing maintenance) of an infiltration facility. The estimated cost for a 12-acre passive recharge site would be approximately $1.3 million (Appendix The cost per delivered acre-foot of water (if basin has sufficient infiltration capacity to recharge 1,100 af per year) would be approximately $1,270 per af. The estimated cost for a 32-acre passive recharge site would be approximately $1.46 million (Appendix The cost per delivered acre-foot of water (if the basin has sufficient infiltration capacity to recharge 1,100 af per year) would be approximately $1,330 per acre-foot. Although the costs of these passive-recharge options are relatively low, the likelihood of successfully recharging 1,100 af in a 12-acre or 32-acre facility are also low. It is unlikely that passive infiltration rates will be sufficient to support this level of recharge. However, site characteristics may be sufficient to enable recharge at lower rates. Diversion works for lower diversion rates would be less costly. The size of diversion works could be determined based on site investigation results. The most expensive component for the passive-recharge diversion works is a water- clarifying facility. This is needed to reduce sediment in the water that could clog pore Infiltration Area (acres) Comment (gpm) (cfs) (in/hr) (in/d) (acres) 2,071 4.61 0.38 9.12 12 2,071 4.61 0.15 3.48 32 Infiltration rate needed for recharge of 4.61 cfs over given area (see text) Infiltration Area Desired Flow Rate (yields ~1,100 af Required Infiltration Rate ---PAGE BREAK--- SPF/TerraGraphics Page 58 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 spaces in sediments underlying an infiltration basin, thereby reducing infiltration capacity. 4.8. Aquifer Storage and Recovery – Discussion The appeal of ASR is the opportunity to store surface water when available during the winter and spring for use during times when surface water is not available. Active injection would require treatment of surface water to drinking water standards. Passive recharge requires enough land to facilitate sufficient recharge during times when surface water is available. Passive recharge – accomplished with spreading basins, infiltration galleries, etc. – has appeal because it provides an opportunity to purify recharge water through filtration, adsorption, and microbial/chemical degradation. However, the effectiveness of passive recharge will be limited by permeability of sediments extending from ground surface to the target aquifer and the hydraulic properties of upper portions of the target aquifer (e.g. Wanapum Basalt). Some surface water treatment clarification) may be required even with passive recharge to reduce a sediment load that could eventually clog pore spaces in overlying sediments (which is why the passive-diversion works described above include a water clarifier). Extensive site- specific analysis would be required to determine infiltration rates, infiltration capacity, the quality of water reaching the aquifer, local aquifer transmissivity document that managed recharge reaches pumping wells), etc. On the other hand, the ability to recharge target aquifers (or specific locations within the target aquifer) with direct injection is much more certain. Injection volumes can be directly measured. With direct injection, an ASR strategy could be used to pump the same water that was previously injected. Water quality would be an important ASR consideration. At a minimum, surface water would need to be treated to drinking water standards for regulatory approval. Concentrations of CECs in source water would need to be better quantified and understood. CECs, while not regulated, may require additional treatment21 (or at least monitoring). Water from Moscow Mountain (such as from a South Fork Palouse River impoundment) would likely require less treatment. Water from Moscow Mountain will 21 Treatment cost estimates for this analysis are based on membrane filtration technology, which is about 20% more expensive than conventional water treatment. Membrane filtration, however, would be insufficient to completely remove all CECs. Reverse osmosis technology could be used to remove CECs, but the cost would be substantially greater than the membrane filtration technology. ---PAGE BREAK--- SPF/TerraGraphics Page 59 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 contain less suspended sediment and is much less likely to contain CECs or agricultural chemicals. The same would be true for water diverted from Dworshak Reservoir. In summary, ASR with passive recharge could be less expensive than active recharge (which requires substantial water treatment prior to recharge). However, successful passive recharge requires sites require adequate subsurface permeability, which may be limited in the Palouse. ---PAGE BREAK--- SPF/TerraGraphics Page 60 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 5. SUMMARY OF PRELIMINARY COST OPINIONS FOR WATER- SUPPLY ALTERNATIVES Water-supply alternatives considered in this analysis, consisting of Moscow Mountain reservoir alternatives, previously-identified surface-water alternatives, and wastewater reuse, range in cost from $1.28 million to $149 million (Table 14). The estimated construction cost per acre foot of annual yield ranges from approximately $1,200 to $36,700. ---PAGE BREAK--- SPF/TerraGraphics Page 61 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Table 14. Summary of water-supply alternatives (ranked by total cost). Number Alternative Name Annual Yield (MG) Annual Yield (af) Construction cost Construction cost per AF yield A6 Dworshak reservoir direct use 7,270 22,300 $149,000,000 $ 6,700 A7a Snake River direct use (USACE estimate) 7,270 22,300 $ 92,000,000 $ 4,100 A2 Hatter Creek direct use 782 2,400 $ 65,386,000 $ 27,200 A7b Snake River direct use (pipeline to Moscow, SPF/TG estimate) 2,360 7,240 $ 56,240,000 $ 7,800 A1 Flannigan Creek direct use 1,430 4,400 $ 53,664,000 $ 12,200 A7c Snake River direct use (pipeline to Pullman only, SPF/TG estimate)(1) 2,360 7,240 $ 46,360,000 $ 6,400 A5 North Fork Palouse River direct use 1,550 4,760 $ 40,700,000 $ 8,600 A4 Felton Creek direct use 424 1,300 $ 32,005,000 $ 24,600 A3 South Fork Palouse direct use 228 700 $ 25,685,000 $ 36,700 C3 South Fork Palouse River ASR (with reservoir) 228 700 $ 13,497,000 $ 19,300 D3a Paradise Creek or South Fork Palouse River ASR (direct diversion, treatment, active injection, no reservoir) 358 1,100 $ 12,940,000 $ 11,800 B4 Felton Creek non‐potable irrigation 424 1,300 $ 12,720,000 $ 9,800 B8 Wastewater resuse 44 136 $ 7,000,000 $ 51,400 B3 South Fork Palouse River non‐ potable irrigation 228 700 $ 4,845,000 $ 6,900 D3b Paradise Creek or South Fork Palouse River ASR (direct diversion, passive recharge, no reservoir) 358 1,100 $ 1,280,000 $ 1,200 Summary of Alternatives (ranked by total cost) This option provides capacity in excess of that needed by the City of Pullman and Washington State University alone (see text). ---PAGE BREAK--- SPF/TerraGraphics Page 62 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Table 15. Summary of water-supply alternatives (ranked by cost per unit annual yield). Number Alternative Name Annual Yield (MG) Annual Yield (AFA) Construction cost Construction cost per AF yield B8 Wastewater resuse 44 136 $ 7,000,000 $ 51,400 A3 South Fork Palouse direct use 228 700 $ 25,685,000 $ 36,700 A2 Hatter Creek direct use 782 2,400 $ 65,386,000 $ 27,200 A4 Felton Creek direct use 424 1,300 $ 32,005,000 $ 24,600 C3 South Fork Palouse River ASR (with reservoir) 228 700 $ 13,497,000 $ 19,300 A1 Flannigan Creek direct use 1,430 4,400 $ 53,664,000 $ 12,200 D3a Paradise Creek or South Fork Palouse River ASR (direct diversion, treatment, active injection, no reservoir) 358 1,100 $ 12,940,000 $ 11,800 B4 Felton Creek non‐potable irrigation 424 1,300 $ 12,720,000 $ 9,800 A5 North Fork Palouse River direct use 1,550 4,760 $ 40,700,000 $ 8,600 A7b Snake River direct use (pipeline to Moscow, SPF/TG estimate) 2,360 7,240 $ 56,240,000 $ 7,800 B3 South Fork Palouse River non‐ potable irrigation 228 700 $ 4,845,000 $ 6,900 A6 Dworshak reservoir direct use 7,270 22,300 $149,000,000 $ 6,700 A7b Snake River direct use (pipeline to Pullman only, SPF/TG estimate)(1) 2,360 7,240 $ 46,360,000 $ 6,400 A7a Snake River direct use (USACE estimate) 7,270 22,300 $ 92,000,000 $ 4,100 D3b Paradise Creek or South Fork Palouse River ASR (direct diversion, passive recharge, no reservoir) 358 1,100 $ 1,280,000 $ 1,200 Summary of Alternatives (ranked by construction cost per acre foot of yield) This option provides capacity in excess of that needed by the City of Pullman and Washington State University alone (see text). ---PAGE BREAK--- SPF/TerraGraphics Page 63 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 6. CONCLUSIONS AND RECOMMENDATIONS 6.1. General Conclusions General conclusions from Phases 1 and 2 of this surface-water supply evaluation include the following: 1. The demand for water will continue to increase in the Palouse as population increases and the universities grow. 2. There are a number of surface-water sources in or near the Palouse that could be used to augment diversions from Palouse-area aquifers. 3. Preliminary estimates of capital costs for constructing these alternatives range from approximately $1.4 million to $149 million (Table 14). 4. Preliminary estimates of construction costs per acre foot of annual water yield range from approximately $1,200 to $51,400 (Table 15). 5. The surface-water supply alternatives reviewed as part of this investigation are not cost-effective if compared with the cost of simply developing additional groundwater resources the cost of drilling one or more new wells). However, continued groundwater-level declines or regulatory constraints on new groundwater development may drive (or force) a move to surface-water sources in the future. 6. Additional water-conservation measures, and the costs of these measures, should be considered to reduce the need for surface-water supplies. 7. Of alternatives that could supply over 3,000 afa regional options), the least expensive option may be diversions from the North Fork Palouse River (Alternative A5). However, if larger volumes or year-round diversions are required, diversions from the Snake River may be the least expensive per-unit-volume alternative. 8. Of options supplying smaller volumes, diversions from a reservoir in the South Fork Palouse River drainage on Moscow Mountain for irrigation purposes non-potable) would be among the least expensive options, both on a total construction cost and on a cost per yield basis. 9. ASR using water from Paradise Creek or the South Fork Palouse River using passive recharge may be even less expensive than water from the South Fork of the Palouse River drainage on Moscow Mountain, but the capacity to recharge sufficiently large volumes of water are uncertain pending the outcome of individual site characterizations. Land-purchase costs were neglected for this analysis, but could become a major cost component if larger infiltration areas are needed. ---PAGE BREAK--- SPF/TerraGraphics Page 64 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 6.2. Specific Conclusions Specific conclusions include the following: Water Demand Projections 1. In 2012 Moscow, Pullman, UI, and WSU used approximately 2.4 billion gallons of water. The two cities used approximately 73% of this amount. 2. Existing water-demand projections for Moscow, Pullman, UI, and WSU suggest that absent conservation, aggregate water demand could rise to approximately 4.31 billion gallons of water per year (13,200 afa) by the year 2060 (Table This would represent an approximate 63% increase over existing water-use rates. 3. If current climate models are correct and the Pacific Northwest experiences increasing evapotranspiration rates as a result of increased irrigation-season temperatures (Table and absent conservation, the aggregate water demand could increase to approximately 4.46 billion gallons of water per year (13,700 afa). This would represent an approximate 69% increase over existing water-use rates. 4. Water conservation could result in a 20% (or more) domestic water- demand reduction (compared to current water-use rates) by the year 2060. This would result in an aggregate water demand by the two cities and universities of approximately 3.7 billion gallons of water per year (11,400 afa) by the year 2060, even with increased evapotranspiration. This future water demand scenario – with conservation but with increased evapotranspiration – would represent an approximate 55% increase over current demand. Additional Water-Supply Alternatives 5. In general, surface-water supply alternatives evaluated in this feasibility analysis include diversions of water from impoundments in the Flannigan Creek, Hatter Creek, South Fork Palouse River, and Felton Creek drainages, direct diversions from the North Fork Palouse River, Dworshak Reservoir, or the Snake River, and various forms of ASR (Table 6. Preliminary cost opinions were prepared for three non-Moscow Mountain surface-water supply alternatives: diversions from the North Fork Palouse River, diversions from the Clearwater River basin Dworshak Reservoir), and diversions from the Snake River near Wawawai, Washington. Each of these alternatives could supply water for regional use. (Cost opinions were previously prepared for the Moscow Mountain alternatives.) ---PAGE BREAK--- SPF/TerraGraphics Page 65 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 7. Diverting approximately 1.56 billion gallons of water per year (4,760 afa) from the North Fork Palouse River, conveying it to Moscow, and treating it for direct use (Alternative A5) would cost approximately $40.7 million. 8. Diverting approximately 7.3 billion gallons of water per year (22,265 afa) from Dworshak Reservoir (Alternative A6) and treating it for direct use by Moscow and others would cost approximately $149 million (based on an USACE cost estimate prepared in 1989 and converted to present-date dollars). 9. Diverting approximately 7.3 billion gallons of water per year (22,265 afa) from the Snake River (Alternative A7a) and treating it for direct use by Pullman, Moscow, and others would cost approximately $92 million (based on an USACE cost estimate prepared in 1989 and converted to present-date dollars). 10. USACE cost estimates for diverting and conveying water from Dworshak Reservoir and the Snake River (Alternatives A6 and A7a) were based on cost required to divert and deliver over 22,000 afa, which is an amount far greater than the projected demand by the cities of Moscow and Pullman and the two universities by the year 2060, even without conservation. A cost estimate for diverting approximately 10 cfs of water from the Snake River (Alternative A7b, yielding approximately 7,240 afa), prepared using an approach similar to that which was used for previous Moscow Mountain water-supply alternatives, suggests a cost of approximately $56 million. 11. A less costly version of this option would be to pump water from the Snake River only to Pullman and WSU (variation of Alternative A7b). The cost of such an option ($46 million) could possibly be shared by the cities of Moscow and Pullman and the two universities, because the 57% drop in pumping from the Grande Ronde Aquifer would provide a regional benefit. A pipeline could be extended from Pullman to Moscow at a later date if necessary. Aquifer Storage and Recovery 12. Diversion of surface water from Paradise Creek and/or the South Fork Palouse River from locations in or around Moscow for ASR could augment local groundwater supplies. A passive recharge strategy (Alternative D3b) could be relatively inexpensive (Table 14), but the ability to recharge large (or even moderate) volumes of water would be limited by low subsurface permeability characteristics in most Moscow locations. Passive recharge of larger volumes of water will likely require land purchases, which entail increased cost. ---PAGE BREAK--- SPF/TerraGraphics Page 66 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 13. In contrast, recharging the Wanapum Aquifer by direct injection of surface water (Alternatives D3a) would have much greater certainty. However, this approach is more expensive because it would require treatment of surface water to drinking water standards. 14. Past and recent water-quality analyses indicated the presence of fecal coliform microorganisms (which are present in most natural surface streams) in Paradise Creek and the South Fork of the Palouse River, elevated nitrate concentrations in winter and early-spring runoff samples, and the presence of caffeine in one of the Paradise Creek water samples. Wastewater Reuse 15. Wastewater reuse has the double benefit of reducing groundwater pumping and reducing wastewater discharge. Keller (2011) estimated that the cost of delivering treated wastewater to currently-irrigated Moscow common spaces would be about $7.9 million, or approximately $58,000 per acre foot of “annual yield.” 16. While expensive compared to other water-supply options, reuse would have other benefits (such as reducing wastewater discharge). 17. The unit cost of wastewater reuse would be less if more reclaimed wastewater could be used for irrigation (up to approximately 976 acre- feet may be available on average basis between May and October – see Table 5.1 in the Comprehensive Sewer System Plan). 18. Pumping reclaimed wastewater to just a few high-use areas may be more cost-effective than serving all of the City’s common-space areas with reclaimed wastewater. 19. Increased use of wastewater by the University of Idaho would similarly reduce the City’s municipal discharge and reduce current use of groundwater. Cost Comparisons of Surface-Water Supply Alternatives 20. Based on total cost, the most expensive option would be diversions from Dworshak Reservoir; the least expensive option would be ASR with passive recharge and in-town diversions from Paradise Creek and/or the South Fork Palouse River (Table 14). However, successful ASR with passive recharge would depend on site-specific conditions. It is highly unlikely that the targeted volume of water (1,100 af/year) could be successfully recharged in the 12-acre Perimeter Drive site (or even the 32-acre South Fork Palouse River site). ---PAGE BREAK--- SPF/TerraGraphics Page 67 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 21. Based on construction cost per volume of annual yield, the most expensive surface-water supply alternative would be direct use of water from a reservoir in the South Fork Palouse River drainage (Alternative A3). The least expensive option based on construction cost per unit of annual yield would be ASR with passive recharge and in-town diversions from Paradise Creek and/or the South Fork Palouse River (Alternative D3b – Table 15). Again, site-specific investigations would be needed to determine whether (or to what extent) ASR with passive recharge would be a viable option. 22. Of options that could supply over 1,000 MGY or over 3,000 afa regional options), the least expensive option (based on total cost) may be diversions from the North Fork Palouse River (Alternative A5). However, if larger volumes or year-round diversions are required, diversions from the Snake River may be the least expensive per-volume alternative (Alternative A7a or A7b). Also, the annual volume of water available from the North Fork Palouse River may be less than projected in low-water years. 23. Of options supplying smaller volumes, diversions from a reservoir in the South Fork Palouse River drainage on Moscow Mountain (Alternative B3) for irrigation purposes non-potable) would be among the least expensive options, both from a total construction cost standpoint and on a cost-per-yield basis. 24. Development of an impoundment and diversion facilities from the South Fork Palouse River drainage on Moscow Mountain (Alternative B3) would not only be the least expensive non-ASR option, but the most scalable. Initial diversions could be used to offset groundwater withdrawals for irrigation of larger common spaces. Diversions from adjacent watersheds could be constructed to augment storage in and diversions from the South Fork Palouse River impoundment. The impoundment could be increased in size, if necessary. A water treatment facility could be added subsequently to treat water for direct use. The same treatment facility could be used to treat water diverted from Moscow Mountain or diverted from Paradise Creek and/or the South Fork Palouse River in Moscow for direct use and/or direct injection for ASR. 25. Average annual yields for alternatives relying on diversions from Moscow Mountain, the North Fork Palouse River, Paradise Creek, and the South Fork Palouse River are based on average conditions. Low-precipitation conditions in some years could result in less water available than the amounts contemplated in this investigation, with the difference being made up in increased groundwater pumping. However, more water could be available in other years, requiring less groundwater pumping. ASR options would allow water to be stored in the aquifer for recovery during low-precipitation years. ---PAGE BREAK--- SPF/TerraGraphics Page 68 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 26. Treatment costs could be less than those projected if conventional treatment is used instead of membrane filtration. Treatment costs could be higher if reverse osmosis technology is needed to remove CECs. 27. The cost comparisons made in this report are based on preliminary cost opinions for impoundment, conveyance, and treatment facilities. Preliminary cost opinions do not include costs associated with land acquisition, nor do they include addressing and/or mitigating potential environmental and/or cultural-resource constraints. Additional investigation of these factors would be required should the City decide to move forward with one or more of the above-described water-supply alternatives. 6.3. Recommendations Recommendations from this surface-water supply evaluation (Phases 1 and 2) include the following: Recommendations for a Regional Supply 28. Develop a plan for regional water-supply and conservation approaches should groundwater levels in the Grande Ronde Aquifer continue to decline. 29. Explore interest in regional water-supply alternatives with other Palouse communities and universities. 30. If there is agreement about the need for additional regional supply, prepare conceptual designs and conduct environmental reviews of the Snake River and North Fork Palouse River alternatives (Alternatives A7b and A5, respectively). Water-Demand Forecasting 31. Prepare more detailed existing water-use metrics (such as cost per residential connection, cost per commercial connection, etc.). Compare existing per-unit water use among Palouse communities. 32. Prepare detailed conservation targets and plans (such as now being done by Moscow) for Palouse communities and universities. 33. Monitor per-unit water usage rates and conservation over time, as the Palouse Basin Aquifer Committee (PBAC) currently does for aggregate pumping and water levels. 34. Explore conservation programs that can be jointly implemented among multiple entities, thereby achieving economics of scale in education efforts, incentive programs, etc. ---PAGE BREAK--- SPF/TerraGraphics Page 69 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 35. Review long-term water-demand forecasts on a periodic basis, revising forecast based on recent population-growth and water-use trends. Aquifer Storage and Recovery 36. Conduct evaluations to better define subsurface stratigraphy and permeability characteristics at potential passive-recharge ASR sites. 37. Evaluate potential active recharge sites based on Moscow well configurations, Wanapum Aquifer thickness, depths to water, etc. Conduct water chemistry testing to evaluate the effects of mixing Wanapum Aquifer water and surface water diverted either from Moscow Mountain or in-town channels. 38. Evaluate geochemical considerations associated with direct injection of surface water (from either in-town or Moscow Mountain sources) into Wanapum Aquifer. 39. Continue periodic water-quality sampling in Paradise Creek and South Fork Palouse River at times during which flows are greater than 5 cfs. South Fork Palouse River 40. To augment irrigation water supplies for Moscow only, prepare a more detailed conceptual design and associated cost estimate of a 40-foot South Fork Palouse River drainage impoundment and associated conveyance to Moscow. 41. Map and investigate land ownership in the upper South Fork Palouse River drainage (and adjacent drainages) 42. Identify specific Moscow common areas that could be irrigated with a non-potable pressurized irrigation system. Prepare conceptual design for a non-potable pressurized irrigation system to irrigate these common areas. 43. Conduct a more detailed analysis of potential environmental and/or cultural-resource constraints to constructing an impoundment in the upper South Fork Palouse River drainage. Water Conservation 44. Develop components of a more aggressive water-conservation strategy. Quantify the amount of water that could be saved with individual conservation components and calculate costs implement these components. Then compare the cost of implementing specific conservation measures with the costs of developing new surface-water supplies. Implement conservation components that, on a community- ---PAGE BREAK--- SPF/TerraGraphics Page 70 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 wide basis, are less expensive than developing new surface-water supplies. 45. Explore opportunities for more aggressive water conservation in new subdivisions (as a result of water-efficient fixtures and reduced and/or water-efficient landscaping). Wastewater Reuse 46. Explore opportunities for more cost-effective wastewater reuse for irrigation of University of Idaho and/or City irrigated areas. ---PAGE BREAK--- SPF/TerraGraphics Page 71 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 7. REFERENCES Baker, M.N., 2013. City of Moscow Water Conservation Plan (Draft), being prepared by and for the City of Moscow. Brown, T.C., 1999. Past and future fresh water use in the United States, General Technical Report RMRS-GTR-39, US Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fort Collins, Colorado. Climate Impacts Group, 2009. The Washington Climate Change Impacts Assessment, prepared by the Center for Science in the Earth System, Joint Institute for the Study of the Atmosphere and Oceans, University of Washington, Seattle, Washington. M. McGuire Elsner, J. Littell, and L Whitley Binder (eds). Available at: http://www.cses.washington.edu/db/pdf/wacciareport681.pdf. GSI, 2012. Technical Memorandum: Pilot Testing Program Report, Boise White Paper Thermal ASR Project, report prepared by GSI Water Solutions Inc., submitted to Washington Department of Ecology, December 2012. HDR, 2007. City of Pullman Water System Plan Update, final draft prepared by HDR Engineering, Inc. HDR, 2011. City of Moscow Comprehensive Water System Plan, consulting report prepared by HDR Engineering, Inc., Golder Associates, and Taylor Engineering, Inc. Jones, R.W., Ross, S.H., Williams, R.E., 1968. Feasibility of Artificial Recharge of a Small Ground Water Basin by Utilizing Seasonal Runoff from Intermittent Streams, Proceedings of the 6th Annual Engineering Geology and Soils Engineering Symposium. JUB, 2010. City of Moscow/University of Idaho Wastewater Reuse Capacity Assessment, consulting report prepared by JUB Engineers, Inc. Keller, 2011. City of Moscow Comprehensive Sewer System Plan, prepared by Keller Associates, September 2011. Kimball Engineering, 2001. Reuse Study for the City of Moscow, consulting report prepared by Kimball Engineering, December 2001. National Research Council, 2008. Prospects for Managed Underground Storage of Recoverable Water. National Academies Press, Washington DC (for the Committee on Sustainable Underground Storage of Recoverable Water, Water Science and Technology Board, Division on Earth and Life Studies, National Research Council of the National Academies. NCADAC, in preparation. Federal Advisory Committee Draft Climate Assessment, prepared by the National Climate Assessment and Development Advisory Committee (DCADAC) for the National Oceanic and Atmospheric Administration (NOAA), http://ncadac.globalchange.gov/. ---PAGE BREAK--- SPF/TerraGraphics Page 72 Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) November 19, 2013 Pyne, R.D.G., 2005. Aquifer Storage Recovery - A Guide to Groundwater Recharge through Wells. ASR Press, Gainesville, Florida. SPF et al., 2010. Rathdrum Prairie Aquifer Water Demand Projections, prepared by SPF Water Engineering, LLC, AMEC Earth and Environmental, John Church (Idaho Economics), and Taunton Consulting for the Idaho Water Resource Board and the Idaho Department of Water Resources as part of the Comprehensive Aquifer Management Planning (CAMP) process (http://www.idwr.idaho.gov/waterboard/WaterPlanning/CAMP/RP_CAMP/PDF/2010/ WaterDemandProjections_Final.pdf). SPF/TerraGraphics, 2011. City of Moscow Surface Water Feasibility Study, consulting report prepared for the City of Moscow by SPF Water Engineering and TerraGraphics Environmental Engineering, November 17, 2011. Stevens, Thompson, Runyon, 1970. report prepared for the Pullman-Moscow Water Resources Committee. Taylor Engineering, 2008. 2008 Water System Plan Update Washington State University Pullman, Washington (Draft Report), report prepared by Taylor Engineering, Pullman, Washington. TerraGraphics/Ralston, 2011. Palouse Ground Water Basin Framework Project Final Report, consulting report prepared for the Palouse Conservation District by TerraGraphics Environmental Engineering, Inc. and Ralston Hydrologic Services, dated January 31, 2011. TerraGraphics/SPF, 2011. City of Moscow Surface Water Feasibility Study, consulting report prepared for the City of Moscow by TerraGraphics Environmental Engineering, Inc. and SPF Water Engineering, LLC. USACE, 1989. Reconnaissance Report Palouse River Basin, Idaho and Washington, prepared by the US Army Corps of Engineers. Veseth, 1985. Erosion Impacts on the Palouse Misunderstood, prepared by STEEP - PNW Conservation Tillage Handbook Series Chapter 1, Erosion Impacts, No. 1, October-November 1985. ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) Appendix A: Hydraulic Profile, North Fork of the Palouse River ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) Appendix B: Supporting Information for Conveyance and Treatment Costs – North Fork of the Palouse River ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) Appendix C: Hydraulic Profile, Snake River to Moscow ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) Appendix D: Supporting Information for Conveyance and Treatment Costs – Snake River ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) Appendix E: Existing Water Quality Information Attachments A-E: Paradise Creek Idaho Department of Environmental Quality, January 1984 Attachment F: Paradise Creek, Idaho Department of Environmental Quality, December 1997 Attachments G-K: Paradise Creek, Brooks and Boll, 2011 Attachments L-Q: South Fork of the Palouse River, Idaho Department of Environmental Quality, February 2007 ---PAGE BREAK--- Existing Water Quality Information The purpose of this document is to present Paradise Creek and South Fork of the Palouse River historical water quality information for the City of Moscow Surface Water Reservoir Phase II project. The data are compiled in order to evaluate surface water quality of possible aquifer storage and recovery (ASR) sources in the Moscow area. Water quality information from the last two decades are provided in the following sections and in Attachments A through Q. 1 Paradise Creek 1.1 Idaho Department of Environmental Quality (IDEQ), January 1994 The Paradise Creek Use Attainability Assessment by IDEQ (1994) evaluates the appropriateness of the current uses of Paradise Creek and determines whether the creek should be further protected for any additional uses. IDEQ (1994) also reviewed previous water quality documents. In addition, four monitoring points were set up in and near Moscow (Attachment The data collected at these four stations were: Temperature, pH, DO, Specific Conductance, Alkalinity, Suspended Solids, Total Nitrogen, Ammonia (NH3), NO3, Nitrite (NO2), Total Phosphorus, Fecal Coliforms, Fecal Streptococcus, and Flow. Samples were collected in the winter (November 1992 through April 1993) and in the summer (May through October 1993). These data can be found in the following attachments: Attachment A – Location map for Use Attainability Assessment stations Attachment B – Water Quality data from Station 1 - Mountain View Park Attachment C – Water Quality data from Station 2 – White Avenue and Troy Highway intersection Attachment D – Water Quality data from Station 3 – Intersection of Sixth Street and Deakin Street Attachment E – Water Quality data from Station 4 – Near the City of Moscow Waste Water Treatment Plant by the Idaho/Washington border Of note is that nitrate (NO3), an indicator of agricultural or septic influence, exceeded typical background concentrations (approximately 2 mg/L) at all locations during at least some winter and summer sampling events. Winter nitrate concentrations were relatively consistent among stations, but summer nitrate concentrations appeared to increase between Mountain View Park and the state line. Higher values of nutrient concentrations total phosphorus) are substantially higher at the state line, presumably reflecting discharge. IDEQ noted there was a large amount of fecal coliform bacteria within the Moscow city limits. ---PAGE BREAK--- Page 2 of 3 1.2 IDEQ, December 1997 The Water Body Assessment and Total Maximum Daily Load report by IDEQ (1997) describes the allocation of pollutant loading of Paradise Creek from three sources: 1) Nonpoint Sources (NPS) from above the 2) outfall, and 3) discharge from the UI Aquaculture Research Facility (Aquaculture). The pollutant loads allocated were TSS, Total Phosphorus, Fecal Coliforms, Temperature, and NH3. A summary of these data can be found in Attachment F – Summary of Paradise Creek pollutant loading. IDEQ (1997) also summarizes historical water quality projects. IDEQ hypothesized nutrients are not a year round problem in Paradise Creek given the fine- grained nature of the sediment and the flushing of these sediments that occurs during high flow. NH3 and total phosphorus were highest at the outfall. Fecal coliforms were highest at the three NPS sites. Note, modifications to the since 1997 have changed Creek characteristics. 1.3 UI, January 2011 The UI Paradise Creek Monitoring Report 2001-2011 by Brooks and Boll (2011) summarizes 2001 to 2011 water quality data from Paradise Creek monitoring stations. The four monitoring stations are named relative to their locations: 1) Rural Station, 2) Urban Station, 3) Moscow RV, and 3) Forested Station. Brooks and Boll (2011) focuses on sediment loading, phosphorus, and NO3. Data for these parameters can be found in the following attachments: Attachment G – Locations of UI-maintained monitoring stations for Paradise Creek Attachment H – Total Phosphorus for UI monitoring locations on Paradise Creek Attachment I – Soluble Reactive Phosphorus for UI monitoring location on Paradise Creek Attachment J – NO3 measurements for UI monitoring locations on Paradise Creek Attachment K – Sediment loading measurements for UI monitoring locations on Paradise Creek High phosphorus was found at all sites, mostly as particulate phosphorus. NO3 concentrations exceeded the infrequently (in less than 1.2% of the annual samples) and only at the Rural Station. 2 South Fork of the Palouse River 2.1 IDEQ, February 2007 IDEQ prepared a Watershed Assessment and Total Maximum Daily Load report (2007) for South Fork of the Palouse River. This document mainly focuses on data collected from November 2001 to November 2002 from four monitoring points along the river (Attachment These data ---PAGE BREAK--- Page 3 of 3 include: DO, Temperature, Conductivity, TDS, pH, Turbidity, TSS, NO2 + NO3, NH3, Total Phosphorus, Fecal Coliforms, E. coli, and Flow. E. coli concentrations from June to July in 2006 are also presented in the report’s data table. These data can be found in the following attachments: Attachment L – Sample location sites (SF1-SF4) on South Fork of the Palouse River Attachment M – Water quality data for SF1 from November 2001 through November 2002 Attachment N – Water quality data for SF2 from November 2001 through November 2002 Attachment O – Water quality data for SF3 from November 2001 through November 2002 Attachment P – Water quality data for SF4 from November 2001 through November 2002 Attachment Q – E. coli concentrations for SF-2, Mill Bridge (assumed on Mill Road), and SF-4 from June 15, 2006 through July 5, 2006 Total phosphorus, Fecal Coliforms, and E. coli were detected at each event at each site. Overall, total phosphorus had similar concentrations at all four sites. Fecal Coliforms were high at all four sites. E. coli was generally lowest at SF-3. TDS was under the National Secondary Drinking Water Standard of 500 mg/L at each site and was generally higher at SF-4. NO2 plus NO3 had the lowest concentrations at SF-1; none of the sites exceeded the of 10 mg/L. NH3 was below the detection limit for most events at each site. 3 References Brooks, and J. Boll. 2011. UI Paradise Creek Monitoring Report 2001-2011. Idaho Department of Environmental Quality (IDEQ), 1994. Paradise Creek Use Attainability Assessment Latah County, Idaho Final Report. Water Quality Summary Report No. 29. January. IDEQ, 1997. Paradise Creek TMDL: Water Body Assessment and Total Maximum Daily Load. December. IDEQ, 2007. South Fork Palouse River Watershed Assessment and February. TerraGraphics Environmental Engineering (TerraGraphics), 2013. Sampling and Analysis Plan for Surface Water Sampling for the City of Moscow Surface Water Reservoir Feasibility Study – Phase II. March. ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) Appendix F: Surface Water Sampling Plan ---PAGE BREAK--- www.terragraphics.com 121 S. Jackson St., Moscow, ID 83843 Phone: (208) 882-7858; Fax: (208) 883-3785 108 W. Idaho Ave., Kellogg, ID 83837 Phone: (208) 786-1206; Fax: (208) 786-1209 3501 W. Elder St., Ste. 301, Boise, ID 83705 Phone: (208) 336-7080; Fax: (208) 908-4980 15 W. 6th Ave., Power Block West, 3rd Floor Helena, MT 59601 Phone: (406) 441-5441; Fax: (406) 441-5443 90 North Frontage Rd, Deer Lodge, MT 59722 Phone: (406) 846-9566; Fax: (406) 846-9567 7000 Smoke Ranch Rd., Las Vegas, NV 89128 Phone: (702) 685-2229; Fax: (702) 685-2223 M E M O R A N D U M To: Les MacDonald, City of Moscow, Moscow From: Robin Nimmer, TerraGraphics, Moscow Date: March 6, 2013 Project Code: 12027-02 Subject: Sampling and Analysis Plan for Surface Water Sampling for the City of Moscow Surface Water Reservoir Feasibility Study – Phase II. 1 Introduction This memorandum provides the plan for surface water sampling for the City of Moscow Surface Water Reservoir Feasibility Study. The purpose of the sampling and analysis is to develop a preliminary assessment of water quality in Paradise Creek and the South Fork of the Palouse River for the purposes of potential managed recharge or aquifer storage and recovery (ASR) applications. The objective of this Sampling and Analysis Plan is to guide the collection and analysis of the surface water samples. 2 Sampling Sites Primary recharge or ASR sources of interest are Paradise Creek and the South Fork of the Palouse River. Surface water samples will be collected at three locations (Figure 1) in these channels. The South Fork of the Palouse River sample site is located near the Highway 95 Bridge near the Fountain Industrial Park south of Moscow. Two sampling sites are proposed for Paradise Creek. The first Paradise Creek sampling site is near the USGS stream gage station on the University of Idaho campus along Perimeter Drive. The second Paradise Creek sampling site is located near the Latah County Fair Grounds near the intersection of White Avenue and Blaine Street. The second Paradise Creek site replaces a site originally proposed at the North Fork of the Palouse River. The team selected the Paradise Creek sampling site because it represents a more likely recharge/ASR source. 3 Sampling Methods and Frequency The field crew will use a depth-integrated, stream-width sampling method for collection whenever possible, and will follow the TerraGraphics Standard Protocol for Water Sampling (TerraGraphics 2006). The field crew will collect one sample from the stream bank or bridge at each of the surface water sites. They will also collect a field duplicate sample for analysis of certain constituents only. Three sampling events will be conducted. The field crew will sample once on the rising limb of the Paradise Creek hydrograph and will sample at two different times on the falling limb. ---PAGE BREAK--- Page 2 of 2 4 Field Parameters and Analyses The field crew will measure field parameters on an aliquot of the water collected from each site using a QED MP20 flow cell. Field parameters will include pH, temperature, specific conductivity, dissolved oxygen, and oxygen-reduction potential. Table 1 lists the chemical and biological analyses, recommended bottles, preservation, and holding times for the samples. The field crew will submit the samples on ice to Anatek Labs, Inc. in Moscow, Idaho, for analysis. Table 1. Sample Analyses, Bottle Details, Preservation, and Holding Times Source Analytes (Analysis Method) Number of Bottles Sample Size/ Container Preservation/Temperature Analysis Holding Time Surface Water Nitrate (EPA 300.0), TDS (SM 2540C), and TSS (SM2540D) 3 1-liter HDPE Cool to 4°C 36 hours (nitrate), 7 days (TDS and TSS) E. coli (SM9223B) 3 Sterile HDPE Sodium Thiosulfate Cool to 4°C 30 hours Caffeine (HPLC\MS\MS) 3 1-liter amber Cool to 4°C 14 days Total organic carbon (SM 5310B) 6 (3*2) 40-milliliter clear vial Sulfuric acid (H2SO4) Cool to 4°C 14 days Total petroleum hydrocarbons 3 1-liter amber Hydrochloric acid (HCl) Cool to 4°C 14 days Field Duplicate Nitrate (EPA 300.0) 1 125-milliliter HDPE Cool to 4°C 36 hours E. coli (SM9223B) 1 Sterile HDPE Sodium Thiosulfate Cool to 4°C 30 hours Notes: TDS – Total dissolved solids TSS – Total suspended solids HDPE – High density polyethylene 5 Quality Control TerraGraphics will validate the analytical data to ensure the laboratory quality control results are within the acceptable limits defined by the analytical methods. TerraGraphics will also verify that the samples met the proper temperature and analysis holding times. 6 Reporting Results of the sampling event will be provided in the summary report for the Phase II of the Moscow Surface Water Reservoir Feasibility Study. 7 References TerraGraphics Environmental Engineering, Inc. (TerraGraphics), 2006. Standard Protocol for Water Sampling. March. ---PAGE BREAK--- ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) Appendix G: Preliminary Cost Opinion for ASR with Passive Recharge ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) ---PAGE BREAK--- SPF/TerraGraphics Moscow Surface Water Supply Analysis Project: 818.0030 (Phase 2) NO. DESCRIPTION QTY UNIT UNIT PRICE 11 PUMPING 146,000 KWH/YR $0.08 $11,680 12 MAINTENANCE OF FACILITIES 5% EQUIP $626,800 $31,340 TOTAL ESTIMATED ANNUAL OPERATION & MAINTENANCE COST $40,000 O&M COST PER MILLION GALLONS $17 COST PER DELIVERED ACRE-FOOT 1,100 AF/YR $1,160 This cost estimate reflects our professional opinion of accurate costs at this time based on current conditions at the project location. This estimate is subject to change through the project planning and design process. Actual construction cost will depend on the cost of labor, materials, equipment, and services provided by others, contractor’s methods of determining prices, competitive bidding and market conditions. COST