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HomeMy WebLinkAbout2/27/01 . Water Board Agenda Regular Meeting February 27, 2001 7:00 PM 1. Call to Order 2. Approve Agenda 3. Approve Minutes -regular, January 23, 2000 4. Continued Discussion Items a) Well #3 Status Report b) Wellhead Protection - Scoping Decision, Proposal for Services 5. New Business a) Well Site Acquisition - Charleswood, Vermillion Grove Developments . b) 2000 Trunk Water Main Project Change Order 6. Approve Bills 7. Financial Report 8. Open Forum 9. Adjourn . . . . --. N fa n 'ffCr:'~,\ r ".. r2 tr::". '-~ ',j ".!..-."" ". '.' .... '. l'\ ~~ ',' ~U)\ --,\:,\ \~~~ \ ! 1001 J@I Protecting, maintaining and improving the health of all Minnesotans February 13, 2001 Mr. Lee Mann Director of Public Works City of Farmington 325 Oak Street Farmington, Minnesota 55024 Dear Mr. Mann: This letter provides notice of the results of a scoping meeting held with you, Mark Janovec (Northern Environmental), Dan Barret (Northern Environmental), Robyn Hoerr (Minnesota Rural Water Association), Art Persons (MDH) , and me on January 19, 2001, at Dakota County offices regarding wellhead protection planning. During our meeting, we discussed the 1) delineation of a wellhead protection area, 2) delineation ofa drinking water supply management area, and 3) assessment of well and aquifer vulnerability related to these areas for the Farmington water supply wells (see enclosed table). It is our understanding that you will serve officially as wellhead protection area manager on behalf of the city. It is also our understanding that you will prepare and send a letter to local units of government notifying them of your intent to develop a wellhead protection plan, as required by the wellhead protection rule (part 4720.5300, subpart 3). Robyn can assist you with this (1 think you were provided with an example letter at the meeting). As you know, the time period for completion of the wellhead protection plan is determined by the rule as described at the meeting. During the meeting we notified you that the city will have until November, 2003 to complete its wellhead protection planning. As described in our January 29, 1999, letter to the city, this time frame corresponds to 3.5 years from the May 2000 date that your new Well No.5 went on-line. During our meeting, we discussed rule requirements and the types of information needed to delineate the wellhead protection area accurately and to conduct the vulnerability assessments. Many oithe data elements identified in the wellhead rule that may need to be considered in conducting Part 1 wellhead activities for Farmington are already available to the Minnesota Department of Health (MDH), and you need only provide documentation for information you use that is not otherwise available to us. Examples of such materials are as follows: · Past and projected well use information; · Conducting a pumping test. The data elements id.entified in the scoping decision notice (enclosed) are those that will be needed to complete Part 1 of the wellhead rule requirements. The three components of Part I are the 1) wellhead General Information: (651) 215-5800. TDD/TTY: (651) 215-8980. Minnesota Relay Service: (800)627-3529. www.health.state.mn.us For directions to any of the MDH locations, call (651) 215-5800. An equal opportunity employer Mr. Lee Mann Page 2 February 13,2001 . protection area delineation, 2) drinking water supply management area delineation, and 3) vulnerability assessment. I have summarized some of the specific information requirements (with respect to rule requirements) in the following paragraphs. Item 1 - Criteria for wellhead protection area delineation. The following criteria specified in the rule language (part 4720.5510) must be used for wellhead protection area delineation: Time of travel - A minimum ten-year time-of-travel must be used to determine the boundaries of the wellhead protection area. Ten years should provide a minimum-sized area in which to 1) detect possible aquifer contamination and 2) provide sufficient reaction time to remediate potential health impacts on the users of your public water supply. You have the option of selecting a time-of-travellonger than ten years. Your consultant can help you make this determination. Also, your submittals must show the one-year time-of-travel capture zone around each well. Aquifer transmissivity - Itis very important to have an accurate estimate of the aquifer transmissivity because it is a key factor affecting the size and shape of a wellhead protection area. The wellhead . protection rule requires that public well owners estimate transmissivity from a pumping test, whenever possible. As we discussed during the meeting, you will need to conduct a pumping test on your system's wells. These tests must be conducted to gather data on the transmissivity of the materials your wells pump from and are required by the wellhead rule. MDH can assist you and your consultant in carrying out the tests. Daily volume of water pumped - The daily volume of water pumped must be calculated for the public wells. According to the rule, this value should be determined from either I) the previous five years pumping information for each well or 2) projected annual pumping over the next five years. The year having the gre~test recorded or projected discharge for each well should be used to determine the maximum daily volume of water pumped. These data and the values used for the wellhead delineation I analysis should be presented clearly in the report documenting the Part I planning activities. Hydrologic boundaries - As we discussed at the meeting, the main hydrologic boundaries in the Farmington area that must be considered for the Prairie du Chien-Jordan Aquifer system are the presence of other high-capacity pumping wells in the vicinity of your wells. The Department of Natural Resources maintains a database of high-capacity pumping wells in the state. This database will likely be the best source of information regarding quantity of water pumped by other wells in the area. Locations of these wells should be confirmed. . . . . Mr. Lee Mann Page 3 February 13, 2001 Groundwater flow field - It will be necessary to determine the ambient direction of groundwater flow up gradient of your public wells. Information regarding the regional groundwater flow conditions in the Prairie !iu Chien-Jordan Aquifer system is available from a number of regional studies. Method used to delineate wellhead protection areas - The complexity ofthe groundwater flow field in the Prairie du Chien-Jordan Aquifer system and the nature of the hydrologic boundary conditions require that a computer code be used to make the wellhead protection area delineation. Several regional models are available that could be used for this analysis. Your consultant can recommend what will work best for your needs. The locations of the city wells that I checked with you at the meeting are listed in the table (Table 2) at the end of this letter. These locations are presented in the form of coordinates using the UTM meters projection and a datum ofNAD83, zone 15 . Your consultant should use these locations for the delineation analysis. All electronic submittals to MDH should use the UTM meters projection and the NAD83, zone 15 datum. Delineation of drinking water supply management areas - Your consultant will work with you to identify the drinking water supply management area using streets, roads, section lines, parcel boundaries or other features that the public can more easily understand for referencing the area that will be included in the city's wellhead protection plan. Item 2 - Well and aquifer vulnerability assessments. Along with the delineation of the wellhead protection areas, you must make an evaluation of the vulnerability of the wells and aquifer used by the city (part 4720.5210). This is needed to determine the scope of the inventory of potential contaminant sources and the resulting strategy for managing them in the future. Based on the information in our files, the department has determined that some of your wells are not vulnerable and others are vulnerable to contamination. This designation is considered preliminary and could change if you have different or more current information about the wells than we had at the time the assessments were made. You will need to consider geologic conditions, well construction, and water chemistry to make the vulnerability assessment. Since we met, I have collected a sample from Well No. 5 for tritium analysis, the result of which will assist your consultant in making the vulnerability assessment. Item 3 - Information describing the physical environment and land use. The wellhead protection plan should include a description of the geologic conditions throughout the drinking water supply. management areas to support the delineation approach and the vulnerability assessment of the aquifers supplying your wells. Geologic maps, regional studies and information Mr. Lee Mann Page 4 February 13,2001 . available from local water well contractors will help fill in some of the gaps in our understanding of subsurface. geological and groundwater conditions. This information should be presented in the report documenting the Part I activities. We understand that your wellhead protection work will be done by Northern Environmental. We talked of the importance of meeting partway through the project - a pre-delineation meeting - to make sure MDH, Northern, and Farmington staff are in agreement relative to the technical details. Northern staff are familiar with the wellhead protection program and its technical requirements. Should you desire additional information on these requirements for either Part I or Part II activities, please contact MDH staff at the numbers listed below. In closing, we look forward to working with you on completing your wellhead protection plan. I will be working on the wellhead protection area delineation and vulnerability assessment in conjunction with Robyn Hoerr and Art Persons. If you have any questions regarding this letter, please contact Robyn (218/821-5028); Art (507/292-5138), or me (651/215-1322). Sincerely, s~~ Stephen W. Robertson, Hydrogeologist Environmental Health Division P.O. Box 64975 St. Paul, Minnesota 55164-0975 . SWR:kmc Enclosures cc: Art Persons, Planner, Source Water Protection Unit, Rochester District Office RobYI) Hoerr, Minnesota Rural Water Association Mr. Mark Janovec, Northern Environmental Mr. Bill Olsen, Dakota County Environmental Management . . . . TABLE 1 Municipal Water Supply Well Information Farmington, Minnesota Local Well Unique Casing Depth Well Year Vulnerability Name Number Aquifer (ft) Depth (ft) Constructed Status 1 Prairie du Not Vulnerable 1 200932 Chien-Jordan 284 402 1938 Prairie du Not Vulnerable 2" 200934 Chien-Jordan 197 399 1952 Prairie du Not Vulnerable 3 201154 Chien-Jordan 130 430 1959 4 235586 Jordan 392 477 1973 Not Vulnerable 5 603051 Jordan 417 512 1999 Vulnerable Note: 1. Vulnerability status based on MDH staff review of well construction, geologic materials encountered during drilling, well use and water quality. · WeIl2 (200934) is currently used as an emergency backup well only and need not be included in the wellhead protection planning activities. TABLE 2 Municipal Water Supply Well Locations Farmington, Minnesota Local Well Unique UTM-East UTM-North Name Number (meters) (meters) 1 200932 488,575 4,942,918 2" 200934 488,561. 4,942,917 3 201154 488,193 4,942,408 4 235586 485,945 4,947,550 5 603051 486,184 4,945,830 WeIl2 (200934) is currently used as an emergency backup well only and need not be included in the wellhead protection planning activities. . . . SCOPING DECISION NOTICE No.1 ~ Delineation of the Wellhead Protection Area ~ Boundaries of the Drinking Water Supply Management Area ~ Vulnerability Assessment of the Well ' ~ Vulnerability Assessment of the Drinking Water Supply Management Area Name of Public Water Supply Date Farmington (PWSID = 1190008) February 13,2001 Name of the Wellhead Protection Manager Lee Mann Address City Zip 325 Oak Street Farmington 55024 Unique Well Numbers Phone 200932,201154,235586,603051 651/463-1601 Instructions for Completin~ the Scopin~ No.1 Form N D V S N = Not required. If this box is checked, this data element is NOT necessary for your wellhead X protection plan. Please go to the next data element. N D V S D = Required for the DELINEATION. If this box is checked, this data MUST be used for the X "delineation of the wellhead protection plan." N D V S V = Required for the VULNERABILITY assessment. If this box is checked, this data MUST be X used for the "vulnerability assessment of the drinking water supply management area." N I D I V I S I S = Submit to MDH. If this box is checked, this data element MUST be included in your wellhead I I I X I protection plan AND submitted to MDH. If there is NO check mark in the "S' box, but there is in the "D" or the "V" boxes, this data element MUST be included in your plan but should NOT be submitted to MDH. This box will only be checked if MDH does not have access to this data element. This will help to reduce the cost by reducing the amount of paper and time to reproduce the data element. 1 DATA ELEMENTS ABOUT THE PHYSICAL ENVIRONMENT An existing map or list of local precipitation gauging stations. . N D V S X An existmg table showmg five years. Technical Assistance Comments: N D V S An existing geologic map and a description of the geology, including aquifers, confming layers, X X X recharge areas, discharge areas, sensitive areas as defmed in Minnesota Statutes, section 103H.005, subdivision 13 and roundwater flow characteristics. Technical Assistance Comments: Information of this type is required to characterize fully the geologic and hydrogeologic setting of the city's well fields and the aquifers within them. This information should be used to define aquifer geometry, location and-magnitude of recharge and discharge areas, and groundwater flow information. Many regional-scale studies in the Farmington area are available to help in this characterization. Submit to MDH only the information that is not available in the public domain. . N V S Existing records of the geologic materials penetrated by wells, borings, exploration test holes, or X X excavations, including those submitted to the department. Technical Assistance Comments: Information of this type may be useful to refine the understanding of the geologic and hydrogeologic setting on a local basis. Submit only if information is not otherwise available to MDH. . 2 . . . N D V S Existing borehole geophysical records from wells, borings, and exploration test holes. X X X Technical Assistance Comments: Submit only if information is not otherwise available to MDH. N D V S Existing surface geophysical studies. X X X Technical Assistance Comments: Submit only if information is not otherwise available to MDH. Existing maps of the soils and a description of soil infiltration characteristics. N X A description or an existing map of known eroding lands that are causing sedimentation problems. 3 An existing map of the boundaries and flow directions of major watershed units and minor watershed units. N D V S An existing map and a list of public waters as defmed in Minnesota Statutes, section 103G.005, X subdivision 15, and public drainage ditches. Technical Assistance Comments: N D V S X The shoreland classifications of the public waters listed under subitem (2), pursuant to part 6120.3000 and Minnesota Statutes, sections 103F.201 to 103F.221. Technical Assistance Comments: N X An existing map of wetlands regulated under chapter 8420 and Minnesota Statutes, section 103G.221 to l03G.2373. D V Technical Assistance Comments: N D V S An existing map showing those areas delineated as floodplain by existing local ordinances. X Technical Assistance Comments: 4 . . . . . . DATA ELEMENTS ABOUT THE LAND USE This information will be helpful in delineating the Drinking Water Supply Management Area. N S An existing map of political boundaries. X D V X Technical Assistance Comments: This information will be helpful in delineating the Drinking Water Supply Management Area. N An existing map of public land surveys, including township, range, and section. This information could be helpful in delineating the Drinking Water Supply Management Area. N D V S A map and an inventory of the current and historical agricultural, residential, commercial, industrial, X recreational, and institutional land uses and potential contaminant sources. Technical Assistance Comments: While not needed for the Part I WHP planning activities, this information will likely be useful in conducting the Part II planning activities. An existing, comprehensive land-use map. N D X Technical Assistance Comments: While not needed for the Part I WHP planning activities, this information will likely be useful in conducting the Part II planning activities. N D V S Existing zoning map. X Technical Assistance Comments: While not needed for the Part I WHP planning activities, this information will likely be useful in conducting the Part II planning activities. 5 An existing map of transportation routes or corridors. . This information will be helpful in delineating the Drinking Water Supply Management Area. N D V S An existing map of storm sewers, sanitary sewers, and public water supply systems. X Technical Assistance Comments: While not needed for the Part I WHP planning activities, this information will likely be useful in conducting the Part II planning activities. N D V S An existing map of the gas and oil pipelines used by gas and oil suppliers. X Technical Assistance Comments: While not needed for the Part I WHP planning activities, this information will likely be useful in conducting the Part II planning activities. N D V S An existing map or list of public drainage systems. X Technical Assistance Comments: . N D V S An existing record of construction, maintenance, and use of the public water supply well and other X X X wells within the drinking water supply management area. Technical Assistance Comments: Data required to satisfy this element include information about the city's wells, and other wells as deep as city wells, that may affect the vulnerability assessment (i.e., changes to the well construction recorded on the original well log due to rehabilitation or reconstruction, changes in pumping rate). Also required is information relative to past and projected use of the well that will be used for wellhead protection area delineation. . 6 . . . DATA ELEMENTS ABOUT WATER QUANTITY An existing description of high, mean, and low flows on streams. May be useful in helping to calibrate groundwater flow model. N D V S An existing list oflakes where the state has established ordinary high water marks. X Technical Assistance Comments: N D V X S An existing list of permitted withdrawals from lakes and streams, including source, use, and amounts X withdrawn. Technical Assistance Comments: Only required if affected surface water bodies are in direct hydraulic connection with the aquiferes) of concern and withdrawals affect water levels in both the surface water and adjacent groundwater systems. N X An existing list of lakes and streams for which state protected levels or flows have been established. N An existing description of known water-use conflicts, including those caused by groundwater pumping. Technical Assistance Comments: Conflicts between use of groundwater resources and surface water bodies would be indicative of a hydrologic boundary that would need to be considered in delineating the wellhead protection area. 7 An existing list of wells covered by state appropriation permits, including amounts of water appropriated, type of use, and aquifer source. Technical Assistance Comments: The intent of this data element is to collect information that may be useful in identifying hydrologic boundary conditions (i.e., pumping wells) that could affect the size and shape of wellhead protection area boundaries. The city must provide past and projected well use information in support of the wellhead protection area. N S An existing description of known well interference problems and water-use conflicts. X D V X Technical Assistance Comments: Interference problems with other wells, if present, likely indicate a hydrologic boundary that would need to be considered in making the wellhead protection area delineation. N D V S An existing list of state environmental boreholes, including unique well number, aquifer measured, X X X years of record, and average monthly levels. Technical Assistance Comments: Only submit if not available to MDH. 8 . . . . . . DATA,ELEMENTS ABOUT WATER QUALITY An existing map or list of the state water quality management classification for each stream and lake. N D V S An existing summary of lake and stream water quality monitoring data, including: 1. bacteriological contamination indicators; 4. sedimentation; X 2. inorganic chemicals; 5. dissolved oxygen; and 3. or anic chemicals. 6. excessive rowth or deficienc Technical Assistance Comments: An existing summary of water quality data, including: 2) inorganic chemicals; and 3) organic chemicals. Technical Assistance Comments: Information of this type would be useful in completing the vulnerability assessment and in generally characterizing the hydrogeologic environment. Submit if information is not available to MDH. N An existing list of water chemistry and isotopic data from wells, springs, or other groundwater sampling points. Technical Assistance Comments: Information of this type would be useful in completing the vulnerability assessment and in generally characterizing the hydrogeologic environment. Submit if information is not available to MDH. N D V S An existing report of groundwater tracer studies. X X X Technical Assistance Comments: 9 N D V S An existing site study and well water analysis of known areas of groundwater contamination. X X X Technical Assistance Comments: Submit if information is not available to MDH. N D V S An existing property audit identifying contamination. X X X Technical Assistance Comments: Submit if information is not available to MDH. - N D V S An existing report to the Minnesota Department of Agriculture and the Minnesota Pollution Control X X X Agency of contaminant spills and releases. Technical Assistance Comments: - Check with Bill Olsen (Dakota County Environmental Management staff) who may have additional information relative to this data element. . . . 10 . . . Northern Environmenta/"u Hydrologists · Engineers · Geologists 372 West County Road D New Brighton, Minnesota 55112 Phone: (651) 635-9100 Fax: (651) 635-0643 TO: Lee Mann, City of Farmington DATE: 01/23/01 FROM: Dan Barrett, Mark Janovec SUBJECT: Completion of Phase 1 Wellhead Protection Activities, City of Farmington At your request, we have prepared this memo for you and the Water Board, to assist in planning and scheduling wellhead protection activities for the City of Farmington. This memo summarizes the results of the scoping meeting held with the Minnesota Department of Health (MDH) on January 19, 2001. Cost estimates are provided for activities required for completion of the Phase 1 wellhead protection planning process. The City of Farmington's wellhead protection project was initiated in November 1994. A ground- water model was constructed by Northern Environmental and a draft wellhead protection area delineation was prepared for the City's planning purposes. At the time, entry in the wellhead protection program was on a voluntary basis. Since that time, the wellhead protection plan rules have been changed and finalized. The program is now mandatory for City's who are ranked as vulnerable on the MDH phasing list or who have recently installed a new municipal drinking water well. The recent addition of Farmington's Well NO.5 has necessitated the City's official involvement with wellhead protection planning. According to criteria specified in the wellhead protection rules, the City of Farmington has until November 2003 to complete both phases of their wellhead protection plan. This time frame is not mandatory, in that the City may wish to complete their plan before that date. Based on the results of the scoping meeting, the following steps are required in order for the City to complete Phase 1 of the wellhead protection planning process: 1. Complete a 24-hour pumping and recovery aquifer test. This test consists of placing a probe in two of the City's wells (one for a pumping well and one for a monitoring well), to calculate the transmissivity of the Prairie du Chien-Jordan (OPCJ) aquifer from which the City draws it's drinking water supply. Prior to the test, an Aquifer Test Plan must be submitted to the MDH for approval. Following completion of the pumping test, data reduction and preparation of the letter report will be submitted within two weeks. The estimated total for the aquifer test, including preparation of the Aquifer Test Plan,field data collection,data analysis, and a letter report is $2,500 (per well tested). It is anticipated that only one of Farmington's wells will have to be tested. C:IWlNOOWSITEMf'ISCOf'ING.OOC 2. Update existing ground-water model to meet MDH requirements for wellhead protection. Several new data elements will need to be added to the existing model. Pumping records from the last 5 years, along with the projected pumping rates for the next 5 years, will also need to be incorporated into the model. The MDH has prepared a regional ground-water model for Dakota County, which will be compared to the City's existing model. New data elements will be added to reflect current understanding of the OPCJ aquifer near the City. Re-calibration of the model will be required after the addition of any new elements, to verify the model is correctly interpreting the ground-water flow system in the vicinity of the City. . The estimated costs for updating and re-calibrating the model are $3,400. 3. Perform an uncertainty analysis for the ground-water model. In meeting with current MDH requirements, an uncertainty analysis must be performed to look for possible shortcomings in the model's calculation. While the model is assumed to be mostly accurate in its calculation of the wellhead protection area,. some data elements are estimates and may not completely reflect real-world conditions. The uncertainty analysis identifies any weaknesses in the model and builds in a margin for error that is incorporated into the delineated wellhead protection area. This is done to make sure a large enough area is accounted for in the planning process. At the same time, it also verifies that the planning area isn't larger than it has to be. Managing an area that isn't necessary creates additional costs for the City when Phase 2 of the planning process is undertaken. The estimated costs for the uncertainty analysis are $1,200. ~ 4. Calculate the boundaries of the Drinking Water Supply Management Area (DWSMA). . This step takes the calculated wellhead protection area and relates it to surface features (parcel boundaries, roads, section lines, etc.), to create a map of manageable areas. In addition to the required 1 O-year time-of-travel (TOT) delineation, a one-year TOT delineation is now required by the MDH. To meet the City's needs for long-term planning, 20 and 30-year TOT delineations will also be prepared. The estimated costs for the calculation of the DWSMA boundary are $1,400. 5. Complete a vulnerability assessment of the City's wells and the associated DWSMA. The vulnerability assessment of the City's wells will update the current MDH rankings, based on current pumping, geologic, and water quality data. Also, the condition of the City's wells will be taken into account during this process. The vulnerability assessment of the DWSMA takes into account the I.ikelihood of contamination reaching the aquifer in the delineated areas. The area around Farmington appears to have a low vulnerability, but an analysis of the geologic conditions is still required by MDH rules. The estimated costs for the vulnerability assessment are $1,500. . C:IWlNOOWSITEMPlSCOPING,OOC . . t . 6. Hold a pre-delineation meeting with MDH staff. This step involves a short technical meeting with MDH staff to review the previous tasks outlined above. The reason for this meeting is to verify whether the model and the delineation appear to meet the needs of the welIhead protection rules. If a deficiency is determined to exist, it is beneficial to identify it at this stage rather than after official submittal of the wellhead protection report. The estimated costs for this meeting are $400. 7. Prepare a report of Phase 1 activities. This report summarizes the previous six tasks outlined above for MDH and City staff. This report will include paper copies of the delineated areas and electronic data files for the DWSMA calculation, as requested by MDH staff. The estimated costs of the Phase 1 report are $1,600. 8. Submit plan to MDH for approval. Following completion of the tasks 1-7, the report is submitted to MDH staff for review. The MDH has 30-60 days to comment on the report. The proposed DWSMA and vulnerability assessments either are approved at this time or are returned to the City for modifications. Past experience shows that the comments returned from MDH are relatively minor and are corrected with minimal effort. The costs associated in responding to comments are met on a time and materials basis, not to exceed $1,000. Phase 2 Wellhead Protection Plannina Following the approval of Phase 1 planning activities, a second scoping meeting is held with MDH staff, to determine the scope and level of effort required to complete the second phase of wellhead protection planning. The second phase of planning consists of developing a contaminant source inventory, creating a management plan for the welIhead protection area, and identifying opportunities and concerns as the City grows and develops it water supply system further. Since the level of effort for this phase is highly dependent on the results of Phase 1 activities, an accurate cost estimate cannot be projected for these activities at this time. In you have any questions regarding the wellhead protection planning process for the City of Farmington, please contact us at (651) 635-9100. C:IWlNDOWSITEMP\SCOPING.DOC