BEMIDJI CITY COUNCIL Work Session Agenda Monday, February 12, 2018

Transcription

1 BEMIDJI CITY COUNCIL Work Session Agenda Monday, February 12, 2018 City Hall Conference Room 5:30 P.M. 1. CALL TO ORDER / ROLL CALL 2. CLOSE THE MEETING: In accordance with Minnesota Statute Section 13D.05, Subd. 3(b) for the purpose of discussing with the City Attorney threatened or pending litigation with regards to the use of PFC-based firefighting foam concentrate. 3. REOPEN THE MEETING 4. DISCUSSION City Water System 5. ADJOURNMENT NOTE: All cellular devices are to be switched to a non-audible function during Council and Committee meetings.

2 Options to Address PFAS in Bemidji Water Supply Wells Presentation to City Council February 12,

3 Introduction PFAS (also known as PFCs ) have been detected in multiple Bemidji water supply wells. PFAS had been below the drinking water standards. In 2017 the MDH recommended lowering PFAS standards. These recommendations are not yet official standards. Expected to become standards this year. One PFAS compound has exceeded the current standard in one well. PFAS in some other wells exceed the recommended standards. Well use has been adjusted so the flow is below the new guidance. 2

4 What will you hear about this evening? Overview of PFAS, existing and proposed rules Summary of Bemidji s current supply wells Options to address short term needs Preliminary costs of potential solutions Next Steps Requested Council Actions 3

5 Overview of PFAS Existing Rules Proposed Rules Points to Consider 4

6 Overview of PFAS PFAS is a large group of chemicals Associated with Teflon Stain, water & grease resistant Uses include: Coating for food packaging Nonstick cookware Stain resistant fabrics Fire fighting foam Personal care products and cosmetics Cleaning products PFBA PFBS PFDA PFDoA PFDS PFHpA PFHpS PFHxA PFHxS PFNA PFNS PFOA PFOS PFPeA PFPeS PFTeA PFTrA PFUdA 5

7 Overview of PFAS PFAS is a large group of chemicals Associated with Teflon Stain, water & grease resistant Uses include: Coating for food packaging Nonstick cookware Stain resistant fabrics Fire fighting foam Personal care products and cosmetics Cleaning products PFBA PFBS PFDA PFDoA PFDS PFHpA PFHpS PFHxA PFHxS PFNA PFNS PFOA PFOS PFPeA PFPeS PFTeA PFTrA PFUdA 6

8 Overview of PFAS Current standards Abbreviation Full Chemical Name Health Risk Limit (HRL) µg/l, Rule PFBA Perfluorobutanoic acid 7.0 PFOA Perfluorooctanoic acid 0.3 PFBS Perfluorobutane sulfonate 7.0 PFOS Perfluorooctane sulfonic acid 0.3 7

9 Overview of PFAS Proposed standards Abbreviation Full Chemical Name Health Risk Limit (HRL) µg/l, Rule Health Based Value (HBV) µg/l, Guidance PFBA Perfluorobutanoic acid 7.0 No change PFOA Perfluorooctanoic acid PFBS Perfluorobutane sulfonate PFOS Perfluorooctane sulfonic acid

10 Overview of PFAS Proposed standards PFHxS special case Abbreviation Full Chemical Name Health Risk Limit (HRL) µg/l, Rule Health Based Value (HBV) µg/l, Guidance PFBA Perfluorobutanoic acid 7.0 No change PFOA Perfluorooctanoic acid PFBS Perfluorobutane sulfonate PFOS Perfluorooctane sulfonic acid PFHxS Perfluorohexane sulfonate none -- (1) 1. There is no HRL or HBV for PFHxS. MDH recommends use of the HBV for PFOS as a surrogate HBV for PFHxS until more research on PFHxS is available. 9

11 Overview of PFAS Example of PFAS in Bemidji Wells Rule Abbrev. Health Risk Limit (HRL) µg/l, Rule Health Based Value (HBV) µg/l, Guidance Present above Health Risk Limit (HRL) RULE PFBA 7.0 No change No PFOA No PFBS No PFOS Yes (Well 4) (2) PFHxS none -- (1) NA 1. There is no HRL or HBV for PFHxS. MDH recommends use of the HBV for PFOS as a surrogate HBV for PFHxS until more research on PFHxS is available. 2. Well 4 had three readings > the HRL. The November 2017 reading was below the HRL. 10

12 Overview of PFAS Example of PFAS in Bemidji Wells Guidance Abbrev. Health Risk Limit (HRL) µg/l, Rule Health Based Value (HBV) µg/l, Guidance Present above Health Risk Limit (HRL) RULE Present above GUIDANCE PFBA 7.0 No change No No PFOA No Yes PFBS No No PFOS Yes (Well 4) (2) Yes PFHxS none -- (1) NA Yes 1. There is no HRL or HBV for PFHxS. MDH recommends use of the HBV for PFOS as a surrogate HBV for PFHxS until more research on PFHxS is available. 2. Well 4 had three readings > the HRL. The November 2017 reading was below the HRL. 11

13 PFOS in City Water Supply Wells 12 HRL Health Risk Limit established in rule that must be met in drinking water HBV Health Based Value currently MDH guidance, not rule Expected to become rule sometime in 2018

14 MDH combines PFAS readings into an HI Overview of PFAS Acknowledges their combined effect Health Index HI There is an HI for the current standards There is an HI for the proposed standards An HI over 1 is an exceedance 13

15 Overview of PFAS Bemidji Wells Health Index HI, Rule Well # Present above Hazard Index RULE 3 No 4 Yes (1) 5 No 6 No 7 No 1. Well 4 had three HI calculations over 1. The Nov calculation was below 1. 14

16 Overview of PFAS Health Index (HI) Current Rule: Cumulative Effect of all PFAS 15

17 Overview of PFAS Bemidji Wells Health Index HI, Guidance Well # Present above Hazard Index RULE Present above GUIDANCE 3 No Yes 4 Yes (1) Yes 5 No Yes 6 No No 7 No Yes 1. Well 4 had three HI calculations over 1. The Nov calculation was below 1. 16

18 Overview of PFAS Health Index (HI) Current Guidance/ Proposed Rule: Cumulative Effect of all PFAS 17

19 Points to consider Current situation Supply meets existing & proposed standards Wells 3 & 4 currently unused Wells 5, 6, and 7 blended to meet standards Current water supply blended to be below HI of 1.0 Risks If PFAS goes up in Wells 5, 6 or 7, HI may go over 1.0 If Well 5 or 6 fails, HI may go over 1.0 Current system has no back-up well w/hi<1.0 No treatment to remove PFAS in use currently 18

20 Points to consider Time Frame Immediate term (Now) Existing wells blended to meet standards Short term (1 to 6 months) Project needed to obtain firm supply Long term (6 to 24 months) Study needed to define long term solution 19

21 Overview of Bemidji s wells Where is does Bemidji s water come from? 20

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26 Options to address short term needs New Water Source Water Treatment 25

27 Options for a New Water Source Groundwater from a New Well Site New well(s) near the Airport Existing Bemidji High School Wells Surface Water Lake Bemidji Mississippi River 26

28 Alternative Source Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Surface Water - Lake Bemidji Surface Water Mississippi River 27 Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates medium desirable characteristics and given a score of 2 Orange shading indicates less desirable characteristics and given a score of 1

29 Alternative Source Compatibility with Existing infrastructure Additional Water Treatment Requirements Complexity of Source Development Water Supply Resiliency Overall Score Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Surface Water - Lake Bemidji Surface Water Mississippi River 28 Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates medium desirable characteristics and given a score of 2 Orange shading indicates less desirable characteristics and given a score of 1

30 Alternative Source Compatibility with Existing infrastructure Additional Water Treatment Requirements Complexity of Source Development Water Supply Resiliency Overall Score Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport More desirable - 3 More desirable - 3 Medium - 2 Medium - 2 Could use existing treatment facility and distribution system No changes from existing treatment system expected if wells are PFAS free and meet other HRLs Sites must be chosen, water quality must be verified, and new wells installed and developed. Improvement from current tight cluster of wells at the airport. 10 Surface Water - Lake Bemidji Surface Water Mississippi River 29 Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates medium desirable characteristics and given a score of 2 Orange shading indicates less desirable characteristics and given a score of 1

31 Alternative Source Compatibility with Existing infrastructure Additional Water Treatment Requirements Complexity of Source Development Water Supply Resiliency Overall Score Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Surface Water - Lake Bemidji Surface Water Mississippi River 30 Medium - 2 Medium - 2 Medium - 2 More desirable - 3 New water main needed to connect with distribution system. New water treatment facility might also be needed. Pretreatment for iron and manganese. If iron is very high this source becomes less desirable. Could be brought online relatively quickly if High School is cooperative. Need water quality verification, permit modifications, new pumps, and controls. If used to supplement airport wells, the combined system would be more resilient. More desirable - 3 More desirable - 3 Medium - 2 Medium - 2 Could use existing treatment facility and distribution system No changes from existing treatment system expected if wells are PFAS free and meet other HRLs Sites must be chosen, water quality must be verified, and new wells installed and developed. Improvement from current tight cluster of wells at the airport. Less desirable - 1 Less desirable - 1 Medium - 2 Less desirable - 1 New water mains needed to connect with distribution system. New water treatment facility would be needed. Sedimentation, filtration and disinfection would be needed. Possible PFAS treatment. Sampling, permitting, and construction of intake structures Single intake would not provide resiliency Less desirable - 1 Less desirable - 1 Medium - 2 Less desirable - 1 New water mains needed to connect with distribution system. New water treatment facility would be needed. Sedimentation, filtration and disinfection would be needed. Possible PFAS treatment. Sampling, permitting, and construction of intake structures Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates medium desirable characteristics and given a score of 2 Orange shading indicates less desirable characteristics and given a score of 1 Single intake would not provide resiliency

32 Alternative Source Compatibility with Existing infrastructure Additional Water Treatment Requirements Complexity of Source Development Water Supply Resiliency Overall Score Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Surface Water - Lake Bemidji Surface Water Mississippi River 31 Medium - 2 Medium - 2 Less desirable - 1 More desirable - 3 New water main needed to connect with distribution system. New water treatment facility might also be needed. Pretreatment for iron and manganese. If iron is very high this source becomes less desirable. Could be brought online relatively quickly if High School is cooperative. Need water quality verification, permit modifications, new pumps, and controls. If used to supplement airport wells, the combined system would be more resilient. More desirable - 3 More desirable - 3 More desirable - 3 Medium - 2 Could use existing treatment facility and distribution system No changes from existing treatment system expected if wells are PFAS free and meet other HRLs Sites must be chosen, water quality must be verified, and new wells installed and developed. Improvement from current tight cluster of wells at the airport. Less desirable - 1 Less desirable - 1 Medium - 2 Less desirable - 1 New water mains needed to connect with distribution system. New water treatment facility would be needed. Sedimentation, filtration and disinfection would be needed. Possible PFAS treatment. Sampling, permitting, and construction of intake structures Single intake would not provide resiliency Less desirable - 1 Less desirable - 1 Medium - 2 Less desirable - 1 New water mains needed to connect with distribution system. New water treatment facility would be needed. Sedimentation, filtration and disinfection would be needed. Possible PFAS treatment. Sampling, permitting, and construction of intake structures Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates medium desirable characteristics and given a score of 2 Orange shading indicates less desirable characteristics and given a score of 1 Single intake would not provide resiliency

33 32 Potential additional water supply well locations

34 Options for Water Treatment Granular activated carbon (GAC) Single pass ion exchange Membrane filtration Advanced oxidation processes 33

35 Treatment Technology Granular Activated Carbon (GAC) Single Pass Ion Exchange Membrane Filtration Advanced Oxidation Processes Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates moderately desirable characteristics and given a score of 2 34 Orange shading indicates less desirable characteristics and given a score of 1

36 Treatment Technology Granular Activated Carbon (GAC) Relative PFAS Removal Efficiency Degree of Use Interference by Other Compounds in the Water Difficulty and Cost of Waste Disposal Relative Capital Expense Relative Operating Expense Overall Score Single Pass Ion Exchange Membrane Filtration Advanced Oxidation Processes Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates moderately desirable characteristics and given a score of 2 35 Orange shading indicates less desirable characteristics and given a score of 1

37 Treatment Technology Granular Activated Carbon (GAC) Single Pass Ion Exchange Relative PFAS Removal Efficiency Degree of Use Interference by Other Compounds in the Water Difficulty and Cost of Waste Disposal High - 3 Medium - 2 Medium - 2 Medium % for both PFOA and PFOS Widely used, but only a few examples specifically for PFAS Organics, TDS and minerals can foul the resin System is regenerable onsite. Some of the liquid regeneration waste can be recycled, rest must be disposed of Relative Capital Expense Lower than GAC - 3 Smaller vessel size and footprint Relative Operating Expense Lower than GAC - 3 Resin cost is higher on a unit cost basis but requires less frequent replacement Overall Score 15 Membrane Filtration Advanced Oxidation Processes Green shading indicates desirable characteristics and given a score of 3 36 Yellow shading indicates moderately desirable characteristics and given a score of 2 Orange shading indicates less desirable characteristics and given a score of 1

38 Treatment Technology Granular Activated Carbon (GAC) Single Pass Ion Exchange Membrane Filtration Advanced Oxidation Processes 37 Relative PFAS Removal Efficiency Degree of Use Interference by Other Compounds in the Water Difficulty and Cost of Waste Disposal Relative Capital Expense Relative Operating Expense High - 3 High - 3 Low - 3 Medium - 2 Base case - 2 Base case % for both PFOA and PFOS Widely Used Low potential for competitive adsorption Spent GAC requires Offsite thermal regeneration or landfill disposal High - 3 Medium - 2 Medium - 2 Medium % for both PFOA and PFOS Widely used, but only a few examples specifically for PFAS Organics, TDS and minerals can foul the resin System is regenerable onsite. Some of the liquid regeneration waste can be recycled, rest must be disposed of Base case Lower than GAC - 3 Smaller vessel size and footprint Base case Lower than GAC - 3 Resin cost is higher on a unit cost basis but requires less frequent replacement High - 3 Medium - 2 High - 1 High - 1 Highest - 1 Highest % for both PFOA and PFOS Widely used, but only a few examples specifically for PFAS May require extensive pretreatment to prevent fouling membranes Concentrate would require evaporation, then incineration or landfilling of residuals Low - 1 Low 1 High - 1 Medium - 2 Least effective at breaking down PFAS, supplemental treatment with GAC likely needed Experience and research is limited compared to the other technologies Other contaminants will compete, reducing treatment efficiency Spent GAC for supplemental treatment would need disposal Green shading indicates desirable characteristics and given a score of 3 Yellow shading indicates moderately desirable characteristics and given a score of 2 Orange shading indicates less desirable characteristics and given a score of 1 Similar to Membrane Filtration - 1 Similar to Membrane Filtration - 1 High energy demand and need for supplemental treatment Overall Score

39 Preliminary costs of potential short term solutions Costs are preliminary and based on what is known at this time. They will likely change as more is learned. 38

40 Preliminary Option Description Cost Estimates for New Water Sources and Water Treatment New Water Sources Water Treatment Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Granular Activated Carbon (1,000 GPM) Ion Exchange (1,000 GPM) 1,000 gpm 39

41 Preliminary Option Description Cost Estimates for New Water Sources and Water Treatment New Water Sources Water Treatment Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Granular Activated Carbon (1,000 GPM) Ion Exchange (1,000 GPM) Granular Activated Carbon (2,500 GPM) Ion Exchange (2,500 GPM) 2,500 gpm 40

42 Preliminary Cost Estimates for New Water Sources and Water Treatment New Water Sources Water Treatment Option Description Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Granular Activated Carbon (1,000 GPM) Ion Exchange (1,000 GPM) Granular Activated Carbon (2,500 GPM) Water Treatment Equipment Vendor Estimated Capital Cost Accuracy Range -10% +30% 6 Ion Exchange (2,500 GPM) 41

43 Preliminary Cost Estimates for New Water Sources and Water Treatment New Water Sources Water Treatment Option Description Groundwater Existing Bemidji High School Wells Groundwater New Wells near Airport Granular Activated Carbon (1,000 GPM) Ion Exchange (1,000 GPM) Granular Activated Carbon (2,500 GPM) Water Treatment Equipment Vendor Estimated Capital Cost Accuracy Range -10% +30% Tonka $ 2,814,000 $ 2,533,000 $ 3,659,000 Not Applicable Evoqua $ 1,620,000 $ 1,458,000 $ 2,106,000 $ 4,986,000 $ 4,488,000 $ 6,482,000 $ 3,954,000 $ 3,559,000 $ 5,141,000 $ 7,955,000 $ 7,160,000 $10,342,000 6 Ion Exchange (2,500 GPM) $ 6,510,000 $ 5,859,000 $ 8,463,000 42

44 Next Steps Maintain near-term water supply Plan for temporary water supply Plan for long-term water supply 43

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46 45 Well Siting Project

47 Alternate Well Siting Project Investigate three airport well sites High School wells Groundwater modeling for blending & siting Eng. Costs: ~$49-$59K Driller/lab costs: ~$85-95K Plans & specs for new well & raw watermain Eng. Cost: ~$95 - $120K Construction management: ~$95K Contractor: ~$ M 46

48 47 Temporary Treatment Project

49 Plan testing protocol Temporary Treatment Project GAC bench testing with supplier Single pass ion exchange pilot Oversee implementation Analyze results Design temporary treatment system and connecting piping Eng. Cost: ~$45-$59K GAC bench test: ~$15K Ion exchange pilot: $0 48

50 49 Long Term Planning Project

51 Planning for Long-Term Water Supply Why is this needed? Proactive vs. reactive plan for supply Treatment of PFAS at existing wells Alternate water supply Combination of the two Future of Wells 3, 4 and 7 (firm capacity) Understand duration of PFAS impact Control of PFAS at site, if needed Groundwater Soil 50

52 Planning for Long-Term Water Supply Phase I (Data gaps analysis) First Technical advisory committee meeting Review results of pilot and bench testing Review results of airport and HS work Identify data gaps Extent of PFAS at airport Results of pilot and bench testing Plan to close data gaps Plan Phase II Eng. Cost: ~$25K 51

53 Authorize well siting project Requested Council Action Eng. Cost: ~$50,000 Contractor: ~$95,000 Authorize temporary treatment project Eng. Cost: ~$50,000 GAC bench test: ~$15,000 Accept Evoqua offer for free pilot test Future Council action: Authorize plans and specs for new well Eng. Cost: ~$95,000 - $120,000 Well costs to be bid (~$1.2-$1.3M) Authorize Phase I of Long Term Planning Eng. Cost: ~$25,000 52

54 Questions & Discussion of Next Steps 53

55 Water Delivered (GPM) 2000 Bemidji Peak Water and HI Recommendations, PFAS Blend Chart HI calculated per MDH recommendations HI based on MDH recommendations, includes PFHxS: Well 5 at 551 gallons Well 6 at capacity (1,100 gallons) Well 7 at 135 gallons Jan-17 Feb-17 Mar-17 Apr-17 May-17 Jun-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec Peak Day Water Delivered

56 Water Delivered (GPM) 2500 Bemidji Peak Water and HI Recommendations, PFAS Blend Chart without PFHxS HI based on MDH recommendations, excludes PFHxS: Well 5 at capacity (750 gallons) Well 6 at capacity (1,100 gallons) Well 7 at 388 gallons Jan-17 Feb-17 Mar-17 Apr-17 May-17 Jun-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec Peak Day Water Delivered

57 Bemidji Airport FAA Notice Area 56

58 Phase II: Plan For Long-Term Water Supply Review data from data gap closing work Select a long-term supply option Feasibility Study Report for long-term option Provide the City information to select an approach for long-term drinking water supply. Integrate the cost and scheduling information from the water treatment study and the alternate well location studies, comparing multiple scenarios. Evaluate effectiveness, cost, speed of implementation, water supply resiliency, and contribution to potential future PFAS remediation requirements at the airport. Costs to be determined after Phase I 57