1. Minnesota Drinking Water Designated Use Assessment Workshop Tom Poleck EPA Region 5, Water Quality Branch May 20-21, 2015 1

2. Primary Workshop Goal To draft an assessment methodology that reasonably and appropriately identifies waters impaired for drinking water use and with enough detail to be implementable in the next two years and to form the foundation for future enhancements for future listing cycles. U.S. EPA Region 5 2

3. Other Workshop Goals ID places for increased collaboration between programs; within CWA programs and between CWA and SDWA programs. U.S. EPA Region 5 3

4. Workshop Objectives 1.Identify and compile a prioritized list of parameters or indicators; 2.Identify available and desired data from State monitoring programs and other sources; 3.Identify components of the methodology; 4.Consolidate individual parts identified above into a complete assessment methodology; 5.Others? U.S. EPA Region 54

5. Concept of Water Quality Parameters and Indicators U.S. EPA Region 55 An indicator is a parameter, or a value derived from parameters, that points to, provides information about and/or describes the condition of an environmental component (or human health, e.g., drinking water), usually with a significance that extends beyond the measurement or value itself. Used alone, or in combination, indicators provide the means to assess progress toward one or more objectives: are conditions improving so that the objective is closer to being met, or are conditions deteriorating?

6. Selection of indicators based on*: U.S. EPA Region 5 6 1.Documented or suspected human health impacts; 2.Availability of adopted numeric and narrative water quality standards; 3.Availability of reliable data; 4.Feasibility of implementation; the ability to conduct future monitoring/data collection; 5.Response variability; measurement error, natural variability (spatial, temporal); 6.Impact of the indicator on water treatment processes and costs; and, 7.Interpretation and utility: convey information on DW use that is meaningful to decision-making. *Modified from: Ecological Indicator Evaluation Guidelines (USEPA 2000) and Ohio 2014 IR

7. Examples of Water Quality Parameters and Indicators U.S. EPA Region 5 7 PWSs with treatment beyond conventional PWS MCL violations Permits for application of algicides to lakes Drinking water advisories tied to source water contaminant(s) Source Water Assessment Program results Frequent taste and odor problems/complaints Monitoring data from other state agencies Monitoring data from USGS and other agencies PWS collected source water data Volunteer monitoring by watershed protection groups and others Chemical company data – pesticide registrations Data Indicators

8. 8 Overview of Other State Assessment Methodologies Illinois – 2014 IR Fully Supporting (Good) For each substance in untreated water (1), for the most-recent three years of readily available data or equivalent dataset, a) < 10% of observations exceed an applicable Public and Food Processing Water Supply Standard (2); and b) for which the concentration is not readily reducible by conventional treatment, i) no observation exceeds by at least fourfold the treated-water Maximum Contaminant Level threshold(3) concentration for that substance; and ii) no quarterly average concentration exceeds the treated-water Maximum Contaminant Level threshold concentration(3) for that substance; and iii) no running annual average concentration exceeds the treated-water Maximum Contaminant Level threshold concentration(4) for that substance, and (4), For each substance in treated water, no violation of an applicable Maximum Contaminant Level (3) occurs during the most recent three years of readily available data. Not Supporting (Fair) For any single substance in untreated water, (1) for the most-recent three years of readily available data or equivalent dataset, a) > 10% of observations exceed a Public and Food Processing Water Supply Standard (2); or b) for which the concentration is not readily reducible by conventional treatment, i) at least one observation exceeds by at least fourfold the treated-water Maximum Contaminant Level threshold concentration(3) for that substance; or ii) the quarterly average concentration exceeds the treated-water Maximum Contaminant Level threshold concentration(3) for that substance; or iii) the running annual average concentration exceeds the treated-water Maximum Contaminant Level threshold concentration(3) for that substance. or, For any single substance in treated water, at least one violation of an applicable Maximum Contaminant Level (3) occurs during the most recent three years of readily available data. Not Supporting (Poor) Closure to use as a drinking-water resource (cannot be treated to allow for use).

9. Overview of Other State Assessment Methodologies 9 IndicatorImpaired Conditions Nitrate  Two or more excursions 1 above 10.0 mg/L within the 5 year period Pesticides  Annual average exceeds WQ criteria (atrazine = 3.0 µg/L) Other Contaminants  Annual average exceeds WQ criteria Algae: Cyanotoxins 2  Two or more excursions 1 above the state drinking water thresholds (microcystins = 1.0 µg/L) within the 5 year period Cryptosporidium 3  Annual average exceeds WQ criterion (1.0 oocysts/L) IndicatorFull Attainment Conditions Nitrate  No more than one excursion 1 above 10.0 mg/L within the 5 year period Pesticides  Annual average does not exceed the WQ criteria (atrazine = 3.0 µg/L) Other Contaminants  Annual average does not exceed the WQ criteria Algae: Cyanotoxins  No more than one excursion 1 above the state drinking water thresholds (microcystins = 1.0 µg/L) within the 5 year period Cryptosporidium  Annual average does not exceed the WQ criterion Indicator “Watch List” Conditions Source waters targeted for additional monitoring and assessment Nitrate  Maximum instantaneous value > 8 mg/L (80% of WQ criterion) Pesticides  Running quarterly average > WQ criteria  Maximum instantaneous value > 4x WQ criteria Other Contaminants  Maximum instantaneous value > WQ criteria Algae: Cyanotoxins  Maximum instantaneous value > 50% of the state drinking water thresholds Cryptosporidium  Annual average > 0.075 oocysts/L Ohio – 2014 IR

10. Overview of Other State Assessment Methodologies 10 Wisconsin – Draft Proposal 2016 IndicatorImpaired Conditions Nitrate  Two or more excursions above 10.0 mg/L within a consecutive 3-year period Algae: Cyanotoxins  Two or more excursions above the WHO drinking water thresholds (microcystins = 1.0 µg/L) within a consecutive 3 year period Contaminants w/ HH Criteria  Two or more excursions above criterion within a consecutive 3-year period Cryptosporidium  Annual average exceeds WQ criterion (1.0 oocysts/L) (Bin 3 or 4) Taste and Odor  Any taste and odor compound above state standards.  Need by PWS to install treatment beyond conventional to remove taste and odor IndicatorFull Attainment Conditions Nitrate  No more than one excursion above 10.0 mg/L within a consecutive 3-year period Algae: Cyanotoxins  No more than one excursion above the WHO drinking water thresholds (microcystins = 1.0 µg/L) within a consecutive 3 year period Contaminants w/ HH Criteria  No more than one excursion above criterion within a consecutive 3-year period Cryptosporidium  Annual average does not exceed the WQ criteria (Bin 1 or 2) Taste and Odor  Taste and odor compounds below state standards.  Need by PWS to install treatment beyond conventional to remove taste and odor Indicator “Watch List” Conditions Source waters targeted for additional monitoring and assessment Nitrate  Maximum instantaneous value > 5 mg/L (50% of WQ criterion)