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4.1. ERMUSR 01-11-2011
Elk River Municipal Utilities 130(9 Orono Parkway • P.O. Box 430 Elk River, MN 55330-0430 UTILITIES COMMISSION MEETING Phone: 763.441.2020 Fax: 763.441.8099 TO: FROM: Elk River Municipal Utilities Commission David Berg -Water Superintendent John Dietz, Chair Troy Adams, P.E. - Director of Operations D 1 Thom son, Trustee MEETING DATE: AGENDA ITEM NUMBER: Janu 11,2011 4.1 SUBJECT: Review of City Ordinance 78-51 WATER USE RESTRICTIONS and Elk River Municipal Utilities' 2009 RESOLUTION IMPOSING WATER USE RESTRICTIONS WITHIN THE CITY OF ELK RIVER. BACKGROUND: In July 2009, as authorized under City Ordinance Section 78-51, the Utilities Commission adopted a resolution imposing water use restrictions. The motion to approve this resolution was carried by a 3-0 vote. The scope of 78-51 WATER USE RESTRICTIONS was reviewed by the Utilities Commission in September 2010. It was then proposed to the City Council in October 2010 to amend the scope of geographical area subject to water use restrictions from the City water service area to all of the City limits. The Council chose not to make any changes to the ordinance at that time. At the December 2010 Utilities Commission meeting, the Commission directed staff to bring back for review the water use restriction resolution that had been adopted in 2009. DISCUSSION: The attached 2009 RESOLUTION IMPOSING WATER USE RESTRICTIONS WITHIN THE CITY OF ELK RIVER did not required an amendment to the ordinance and is permanent until revoked or amended by Utilities Commission resolution. The Utilities had water restrictions in place prior to the adoption of this resolution. However, the adoption of this resolution enabled the enforcement of these water restrictions through Ordinance 78-51 PENALTIES. City ordinances 78-51 and 78-52 are attached for Commission reference. Part of the current discussion has focused on the concern that the current water restrictions may be perceived as "crying wolf' during periods when not suffering drought conditions. Based on the information presented below as well as included by reference, the current water restrictions should not be perceived as sending a false alarm, but rather as conserving important resources: water supply, system capacity, system capability, and cost to efficiently run the water distributions system. It should also be noted that during drought conditions, the prudent course of action would likely include more drastic sprinkling restrictions. Because of Elk River's geographical location on the rim of the Mt. Simon-Hinckley Aquifer "bowl" centered under the Twin Cities metro area, water use and/or misuse are always a concern for ERMU and our customers. In 2008, ERMU had a study done to identify water supply alternatives for our City. Although this report does not directly address the issues of sprinkling and water use restrictions, but it does show how precious and sensitive our water resources are in Elk River. This report is attached as information. Revoking or amending ERMU's resolution invoking water use restrictions may seem like it would have an insignificant impact to the Utilities. However, this is the tip of the iceberg of an important topic. Whether it is because of drawdown or aquifer contamination, our alternatives sources of water for the City are limited and could be costly. In addition to water usage concerns during drought conditions, the invoking of water use restrictions serves other equally important functions. The "odd-even" and "time of day" sprinkling restrictions communicate our commitment to the conservation of our precious resources. This is consistent with City of Elk River's Energy City Board's position on conservation. The use restrictions help to mitigate the volatility in pumping flow rate. This is similar to the demand side management used to control air conditioner use during the summer. By controlling the peaks, the system can more cost effectively sized. This helps to proactively control system costs that would inevitably be borne by the customer. The methodology is not unique to Elk River. As noted at the December 2010 Utilities Commission meeting, approximately 65% of the 71 cities surveyed by the Suburban Utilities Superintendent Association (SUSA) employ similar water use restrictions. These water use restrictions are not too "progressive" but rather the norm. These types of proactive water conservation methods also become important when the need comes to increase our water use appropriations from the Department of Natural Resources (DNR). As you may recall, in September 2006, ERMU submitted to the DNR a Conservation and Emergency Management Plan for Elk River Municipal Utilities Water System. This was an important step in the DNR amending our water use permit increasing our water use appropriations. Attached for reference is the letter from the DNR approving the requested increase in water use appropriations. ACTION REQUESTED: Based on the above discussion, included materials, and staff expertise, the recommend is to make no change to the current resolution invoking water use restrictions. RESOLUTION #09- BOARD OF COMMISSIONERS ELK RIVER MUNICIPAL UTILITIES A Resolution Imposing Water Use Restrictions Within the City of Elk River WHEREAS, Section 78-51 of the City of Elk River Code of Ordinances authorizes the Board of Commissioners of the Elk River Municipal Utilities to invoke water use restrictions to ensure adequate water supplies to meet the health, safety and welfaze needs of the City of Elk River and its residents; and WHEREAS, the Board has determined it necessary to impose perrnanent restrictions on lawn sprinkling in order to ensure adequate water supplies to meet the health, safety and welfare needs of the City of Elk River and its residents. NOW, THEREFORE, BE IT RESOLVED: Pursuant to its authority under Section 78-51 of the City of Elk River Code of Ordinances, the Board of Commissioners hereby adopts the following water use restrictions: a. No lawn sprinkling shall be allowed on any day at any location within the City of Elk River between the hours of 10 a.m. and 6 p.m. b. Lawn sprinkling before 10 a.m. and after 6 p.m. will be allowed on properties with even numbered addresses on the even numbered days of the month, and on properties with odd numbered addresses on the odd numbered days of the month. 2. These restrictions shall remain in effect perrnanently, unless and until revoked or amended by resolution of the Board of Commissioners. 3. These restrictions shall take effect immediately upon adoption of this Resolution, as provided in Section 78-51 of the City of Elk River Code of Ordinances. 4. Penalties for violation of these water use restrictions shall be as set forth in Section 78-52 of the City of Elk River Code of Ordinances. Adopted this 14'" day of July, 2009. John Dietz, Chair Board of Commissioners Elk River Municipal Utilities GP:2612429 vl THE CITY OF ELK RIVER -CODE OF ORDINANCES CHAPTER 78 UTILITIES ARTICLE II. WATER SYSTEM DIVISION 5 RESTRICTIONS AND ENFORCEMENT SEC. 78-51. WATER USE RESTRICTIONS. The public utility commission of the city is hereby authorized to invoke water use restrictions in cases of emergency to ensure adequate water supplies to meet the health, safety, and welfare needs of the city and its residents. Such water use restrictions shall be invoked by resolution of the public utility commission, and shall take effect immediately upon adoption of such resolution. The public utility commission may designate its general manager or water superintendent authority to impose temporary water use restriction until the commission can meet to consider a resolution. The penalties imposed below in section 78-52 may be invoked upon publication of the resolution imposing restrictions. SEC.78-52. PENALTIES. The first violation of the restrictions contained in this article shall subject the offending person, fine, corporation or association to a written warning. A second violation of the restrictions shall be a petty misdemeanor with a penalty of $50.00 and shall increase to the sum of $100.00 for the third violation. A fourth violation shall result in water shut-off with the reconnection fee to be paid by the offending property owner according to the policies of the public utilities commission. No penalty can be imposed unless a person had, or should have had, prior knowledge of the ordinance restrictions. This maybe shown by the fact that prior warning was delivered to the person or to an occupant of the premises to be assessed. Identification of Water Supply Alternatives for Elk River Prepared for Elk River Municipal Utilities January 28, 2008 Identification of Water Supply Alternatives for Elk River Prepared for Elk River Municipal Dtilities January 28, 2008 I hereby certify that this report was prepared by me or under my direct supervision and that I am a duly Licensed Professional Geologist and Professional Engineer under the laws of the state of Minnesota. ,, ll , 1 Signature~W. w~G-~ Rav W. Wuolo Date:_ Jantl~rv 28. 2008 Reg. No. 19897 a~ao wesr ~r" sneer Minneapolis, MN 55435-4803 Phone: (952) 832-2600 BARB Fax, i952,83z.zso, Identification of Water Supply Alternatives for Elk River Table of Contents 1.0 Introduc[ion .............................................................................................................. ..............................1 1.1 Scope and Purpose ........................................................................................ .............................. 1 1.2 Report Organization ...................................................................................... .............................. l 1.3 Other Relevant Studies and Initiatives .......................................................... ..............................2 1.4 Regional Water Demand and Use ................................................................. ..............................2 2.0 Groun dwater Supplies ............................................................................................... ..............................4 2.1 Regional Geologic Setting ............................................................................ ........................:.....4 2.2 Geologic Conditions in the Elk River Area .................................................. ..............................7 2.3 Regional Aquifer Sys[ems ............................................................................ ............................10 2.4 Regional Groundwater Contatination and Water Quality ........................... ............................15 2.5 Available Aquifers in the Elk River Area ..................................................... ............................16 2.6 Regional Groundwater Use ........................................................................... ............................19 2.7 Groundwater Use in the Elk River Area ....................................................... ............................ 20 3.0 Surface-Water Supplies ......................................................................................... ...............................25 3.1 Regional Surface Water Supplies .............................................................. ...............................25 3.2 Regional Surface-Water Reliabili[y ........................................................... ...............................25 3.2.1 Water Treatment and Contamination ............................................ ............................... 26 3.2.2 Low-Flows and Drought ............................................................... ............................... 26 4.0 Summary of Alternative Water Supply Options .................................................... ...............................28 4.1 Continued Use of Mt. Simon-Hinckley Wells ........................................... ...............................28 4.1.1 Description .................................................................................... ...............................28 4.1.2 Technical Feasibility and Reliability ............................................ ............................... 28 4.1.3 Cost ............................................................................................... ...............................28 4.1.4 Challenges and Other Considerations ........................................... ............................... 28 4.2 New Wells in the Surficial (Unconsolidated) Aquifer ............................... ...............................29 4.2.1 Description .................................................................................... ...............................29 4.2.2 Technical Feasibility and Reliability ............................................ ............................... 29 4.2.3 Cost ............................................................................................... ...............................29 4.2.4 Challenges and Other Considerations ........................................... ............................... 29 4.3 A uifer Stora a and Recover ASR 9 g Y ~ ) ....................................................... ........................30 ....... 4.3.1 Description .................................................................................... ...............................30 4.3.2 Technical Feasibility and Reliabilily ............................................ ............................... 30 4.3.3 Cost ............................................................................................... ...............................30 4.3.4 Challenges and Other Considerations ........................................... ............................... 30 4.4 Artificial Rechazge by Infiltration Basins .................................................. ...............................31 P:\Mpls\23 MN\7t\2371105 Water Supply Alternative Stady\FiualDeliverables\Alternatives_Report_final.doc i 4.4.1 Description ............................................................................................... ....................31 4.4.2 Technical Feasibility and Reliability ....................................................... .................... 31 4.4.3 Cost .......................................................................................................... ....................31 4.4.4 Challenges and Other Considerations ...................................................... ....................31 4.5 Collection and Treatment of Mississippi River Water .......................................... ....................31 4.5.1 Description ............................................................................................... ....................31 4.5.2 Technical Feasibility and Reliability ....................................................... .................... 32 4.5.3 Cost .......................................................................................................... ....................32 4.5.4 Challenges and Other Considerations ...................................................... .................... 32 4.6 Ranney Well and Treatmen[ ................................................................................. .................... 32 4.6.1 Description ............................................................................................... ....................32 4.6.2 Technical Feasibility and Reliability ....................................................... .................... 33 4.6.3 Cost .......................................................................................................... ....................33 4.6.4 Challenges and Other Considerations ...................................................... .................... 33 4.7 Interconnect with Minneapolis Water Works ....................................................... ....................33 4.7.1 Description ............................................................................................... ....................33 4.7.2 Technical Feasibility and Reliability ...................................................... ..................... 33 4.7.3 Cost ......................................................................................................... .....................34 4.7.4 Challenges and O[her Considerations ..................................................... ..................... 34 4.8 Alternate Source for Lawn Water ........................................................................ .....................34 4.8.1 Description .............................................................................................. .....................34 4.8.2 Technical Feasibility and Reliability ...................................................... ..................... 34 4.8.3 Cost ......................................................................................................... .....................34 4.8.4 Challenges and Other Considerations ..................................................... ..................... 35 4.9 Water Conservation ............................................................................................. ..................... 35 4.9.1 Description .............................................................................................. .....................35 4.9.2 Technical Feasibility and Reliability ...................................................... ..................... 35 4.9.3 Cost ......................................................................................................... .....................35 4.9.4 Challenges and Other Considerations ..................................................... ..................... 35 5.0 Evalu ation of Paired Mt. Simon Hinckley and Drift Wells ............................................ .....................36 5.1 Thickness of the Eau Claire Formation ................................................................ ..................... 37 5.2 Thickness of Unconsolidated Deposits ................................................................ .....................37 5.3 Saturated Thickness and Permeability of Unconsolidated Deposits .................... .....................40 5.4 Estimated Well Yield for the Unconsolidated Aquifer ........................................ .....................41 5.5 Suggestions for Further Site Evaluation .............................................................. .....................42 6.0 Summary and Discussion ................................................................................................ .....................43 References .............................................................................................................................. ..................... 46 P:\Mpls\23 MN\7l\2371105 Water Supply Alternative Study\FinalDeliverables\Alternatives_Report_final.doc jj List of Tables Table 1 Summary of Water Supply Alternatives List of Figures Figure 1 Location of Hollandale Embayment Figure 2 Schematic Geologic Cross Section Through the Twin Cities Area Figure 3 Uppermost Bedrock in the Vicinity of Elk River Figure 4 Approximate Depth to Bedrock Figure 5 Aerially Averaged Percentage of Sand or Gravel in Unconsolidated Deposits Figure 6 Outcrop Area of the Mt Simon-Hinckely Aquifer Where Recharge Likely Takes Place Figure 7 Conceptual Cross Section of Aquifers, Aquitards, and Groundwater Flow Figure 8 Relative Aquifer Yield Figure 9 Groundwater Pumping in the Greater Twin Cities Area: 2005 Figure 10 Areas of Increased Pumping Between 1990 and 2005 Figure 11 Locations of High-Capacity Wells Put Into Service Since 1990 Figure 12 Metropolitan Council Estimates for Water Demand in 2004 and 2050 Figure 13 Groundwater Use in the Elk River Area Figure 14 2005 Pumping of Appropriated Wells Figure 15 Major Appropriated Groundwater Use in the Elk River Area: 1988-2005 Figure 16 Trend of Groundwater Withdrawals in the Elk River Area: 1988-2005 Figure 17 Appropriated Groundwater Withdrawal in the Elk River Area by Aquifer P:\Mpls\23 MN\71\2371105 Water Supply Alternative Stndy\PinalDeliverables\Alternatives_Report_final.doc iii Figure 18 Domestic Wells in the Vicinity of Elk River, by Aquifer Figure 19 Areas Served by Surface Water Supplies Figure 20 Thickness (feet) of the Eau Claire Formation in the Vicinity of Existing and Proposed ML Simon-Hinckley Wells in Elk River Figure 21 Thickness (feet) of Unconsolidated Deposits in the Vicinity of Existing and Proposed Mt. Simon-Hinckley Wells in Elk River P:\Mpls\23 MN\7l\23X105 Water Supply Alternative Study\PinalDeliverables\Alternatives_Report_final.doc j~ 1.0 Introduction 1.1 Scope and Purpose This report was prepazed for Elk River Municipal Utilities and summarizes a preliminary evaluation of water supplies and alternatives for the Elk River area. The purpose of this evaluation is to provide Elk River Municipal Utilities with an overview of the sources of water, Che current use of these sources, and projections on how these sources and uses may change in the future. This evaluation is based on existing data and reports - no new data were collected. This evaluation is not intended to be exhaustive or definitive. The intent of this evaluation is to provide an indication of the available water alternatives, the uncertainties associated with these alternatives, and a prognostication on how future conditions and growth may affect these alternatives. Elk River is not in the seven county metropolitan area of the Twin Cities and is not in the jurisdiction of the Metropolitan Council, who is undertaking substantive water-supply planning activities. However, from awater-supply perspective, Elk River is definitely influencing (and being influenced by) water-supply pressures within the seven-county-metropolitan area - from a population perspective and from asurface-water and groundwater perspective. We have attempted to place Elk River in the context of the regional water-supply conditions of the Twin Cities metropolitan area because future challenges and future solutions will likely be regional in nature. 1.2 Report Organization This report is organized according to the two main sources of water: groundwater and surface water. These two sources are, in fact, closely related, but the regulatory framework for their utilization is different. Sections are included that discuss the availability and occurrence of these two water sources. An additional section is included that discusses different approaches for using these resources and the regulatory, economiq and societal challenges that are associated with the different alternatives. We have attempted to keep the amount of technical "jargon" as limited as possible in this report. We feel that it is important that the contents of this report be as instructive and useful as possible. We have attempted to provide some definitions of some of the more important concepts within the body of [his text. P:\Mpla\23 MN\71\2391105 Watec Supply Alternative St^dy\FinalDeliverables\Altematives_Report_final.doc 1.3 Other Relevant Studies and Initiatives Water supply and water sustainability issues are being evaluated with increasing urgency in Minnesota and the Twin Cities metropolitan area. The U.S. Geological Survey and the University of Minnesota are evaluating water sustainability on a regional and state-wide basis from the perspective of groundwater recharge (groundwater rechazge is the primary limiting factor for the amount of available water). Biofuels (primarily ethanol) production, which requires substantial amounts of water, is a significant driver for these efforts. These efforts are expected to continue for the foreseeable future because the quantification of groundwater recharge is very difficult. The Metropolitan Council has organized the informal Northwest Metro Groundwater working group to address water-supply issues in northwestern Hennepin County and portions of Anoka County. This area has had challenges in obtaining water supply for future growth (based on projections) because many of [he bedrock aquifers that are available to other communities in the metro area aze not present here. The Metropolitan Council has, over the past three to five years, initiated several studies to better chazacterize the groundwater conditions in this area -many of which have been executed by the Minnesota Geological Survey. More recently, the Metropolitan Council has been assisting the City of Ramsey in identifying possible water-supply alternatives, with emphasis on a surface-water source and treatment plant. The economics oP developing asurface-water source would likely require the participation of nearby communities. The most recent (and most comprehensive) water-supply initiative is a regional water-supply alternative analyses that is being performed by the Metropolitan Council, with participation from state regulatory agencies. This study began in 2006 with a regional analysis of the seven-county metro area's water-supply infrastructure (piping, wells, treatment plants, etc.). The second part of this study commenced in 2007 and involves (1) the construction of a regional, multi-aquifer groundwater flow model and (2) use of this model to aid in evaluating water-supply alternatives for selected locations in the seven county metro area. This study is slated to be completed in the second quarter of 2008 and being performed by Barr Engineering Company. 1.4 Regional Water Demand and Use According to the Metropolitan Council (2005) regional water demand in 2003 for the seven-county metro area totaled over 1.3 billion gallons per day (BGD). About 65 percent of the demand was for power generation (from surface water) and this water was returned to the region's three major rivers in almost the same volume as was withdrawn. The remaining 35 percent was withdrawn by municipalities (waterworks) for domestic, commercial and industrial uses; self-supplied P:\Mpls\23 MN\71\2371105 Water Supply Alternative Study\FinalDeliverables\Alternatives_Report_final.doc commercial/industrial uses; agricultural and non-crop irrigation; water-level maintenance; special categories; and air-conditioning uses Approximately 880,000 people in the metropolitan area rely, at leas[ in part, on surface water as their drinking water source. The Mississippi River serves as the primary water source for the Minneapolis Water Works (MWW) and the St. Pau] Regional Water Services (SPRWS), which together serve 16 additional communities with wholesale or retail water delivery. All of the water appropriated by Minneapolis is drawn from the Mississippi River. However, groundwater sources provide approximately two-thirds of the water consumed in the metropolitan area and serve about 1.6 million people through approximately 100 municipal water systems. The Prairie du Chien-Jordan aquifer provides most of the groundwater in the metropolitan network. The Franconia-Ironton-Galesville aquifer, the Mt. Simon-Hinckley aquifer, and local glacial drift aquifers provide water where the Prairie du Chien-Jordan aquifer is not present. About 290,000 people in the metropolitan area obtain their water from private wells (Metropolitan Council, 2007a). The metropolitan area is expected to grow by about 33% by 2030 and by about 60% by 2050. The Metropolitan Council's projections for related municipal water-use demands include a 27% increase by 2030 and 52%o increase by 2050 (the rate of water use is projected to increase at a slightly lower rate than population growth because of water efficient appliances and general water conservation). Total water demand is projected to increase by only 16% between 2004 and 2030 and by 35%o from 2004 to 2050, due to expected improved efficiency as well as reductions in withdrawals associated with once-through cooling, quarry dewatering and agricultural uses during this period (Metropolitan Council, 2007a). The Metropolitan Council (2007a) expects that the largest increases in water use between now and 2030 will take place in areas served by the Minneapolis and St. Paul water-works systems, which use Mississippi water. The Council projects the next tier of increases will take place in several rapidly growing suburbs and rural growth centers. Projections show several older suburbs and most rural areas experiencing nominal increases or even small decreases in water use, due to conservation measures (e.g., low-flow toilets, etc.) and stable lawn-water needs. Similaz water use trends are expected to continue in the region through 2050. Changing transportation corridors will likely experience concentrations of population growth. For the Elk River azea, this will likely be along the North Staz commuter rail corridor and along Interstate 94 and Highway 10. P:\Mpls\23 MN\71\2371105 Waler Supply Altema[ive Study\FinelDeliverables\Alterna[ives_Report_final.doe 2.0 Groundwater Supplies This section discusses the availability of groundwater supplies in the 81k River area. Groundwater supplies are discussed in the context of the regional setting. Groundwater flows through bedrock and through surficial sand and gravel deposits. Therefore, we have included a description of the geology of the area in this section. 2.1 Regional Geologic Setting The Twin Cities metro area is situated above a relatively thick sequence of permeable bedrock units that extend south into Iowa and east into Wisconsin.'Chese bedrock units were formed by the ~~, y.l. Fem.. I •- _ /'uk.K~.r~f:~rr m EXFLANA710[V wro~rscn.~ ~-^. ._ •._.~-'Ll' ~~ -~ .~.~''~' ,~~'• t; %=_I p` r: ~_--. LGCatlon o{ northern IT`~I. Wk' j~ fk'(~:f}Pt S~ , ~ . . ~~~~~1 ~ '• I' ~ ~ ~ .. - -L.9CJtlUA oS at~a i11 k:547.1.6. 1 ~a ~ ~• ~. ~ ~ ~' atu)y area ~ r v its ~}` ~ ' ~~ ,' '; ~ (Holland,ile Embayment) `, ,, l~ ~r1 , ,., .\.,..,. ,-f-lS .~ . ~. - ~= ~ -' ~ r 1 I _, ~ ` __~...a ~. ~.._ r 9-~ Y l rCj i q~,pl ~~_.> t 0 fC h.llf;'v_ !h Figure 1 Location of the Hollandale Embayment from I?.c~uu and «'oad~-•ard, 19Ra ', __ _ _~ deposition of marine sediments in a shallow sea about 450 [0 600 million years ago. This sea covered what is now Iowa, Illinois, Missouri, Indiana, lower Michigan, and southern Wisconsin. A bay of [his sea, called the Hollandale 8mbayment, extended up into southeastern and east-central Minnesota. Within this bay, sea level periodically rose and Cell in response to changes in climate. During periods p:AMpls~23 bINVlA2371105 Water Supply Alternative SLUdyV~inalUcliver'abler'AAtlema[ivu_Repon finel.doc 4 of higher sea level, calcium-rich mud and clay was deposited in the sea bottom. As the seas periodically fell, beach and near-shore marine environments encroached over the mud, depositing sand. Over the course of millions of years, the sands and mud formed into rock. The calcium-rich mud formed limestone, the mud formed shale, and the sand formed sandstone. The sea-level fluctuations (called "transgressions" and "regressions"), combined with the rock-forming processes, are responsible for the "layer cake" stratigraphy of bedrock deposits that are found in the Twin Cities area. In the millions of years that followed, "tectonic" processes acted on the region to cause the rocks to be further buried. The Twin Cities structural basin formed as much deeper crystalline rocks that are part of one arm of the Lake Superior rift basin dropped down.' The rocks near what is now Minneapolis slowly became deeper than surrounding areas. A series of faults step the bedrock down to this slightly deeper depth. These faults are most prevalent in southeastern Washington County and southwestern Scott County. There is some evidence to suggest that the transgression-regression sequences continued for periods later than 450 million years ago, depositing sediment that became younger rock formations. However, continental glaciation that took place beginning about 2 million years ago and ending about 200,000 years ago, "planed off' much of these younger rocks, leaving behind a hodge-podge of clayey silt (called "glacial till") and gravelly sand (deposited from the flowing water of the melting glaciers). Meltwaters from the glaciers, on occasion, ponded into massive lakes, such as Glacial Lake Agassiz in northwestern Minnesota-eastern North Dakota. A natural rock and ice dam at the southeast end of Glacial Lake Agassiz failed catastrophically, sending massive torrents of water down what is now the Minnesota River Valley. Other, less energetic glacial streams incised tributaries through bedrock, forming the Mississppi River. These unconsolidated glacial deposits have not had enough time to form into rock. Processes of erosion and deposition by flowing water About 700-million years ago, the beginnings of a new ocean began to form in what is now part of Lake Superior. This process, however, stopped prematurely, leaving behind a rifr valley, similar to the rifr valley in Ethiopia. The remnants of this "failed rift valley" is the Mid-Continent Gravity Anomaly then trends from Lakes Superior, southwest through the Twin Cities and into Missouri. This arm of the failed rift valley has been the location of periodic tectonic activity over geologic time. P:\Mpls\23 MN\7I\2371105 Watec Supply Alternative Study\FinalUeliverables\Allematives_Repo~t_final.doc continue to this day in the streams and river valleys of the area. Some of the streams have cut down into the rock. In several places, the streams deposited sand, gravel, and clay into these alluvial valleys and the stream has changed course, leaving behind a "buried bedrock valley" with little surface topographic expression. A generalized cross section from northwest to southeast through the Twin Cities mcfropolitan area is shown on Figure 2. The crystalline Precambrian bedrock consists of very old rocks (greater than about 600 million year old) that are composed mostly of granite-like rocks. The Mt. Simon and Hinckley Formations (which typically are not differentiated from one another) are sandstones. Overlying the Mt. Simon-Hinckley Formations is the F,au Claire Formation, which is a relatively low-permeability shale. The [ronton and Galesville Sandstones overlie the Eau Claire Formation, followed by [he Franconia Formation, which is a sandstone in some locations and a shale or NORTHWEST RIVER ~\~~ ~\ s _ `~ \\\ ~~ ., \ 0 Glacial duff (sand. gravel. clay) U Platteville formation (limestone) 0 St. Peter Sandstone Prairie du Chien Group Qimestone) 0 Jordan Sandstone ® St. Lawrence Formation (shale) ® Franconia Fm. (sandstone & limestone) Ironton 8 Galesville Sandstones Eau Claire Formation (shale) ~ Mt. Simon & Hinckley Fms. (sandstone) Precambrian Crystalline Bedrock 1... Is Figure 2 Schematic Geologic Cross Section Through the Twin Cities Area (not to scale) SOUTHEAST ST CROIX RIVER limestone in others. The St. Lawrence Formation (a sandy shale) overlies the Franconia Formation. The Jordan Sandstone (which is typically about 90 feet thick) and the Prairie du Chien Group P:AMpls\23 MNV71A2371105 Watee Supply Altemati ve SWdyVfSnulDellvereb les'VAltcrnelives _Rcpon Fnal.doc 6 (dolomitic limestone) make up the major aquifer system in the Twin Cities. The St. Peter Sandstone overlies the Prairie du Chien Group in some locations and in a few location (such as in Minneapolis). the Platteville Formation is the uppermost bedrock. 2.2 Geologic Conditions in the Eik River Area Elk River is located near the western edge of the Hollandale Embayment. Many of [he bedrock emits chat are present beneath Minneapolis and St. Paul are not present undernctth F,Ik River neither they were never deposited or were long ago eroded away). A Lew miles west of Elk River, even the Mt. Simon and Hinckley Formations are not present. P~.AMpls~23 MNV71A.371105 W:ne~ Supply Altcmati ve Study\Flnal Denveeables\~V~amativu Kaport finnl.doc '~ Figure 3 Uppermost Bedrock in the Vicinity of Elk River The uppermost bedrock unit in the vicinity of Elk River is shown on Figure 3. ~Che VI[. Simon- Hinckley Formations and the Eau Claire Foemation are the uppermost bedrock units over most of Elk River. the Ironton-Galesville Sandtone is the uppermost bedrock in the southeast corner of Elk River. Approximately 4 miles west, near Big Lake, the uppermost bedrock unit is Precambrian Crystalline rocks, which marks the western edge of the Hollandale Embayment. The depth to bedrock in Elk River is generally greater than 50 feet and in several areas, the depth to bedrock exeeds 200 feet, as shown on Figure 4. The brown and orange areas shown on Figure a P-AMpls\27 MNV71A2371 105 Wa[ar Supply AI[emafive StudyVPinalUelivc~nblesVAlfemab vas_Report_final.doc Figure 4 Approximate Depth to Bedrock (feet) suggest an erosional channel in the bedrock surface that was subsegaendy filled by unconsolidated deposits. It is likely that this channel was formed by meltwater during the last glaciation and became a tributary to the ancestral Mississippi River. It was subaequen[ly tilled by glacial deposits.'I'he preponderance of sand and gravel in Elk River suggests that the till material is Iikcly glacial outwash deposits (sand and gravel). The thickest surficial deposits (i.e. the greatest depth to bedrock) shown ~,, .. ~ ~ ~ ~ ~~ c 4, rg f i t a ~ - f ~ , ~~ & .. t'~ < . q . yP $.~ 1 y..Y l~~ .f} +" `.. ~ ~ V , RVi. T"" ~ ~ ~ti 'x~o- ~ a 'n3 F is~ , ~. yy ~., 4S ~j 3 t } , we f + +? .~ ... r~•~*.-fie, A~~.'~i .r .... ~ .~ ~. X ~ '~ RNA e J ~ ~ ~~ „~~a ~• t,~ ~ I` .' ~, ~ , , , r r ° ` ~ ~ ~ A ll A d ~. ~ ~' , ; ,~ ~ rea y verage :E ; ~ ' ~ =- Percent Sand ~{ `gc. • - '. nk `~ ;' '~.~" : ` !^:~ • 0- 3 712 r Y ~ j } ~' ,,,~ '~, ~. ~: Y ..' '~- 9712 19425 a i' ti ~ ~ 9egp + T 1' 7 "~~ ~ ~ F 4 i 19 425 - 29.137 ~ ". ~~ r .'~ e~.,. ~ -~ *' ; 7 ~ 29 137 -38 86 { ~ ~ ' ~ ~ ~ '~` 1 ~ 3B 85..98 562 Y ~f a. r' j~ - ' • a- x - ' 48 562 58 275 R -„ e ~V -, C~ 58 PS 67 987 2 fl 2 4 Miles '~ ~ -- • ' , ~ 67 9s~ - n ~ ^ ~~ .,. ' ~, ~. ~. L - ~J ni-s~ar2 - - --- Figure 5 Aerially Averaged Pe rcentage of Sand or Gravel in Unconsolidate d Deposits on Figure 4 corresponds approximately to the areas where the Eau Claire Formation has been eroded away and the first bedrock unit is Che Mt. Simon-Hinckley Formations, ash shown on E'igure 3. Unconsolidated glacial drift deposits are typically heterogeneous. in one location, the unconsolidated deposits can be mostly sand or gravel and in a nearby location, only clay may be found. These abrupt changes from sand to clay in glacial deposits makes siting wells difficult in some locations because it is difficult to predict how much water a well in these deposits might yield. Using the Minnesota P:AMplsA23 MNV71A2771 105 Water Supply ~Vtunative Study\FinalDelfvecabiesVAI[erna[ives Rapo~t_final.doc 9 Geological Survey's County Well Index (CWI) data base, an estimate of the distribution of sandy areas and clayey areas can be made. The aerially averaged percentage of sand in a given area is shown on Figure 5. High percentages of sand and gravel are found along the Mississippi River and north, along Highway 10. 2.3 Regional Aquifer Systems Aquifers are geologic units (or unconsolidated sediment) of sufficiently high permeability that can transport useable quantities of water. Aquitards are geologic units (or unconsolidated sediment) of relatively low permeability that cannot transport usable quantities of water. Examples of aquifers are sandstones, fractured limestones, and sand. Examples of aquitards are shales (formed from mud) and glacial till (silts and clays). Aquifers and aquitards generally must be of large enough aerial extent that they can be mapped. Aquitards typically separated aquifers from one another. Groundwater typically flows horizontally in aquifers and vertically in ayuitards. The vertical flow in aquitards represents leakage between aquifers. Groundwater always flows "downhill" -from areas of high pressure to low pressure. The major aquifers and aquitards in the Twin Cities area (from deepest to shallowest) are: 1. The Mt. Simon-Hinckley Aquifer. The Mt. Simon Sandstone and the Hinckley Sandstone together make up the Mt. Simon-Hinckley Aquifer. This is the deepest aquifer system in the Twin Cities area. It varies in thickness up to about 300 feet thick. The aquifer is underlain by lower permeability Precambrian rocks. The Mt. Simon- Hinckley Aquifer is recharged primarily by infiltrating precipitation and downward leakage from unconsolidated units where it "crops out" (i.e. is the uppermost bedrock aquifer) along the edges of the Hollandale Embayment. The rechazge area for the Mt. Simon-Hinckley aquifer is shown on Figure 6. Elk River is in an area where the Mt. Simon-Hinckley Aquifer is recharged. Groundwater in the Mt. Simon-Hinckley Aquifer generally flows toward the Minneapolis area, where water leaks slowly upward through the overlying Eau Claire Aquitard into shallower aquifer systems. The Mt. Simon-Hinckley Aquifer is unique in the Twin Cities area because it generally has a poor hydraulic connection with the major river systems (i.e. the Mississippi, St. Croix, and Minnesota Rivers) and is not readily recharged by leakage from overlying aquifers. Groundwater pumping out of the Mt. Simon-Hinckley Aquifer in the Minneapolis area during the 1970's and 1980's was depleting storage in this aquifer. As a result, the Minnesota DNR generally does not issues P:\Mpls\23 MN\71\2371105 Water Supply Alternative Smdy\FinalDeliverables\Alternatives_Report_final.doc 10 appropriations permits for this aquifer and has attempted to phase out pumping in all areas where another aquifer or water supply is available. from Delin and ~``oodW ard, 198-1 57 A`td w):<r~•yui~il bbbtYa~! l__-._ ~ _ `~'~..~r}~ benea~h d~rr 1 ~_._ ~ Vii'. :~sr.) wbem rqu-grt s~obcrolx ~ V lainen`hfW7diCVU: a<;UIteI , "..,{"/i. r ',. - &wrdan. or :nrdy give ', I ~ tlac]Jdrr of aq+iter I --'-- Buundrry o1 f:J9 C;Inirc rnnMi~ b,ed ~- -'- ' ' "1 r i I ~ ' -9d0-Pnrunto~eulc cmr~ir-DdaaM ' --_ ~' ', I 1 w'tare JV V]nvl.t]al<ly lo.nlia. I , YL~~•"' ~ '. 'I CO[NOU- iNH~'dla Stl and 'rJ ', I 100 t•at Vdtbu<I gyypr!<tk ' `r~ i, ~ ~^ , ~~ ~'~J '. L i[Xtdl fJmm~ O' 1729 i '~ j i fYocti~m 6'Q[dbna wnler nl~P{:O<OI 1.`~ ~. \ • Ma,ic:ipn •nell ~ ~ ': n ~ .. ~~• I ~~ "~ ~ •~- Elk River ~~. ! Yr • .'tea _f s+ MI p i ~ _ . ,..~_ Y %. ~ -lam _ _ ~, J ]' I I .' F 1 I:R1 ~ L. , ~ !!I _-~'`~ f] Q ~ J-r - 17~ - 4. ~ 1l ] ` _ ~ i i _~, i ~~' ~ ~ Y-~ •`1' ' t 1 / '> _ 1~i /r 1~~ ~ , >~. 1 ~ figure 6 Outcrop Area of the Mt. Simon-Hinckely Aquifer Where Recharge Likely Takes Place __ Figure 7 is a conceptual cross section that portrays the aquifers, aquitards, and general movement of groundwater in the Twin Cities area. P.AMpls\23 MNV71A2171105 Watel Supply Nternalive Study\NfnulDellverublesVAllernatives' Repuct _final.doc NORTHWEST IIIIiI11.M1o1111oI11 ~ICf IP~~111011 I Imm~Lna~~~ mlwl w ~~~nn.w~a~ ELK RIVER MINNEAPOLIS __ --- __ 2. 'l'he Eau Claire Aquitard ST CROI% RIVER The Eau Claire Formation is aloes-permeability shale that overlies the Ml. Simon-Hinckley Formation. It is a significant regional aquitard that limits leakage between the Mt. Simon-Einckley Aquifer and overlying aquifer systems. 3. The Franconia-Ironton-Galesville Aquifer The Ironton and Galesville Sandstones are moderately permeable. These two units are sometimes treated as an aquifer system separate from the overlying Franconia Formation but more typically the three units are Lumped together us a single regional aquifer system (the lower portion of the Franconia Formation is sometimes considered an aquitard). In some locations, this aquifer can produce substantial quantities of water (e. g., Brooklyn Park and Champlain) but in other areas, testing as shown very little yield potential. Where other aquifers are available (e.g., the Prairie du Chien-Jordan aquifer system), the FrancoNia-Ironton-Galesville (FIG) Aquifer is not tapped but 1 SOUTHEAST P:AMpls\2l ~NA71A2371105 Water Supply Nlcmativc Study\Y'inalDeli verableeAAltemativcs_Rcpon_ final doc LZ Figure 7 Conceptual Cross Section of Aquifers, Aquitards, and Groundwater Fluw where these units are the uppermost aquifer, the DNR has strongly encouraged its use as a municipal water supply -particularly in the northwest metro area. The Minnesota Geological Survey (MGS) has conducted extensive evaluation of the FIG Aquifer in the northwest metro area and has found that where the Franconia Formation or the Ironton-Galesville Sandstones are the uppermost bedrock unit, they are more highly fractured and thus, more permeable. Where these units are overlain by other bedrock units (e.g., the St. Lawrence Formation), the fracturing is much more poorly developed and the ability to produce usable quantities of water is substantially reduced. The fracturing appears to be associated with `9ithostatic pressure relief' -the fractures develop where the weight of the overlying bedrock had been removed. 4. The St Lawrence Aquitard The St. Lawrence Formation is afine-grained sandy shale of relatively low permeability. It is considered a regional aquitard that separates the underlying FIG Aquifer from the overlying Prairie du Chien -Jordan aquifer system. While of relatively low permeability, the St. Lawrence Aquitard does allow substantial leakage between the two adjoining aquifers and in some locations it can produce usable quantities of water. 5. The Prairie du Chien-Jordan Aquifer System The Jordan Sandstone, combined with the overlying Prairie du Chien Group, is the most important aquifer system in the Twin Cities. Many cities rely on this aquifer system to supply most or all of their water needs (e.g., Eden Prairie, Plymouth, Chanhassen, Minnetonka, St. Louis Park, Edina, Woodbury, Oakdale, Eagan, Burnsville, Apple Valley, Cottage Grove, etc.). The Prairie du Chien Group is divided up into two Formations: the basal Oneota Dolomite (which is not very permeable) and the Shakopee Formation (which is very permeable and transmits water in horizontal fracture systems - pazticulazly near the contact with the Oneota Dolomite). At a local scale, the Shakopee Formation and the Jordan Sandstone are sometimes considered different aquifers but there is enough leakage through the Oneota Dolomite for them to act as a single aquifer system at a more regional scale. Many municipal wells aze open to both units. Typical well capacities in this aquifer exceed 1,000 gallons per minute (gpm). The Jordan Sandstone is about 90 feet thick and the Prairie du Chien Group is about 150 feet thick (unless it has been eroded down). The Prairie du Chien-Jordan Aquifer System has proven to be very reliable because it typically the uppermost bedrock unit, where present, and is readily rechazged by precipitation that infiltrates P:\Mpls\23 MN\71\2371105 Water Supply Alternative Smdy\FinalDenverables\ALemativea_Report_final.doc 13 through the overlying glacial drift. This aquifer system is also in direct hydraulic connection with major rivers. All groundwater that is not pumped (with the exception of the Mt. Simon-Hinckley Aquifer) discharges into the major river systems in the Twin Cities. 6. The Basal St. Peter Aquitard The lower 50 feet of the St. Peter Sandstone is a shale that is considered a regional aquitard. This unit can yield domestic-quantities of water to wells in some locations 7. The St. Peter Agnifer The upper 100 feet of the St. Peter Sandstone is a very uniform, clean sand. In most locations, it can yield domestic quantities of water but it is generally not permeable enough to be used as a domestic water supply. It is typically present only near Minneapolis-St. Paul and in isolated locations i^ Washington and llakota Counties. 8. The Platteville-Glenwood-Decorah Aquitard The Platteville Formation is a relatively low permeability dolomitic limestone that is underlain by the Glenwood Shale and in some locations it is overlain by the Decorah Shale. These units rarely produce usable quantities of water but the Platteville Formation is the site of many springs along the Mississippi River in Minneapolis. 9. Quaternary Buried and Water Table Aquifers and Aquitards The glacial sediments (drift) in the Twin Cities area consist of tills (clays) and outwash (sand and gravel). The outwash can be very permeable and can be used as an aquifer where it is present. The till layers act as aquitards. Glacial outwash deposits can be of irregular and unpredictable extent. Glacial stratigraphy is very complex, with tills interfingering with sands over very short distances. The water table is typically in these deposits. In some locations, a till layer may overlie a buried outwash deposit, resulting in a buried or "confined" glacial aquifer. Some communities produce substantial quantities of water from these outwash deposits (e. g., Maple Grove, Brooklyn Park). They can be subject to contamination (and have higher levels of nitrate) and they are more susceptible to drought than bedrock aquifers. In many locations, the glacial sediment (or "Quaternary") aquifers are directly connected to the bedrock aquifers. In 2007, pumping in the Prairie du Chien-Jordan Aquifer System in Chanhassen depleted the storage in an overlying buried glacial aquifer that was connected to the Prairie du Chien Group. P:\Mpls\23 MN\71\2371105 Water Supply Alternative Stady\FinalDelive~ables\Alternativea_Repon_finatd°c 14 [t is also important to keep in mind that in order Ibr a glacial sediment aquifer to be usable, it not only has to have permeable deposits (sand and gravel) of a large aerial extent. it also must he thick (typically at least 30 feet thick) and it must be saturated or have a substantial saturated thickness. A sand and gravel unit that is only saturated [o about 10 feet is not a good candidate For a water supply. The Metropolitan Conncil (2007h) ranked the availability of groundwater water supplies in the seven-county metropolitan area using criteria such as number and productivity of aquifers, presence of known contamination, population growth, well-interference effects, and presence of nearby natural ~ -~ I I it Poronlial AquNer Yield _ _,_i ~' Ras mRW ~ ~ ~ M o: ~. ~~~~~ _ i Hg~ MOGAOIe -~r-F ~ Y( ®~~ F ~ }~ Figure 8 Relative Aquifer Yield (from Metropolitan Council, 2007b) for resources that are sensitive to groundwater withdrawals. Their map (included here as Figure K) shows areas of relative aquifer yield. The areas of highest aquifer yield are in eastern Hennepin, Ramsey, and Dakota Counties, where the Prairie du Chien-Jordan Aquifer System is available. Northwestern Hennepin County and western Anoka County area are shown as having only "moderate° to high moderate" potential ayuifer yield. 2.4 Regional Groundwater Contamination and Water fluality Contamination of groundwater impacts water-supply availability in some parts of the metropolitan area. Nompoint source pollutants, such as nitrate, pesticides, and herbicides have impacted groundwater quality in agricultural (or formerly agricultural) areas of llakota, Scott, and Washington Counties, although no wells have been taken out of service due to these contaminants. Nitrate, for example, can be removed from wafer using reverse osmosis (RO) treatment. Pesticide and herbicide levels are generally relatively tow and higher levels are typically isolated and impact domestic wells. The MPCA has identified many leaky underground storage tank (LUST) sites in the region. Typically, these sites are not causes of contamination to community water supply wells. Other potential sources of contamination (e.g., dump sites, etc.) are in various stages of investigation and P:ANlpls\23 N'VV IA'2371 Its Writer Supply NtemeG ve Study\hin~IDeliv erable+AAlte~'nalhe Rtport fin - Ldoc ~ 5 clean-up. Locations of these sites need to be considered when locating new wells. Municipalities are required by the Minnesota Department of Health to identify these potential sources of groundwater contamination in their Wellhead Protection Plans There are three known areas of groundwater contamination [hat have affected municipal water supplies in the metropolitan area: the Riley Tar Site in St. Louis Park; the U.S. Army TCAAP [richloroethene (TCE) plume in Arden Hills and New Brighton; and the extensive perfluorocarbon (PF) contamination in southern Washington County that has been linked to three landfills that received perfuorocazbo^ wastes from 3M. The Riley Tar Site and the TCAAP Site were discovered many years ago and are actively managed. The PF contamination in southern Washington County was first discovered in 2004-2005 and has been the object of intense evaluation since [hen. The PF contamination appears to be very widespread and may have permanent impacts on groundwater supplies in Oakdale, Lake Elmo, Woodbury, Cottage Grove, and St. Paul Park. Studies by the MPCA and MDH suggest the PF compounds may also enter groundwater from more widespread locations associated with municipal landfills and fire-fighting and fire-training sites (PF compounds are associated with fire-fighting materials). Naturally occurring constituents in aquifers can impact the water quality of municipal groundwater supplies. It is not unusual for municipalities to treat for the removal of iron and manganese from groundwater before distributing. Many bedrock aquifers and some glacial aquifers have naturally high levels of iron and manganese. Arsenic concentrations above health limits are a problem in out- state groundwater supplies but are less frequently an issue in the metropolitan area. Arsenic is a naturally occurring [race metal in shaley rocks that were deposits in marine environments. Higher levels of arsenic are occasionally found associated with the Eau Claire Formation. Arsenic is a known human carcinogen and is difficult to remove at very low concentrations. Radium and other trace radio-nuclides are commonly found slightly above health limits in sandstones such as the Jordan Sandstone, the Ironton-Galesville Sandstones, and the Mt. Simon and Hinckley Sandstones. Elk River treats groundwater to remove radium. 2.5 Available Aquifers in the Elk River Area Because Elk River is located along the periphery of the Hollandale Embayment, it does not have available to i[ [he important Prairie du Chien-Jordan Aquifer System. In the southeastern portion of the city limits, the Franconia-Ironton-Galesville Aquifer is likely present and does likely have above- average permeability because it is not overlain by the St. Lawrence Formation. However, the primary P:\Mpls\23 MN\71\2371105 Water Supply Alternative Smdy\FinalDeliverables\Alternatives_Report_final.doc 1f aquifer in Elk River is the Mt. Simon-Hinckley Aquifer (which is currently being used by Elk River Municipal Utilities. 1 -~" N ~ ~ • • o ~ ~~ o ~o n ~ a o ~ Elk River ne o • 0 ~ ~~ ~ ~ ~ ors ~ o `~ o v • o '., o +^, 'o 0 0 ,~ o _ ~~Q G roundwater Use 2005 a~~ (Mllliun Gallons o n is o • io zo ~ • 20-50 • • so ~s 6 ~ • • ~s-iao ! ' 100 - 500 • © 500 1 ,000 ~ > 1 ,000 t 5 0 5 10 15 Miles n 0 +`L1Y~ • ~ • 0 ~.- 0 0 U •~L ~• r~r~~7 Figure 9 Groundwater Pumping in the Grea[er Twin Cities Area: 2005 The Eau Claire Formation overlies the Mt Simon-Hinckley Aquifer in most of Elk River (see Figure 3). In the northern quarter of the City, north to Zimmerman, west to Big Lake, and north into unincorporated parts of Sherburn County, the ML Simon-Hinckley Aquifer is overlain by glacial P:A.Npls\23 NNVIA2371105 Water tiupply ll[ernative Smdy\FinalDeliverablasVAlten!s[ives_Report_tinal.doc i~ deposits. In these areas, the Mt. Simon-Hinckeey Aquifer is recharged (aad these areas may be important recharge areas for the aquifer as a whole). Some stream loss from the Mississippi River to the Mt. Simon-Hinckley Aquifer may take place in this area. Figure l0 Areas oI Increased Pumping Between 1990 and 2005 The Mt. Simon-Hinckley Aquifer has proven [o be productive in the Elk River area. Some of Elk River's wells have begun to experience lowered hydraulic head (water levels in wells) in response to pumping during [he summer. The Mt. Simon-Hinckley Aquifer is locally recharged by downward leakage from the overlying glacial drift (with is mostly permeable sand and gravel outwash) and areas where the Eau Claire Formation is thinner and/or fractured to produce secondary permeability features. N:AMpis\23 MNV71A237110~Wamr Supply NtemaGve SmdyV~innlDeliveeables\Al~emm~vev_Rapon FinuLduc l8 The glacial drift represents another aquifer that may he useable as a municipal water supply. The glacial drift is typically very permeable sand and gravel in the Elk River area (a westward portion of the Anoka Sand Plain). Recharge rases to this aquifer are likely higher than in many other parts of the metro area because of the more permeable surficial soils. The Elk River and the Mississippi River are in direct hydraulic connection with the glacial drift aquifer, providing a stable discharge zone and controlling the minimum groundwater levels. Like other shallow sand and gravel aquifers, glacial drift aquifers are susceptible to contamination from land use activities -particularly non-point agricultural source pollutants such as nitrate and pesticide/herbicides. Treatment to remove nitrate typically involves reverse osmosis or nano-filtration methods, which are expensive. 2.6 Regional Groundwater Use In 2005 the greater Twin Cities metropolitan area (including St. Cloud and Elk River) used approximate 13l-billion gallons of groundwater. The distribution of groundwater pumping is shown on Figure 9. This is an increase of approximately 34billion gallons of annual use since 1990, or an increase of 26%. Figure LO illustrates where the increased appropriations have taken place. In the outer-ring suburbs of the Twin Cities, increases have largely occurred as a result of [he installation of new wells, whereas increased annual pumping of existing wells accounts for the increases in the inner- ring suburbs. The Interstate-94 corridor, running northwest from P:AMpls\23 MYV71A2371105 Wmec Supply Nterna[Ive Study\FinulDelive~ables'AAlteuietives_.Repod Jfnal.doc l9 Figure 11 Locations of High-Capacity Wells Put Into Service Since 1990 the Twin Cities, is an area where new public water supply wells have increased total pumping. Figure I I shows the locations of new high-capacity wells that have been put into service since 1990. The Metropolitan Council has not explicitly predicted future groundwater use in the seven-county metropolitan area; however, they hive predicted future water demand. Figurc L2 is the Metropolitan Council's estimate of water demand in 2004 and their projection For water demand in 2050. "Phis prediction does not differentiate between groundwater use and surface-water use. 2oww~erage w.re. oema~a t+nc W dam-oro s ~,,.o,o o~i-neo ]il I.iO s xso s ~ ,~Y ~soo-~aaa . a~ ~~ Yom.-.~a 2050 hmraaJe Water UemaM ~M90~ ~av a:.. Aso am ~ . Iv >a ~;; ~o> •~ ~ ~ ~_ " _. -.i"~ .- r Figure 12 Metropolitan Council (2007b) Estimates for Water Demand in 20U4 and 2050 2.7 Groundwater Use in the Elk River Area Groundwater in the Elk River area is used for municipal water supplies (e.g., Elk River Municipal Utilises, Ostego, Albertville, Ramsey), Irrigation (especially sod-farm irrigation), aggregate processing (mainly as wash water) and in the Ramsey area, as part of the pump-out system of a groundwater remediation program. Locations of these groundwater uses are shown on Figure l3. Of course, I'. ~ t}~~aa ~~~ ..,o,,.o. ~ ~ >e e y' ~~ ~kRrygc 1y~ ~-• ~_~~~~ ~, r ®t f, ' ~, r r ~~ • ~` '~ A ~~~` ~ ~' . .,A MAR ~'s~i ~'. ~ P ~> .~ ~ . r"~~ n ~. • , r~~ ,~ t . \ ... a c+ ~1 j ~' ~~1 ~ ~ ~1 ~~ y +~ ~ °' Oisegb ~ . ~ ~~ ~S~Xi~~ Albe a ~ Qo Figure 13 Groundwater Use in [he Elk River Area P:AMpls\23 btNV71A2371105 W~tu Supply Aliemativa Study\Final Deli verablesVA lternntivea.Repoe[_finaLdoc ~~ there are also many domestic wells in the area. Domestic well usage is typically low - in the range of about 300 gallons per day. However, many domestic wells in the area can have an effect on groundwater use and availability. The Minnesota DNR requires an appropriations permit Ibr groundwater and surface-water withdrawals that exceed 10,000 gallons over a 30 day period or l million gallons per year. Monthly pumping volumes for these appropriations must be submitted annually to the DNR. Figure l4 summarized the total annual pumping for 2005 for appropriated wells in the Elk River area. Zim ~ an 1 o~~~~ o~~ • "~~ ~i~.,,MEw ,~M fee ~eaKE Elk 12nvar I ~..,,~„»~ ~r.FNE..,,o e ,. ~ oE,r .~ ~~+e oi ew~+aAr+o we ~~~ ~ ~ ~ _ I Annual ?005 Pumping ~e b~ ~ ^ 4RKER ML NICieAl Yilr O'y ~, (Million Gallonsi 1 D ~ O <10 ~ oUp Urixrue~a r~ I • 10 -SU ~uww iti~ O 50 100 p Otsego ( ioo zoo ~~q ao s ~ zoo I - ---r- Albe ~ ~ ~~ ~ 1 D 1 2 3 4 Ml A~w< AAO~q~ Figure 14 2005 Pumpiug of Appropriated Wells vwe Luc ~ ~.~ ~.~, ~arcr n~o~.~, ~,~a~~~ Saint ~Aa= ~~aXe ~2amsey ~ ~ , \Cn;~,E, . ~, P.AMpls\23~1NV71A2371105 Wa~ec Supply Alternative Study\F'InalDellvecable~eAAlternalives_Reporl_tinxl.doe Zl r eao i Too 600 t o 500 V ~ „AND & GRAVEL WASHING a ®MAJOR CROP IRRIGATION ~ ' f ' ^ NON-CROP IRRIGATION w 400 L GREAT RIVER ENERGY ~ PRNATE WATERWORKS s ^ OTSEGO. CIT'/ OF - 300 C ELK RNER MUNICIPAL UTILITIES c c ~ 200 ~ 100 II 0 ~ qa ,'~ ~ n ~' ~ ~ .+'~ a 3. ~~ ~ ~l' ,>a .l ~, v. i Year Figure 15 Nlajor Appropriated Groundwater Use iu the Elk River Area: 1988-2005 ~i Lsoo _ _ ----- --- ---- 1.400 = Lzoo v _ 1.000 ~ ELK RNER MUNICIPAL UTILITIES _ E ^ OTSEGO. CITV OF - ~ PRIVATE WATERWORKS n 800 ~ GREAT RIVER ENERGY ~ ° . g ^ NON-CROP IRRIGATION 3 Ri' MAJOR CROP IRRIGATION ~ G00 ~ SAND & GRAVEL WASHING ~ ~ -_. °e u` aoo 200 i Vear Figure l6 Trend of Groundwater Withdrawals in the Elk River Area: 1988-2005 [n the immediate vicinity of Elk River, water-supply pumping by Elk River Municipal Utilities is the largest groundwater withdrawal, as shown on Nigures LS and 16. Groundwater withdrawals by Elk P1MplsA23 MNVIA2371I0~Water Supply AlternOlrvc StudyVPinal DeliveeableaAAhcrnativcs'_Rcport_finaLdoc 22 River Municipal Otilities have increased from 250 million gul(ons in [he early f990's to over 700 million gallons in ?005. Withdrawals by the second largest groundwater user (major crop irrigation) inn i ^ Gueternery µmconsolldeleA~ ^ Franconia-Ironton-Galesville ®tdl Slmoo-Hinckley _.__ lb Figure 17 Appropriated Groundwater Withdrawal in the Elk River Area by Aquifer have remained relatively ~-oo steady (slightly under 300 million gallons per year). ~ ~°°° Sand and gravel wash- i '~" water pumping has i E increased from about 50 ~ a ~~ million gallons per year in P early 1990's to nearly 200 ~ ~~~ million gallons per year in ,oo 2005. Since 2003, ~~ municipal water-supply pumping by Otsego has Figure 18 Domestic Wells in the Vicinity of Elk River, by Aquifer begun and will he expected to continue to increase as Otsego builds out. the P~AMplsV?3 MNgiA2371IOS water Supply Alternative Study\FinamellverablesVAI[earativev_Repurt_finaLdoc 23 The trend of groundwater use in the Elk River area is increasing. Increasing groundwater use is likely due to increased population served by municipal utilities and increased gravel mining activities. The majority of appropriated groundwater in the Elk River area is from the Mt. Simon-Hinckley Aquifer, as shown on Figure 17. Use of this aquifer has been increasing since 1988, whereas usage from the Franconia-Ironton-Galesville Aquifer and the unconsolidated sand and gravel aquifer has remained relatively steady (or, in the case of pumping from the unconsolidated aquifer, increasing slightly over the past 4 years). In the vicinity of Elk River, the Minnesota Geological Survey's County Well Index reports approximately 1,800 dometic wells. About 55 percent of these wells are completed in the unconsolidated Quaternary aqufier (Figure 18). Some domestic wells are completed in the Eau Claire Formation, which is tyically considered an aquitard but in some locations where it is the uppermost bedrock, it is sufficiently weathered to produce domestic quantities of water. If each of the 1,800 domestic wells pumps at an average rate of 300 gallons per day, the total annual groundwater withdrawal from the domestic wells is about 200 million gallons. P:\Mpls\23 MN\7I\2371105 Water Supply Alternative Smdy\FinalDeliverables\Alternatives_Report_final.doc 24 3.0 Surface-Water Supplies 3.1 Regional Surface Water Supplies Approximately 880,000 people in the metropolitan region rely, at lease in part, on surface water as their drinking water source. The Mississippi River serves as the primary water source for the Minneapolis Water Works and the St. Paul Regional Water Services, which together serve L6 additional communities with wholesale or retail water delivery. All of the wa[el' appropriated by Minneapolis is drawn from the Mississippi River. For St. Paul, the river represents about 70% oC its appropriated water supply with the remainder pumped from high-capacity wells, the Rice Creek Chain of Lakes (Centerville Lake) and tributaries to Vadnais Lake (Metropolitan Council, 2007a). Between 2004 and 2030, the Metropolitan Council expects that the largest increases in water use in the Twin Cities area will occur in areas served by the Minneapolis Water Works and the St. Paul Regional Water Services. St. Cloud also uses treated Mississippi River water Several communities purchase some or all of their water from Minneapolis or SC Paul Examples include the Joint Water Commission (Crystal, New Hope, and Golden Valleyj, Bloomington (partial supply), Edina (partial supply), and Roseville. The surface-water service areas are shown on Figure 19. All other communities rely on groundwater, which does not require the extensive treatment necessary for any Metropolitan Council, 2007a) surface water. The Minnesota River is used, in part by the City of Mankato, which collects surface water though collector wells (also known as "Ranney Wells) advanced underneath the river bed. 3.2 Regional Surface-Water Reliability The water intakes for the Minneapolis Water Works are in Fridley and the intake from the Mississippi River for the St. Paul Regional Water Services is in Columbia Heights (the water is P:\Mpls\23 MN171\2371105 Water Supply Altema~ive Study\Fi nalDelive~ables\AI[emati ves'_Repon_finaLdoc Z5 Figure 19 Areas Served by Surface Water Supplies (from pumped to the Vadnais chain of lakes, north of St. Paul for storage prior to treatment) Under most conditions, Mississippi River supplies far exceed the water needed by communities that rely on the river. In times of drought or contamination, however, use of river water may be limited. The Minneapolis Water Works currently has no alternative water sources to the Mississippi River. This leaves its system vulnerable to events that may limit availability of supplies from the river. St. Paul Regional Water Services maintains a reserve to supply approximately 60 days of its `practical' water demand. It stores its reserve in the Rice Creek Chain of Lakes (Centerville Lake) and tributaries to Vadnais Lake, where the water can be withdrawn for use if Mississippi River supplies are limited. The St. Paul Regional Water Services is currently evaluating groundwater as a back-up supply (Metropolitan Council, 2007a). 3.2.1 Water Treatment and Contamination Surface water must be treated before distribution to remove water-borne contaminants, such as bacteria, viruses, pazasites, and a vaziety of natural and man-made constituents. Formerly, both the Minneapolis Water Works and the St. Paul Regional Water Services used a lime softening process to treat raw water. Minneapolis has invested considerably to change over to nano-filtration technologies that a designed, in part, to remove newly emerging contaminants such as pharmaceuticals and hormones. Both the Minneapolis Water Works and the St. Paul Regional Water Services are believed to have considerable excess capacity to treat water, or can bring such capacity on line. Surface-water sources on the Mississippi River are vulnerable to release of upstream contaminants that may overwhelm the treatment system (e.g., an oil spill) and to low-flow conditions in the river that may make it impossible for the water works' intakes to keep up with minimum demands. Surface-water supplies aze susceptible to both chronic contamination and accidental or intentional releases of contaminants from a vaziety of sources. Water-treatment plants may shut intakes to allow responders to mitigate an upstream release, with the duration of shut downs related to a number of factors, including the types of contaminants as well as the volumes and locations of the spills (Metropolitan Council, 2007a). The federal government requires all surface-water suppliers in the United States to include filtration and disinfection in their treatment processes as final barriers of defense against contaminants. 3.2.2 Low-Flows and Drought In response to the 1988 drought, [he Metropolitan Council prepared ashort-term water-supply plan which establishes a critical flow of 554 cubic feet per second (cfs) in the Mississippi River at Anoka to supply municipal water systems, generate power, and allow navigation. These minimum flows P:\Mple\23 MN\71\2371105 Water Supply Alternative Smdy\FinelDelivecables\Altematives_Repod_fiual.doc 26 assume that communities relying on the river as a source of drinking water would implement conservation measures to reduce high summer demands. Intake flows of 85 million gallons per day for the Minneapolis Water Works and 45 million gallons per day for the St. Pau] Regional Water System are likely possible during critical flow periods. Navigation lockages could be restricted or suspended during low-flow periods. Historical records indicate that flows at Anoka have been as low as 602 cfs in 1934, 529 cfs in 1976, 842 cfs in 1988, and 1,530 cfs during the drought period in 2006. The 529 cfs measured in 1976 was an instantaneous flow resulting from automatic gate operations at the Coon Rapids Dam. The lowest daily average recorded that year was 728 cfs. The short-term water-supply plan includes a drought response plan that is triggered by a 72-hour average flow of 2,000 cfs at Anoka, with subsequent decision points occurring at 1,200, 1,000 and 750 cfs (Metropolitan Council, 2007a). Low-flow conditions in the Mississippi River at Fridley during the 1988 drought reached critical conditions. Governor Perpich was faced with the decision to release water from upstream reservoirs at Pokegama and Winibabigoshish reservoirs. That impending decision was greeted with significant controversy by businesses and residents of the upstream reservoir communities that have come to rely on the reservoirs for tourism and tourism-related income. The 1988 drought passed without releasing water from the reservoirs but the pending actions resulted in a review of contingency plans. The Army Corps of Engineers (ACOE) developed draft drought contingency plans in 1992 for the six Mississippi River Headwaters Reservoirs. The plans describe in detail how reservoir operating decisions will be made during a drought. In 1994, in response to a request from the City of Minneapolis, the ALOE prepared a study for determining the volume and travel time for various releases from the headwaters reservoirs and how flows will recede at Anoka under a variety of conditions. The report highlighted the limited potential of relying on the headwater reservoirs as a source of water supply in the metropolitan area. For instance, if the flow at Anoka is 750 cfs and is forecast to fall to 554 cfs in 37 days, an extra 100 cfs released from Lake Winnibigoshish and Leech Lake (total of 200 cfs) would cause the flow at Anoka to rise [0 760 cfs (a 10 efs net increase) and extend the time it would take the flow at Anoka to fall to 554 cfs by 19 days (Metropolitan Council, 2007a). The ACOE is required with various entities (e.g., DNR, tribal governments, resort owners, etc.) before making its final decision on whether to release additional water. However, release from the reservoirs has never been executed and it is unclear how that process would actually proceed if it was undertaken. P:\Mpls\23 MN\71\237] 105 Water Supply Alternative 5[udy\FnalDeliverablea\Altematives_Report_tinal.doc 27 4.0 Summary of Alternative Water Supply Options This section summarizes various alternatives for future water supplies for Elk River Municipal Utilities. Each alternative includes a brief description of the infrastructure, the availability and reliability, the benefits, and the challenges of implementing the alternative. These alternatives are described in the context of (1) likely increases in future wafer demand by the Utilities' customers and (2) likely increases in water demand for surrounding areas. 4.1 Continued Use of Mt. Simon-Hinckley Wells 4.1.1 Description The Mt. Simon-Hinckley Aquifer is a proven water supply in Elk River. Additional wells could be installed to provide additional supply. Wells can be installed on an as-needed basis. Additional wells would need to be balanced with the need for adding additional water treatment (principally for removal of iron, manganese, and radium). Wells need to be located with a consideration for piping, land availability, storage, and service area infrastructure. 4.1.2 Technical Feasibility and Reliability The technical feasibility is high and the reliability of the alternative is high. The potential for wells to become contaminated is low (because of the presence of the overlying Eau Claire Formation). If one well becomes contaminated, it is unlikely that the entire system will be affected 4.1.3 Cost Capital costs include the cost of drilling a well and the piping, electrical, and control appurtenances. Additional cost may include expansion of water-treatment facilities or the construction of a second water-treatment unit. Capital costs are relatively low. Operation and Maintenance costs are generally low. Well systems and treatment facilities need to be installed to meet peak summer capacity, which is a multiple of base (winter) demand. This results in expenditures for parts of the well system that are used for only a portion of the year. 4.1.4 Challenges and Other Considerations As pumping in the Mt. Simon-Hinckley Aquifer increases (through a combination of new wells by Elk River Municipal Utilities and growth in surrounding areas), the aquifer's storage may begin to deplete (i.e. recharge is less than pumping). Additional wells may cause well interference effects that result from the intersection of the drawdown cones of adjacent wells, thereby causing a reduction in the capacity of an individual well. If pumping conditions begin to cause a depletion in storage, the P'\Mpls@3 MN\71\2371105 Water Supply Alternative Study\FiualDeliverables\Alternatives_Report_final.doc 28 Minnesota DNR could place a moratorium on additional wells. These conditions do not appeaz [o be likely in the short term but they could manifest themselves in the next 10 to 15 yeazs. 4.2 New Wells in the Surficial (Unconsolidated) Aquifer 4.2.1 Description The sand and gravel of the Surficial aquifer in the Elk River area is likely very permeable and capable of yielding lazge quantities of water where the saturated thickness is greater than about 50 feet. Locating these areas (and delineating their extent) would likely require a combination of surface geophysical surveys and test drilling. Wells completed in the Surficial aquifer could supplement the existing Mt. Simon-Hinckley wells. 4.2.2 Technical Feasibility and Reliability Utilizing Surficial unconsolidated aquifers through wells is generally a proven method for obtaining water supplies. Surficial aquifers are generally more subject to reduced yields during extended drought conditions. Surficial aquifers are also more likely to become contaminated by land use activities and typically have higher levels of nitrate and pesticides than bedrock aquifers (although these levels are typically below drinking water standards). Surficial wells have a higher likelihood than bedrock aquifers to become contaminated by spills and leaks. Pumping in the Surficial aquifer could reduce recharge to the underlying Mt. Simon-Hinckley Aquifer. 4.2.3 Cost The cost for a Surficial well system would likely be slightly less than the cost for a similar Mt. Simon-Hinckley well system, due to reduced drilling costs for shallower wells. However, the cost differential is likely small. In some locations, a Mt. Simon-Hinckley well and a Surficial aquifer well could be located close together without causing yield losses due to well interference effects. This could result in some cost savings in piping and land acquisition. 4.2.4 Challenges and Other Considerations Pumping from the Surficial aquifer may reduce recharge conditions (over the long term) to the underlying Mt. Simon-Hinckley aquifer. Wells located very near the Elk River or the Mississippi River may be deemed to be "under the direct influence of surface waters" by the Minnesota Department of Health and may require much more stringent treatment. P:\Mpla\23 MN\71\2371105 Water Supply Alternative Study\PinalDelive~ables\Alrernntives_Repoc[_final.do° 29 4.3 Aquifer Storage and Recovery (ASR) 4.3.1 Description Injection of water into an aquifer through one or more wells and recovery by pumping of that water at some later date. As originally envisioned by Elk River Municipal Utilities, treated water Mt. Simon-Hinckley water would be injected in one well during the winter in order to make use of the excess treatment plant capacity. During summer peak use, this treated water could then be recovered, thereby obviating the need for increased treatment plant capacity and storage of treated water. ASR may also be implemented by injecting treated surface water or water from the surficial aquifer into the Mt. Simon-Hinckley aquifer, although these methods aze more unlikely from a permitting standpoint. 4.3.2 Technical Feasibility and Reliability ASR that utilizes treated Mt. Simon-Hinckley Aquifer water is technically feasible. Issues of dissimilar water quality need to be addressed to minimize fouling of the wells. This is a method employed in other parts of the county but not in Minnesota. The Minnesota Department of Health has indicated that they would considering permitting an ASR system. U.S. EPA Region V regulates injection well systems and requires extensive study before permitting. Injection of water from surface water is much more technically challenging. First, this water would likely need to be treated to drinking-water standard using asurface-water treatment plant. Second, the issues of dissimilaz water are compounded in cases of dissimilar water sources. Injection of water from the surficial aquifer would require variances from the Minnesota Department of Health. 4.3.3 Cost The cost of constructing and implementing ASR is likely prohibitive. 1Vlonitoring costs may be significant and will likely require the installation of a monitoring well network. However, the permitting costs and studies required to obtain permits may be very costly because ASR is not routinely implemented in the upper Midwest. 4.3.4 Challenges and Other Considerations ASR is not a routine technology and implementation will require significant evaluation and monitoring. If ASR is implemented by other communities, the cost of permitting may come down as regulatory agencies gain familiarity with the approach. Risk from unforeseen technical failures are higher than with pumping well systems. P:\Mple\23 MN\71\2371105 Water Supply Alternative Smdy\P[aalDeliverables\AI[ernativesJteport_final.doc 30 4.4 Artificial Recharge by Infiltration Basins 4.4.1 Description Raise regional groundwater levels, increase aquifer storage, and promote additional recharge to the surficial aquifer and the Mt. Simon-Hinckely Aquifer by routing runoff and precipitation into permeable basins (e.g., abandoned aggregate mines). Natural process will act on [he infiltrating water to remove suspended sediment and many water-borne contaminants. Increased water levels can increase the available drawdow^ in existing wells, thereby increasing the maximum yield. Reduced yield during extended droughts can be minimized. 4.4.2 Technical Feasibility and Reliability Promotion of infiltration in basins is a widely practiced in some watersheds in the metro area and is an emerging best management practice. Infiltration basins improve the water quality of surface-water bodies by reducing runoff during the first parts of high-intensity precipitation events. Reductions in recharge caused by urbanization can be reversed and recharge can be increased even beyond natural levels. Implementation is not complicated. 4.4.3 Cost The cost of implementation is relatively small and sites for future infiltration can be incorporated into land use plans. Basins are typically left dry but vegetated. Some land may be lost from furore development. 4.4.4 Challenges and Other Considerations Increased infiltration may not necessarily translate into meaningful increases groundwater availability to wells. In general, the water quality of infiltrated water is likely as good or better than the water quality of infiltration through natural soils. However, the temperature of some infiltration basin water may be higher. There is also the potential to raise water levels in the surficial aquifer to such an extent that they might cause wet basement conditions near the infiltration basins (although these conditions can be substantially mitigated through proper design). This approach would indirectly affect available water supplies but would not necessarily represent a new water supply. 4.5 Collection and Treatment of Mississippi River Water 4.5.1 Description Construct an intake structure on the Mississippi River and treat the pumped water in a surface-water treatment plant. P:\Mpls\23 MN\71\2371105 Water Supply Alternative S[udy\FinalDeliverables\Alternatives_Report_final.doc 31 4.5.2 Technical Feasibility and Reliability A surface-water intake and treatment system is a proven technology -examples include St Cloud, Minneapolis, and St. Paul. Reliability issues similar to those associated with existing surface-water works may result during low-flow periods. 4.5.3 Cost The cost of a plant to treat surface water depends on a number of factors, including capacity, whether or not to include softening, availability of land, and the location and type of intake structure. The Kraemer & Sons Inc. quarry in Burnsville is planning construction of a 4 million gallon per day plant to treat quarry dewatering water (which is considered to be under the influence of surface water and requires surface-water treatment). The estimated cost of that plant is approximately $13 million (and does not include softening). A plant in Elk River that is capable of supplying between 8 and 12 million gallons per day would likely be in the range of $20-million to $30-million, including intake structures. As capacity increases, Che cosC per gallon treated would tend to go down. Thus, there would likely be savings realized with a lazger customer base. 4.5.4 Challenges and Other Considerations Capital cost of implementation is likely the biggest obstacle for this alternative. The cost differential for a small treatment plant compared to a large plant is not substantial. Therefore, per capita cost of implementation could be reduced substantially if multiple communities combined resources to build a single facility that would serve a large area. Risks associated with contamination and low flow could be substantially reduced for Elk River with the continued maintenance of the existing well system as a back-up water supply. Softening in the treatment plant would likely improve overall water quality. Mixing of water from two sources (treated surface water and untreated groundwater) could cause water-quality issues through a repetitive cycle of precipitation and dissolution in the piping networks, leading to fluctuating water hardness, iron staining, and scaling. 4.6 Ranney Well and Treatment 4.6.1 Description Ranney wells are horizontal collector wells advanced underneath the bed of river. In this case, one or more collector well laterals would be advanced below the Mississippi River from a central caisson to obtain Mississippi River water that has undergone some filtration through the river-bed bottom. Treatment to surface-water quality standazds would still be required because this water would be considered "groundwater under the direct influence of surface water". However, some filtration steps in the treatment process might be eliminated from the treatment plant by using Ranney wells. P:\Mpls\23 MN\71\2371105 water Supply Alternative Smdy\FiualDeliverables\Alternatives_Report_finard°c 32 4.6.2 Technical Feasibility and Reliability Ranney wells are a proven technology, employed by many communities, including St. Louis, Kansas City, and Des Moines. Ranney wells typically replace intake structures that are subject to washing out. Reliability issues associated 4.6.3 Cost The Ranney well alone would likely cast $1,000,000 to $2,000,000. A treatment plant similar to the surface-water alternative would also be necessary. 4.6.4 Challenges and Other Considerations This alternative has a high probability of success. The advantage that this alternative has over the surface-water alternative is in the reliability of the intake (i.e. not subject to wash-out) and the less susceptibility of the water source to low-water conditions and contamination from spills or other accidental releases. 4.7 Interconnect with Minneapolis Water Works 4.7.1 Description The Minneapolis Water Works has an excess capacity for treated water and is likely amenable to supplying (selling) other communities with softened, treated water. A treated water main would need to be constructed from Che Minneapolis to Elk River, most likely along the future North Star corridor. 4.7.2 Technical Feasibility and Reliability This alternative involves constructing a water main over a distance of approximately 20 miles. Significant cost savings might be achieved by installing a pipe line in conjunction with improvements to the North Star rail corridor. Existing storage in Elk River would need to be evaluated to determine adequacy because water transmission would likely be during the night in order to obtain the best price for water. Reliability issues associated with the Minneapolis Water Works would apply to this alternative. However, if Elk River Municipal Utilities maintained their well network as a back-up supply, those risks would be substantially reduced. In addition, some credit would likely be realized with Minneapolis in providing an emergency interconnect. As with any long pipeline, there is a potential for short-term shut-down for repair or damage. The DNR is strongly encouraging the City of Ramsey to pursue this alternative and is also encouraging Elk River to participate. P:\Mpls\23 MN\71\2371105 Water Supply Alternative Sludy\FinalDeliverablea\Allematives_Repon_nnatd°c 33 4.7.3 Cost The cost of the pipeline would likely be about $ 20 million. Purchase of water would need to be negotiated with Minneapolis but would likely be in the range of $3.00 to $ 4.00 per 1,000 (including cost of service). 4.7.4 Challenges and Other Considerations It is highly unlikely that Elk River Municipal Utilities would pay for all of the pipeline because other communities in the area with more pressing water-supply needs would also likely be purchasers of water from Minneapolis. Water from Minneapolis would be softened and would likely be of excellent quality. Elk River Municipal Utilities may lose some potential revenue by no longer being the supplier of source water. 4.8 Alternate Source for Lawn Water 4.8.1 Description Water for lawn sprinkling greatly increases overall water demand in the summer and places demands for larger water-supply infrastructure (e.g., mare wells, larger treatment facilities). Lawn sprinkling water comes from the same water distribution system as all other water supplies. Separating lawn sprinkling water from drinking water provides opportunity to use a different (and perhaps untreated) water supply, such as water stored in basins or river water. In order to implement such a system, a second water distribution network would be required, with a nearly redundant pipe network. 4.8.2 Technical Feasibility and Reliability While technically feasible, a second water distribution system is likely impractical in a community that is already significantly developed. Water mains and service lines would need to be installed in service areas. Safeguards would need to be instituted to minimize the likelihood that untreated water was used for potable supplies. 4.8.3 Cost The cost of implementing a second water-distribution system for lawn sprinkling would likely be prohibitively high. In addition to piping and maintenance, a redundant system of elevated storage would likely be required. If surface water was used for sprinkling, intake structures and pumps would be required. P:\Mpls\23 MN\71\2371105 Water Supply Alternative Study\FinalI)eliverables\Alternativea_Repon_final.doc 34 4.8.4 Challenges and Other Considerations An alternative source for lawn water may be feasible for a single development or a large water user. A local well, installed in the surficial aquifer, or an intake in a retention basin, could provide non- potable water. On a City-wide scale, such a system seems impractical. 4.9 Water Conservation 4.9.1 Description Elk River Municipal Utilities already employs water-conservation measures. Water conservation is most directly applicable Co lawn sprinkling because this is the largest use of water during the summer. More stringent water-conservation measures could be employed to further reduce summer water demand, such as a permanent ban on irrigation and sprinkling, requirements for drought- resistant plantings, etc. Amulti-tier cost of water is another alternative, whereby the cost per 1000 gallons increases proportional to use. We understand that Elk River Municipal Utilities is planning on a three-tier program. 4.9.2 Technical Feasibility and Reliability Severe and permanent water-conservation measures are difficult to enforce and are widely unpopular. Cheating would Likely be widespread. Enforcement would be an issue. Multi-tier cost of service is generally only moderately effective unless unit costs increase substantially. 4.9.3 Cost Additional costs would be realized for enforcement and education. Cost savings would likely be realized overall for the utihty by deferring future capital expenditures for wells and treatment. 4.9.4 Challenges and Other Considerations Very stringent water conservation measures have generally been proven to be unpopular. Land owners expect to be able to obtain nearly unlimited quantities of water at a low price. Water demand is generally very inelastic in that substantial increases in the cost of water generally does not deter use because it is still considered a bargain. Ordinances that require changes to landscaping to reduce water consumption, such as xeriscaping, require community and political acceptance. Short-term bans on sprinkling are typically acceptable during droughts but are typically tolerated only once or twice. P:\Mpls\23 MN\71\2371105 Water Supply Alternative Study\FinalDeliverables\Altematives_Report_finel.doc 35 5.0 Evaluation of Paired Mt. Simon-Hinckley and Drift Wells This section describes in more detailed the concept of installing new wells in the sand and gravel drift aquifer in close proximity to existing or proposed Mt. Simou-Hinckley wells. As previously discussed, this approach could prove to be the most viable alternative to meeting future water needs in Elk River.2 It has the following advantages: 1. Sand and gravel is plentiful in the Elk River area. There is a high likelihood that the sand and gravel aquifer will be productive. 2. The Eau Claire Formation separates the Mt. Simon-Hinckley aquifer from the overlying sand and gravel deposits. The Eau Claire Formation is generally a very competent separating aquitard with minimal leakage. This allows for very little interference between wells installed in close proximity to one another but in different aquifers. 3. Significant savings can be realized in locating wells in pairs. Piping runs are short. A common well house might be possible at a given location. Wellhead treatment, if any, can be shared. Some well controls can be shared. Power infrastructure to the well heads can be shared. Land acquisition costs would likely be reduced. Operation and maintenance activities could be reduced. 4. Installing wells in another aquifer improves water-supply reliability in the unlikely event that one aquifer becomes contaminated. 5. Iron, manganese, and radium concentrations in drift aquifers are usually lower than in the Mt. Simon-Hinckley aquifer. Opportunities for blending water from the different aquifers could result in treatment savings. In Brooklyn Park, for example, blending drift aquifer water with z Elk River recently received an annual appropriations increase from the DNR for the Mt Simon-Hinckley Aquifer from 875 million gallons to 1,600 million gallons using five new wells. This increased appropriation is expected to meet demand through the year 2016. IC is likely that future appropriations will need to be satisfied from other sources. P:\Mple\23 MN\7l\2371105 Water Supply Alternative Study\Fivamenverables\Alternatives_Report_finatdoc 36 Franconia-Ironton-Galesville aquifer water has allowed Che City to forgo the construction of additional treatment facilities. 6. Future appropriations from the drift aquifer aze likely to be met more favorably by the DNR because this aquifer is quickly rechazged by infiltrating precipitation and pumping effects are localized rather than regional. 7. As gravel mining operations in the azea diminish, water availability from the drift will likely become more plentiful There are two main disadvantages to the paired well approach. Drift aquifers, because they are shallow, will be more susceptible to long-term drought conditions. Drift aquifers are also more vulnerable to contamination from land-use activities, including leaky underground storage tanks, urban runoff, and non-point source contamination form agricultural activities. In southern Washington County, applications of anhydrous ammonia fertilizers from decades past have resulted i^ elevated nitrate levels in the shallow groundwater. 5.1 Thickness of the Eau Claire Formation Paired wells should only be considered where the Eau Claire Formation is relatively thick in order to minimize well interference effects caused by leakage through the Eau Claire Formation. It is not possible in this evaluation to determine precisely what the minimum thickness should be, but as a guideline, the Eau Claire Formation should be at least 25 feet thick and preferably greater than 50 feet [hick. The thickness of the Eau Claire Formation in [he vicinity of the existing and proposed Mt. Simon-Hinckley wells is shown on Figure 20'. Based on existing information, the thickness of the Eau Claire Formation is greater than 25 feet at all well locations except Existing Well #4. 5.2 Thickness of Unconsolidated Deposits In order for an drift aquifer well to be productive, the unconsolidated deposits must be relatively thick (although there are other considerations, such as saturated thickness and permeability). The thickness of unconsolidated deposits is shown on Figure 21. The thickness of unconsolidated deposits is generally over 100 feet at each well location. s The locations of proposed wells were provided by Elk River Municipal Utilities. P:\Mpls\23 MN\71\2371105 Water Supply Alternative Stndy\PinalDeliverables\Allematives_Repon_finatdoc 37 Proposed Mt. Simon-Hinckley Wells in Elk River P:AMpls\23 MNVIA2371105 Writer Supply Al[emaUVe SNdy\FinalDeliveeablesVAlteena~Ives_Repod_IinaLdoc 3g Figure 20 Thickness (feet) of the Eau Claire Formation in the Vicinity of Existing and Proposed Mt. Simon-Hinckley Wells in Elk River P:AMpls\23 MNV71A2371105 Waler Supply Alternxtfve Study\FinalDeli veeablesAA ltcrnali ves_Report_linal.doc 39 Figure 21 Thickness (feet) of Unconsolidated Deposits in the Vicinity of Existing and 5.3 Saturated Thickness and Permeability of Unconsolidated Deposits The maximum possible saturated thickness of the unconsolidated deposits is the vertical distance between the top of the Eau Claire Formation and the water table. The elevation of the water table varies from about 1,000 feet above mean sea level in the northern portion of the wellfield area to the stage elevation of the Mississippi River (approximately 860 feel, above mean sea level). This suggests that the maximum possible saturated thickness of the unconsolidated deposits is in the range of approximately 125 to 250 feet. Provided that the permeability is sufficiently high, saturated thickness is this range indicate that wells in the unconsolidated deposits would have relatively high yields. The actual saturated thickness, however, is the thickness of continuous unconsolidated deposits below the water table that are permeable (generally sand or coarser). In most locations, there will be layers of clay, which will result in the actual saturated thickness being lower than the possible saturated thickness Unconsolidated deposits that are mostly sand and gravel can be expected to have high permeabilities: it the range of 30 to 100 feet per day. Silts and clayey silts generally have permeabilities less than 10 feet/day and clays can be expected [o have permeabilities less [an 1 foot/day. In order for an area [o be considered a likely candidate for further evaluation as a paired well site, the unconsolidated deposits in and around that area must be at least as permeable as medium sand. The following table summarizes the estimates of saturated thickness and permeability at Che well sites: P:\Mpls\23 MN\71\2371105 Waler Sapply Alternative Smdy\FinalDeliverables\Altema[ives_Report_final.doe 40 Well Site Estimated Unconsolidated Estimated Estimated Saturated Materials Average Transmissivity Thickness (feet) Permeability (thickness x (ft/day) permeability) ftZ/da #2 50 Sand on top of 50 2,500 cla #3 60 Sand and clayey 30 1,800 sand #4 20 Sand ravel 100 2,000 #5 180 Sand and gravel 50 9,000 with cla lenses #6 90 Sand and ravel 100 9,000 #7 80 Sand with some 30 2,400 cla #8 50 Sand and gravel 100 5,000 (buried drift) #9 30 Fine sand 20 600 #10 60 Sand (buried 30 1,800 drift) #11 & #12 120 Sand with ravel 70 8,400 #13 40 Sand with cla 25 1,000 5.4 Estimated Well Yield for the Unconsolidated Aquifer A (very) approximate estimation for maximum sustainable well capacity is: Well Capacity (gpm) = T/267 x 0.3 x Saturated Thickness (where T is the transmissivity) Well Site Estimate Well Ca acit ( m) Well Site Estimate Well Ca acit ( m #2 140 #8 280 #3 120 #9 20 #4 50 #10 120 #5 1.,820 #11 & #12 1130 #6 910 #13 50 #7 215 Based on this estimations, the best well sites to install pairs of wells (one well in the Mt. Simon- Hinckley Aquifer and one well in Che unconsolidated aquifer) are Wells Sites #5, #6, and #11-#12. These estimates must be used with caution because geologic conditions can vary sharply over a short distance. These wells site would be could candidates for further evaluation. Wells Sites #2, #3, and P:\Mpls\23 MN\71\2371105 Water Supply Alternative Smdy\FivalDelive~atrles\Alte~natives_Repo~t_finatdoc 41 #4 should be avoided because these locations are too close to surface-water bodies and water-quality issues associated with drawing in surface water may occur. It is also important to note that only one well in each aquifer should be placed at each well site. A well spacing of about 2,000 feet between wells pumping in the same aquifer is important to keep well-interference effects to a minimum. 5.5 Suggestions for Further Site Evaluation As a next step in evaluating the well sites for suitability as paired wells, the following (in order) are recommended: 1. Construct hydrogeologic cross sections through promising well-site areas, using well logs from existing wells, to better evaluate the aerial extent and connectivity of the permeable deposits in these areas. Isopach (thickness) maps of each well site should be constructed). 2. Test wells at candidate well sites should be installed, along with one monitoring well in the unconsolidated aquifer a short distance away from the test well. A series of controlled aquifer tests should be performed at each well site to obtain better estimates of transmissivity, storativity, specific capacity, sustainable well yield, and to determine the degree of interaction between the unconsolidated aquifer and the Mt. Simon-Hinckley aquifer. 3. Water-quality tests should be performed on samples collected at various times during aquifer tests to verify that the water-quality of the aquifer is suitable for apublic-water supply. P:\Mpls\23 MN\71\237] 105 Water Supply Alternative Study\FinalDelive[ables\Altematives_Repott_final.doc 42 6.0 Summary and Discussion Elk River Municipal Utilities currently obtains all of their water supply from seven wells completed in the ML Simon-Hinckley Aquifer. These wells represent approximately 8.1 million gallons per day of capacity. The Utility provides water to approximately 4,300 metered services in the southern portion of the Elk River municipal boundary. Total annual consumption is about 875 million gallons. At present, the Mt. Simon-Hinckley Aquifer is a reliable water supply that is capable of meeting current demand. Elk River Municipalities recently received an appropriation increase from 875 million gallons per year to 16,000 million gallons per year to cover approximately the next 10 years of projected demand. It is likely that this aquifer will be able to meet increases in demands for at least the next 8 years, although increased demand may require the installation of new wells. Greater confidence in this prognostication could be achieved by additional studies that involved computer modeling of groundwater flow.° Conditions that may adversely affect the Utilities' ability to meet future demand with the Mt. Simon- Hinckley Aquifer are: ] . Climatic changes that result in extended periods of drought, reducing recharge to the aquifer and placing increased demand on groundwater to meet various water demands. 2. Increased pumping in surrounding areas that are not served by the Utilities, including adjacent communities. Iucreased pumping could result in well-interference effects that reduce the well yield of individual wells or initiate a more regional depletion of storage and associated lowering of groundwater levels. 3. Increased urbanization that reduces recharge to the aquifers. Increased urbanization with infiltration basins that collect storm water from impervious areas may actually increase ° The Metropolitan Council is working on a regional model of groundwater flow that includes the Elk River area. This model is scheduled to be completed in early 2008. This model could be used as a basis for constructing a more detailed model of the Elk River area for further evaluation. P:\Mpls\23 MN\71\2371105 Water Supply Alternative Study\FinalDeliverables\Alternatives_Report_final.doc 43 recharge but if the storm water is routed by sewer systems to the rivers, recharge could be reduced. 4. Further regulatory limitations on use of the Mt. Simon-Hinckley Aquifer in response to regional lowering of water levels in the Mt. Simon-Hinckley Aquifer. 5. Unforeseen contamination of the aquifer. An example of unforeseen contamination of an aquifer is the Woodbury-Cottage Grove area where a previously unknown contaminant (poly- fluoro compounds) was discovered to be widespread in occurrence Elk River Municipal Utilities currently does not have aback-up water supply (neither do many other communities). Interconnections with adjacent communities are highly encouraged by the Minnesota DNR to provide emergency water incase of unforeseen circumstances. Elk River is less vulnerable in this regard than, for example, Minneapolis, which relies on a single intake for their water supply - Elk River has seven wells and it is unlikely that all seven would experience a simultaneous failure or contamination. The surficial aquifer could provide aback-up water supply via wells, although additional study would be necessary to determine the viability of the surficial aquifer in [he Elk River area. Depending on the permeability of the Eau Claire Aquitard in [his area, it may be possible to pair surficial aquffer wells with Mt. Simon-Hinckley Aquifer wells without inducing significant well- interferenceeffects. Well Sites #5, #6 and #11-#12 appear to be the most promising and well yields over 1,000 gallons per minute might be realized from these wells. Additional testing would need to be performed to verify these estimates. The surficial aquifer is more susceptible to contamination and to drought conditions than the Mt. Simon-Hinckley Aquifer. Any use of surface water requires a level of treatment that is substantially more expensive than treatment of groundwater. It is unlikely that Elk River Municipal Utilities could support the construction and operation of a surface-water treatment plant and intake structure with its existing customer base. The economics of a surface-water source might become viable if additional customers could be added (e. g., by selling treated water to neighboring communities) or by partnership with other communities in a jointly owned and operated plant. Purchasing water from other parties to meet future demand may also be viable. It is unlikely that nearby communities will have excess groundwater [o sell to Elk River because communities in this area are already experiencing limits on groundwater availability. Therefore, any purchased source P:\Mpls\23 MN\71\2371105 Water Supply Alternative Stady\FinalDeliverables\Alternatives_Report_final.doc 44 will likely be treated surface water from an entity [hat has excess capacity. St. Cloud has a 16-million gallon per day lime-softening plant with plans for expansion in 2010. It is unknown if St. Cloud has plans or would be amenable to selling treated water. Minneapolis Water Works has slime-softening plant with micro-filtration treatment. The Minneapolis Water Works likely has sufficient capacity to sell treated water to additional communities. Either source (St. Cloud or Minneapolis) would require the construction of a relatively long pipeline. The cost of the pipeline could be substantially reduced if it served additional communities in the Elk River area or in the area of the likely pipeline route. Elk River Municipal Utilities would be in a somewhat advantageous position if it were to obtain treated water from another source. By retaining the capacity to supply water from the existing wells during emergencies, Elk River could substantially improve its overall water-supply reliability. It would likely not be economically feasible to purchase treated water only for peaking purposes -any purchase would likely be for base demand. Also, it is important to recognize that there may be technical issues related to precipitation and dissolution with mixing water in the distribution system from different sources (e.g., softened surface water and unsoftened groundwater). It is also important to recognize that if a long-term drought condition does occur in the central Minnesota, the drought conditions will likely adversely affect both surface-water supplies and groundwater supplies. P:\Mpls\23 MN\71\2371105 Water Supply Alternative Study\FivalDenvecables\Altematives_Repott_final.doc 45 References Delin, G.N., and Woodward, D.G. 1984. Hydrogeologic Setting and the Potentiometric Surfaces of Regional Aquifers in the Hollandale Embayment, 1970-1980, Southeastern Minnesota. USGS Water Supply Paper, WS 2219. Metropolitan Council, 2005. 2030 Water Resources Policy Management Plan, adopted May 25, 2005. Metropolitan Council, 2007a. Water Supply Planning in the Twin Cities Metropolitan Area, Report to the 2007 Minnesota Stale Legislature, January 2007. Metropolitan Council, 2007b. Water Supply Planning in the Twin Cities Metropolitan Area, Technical Report, January 2007. P:\Mpls\23 MN\7l\2391105 Water Supply Alternative SNdy\FinalDeliverables\Alternatives_Repor[_finatdoc 46 v A R F 7 V .b v d d a 0 it .~-~ w O T R 0 .N+ `~ G y ~ <tl U G 0 G 0 ~~ v y ,y. a "~" y °~ ' .+ O4 a l-. by a ,-. I tp V .fJ a~ Q. O d ~ p U is o w b o o aCi o~ 'd o is o v 'O ~ .Q c o b .n ~ aCi Y o o `' E d C 3 . ^~ w ~ o aw. ~' o a w . ~ ~ ..°.°p ~~ ~ I o ~ 3 Y ~ ~ ~,~ ~ 0 a l b a~ b ] ~ 'D a ~ b ~~~ p o 3 ~ ~ x l ~ a ~ . , a . c a :, o C ~ 3 y 3 a a y a c .". c ~~. 5 p; ro 0 0 W . ~ ~ ~ w v m~ o o m ceA ~ o o a o a ` o ~ x n c ~ x a a ~ ~! ~ ~r g ' ° N ~ . . ~ G m /-. k y o v ~b ' ' R C ~ G C . ~ ~ ~ C w a O '~ p w id .G O P ~=, id C O R 0 G a O d/ ~ a O G? W t a a y O a ~ ~0Oi F i bL ~ F VI 4 V ~ Q yO / N H ~ ! 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FG ~ v>'i 'c 3 fYi w ~" 3 W p 3 rn b ti °' .7. ~ W~ C.' o a ~ ~~ .a' ~ N .~ c y N U c ~ ~ w o ii.. N c 0 v ~ w 0 ~ ~ ~ 3~ ~ ° ~ ~ n, o w ~ a o 3 >, ^ ~ ~ C U a w ' ° ': ~ %n p ^O 'iy ~ ~ o > a ^ b ~ ,~ C is :: a 3 . Q U : ~ .~ 3~~ Q~ a-1 3 0 a ~, U O 'D U O ro a ,= ~ ~ ~ 0 ow dab 0 z b T O U ~' ~ ... x . b _ ~b ~ ~ ~ y Tti ~ Q Q G fd O W ~ ~ ~ ['i ~ 3 ~ 3 ~ en c a'~ ~ o m .C v ~ .. ~ y O I ~ ~ O 3 'C ~ ;; ti .c c.c eo v v y c~c h x e E ~ ~; aCi ~ a v c ~ c o 3 co y ~ o on~ '° ~ G ~ i N C .b ~ U a +N v' O `~ N Y C id N U w q ..U. U C '~ 9 u ' ~-r \'~ O a N ~ ~ ~ U y ~ v, O ~ C O _ N ~ C ~ O ~+ J i 'b C N Q ~ U Minnesota Department of Natural Resources Central Region Waters - 1200 Warner Road, St. Paul, MN 55106-6793 Telephone: (651) 772-7910 Fax: (651) 772-7977 July 17,2007 Elk River Municipal Utilities Bryan Adams, General Manager 13069 Orono Parkway EIk River, Minnesota 55330 RE WATER EMERGENCY AND CONSERVATION PLAN APPROVAL; AND AMENDMENT OF PERMIT NO. 1975-3215 Dear Mr. Adams; The Department of Natural Resources (DNR) has reviewed the "Conservation and Emergency Management Plan for Elk River Municipal Utilities Water System" dated September 2006 for compliance with Minnesota Statutes, Section I03G.291, Subd. 3 and the guidelines posted on the DNR website. 1 am pleased to advise you that on behalf of the Commissioner of Natural Resources [hereby approve your Plan. This approval is effective upon the Department's receipt of a completed copy of the attached "Certification of Adoption" form. Please return the form to my office. As also was discussed in our previous correspondence, with this agreement and approval, your water use permit has also been amended so that all water use increases and new wells discussed in your Plan are approved in advance. ,4 copy of your amended permit attached. Please note that for bookkeeping purposes, you will need to submit a copy of the attached notification form (including the well log and pump test results) before you utilize any of the proposed wells in your system. Please read the Conditions of your new permit carefully, especially Conditions 10, l 1, and 12. Thank you for you efforts in planning for the future of Elk River's water supply and for conserving the water resources of the State of Minnesota. Sincerely, f/ ~~ ` `.i2 Dale E. Homuth Regional Hydrologist ENCLOSURES e: City of Elk River Sherburne County SWCD, Bill Bronder DNR Waters, Laurel Reeves DNR Area Hydrologist, Roger Stradal DNR Conservation Officer, Mitch Sladek Minnesota Department of Health, Bruce Olsen Central Office Appropriation Permits; Central Office SWUDS DNR Information: 651-296-6157 • ]-888-646-6367 TTY: 651-296-5484 1-800-657-3929 An Equal Opportunity Employer ®y Pointed on Recycled Paper Containing a Who Values Diversity ~~p Minimum of 10% Pos[-0onsumer Waste Good examples of water Restrictions throughout the State of Minnesota. 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