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HomeMy WebLinkAbout9A - Jordan Well CITY COUNCIL AGENDA REPORT 5+a.: A \ sew~' 1:.0\~~bl' J -elite 6f~ IJ... vel { fIJ r~ :t;lJ.~~ REVIEWED BY: SUBJECT: APRIL 3, 2000 9A . BUD OSMUNDSON, DIRECTOR OF PUBLIC WORKS I CITY ENGINEER FRANK BOYLES, CITY MANAGER CONSIDER APPROVAL OF PROPOSAL TO RETAIN A CONSULTING ENGINEER IN PREPARATION FOR DEVELOPMENT OF A JORDAN WELL ON THE WEST SIDE OF PRIOR LAKE DATE: AGENDA #: PREPARED BY: DISCUSSION: HISTORY M :',OC10 The city has been working with the Minnesota Department of Natural Resources on a new city production well since 1997. The city currently has three wells that are pumping from the Prairie Du Chien Jordan Acquifer. The DNR has not allowed the city to drill an additional Jordan Acquifer well due to the concerns by various agencies that the pumping from this aquifer would have a detrimental affect on the Savage Fen wetland complex. The City had an engineer for this project but the budget was completely utilized in attempting to convince the permitting agencies to allow the city to drill an additional Jordan or Mount Simon Hinkley well within our existing well field. D~ S\\\~\~ \\\- For the past three years, the DNR has been attempting to convince Savage, Shakopee, and Prior Lake to utilize the Franconian-Ironton-Galesville Acquifer (FIG) as an alternative source of water to the Jordan Acquifer. The other source of water, the Mount Simon Hinkley Acquifer, the deepest of the three has been protected from any new well construction by State statute since 1988. The City of Savage has spent a considerable amout of money and time on ground water modeling and looking for alternatives to the Jordan Acquifer as a source of water. The FIG Aquifer mayor may not perform adequately as a city water supply well. Savage has done extensive testing of the FIG and the pumping rates are low and the draw-down is considerable in this aquifer. Typically a good Jordan well can be expected to produce 1,000 gallons per minute 16200~ekoocAve. S.E., Prior Lake, Minnesota 55372-1714 / Ph. (612) 447-4230 / Fax (612) 447-4245 AN EQUAL OPPORTUNITY EMPLOYER (GPM). The highest production rate we are aware of for a FIG well is 750 GPM (the Mdewakanton Sioux well). Savage has performed testing and modeling which shows that only one FIG well would be productive in the entire City of Savage and that well would be only marginally productive. Letters to and from the DNR and other general information regarding wells and these issues are attached. The city has been growing for the past three years and is now at least three years behind in providing firm well capacity for its population. The attached chart shows the total water pumped plus the average and maximum daily water demand for each five year period since 1980. As you can see, the water pumped and the average daily demand on our system has more than doubled since 1980. The city has done a commendable job in trying to conserve water and will be required to do more in the water conservation area in the future. However, as the city continues to grow, we do need another well on-line as soon as possible to meet the water demand. Over the last few months, the DNR has worked with other agencies who, like us, are involved in the Southwest Metro Groundwater Work Group and have done more groundwater modeling and study of the impact Jordan wells have on the Savage Fen complex. Now they have come to the conclusion that if the city were to drill a Jordan Aquifer well on the west side of Prior Lake, there may be no detrimental impact to the Savage Fen. Staff met with representatives of the DNR on March 15th and they have indicated that a Jordan well on the west side of the lake would be allowed with the stipulation that an observation well to monitor the water level in the Jordan Acquifer also be supplied by the city (cost estimated at $10,000.00). This may be done with an existing well or an abandoned well in a newly developed area or the city may have to drill this observation well. ISSUES The city's Comprehensive Water Supply Plan has always shown an additional well outside of the existing well field. The city has an existing sixteen inch trunk water line adjacent to County Road 82 near the Glynwater area which could provide the capacity for a well in this area. The geology would have to be studied and the appropriate land acquired prior to beginning the construction of Well NO.6. WELL6AG.DOC ALTERNATIVES: RECOMMENDED MOTION: WELL6AG.DOC . -.-' - The alternatives to drilling a Jordan well on the west side of the lake is to continue to try to get special permission to drill a Mount Simon Hinkley Well in our existing well field. Besides being very difficult to get this permission, the Mount Simon Hinkley water can contain high levels of radon and/or radium which require treatment. Furthermore, the Mount Simon Hinkley well would be approximately 30 to 40% more expensive than a Jordan well due to the deeper drilling. Another alternative would be to drill a FIG well which also has its liabilities. As previously stated, it is a very poor producing aquifer and we may not achieve the desired flow from it. The FIG well would also cost more than a Jordan well. Staff recommends that we move forward with the Jordan well on the west side of the lake. The first step would be to hire a consultant who would study the geology and determine the appropriate area for a new well. The estimated cost of the engineering, well construction, and pumphouse construction of a new well can be up to $600,000.00 as identified in the City's Capital Improvement Program. The attached sheet shows the proposed schedule if we move forward at this time. With this schedule the well would not be providing water to our residents until summer of 2001., 7"":1.- \ (.\! <:...--' V\._ The alternatives are as follows: ,I:".' ", ./ i" i ( i' '1( fl'--? /'1, /" ~ I,) p, 0/" i I I ',t,.~, I 1. Direct Staff to solicit' engineering proposals for the development of a new Jordan well on the west side of the lake and bring a recommendation for consultant selection back to the City Council at its earliest convenience. 2. Direct Staff to investigate other water sources. Alternative No 1. REVIEWED BY: T J..1'..L~LL '-'I '-"'-'..AI.~'-" . - ~_'__ ______0_ 5'YI\. 1/3 /q 97 The race for water For five southwestern suburbs in the Twin Cities area, the race to drill deeper into the ground for water is drawing the attention of state offICials and may be an early sign of a metrowide problem. Growth projections show the five suburbs, which already have 42 municipal wells and plan to drm 25 more, will have a 67 percent pcpulatkin increase by 2020. But state officials, concerned that the existing wells are draining nearby wetlands and streams, are worried that simp.lY drilling deeper may cause even more environmental problems and that the cities have done 6tt1e to conserve water. 1.200 ft. 1.000 800 600 40Q 200 II Wells Sea level 0 -200 By 2020, five cities - Shakopee, prior Lake, Savage, . Bwnsville and Lakeville- wBI see big increases in popula- tion lUld in the total amounts that their wells can pump. Population (in thousands) 200 ...... 150 . .........100 ~'~j , '-:--.~ 50 'SO I '70 I '90 2020 0 'SO '80 1950 '60 '70 'SO . '90 2000 '10 '20 [3 Aquifers: R~k formations with interconnected pores and fractures that can readily transmit water. They recharge <frcftn precipitation that soaks into the .. "'. 'di~~.or frol11. streams, lakes . Confining layers: less saturated, less permeable rock formations that retard water movement i.."~~J'\ aquifers. Note: Illustration is representational of actual location of aquifers and has been exaggerated vertically by approximately 15 times. Sources: Minoesota Geological Survey. Metropolitan Council, U.s. Census WATER from. B1. . .o! Minnesota Department of Natural Resp.l:ll:fes . /i';'l r r.,,~ r/ II LL,~ is} r: . )()(l L~fay"lt(' R(l~Jr @ <<S' 1/ (IIi "> . - - _. , . , I.' ", SLPa\lI.\linnCS(lla))I)).-l()~ r F~8 l!J I/:I_~ CJ 10 ~/I.'iJ &Y~~:::f!l February 17, 2000 Tom Roushar Bonestroo, Rosene, Anderlik and Associates 2335 West Highway 36 St. Paul, MN 55113 Dear Mr. Roushar: RE: Additional Jordan Well, City of Prior Lake Recently, you contacted me concerning the expansion of Prior Lake's water supply system. You were wondering whether a Jordan aquifer well located west ofthe buried glacial valley would be acceptable (Attachment A). From my review ofthe available data and in consultation with DNR's Regional and Area Hydrologists and other hydrogeologists in Waters' Ground Water Unit, I'v.e detennined that a Jordan aquifer well in the area indicated on your map would be an acceptable alternative provided that suitable water level observation wells can be found or drilled on both sides of the buried valley so that the aquifer can be monitored closely. Infonnation obtained during the course of placement and pumping from this site can then be used to determine whether further withdrawal from the Jordan west of the buried glacial valley would be acceptable. Please note that your inquiry does not constitute a formal request by the City and, therefore,this response is only for your infonnation in determining the City's next steps. Before responding to your inquiry, I reviewed, con'sidered and consulted the following: . . Geologic Atlas Scott County, Minnesota, County Atlas Series Map C-1, Plates 5 & 6, 1982. - The general location ofthe site that you identified is west ofa buried glacial valley and on the opposite side of that feature from the Savage Fen and other surface water features of concern. This buried glacial valley was incised through both the Prairie du Chien and Jordan (PduC/J) formations into the FranconialIrontonlGalesville (FIG). Also, on Plate 6, the directions of ground water flow in both the PduC/J and FIG aquifers are indicated. Ground water flow in the PduC/J and the FIG at the requested site is toward the northwest rather than the north or northeast toward Savage Fen. One note of caution, however, is that this map is nearly 20 years old and no published update is available. Therefore, if or when these maps are redone with all the new well riNR Information: 651-296-6157 · 1-888-646-6367 · TIT: 651-296-5484 · 1-800-657-3929 An Equal OpponunilY Employer Who Values Diversity () Prinled on Recyded Paper Containing a Minimum of 10% Posl.Q)nsumer Waste construction data since that time period, the depth and location of the buried glacial valley and the direction of ground water flow may be adjusted. . Savage aquifer test data Jan. 1998 and Sept.- Oct. 1998 (unpublished), and an unpublished well record for a FIG well at the Shakopee Mdewakanton Sioux Community (SMSC) - Water levels in wells which were measured during aquifer tests ofthe PduC, the Jordan and the FIG aquifers plus the as-constructed water levels in a FIG well at SMSC were plotted and generally confirmed the FIG flow directions and the PduC/J flow in the vicinity of the Savage Fen as they were mapped on the County Atlas geologic maps (see first item). Additional water level data for Jordan wells in Prior Lake and Shakopee have not yet been analyzed. The results of the Sept. - Oct. 1998, aquifer tests confinn that the PduC and Jordan aquifers are hydraulically connected to some degree in this vicinity. This connectivity has been the subject of considerable study and discussion in the last couple of years. The consensus is that, particularly along existing or buried valleys, the degree of hydraulic connection between the two formations/aquifers increases greatly near the edges ofthose valleys. The area surrounding the Savage Fen, the location of Prior Lake's current Jordan wellfield, and the proposed location of this new Jordan well are all near valley edges and thus will likely have a greater hydiaulic connection between the two formations. . USGS Open-File Report 96-182, Analysis of Hydrogeologic Properties in the Prairie du Chien-Jordan Aqllifer. Shalropee Mdewa1n'l'lton Sioll..'l!: Co!!'_'!!u!'ity, Southeastern Minnesota; USGS Water-Resources Investigations Report 99-4183, . . Hydraulic Properties ofthe Prairie du Chien- Jordan Aquifer, Shakopee Mdewakanton Sioux Community, Southeastern Minnesota, 1997, and Prior Lake Savage Fen Impact Report, Barr, June, 1995 - These documents present the results of either pumping tests or modeling and vary in their presumptions of the effect of the sediments in the buried glacial valley on the flow in PduC/J on either side ofthe valley and, therefore, on the Savage Fen. In my opinion it is likely that the type of valley fill is quite variable depending upon the volume of flow through the valley at the time of deposition. With that in mind and with the direction of flow shown on the available geologic maps, it is my opinion that the buried glacial valley may constitute more of a boundary to ground water flow in the PduC/J than a path for uninterrupted flow. Additional mapping of new well records would potentially verify or disprove this opinion; however, that work has not been done and I do not know of any plans to do that at this time. . Water level observation wells - In a recent phone Conversation with me, you indicated that there are likely to be existing, unused domestic wells in the Jordan aquifer which are located east and northeast of the proposed site between -that site and the Savage Fen area. The DNR would require that observation wells be in place prior to pumping at the new location. There would need to be at least one observation well on each side of the buried glacial valley at mutually agreeable locations. Since there is a 16" water main within a reasonable distance, little new infrastructure would need to be constructed. If for some reason this location does not prove to be a desirable site for further expansion or that use of this new well has to 2 I ---.----------- .-----r...--..----------.....-----.. be restricted, then the inv~stment has been relatively small. Another option at this site is to design the well so that it could be extended in the FIG or perhaps the Mt. Simon if things didn't work out. This option for a new Jordan well location appears to be a good alternative which could not only meet Prior Lake's immediate supply needs, but also provide quantitative data on propagation of drawdowns in the Jordan due to pumping ofthe Jordan. Of course, quantitative data is preferable to system modeling based on assumptions when making water management decisions. If you have any questions, please feel free to contact me at 651-296-9231. Sincerely, DNR Waters rv-J ~li f ~( L--,1'-'.<e~ Laurel D. Reeves, PG Hydrogeologist cc: Frank Boyles, Prior Lake City Manager Bud Osmundson, Prior Lake Div. of Public WorksICity Engineer Gary Oberts, MCES Dale Homuth, DNR Waters Pat Lynch, DNR W~ters Jim Japs, DNR Waters John Line Stine, DNR Waters 3 ~~ Minnesota Department of Natural Resources Metro Waters - 1200 Warner Road, St. Paul, MN 55106-6793 Telephone: (651) 772-7910 Fax: (651) 772-7977 Novemberl2, 1999 Frank Boyles, City Manager City of Prior Lake 16200 Eagle Creek Ave. S.E. Prior Lake, MN 55372-1714 RE: Proposed New Well, City of Prior Lake Dear Mr. Boyles: My apologies for taking so long to respond to xour October 4, 1999-letter. As we discussed on the phone the other day, the questions and issues you bring up relate to opinions of another Unit within DNR Waters. Because this is a very busy time of the year for that Unit, it took some time to get their opinions on these issues. The law that restricts the use of the Mt. Simon/Hinckley aquifer requires that no feasible or practical aitemative water suppiyexist before the DNK can issue permits for use of water from this aquifer. Therefore, when you construct your new well, you must show that the FranconialIrontonlGalesville (FIG) aquifer is not a feasible or practical water source. The DNR has found that there is sufficient variation of the geologic and hydrogeologic properties of the FIG aquifer in Scott County to warrant careful consideration of this aquifer for your water supply. The DNR is unwilling to set any minimum pumping rate or specific capacity in an attempt to define what is "feasible or practical." We have found that the feasibility of using lower yield aquifers varies considerably depending on a City's needs. Instead, I propose the following procedure: 1) If there is agreement during the drilling through the FIG between the City and the DNR that the FIG will meet th~ City's needs, then the City will develop and utilize the AG. 2) If there is agreement by both DNR and the City that the FIG is inadequate, then the City continues to the Mt. Simon/Hinckley aquifer. 3) If the DNR feels that use of the FIG may be feasible and practical, but the City does not, then the City will need to conduct a FIG aquifer test of a minimum three days to demonstrate the FIG's parameters. In any instance, we aslc the City to provide or contribute to the construction of an observation well in the aquifer they will be using. Since the City of Shakopee is also requesting additional water usage from the Mt. SimonlHinckley aquifer, they too will be asked to provide such an observation well. I am advised that one such observation well would be adequate between both cities. If you want more information on the possible location and specifications for such an observation well, pleasecontact Laurel Reeves at 651-296-9231. DNR Information: 651-296-6157 · 1-888-646-6367 · TIY: 651-296-5484 · 1-800-657-3929 An Equal Opportunity Employer Who Values Diversity ....\ Printed en Recycled Paper Containing a ".... Minimum of 10% Post-Consumer Waste . / I ~/ / I , / /1' J .' Frank Boyles, City Manager City of Prior Lake November12,1999 Page 2 I fully understand that the City has immediate needs for a well that will provide a certain pumping rate. We will consider the timing of these needs when we work \\lith you in deciding whether use of the FIG is practical and feasible. However, please be aware that even if we agree that use of the FIG is not practical and feasible under current conditions, we would expect the City to plan-any expansions or replacements of its water supply system by considering water sources other than the Mt. Simon/Hinckley aquifer. DNR Waters is also concerned about the long-term viability of the Mt. SimonlHinckley aquifer as a public water supply source, as use from it increases. As you are aware, head levels of this aquifer have been steadily declining in your area. Therefore, we would urge the city to consider other supplies in your future planning, such as 1) use of interconnections with neighboring cities, 2) smaller capacity FIG wells, or 3) use of the Prairie du Chien/Jordan aquifer, if extensive testing proves that it does not affect the Savage Fen and other valuable surface water resources. Please do not hesitate to contact me or Pat Lynch, at 651-772-7910, if you have any questions or concerns abOut this response. Sincerely, OJ ;;/~ Dale E. Homuth Regional Hydrologist c: Tom Roushar, Bonestroo Rosene Anderlik & Assoc., 2335 West Hwy 36. St. Paul, 55113 Gary Oberts, MCES John Linc Stine, DNR Waters Jim laps, DNR Waters Laurel Reeves, DNR Waters' Pat Lynch, Area Hydrologist . October 4, 1999 Mr. Dale E. Homuth Regional Hydrologist - Metro Waters Minnesota Dep1. of Natural Resources 1200 Warner Road S1. Paul, MN 55106-6793 Re: City of Prior Lake / Well No.6 (City Project No. 97-03) n__... .. 1_ l.I___ ..&.L. Ut::dl IVII. nVIIIUlIl. I am in receipt of your letter dated September 15, 1999. I would like to thank you for the positive approach outlined in that letter and your willingness to work with the City of Prior Lake. As I explained during our meeting on August 23, 1999, Well No. 6 is an important project for the City - one that is critical in order to meet the needs of our growing pop~ation. During the August 23rd meeting, our consultant, Tom Roushar, made a case for determining the viability of developing the FIG aquifer by comparing cuttings and resistivity tests with three recent FIG wells in our area; Savage Well No. 8,Shakopee Well No. 10, and Mdewakaton Sioux Community Well (Mystic Lake). Your letter states "however, if in the opinion of our Groundwater Unit, the cuttings do not clearly show the inadequacy of the FIG, the DNR would require a pump test of the aquifer. As we discussed, I am unable to give you clear guidance as to what would happen if yields from the FIG turn out to be higher than expected, but less than the 1,000 gpm rate." The City of Prior Lake is not opposed to a FIG well. However, we are opposed to a 350 gpm well with drawdown approaching 200 feet. If the FIG formation is promising, I believe that the City Council would support an attempt to finish Well No.6 as a FIG well. Prior Lake would like to avoid the additional cost of a Mt. Simon / Hinckley well and the risk of higher radium levels. Rather than drilling into the FIG formation and then debate cuttings, resistivity and acceptable yields as I understand was the case for Savage's Well No.8, I would like to better define the two sentences from your September 15, 1999 letter now. J 16200 Eagle Creek Ave. S.E., Prior Lake, Minnesota 55372-1714 / Ph. (612) 447-4230 / Fax (612) 447-4245 AN EQUAL OPPORTUNITY EMPLOYER -..------r--...-.------...--- D. Homuth October 1, 1999 Page 2 of 2 As you know, neither the Savage well, nor the Shakopee well, has significant capacity at an acceptable drawdown. Our consultant has learned the following regarding the Dakota Community well: . FIG well with only the bottom 20 feet of the Franconia open . Good coarse sandstone (55 to 60 feet thick) at the bottom of the Galesville . Extensive development .. Test pumped at 750 gpm with 165 feet of drawdown. . I propose that the Sioux Community FIG well be the basis of the definition for your two undefined sentences. For a FIG well to be considered viable for Prior Lake, it will have both of the following characteristics: (1) the presence of a good coarse sandstone layer of approximately 60 feet in thickness will be used as the criteria to determine whether the FIG formation is to be test pumped; and (2) A pumping rate of no less than 750 gpm with a specific capacity of approximately 5 gpm per foot of drawdown will be used as the definition of acceptable yield. Prior Lake will act in good faith regarding the FIG aquifer. However, public money must be spent wisely. We cannot spend money to drill a FIG well with very limited capacity. A recent study conducted for the City of Savage indicates that the FIG aquifer has very limited capacity overall. Only if the FIG aquifer is found to be markedly better in Prior Lake than it is in Savage should the MnDNR require that Well No.6 be a FIG well. Please review the above definition. If you concur, please confirm in writing and we will proceed to the next step in the approval process. I look forward to hearing your comments. I can be reached directly at (612) 447-9801. cc: Sue McDermott 1:\FRANK\LETTERS\99\HOMUTH.DOC CITY OF PRIOR LAKE AVERAGE AND MAXIMUM DAILY WATER DEMAND (IN MILLION GALLONS) YEAR TOTAL AVERAGE MAXIMUM WATER DAY DAY PUMPED 1980 228.1 0.62 -- 1985 287.4 0.79 -- 1990 345.9 0.95 2.57 1995 407.7 1.12 3.52 1996 466.7 1.28 4.03 1997 446.4 1.22 3.88 1998 474.3 1.30 3.74 1999 503.6 1.38 3.28 . Q .... lU .... La.. .... .... LLI ~ CJ ~ .... .... CI) .... >< LLI I ~ ~-~ . - I ~ ~ I ~ I ~ ~ I ~ ~O~.O~ l~_~_ c o ;; !; ~ .", ~-~-~_"o\o\.--t ~-~- I" I ~ I i...o~. ~ L~ o LLI .... ~ .... CI) CI) o a.. o o co -.r o o -.r ('oj o :t ~ a: o ~ I- I.JJ li ~ I.JJ ...J <( U V) a. o Q.l~ ~\., 0;:) ...JO ~ \.,.c 00 .;: u a.. ~ ....U 00 a. ~E (}~ Q.l lL.. >.c '(i;4JL.. o g '~.2 'C :] ...... c 0..... C Ill._ Ill. ~~c:O~\()' OES 1Il0l "00 "0 "'- :lNOlll50l ~.!! U._~ "0 Q. >'.51 tl ...... ..Q Q.;:l0l E~"O=-t; Gi :J--4)Q)c__ E c III ~._ 0 'X'- 5 GJe OL.U5Ql E~c'EV)ci. ~g~~JlE ::2 ~ E .3 .!!l ai5g~\.:s III ): 0 .Q.... ~-V)gcto g.,g~Il)CQl L...... -' 0'10- ~ ~-=?s:z 5 ~ o~-o e:g 0.. t:cg8.ge 8:.::-.co_Q. N ~ ;:) 01 LL: ~ .... CI) ..... .... LI.I 3t WELL NO.6 PROPOSED SCHEDULE ITEM Update City Council Receive Engineering Proposals Contract Engineer Study Geology/Select Possible Sites Prepare Well No.6 Plans & Specs. Acquire Property Advertise for Bids for Well Construction Receive Bids for Well Construction Award Well Construction Contract Well Drilling & Development Prepare Pumphouse Plans & Specifications Advertise for Bid for Pumphouse Construction Award Contract for Pump house Construction Pumphouse Construction Well On Line WELL6AG.DOC ----.----------_..--- DATE April 3, 2000 April 17, 2000 May 1, 2000 May - June, 2000 May - June, 2000 Aug. 1,2000 Aug. 4, 2000 Aug. 25,2000 Sept. 4, 2000 Sept., 2000 - Feb., 2001 Sept. - Nov., 2000 Dec. 1,2000 Jan. 1,2001 Jan.-June, 2001 July, 2001